ACT Urban Habitat and Connectivity Project

Introduction

This document summarises the Round 1 - Initial estimates of the ACT Urban Habitat and Connectivity Project expert elicitation for grassland reptiles using the IDEA protocol (refer to Hemming et al. 2018 “A practical guide to structured expert elicitation using the IDEA protocol” and Burgman 2016 “Trusting Judgements: How to get the best out of experts”).

Below we have presented and summarised the results for each question asked in the expert elicitation. All responses from the expert elicitation remain anonymous, with visualised experts estimates being denoted by a number on the x- axis. Below each visualised estimate, the comments provided by experts are collated.

The intervals displayed are for a Three-Step Elicitation.

Shared resources

Please click the link provided to access the PDFs and documents provided by experts in the initial estimates round

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Structural habitat metrics

The next series of visualisations relate to structural habitat metrics.

Structural habitat metrics describe how the various elements of a species’ habitat are arranged in space. For example, some arboreal species may need tree canopies a certain distance apart to be able to successfully navigate from one to the next. Another species might require grass heights of a certain amount to escape predation, whilst another species might only be able to persist within a certain distance from a water body.

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Preferred distance between tree canopies

This could be related to the amount of shade the taxon group prefers or is tolerant of in its preferred habitat, the distance an arboreal species can move from one tree to the next without going along the ground, or some other feature of the taxon groups’ general biology or life history. This metric considers the availability of both exotic and native tree species in the environment, as well as both young and mature trees (> 3m height). The answer to this question will give an equivalent score to something like “percentage canopy cover”, which might be a more familiar (but harder to map) version of this metric.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0	0	0	Not relevant to grassland reptiles.	0	Grassland_reptiles	tree_canopy	Initial
27	10	3	75	Space between trees creates a mosaic of sun-shade, and accumulation of leaf litter and fallen branches. If trees are too close or too far apart, these resources become too scattered.	60	Grassland_reptiles	tree_canopy	Initial
28	15	4	40	Many of the reptile species in Canberra are terrestrial or grassland specialist, so too much canopy cover reduces their ability to thermoregulate. We also have a dataset (unpublished at the moment) that shows higher bird predation risk for small snakes in urban Perth woodlands, compared to more open grassland. Small shade skinks like Lampropholis will prefer shaded woodlands, but they are the minority. Hard to pick estimates covering all reptile taxa, but I’m leaning towards more grassland/open woodland species.	65	Grassland_reptiles	tree_canopy	Initial
29	5	3	10	Grassland reptiles need a sufficient tree density to provide the necessary leaf litter to provide shelter and habitat. However, there is a trade off between it being too shaded (& not enough grass cover), and it being too open (i.e. no shade, limited leaf litter).	70	Grassland_reptiles	tree_canopy	Initial
30	0	0	0	0	0	Grassland_reptiles	tree_canopy	Initial
31	50	50	100	Technically NTG can have up to 10% midstorey/overstorey cover. Generally if we are talking grassland reptiles, such as a Grassland Earless Dragon, these species do not require or utilise canopy cover at all, so there would need to be a substantial distance between canopies/low density of trees. However there are other species that transition between more wooded areas and open grasslands (e.g. Delma inornata), and so could tolerate less distance between canopies. I estimate 50m to nearest tree based on my experience finding grassland reptiles that will also utililise trees in the field. However, this may be 50m from one patch of trees in one direction, and perhaps several hundred metres to trees in another direction. There may be some local knowledge for species such as Aprasia parapulchella, as they appear to occur in closer proximity to canopy cover. Other outlier species such as Dwyers snakes occur in rocky outcrops in grasslands, and can occur in outcrops very close to trees.	80	Grassland_reptiles	tree_canopy	Initial
32	100	50	100	There are a number of species of grassland reptile that could/do take advantage of trees and tree cover. They are not 100% necessary, particularly in the middle of a grassland environment so figuring out their use or preferred covered would be difficult to calculate. I am not aware of any local studies that explicitly look at this for grassland reptiles, my answer on this is based of the rough distances I have encounter larger grassland reptile species in grassland environments and their proximity to tree cover - such as T. scincoides, P. barbata and P. textilis. These are all species that also exist in well timbered ecosystems. There needs to be a lower density as it would likely impact a number of smaller grassland species ability to thermoregulate properly.	80	Grassland_reptiles	tree_canopy	Initial
33	15	0	20	Trees are generally not a component of grassland reptile habitat. In fact, the presence of trees in grasslands is generally a negative thing as they provide dense shade which prevents grass growth, roosting positions for predatory birds, and potentially barriers to dispersal. Accordingly, I have provided estimates based on the tree canopy cover that is generally tolerable for grassland reptile species.	75	Grassland_reptiles	tree_canopy	Initial
35	5000	50	10000	This is the context of grassland species. Trees are generally a hazard to reptiles native to natural temperate grasslands which will generally require an open canopy or no tree canopy at all.	80	Grassland_reptiles	tree_canopy	Initial
36	0	0	0	Grassland reptiles do not require trees.	0	Grassland_reptiles	tree_canopy	Initial
37	500	50	1000	Grassland reptiles will tolerate some occasional trees, but generally inhabit treeless landscapes with <2% canopy cover by definition.	80	Grassland_reptiles	tree_canopy	Initial
38	50	40	80	Grassland specialist (very few but very threatened) dont really want any trees, but reptiles that are grassland/ woodland like trees. So this estimate is more about grassland/woodland species	80	Grassland_reptiles	tree_canopy	Initial
39	10000	500	10000	grassland	100	Grassland_reptiles	tree_canopy	Initial
Aggregated	1211	58	1648	NA	59	Grassland_reptiles	tree_canopy	Aggregated

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Percentage of trees which need to be native

This relates to the composition of the urban forest or remnant woodland in terms of native and exotic trees. What percentage of trees need to be native for an area to be suitable habitat for this species group? This will relate to things such as food availability or the year-round availability of canopy cover. For some species, only native trees will be beneficial whilst other species might happily utilise any tree species as part of core habitat structure.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0	0	0	Not relevant to grassland reptiles	0	Grassland_reptiles	native_trees	Initial
27	100	0	100	I’m not sure it really matters if the tree species is native or exotic, it’s more about the structure the tree provides. A non-native tree can still support tree hollows, leaf litter accumulation, and woody debris, which are all important for reptiles. I think some native and some exotic trees can suit the needs, depending on their own characteristics. However, I would think native trees that support leaf litter, woody debris, etc. would be a better option than all exotic trees that do the same thing.	80	Grassland_reptiles	native_trees	Initial
28	80	60	90	Some species will occur in urban backyards (shinglebacks) which will have exotic trees, but usually they do not create the correct leaf litter for small skinks and snakes to use. Any exotic pine forests will barely support reptile species, based on survey experience.	80	Grassland_reptiles	native_trees	Initial
29	100	25	100	Ideally, it would be best if all of the trees were native. However, if this was not possible, the key thing would be to have tress that provided the necessary shade, and produced the require leaf litter layer (which many non-native trees are able to provide).	70	Grassland_reptiles	native_trees	Initial
30	0	0	0	0	0	Grassland_reptiles	native_trees	Initial
31	0	0	0	Given we are speaking of grassland reptiles, I imagine the tree species is not a dealbreaker as theoretically these species are not dependent on the trees. Obviously in an ideal world, you would have native Eucalypt and Acacia species. Eucalypts drop large pieces of bark that some grassland reptiles could use (such as Eastern Bearded Dragons that I know to move through both grassland and woodland), and may encourage a natural invertebrate assemblage that could be prey items. However, if Briar Rose were in a connectivity patch to serve other species such as woodland birds, I would not think this would be a huge issue (as this is common in our grasslands).	0	Grassland_reptiles	native_trees	Initial
32	80	50	100	As discussed on the prior question, tree density is not incredibly important. But I would imagine (and I assume most would agree) that were we want trees - we want natives. As they would also drop barks and timbers used by species living in the edge of the grasslands that may be boadering a woodland. However, if the tree density is very low, I would think non-natives would have insignificant impacts on grassland reptiles.	50	Grassland_reptiles	native_trees	Initial
33	0	0	0	I do not believe that this metric is at all important for this taxon group.	100	Grassland_reptiles	native_trees	Initial
35	5	0	10	Trees are generally not essential for grassland reptiles. these numbers draw on my experience with natural temperate grassland reptiles. These grasslands can be extensive and generally do not have expanses of trees - native or otherwise.	80	Grassland_reptiles	native_trees	Initial
36	0	0	0	Grassland reptiles do not require trees.	0	Grassland_reptiles	native_trees	Initial
37	100	0	100	Whether or not trees are native probably doesn’t matter for grassland reptiles, since they live in naturally treeless landscapes. However native trees are likely to be indicative of more intact habitat which might bring other benefits.	80	Grassland_reptiles	native_trees	Initial
38	0	0	0	I dont know of any research on this for trees for this group. Certain tree species are definitely important to reptiles in woodlands as they provide resources like fissured bark. If we are taking this as grassland reptiles then they prefer no trees, native or otherwise	100	Grassland_reptiles	native_trees	Initial
39	0	0	0	grassland	100	Grassland_reptiles	native_trees	Initial
Aggregated	36	10	38	NA	57	Grassland_reptiles	native_trees	Aggregated

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Preferred distance between mature trees

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0	0	0	Not relevant to grassland reptiles	0	Grassland_reptiles	mature_trees	Initial
27	20	5	75	Some spacing will allow scattering of light, and disperse piles of woody debris from fallen branches and leaf litter accumulation.	60	Grassland_reptiles	mature_trees	Initial
28	25	6	40	Very few Canberra reptiles would use or rely on tree hollows, but logs and fallen branches are beneficial. Again, hard to average to satisfy both grassland and woodland specific species.	65	Grassland_reptiles	mature_trees	Initial
29	8	5	10	Again, it gets back to the availability of leaf litter, fallen branches/logs, both of which provide the necessary, refuge sites and basking sites that most grassland reptiles require. Leaf litter and fallen branches/logs also provide the perfect environment for the invertebrates that most grassland reptiles feed upon.	50	Grassland_reptiles	mature_trees	Initial
30	0	0	0	0	0	Grassland_reptiles	mature_trees	Initial
31	200	50	500	Based on my knowledge of some sites in the ACT with recorded grassland species such as Delma impar, and the distances to nearest mature trees (>50DBH), I have made an informed estimate. Larger species which may be more likely to utilise fallen branches and tree hollows (e.g. shingleback or large elapid) would be more capable of moving larger distances to these areas, while smaller species are unlikely to be able to move to reach far away large trees but are not likely to use these resources anyway. Outlier species such as Dwyers snakes occur in rocky outcrops in grasslands, and can occur in outcrops very close to trees.	70	Grassland_reptiles	mature_trees	Initial
32	0	0	0	I don’t have suitable knowledge to confidently answer this question	0	Grassland_reptiles	mature_trees	Initial
33	0	0	0	I do not believe that this metric is at all important for this taxon group.	100	Grassland_reptiles	mature_trees	Initial
35	5000	0	10000	In the context of natural temperate grassland reptiles, trees are not generally required. They represent a problem for some species by providing shade and perching opportunities for predators.	80	Grassland_reptiles	mature_trees	Initial
36	0	0	0	Grassland reptiles do not require trees.	0	Grassland_reptiles	mature_trees	Initial
37	500	50	5000	Mature trees are not an important habitat feature for grassland reptiles, however their absence is.	50	Grassland_reptiles	mature_trees	Initial
38	30	0	40	This depends again on how strict your definition of grassland reptile is. Grassland specialist = 0 tree density but grassland/woodland reptiles benefit from moderate density but highly dense can have a negative impact.	80	Grassland_reptiles	mature_trees	Initial
39	1000	1000	1000	Why are these in the grassland section.	100	Grassland_reptiles	mature_trees	Initial
Aggregated	522	86	1282	NA	50	Grassland_reptiles	mature_trees	Aggregated

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Preferred distance between mid-storey canopies

This metric might reflect the overall amount of mid-storey cover (0.5 – 3m height) required by a taxon group, or how far they can move between shrubs. This metric considers the availability of both exotic and native mid-storey species in the environment. The answer to this question will give an equivalent score to something like “percentage mid-storey canopy cover”, which might be a more familiar (but harder to map) version of this metric.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0	0	0	Not relevant to grassland reptiles	0	Grassland_reptiles	mid_canopy	Initial
27	5	0	20	I think this would be especially important for shrub dwelling geckos and lizards, but also provides structural complexity in the understory for many reptiles to reduce predation from avian predators.	50	Grassland_reptiles	mid_canopy	Initial
28	20	10	50	I don’t think most or any of the Canberra reptile species rely on bushes of mid-story canopy, but I think too much would deter reptiles. Although it could offer shelter for movement corridors in an urban landscape.	80	Grassland_reptiles	mid_canopy	Initial
29	15	10	20	The important thing is probably the clumps of mid-storey vegetation, rather than the distance between individual trees/shrubs. It is probably more important for this vegetation to occur in patches, rather than being uniformly dispersed across the landscape.	50	Grassland_reptiles	mid_canopy	Initial
30	0	0	0	0	0	Grassland_reptiles	mid_canopy	Initial
31	50	50	100	As with distance to trees - technically NTG can have up to 10% midstorey/overstorey cover. Grassland reptiles, such as a Grassland Earless Dragon, do not require or utilise canopy cover at all. However there are other species like Jacky dragons, shinglebacks and skinks that may use shrubs for cover. I estimate 50m to nearest midstorey cover. This may be 50m from one patch of trees in one direction, and perhaps several hundred metres to trees in another direction. There may be some local knowledge for species such as Aprasia parapulchella, as they appear to occur in closer proximity to canopy cover. Other outlier species such as Dwyers snakes occur in rocky outcrops in grasslands, and can occur in outcrops very close to trees/shrubs.	70	Grassland_reptiles	mid_canopy	Initial
32	80	50	100	I think that mid-story canopies provided by plants such as small shrubs would be more beneficial to certain grassland reptile species than mature tree canopy (excluding the fallen timber they may provide). A number of species may choose to take advantage of such refuge sites where they have the opportunity.	70	Grassland_reptiles	mid_canopy	Initial
33	15	0	20	Midstorey trees and shrubs are generally not a component of grassland reptile habitat. In fact, the presence of midstorey vegetation in grasslands is generally a negative thing as they provides dense shade which prevents grass growth, refugia and roosting positions for predators, and potentially barriers to dispersal. Accordingly, I have provided estimates based on the tree canopy cover that is generally tolerable for grassland reptile species.	75	Grassland_reptiles	mid_canopy	Initial
35	5000	200	10000	Grassland reptiles generally don’t require mid-storey canopies.	70	Grassland_reptiles	mid_canopy	Initial
36	0	0	0	Grassland reptiles do not require trees.	0	Grassland_reptiles	mid_canopy	Initial
37	60	40	400	Occasional small shrubs occur in grasslands which may provide suitable cover for grassland reptiles, particularly the larger ones. However I am not sure that these get to 50cm height and hence are relevant to this taxa group.	30	Grassland_reptiles	mid_canopy	Initial
38	0	0	10	Grassland specialist = 0 mid storey but more gernalist can benefit from some midstorey. Rarely examined in reptile studies and midstorey definitions can vary.in different environments.	50	Grassland_reptiles	mid_canopy	Initial
39	1000	1000	1000	Again its a grassland.	100	Grassland_reptiles	mid_canopy	Initial
Aggregated	480	105	902	NA	50	Grassland_reptiles	mid_canopy	Aggregated

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Percentage of native mid-storey vegetation

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0	0.0	0	Not relevant to grassland reptiles	0	Grassland_reptiles	native_mid	Initial
27	100	0.0	100	Similar to the tree question, I think as long as the shrub/mid-story veg provides adequate structure, it doesn’t matter so much if it’s native or non-native. However, we should strive to support 100% native vegetation.	80	Grassland_reptiles	native_mid	Initial
28	50	0.0	80	As I believe most Canberra reptile would only use this for movement shelter, exotic species should be fine.	70	Grassland_reptiles	native_mid	Initial
29	100	25.0	100	Again, it would be best if all of this vegetation was native, but there are numerous non-native species that could perform a similar role, and provide the necessary habitat for grassland reptile species.	75	Grassland_reptiles	native_mid	Initial
30	0	0.0	0	0	0	Grassland_reptiles	native_mid	Initial
31	0	0.0	0	Given we are speaking of grassland reptiles, I imagine the midstorey species is not a dealbreaker as theoretically these species are not dependent on the trees. Obviously in an ideal world, you would have native Eucalypt and Acacia regen, and native shrubs. However, if Briar Rose were in a connectivity patch to serve other species such as woodland birds, I would not think this would be a huge issue (as this is common in our grasslands), and I have actively seen species such as small skinks and Shinglebacks using Briar Rose and Blackberry for cover (a bonus of being scaley is that thorny bushes don’t particularly bother you). However, the native component may affect invertebrate assemblages and available prey, so this if others have more thoughts that would be of interest.	0	Grassland_reptiles	native_mid	Initial
32	0	0.0	0	Preferably, like with most things, we should be encouraging natives. I have not witnessed or aware of negative impacts of non-native mid-story vegetation (where it is present) on grassland reptiles. I have seen reptiles navigate through blackberry with ease.	0	Grassland_reptiles	native_mid	Initial
33	0	0.0	0	I do not believe that this metric is at all important for this taxon group.	100	Grassland_reptiles	native_mid	Initial
35	2	0.0	10	Grassland reptiles generally do not require mid-storey vegetation and therefore the % cover is generally low.	80	Grassland_reptiles	native_mid	Initial
36	0	0.0	0	Grassland reptiles do not require trees.	0	Grassland_reptiles	native_mid	Initial
37	100	0.0	100	As for trees, shrubs may not be important at all but native shrubs may be more indicative of intact native ecosystems.	30	Grassland_reptiles	native_mid	Initial
38	80	0.0	100	As for previous, very little research. Gorse bushes in Tasmania have been shown to provide shelter for reptiles in Northern Midlands	20	Grassland_reptiles	native_mid	Initial
39	100	0.0	100	grassland so these are not relavent.	100	Grassland_reptiles	native_mid	Initial
Aggregated	41	1.9	45	NA	43	Grassland_reptiles	native_mid	Aggregated

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Preferred distance from ground layer vegetation

This metric enables mapping of the potential distribution for those species which are tied in some way to ground layer vegetation. This might be a small species which lives within the grass layer (e.g. invertebrates, reptiles) or a larger species which relies on grass as food (e.g. kangaroos). How far will this taxon group be found from ground-layer vegetation?

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	1.0	1.00	30	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. I have seen other Parasuta species and similar sized elapids cross roads but don’t feel they would typically move too much further than the width of an open road.As for T. osbornei I have never found one away from grassland and am very confident that they would not disperse in exposed areas. For this species I would select less than 1 m if I could. Delma will cross roads on warm nights but again would not cover open exposed ground extensively.	75	Grassland_reptiles	ground_layer	Initial
27	0.0	0.00	10	I’m not entirely sure I understand the question. Most reptiles will be found on the ground or on/in ground vegetation (grass, rocks, logs), so that makes the estimate 0m. However, for arboreal animals, they may be found in trees, up to 10m.	20	Grassland_reptiles	ground_layer	Initial
28	0.0	0.00	4	Grass vegetation is critical habitat for most reptiles in Canberra. Some species require breaks of habitat - such as rocks/logs - to bask, but many small species can suffer high avian predation if there’s no grass the shelter in.	100	Grassland_reptiles	ground_layer	Initial
29	5.0	1.00	10	The ground level vegetation is extremely important in terms of providing basking sites, the grass being long enough to provide refuge and shelter sites, and promoting a diverse invertebrate assemblage, which aids in generating the necessary food items for grassland reptiles.	60	Grassland_reptiles	ground_layer	Initial
30	0.0	0.00	20	I would assume the majority of grassland reptile species would prefer contiguous or near contiguous vegetation cover. The 20m upper estimate reflects the distance over which I believe the average grassland reptile could travel in the absence of ground layer vegetation cover (i.e. a road).	75	Grassland_reptiles	ground_layer	Initial
31	0.0	0.00	0	Assumed grassland reptile always at ground vegetation level. Species such as Bearded Dragons may be in a tree or on a fence for periods of time (for basking), but overwhelmingly they would be in the grassy layer. Would this encompass when reptiles are using burrows, or under rocks? e.g. Dwyers Snakes or Pink-tailed Worm Lizards under rocks in a grassland, or Dema impar or a Brown Snake down a burrow in a grassland.	0	Grassland_reptiles	ground_layer	Initial
32	0.0	0.00	0	Most grassland reptiles (excluding species such as P. barbata) heavily rely on ground layer vegetation and are usually amongst it, within it or utilising burrow systems underneath it. They are not usually more than 1 meter from it which is why I have answer 0.	100	Grassland_reptiles	ground_layer	Initial
33	4.0	1.00	10	My experience has been that grassland reptiles very rarely venture beyond the boundary of their grassland habitat. If they do then it is generally only for a short distance. Examples of this are that species such as the Striped Legless Lizard and Grassland Earless Dragon will usually not cross well-established gravel driveways and certainly won’t cross a sealed road. I have however known these species to traverse farm tracks where the wheel ruts are cleared (approx. 1m wide) but there is a strip of grass retained down the middle.	80	Grassland_reptiles	ground_layer	Initial
35	10.0	0.00	200	Genetic data for T.lineata and A.parapulchella suggest that even modest distances of non-grassland habitats are barriers.	80	Grassland_reptiles	ground_layer	Initial
36	0.0	0.00	0	Grassland reptiles inhabit ground layer vegetation.	0	Grassland_reptiles	ground_layer	Initial
37	6.0	0.00	10	I would expect that small grassland reptiles (small skinks, delma, etc) would not go far from grassy layer vegetation. Some of the larger skinks might however, so have increased my estimate from just a couple of meters.	10	Grassland_reptiles	ground_layer	Initial
38	2.0	0.00	10	Depends what is meant by vegetation (are we excluding leaf litter etc or just talking about human surface vs natural ground cover. I have assumed that one	50	Grassland_reptiles	ground_layer	Initial
39	5.0	0.00	20	Many have limited dispersal	80	Grassland_reptiles	ground_layer	Initial
Aggregated	2.5	0.23	25	NA	56	Grassland_reptiles	ground_layer	Aggregated

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Percentage of native ground layer vegetation

This metric relates to the composition of the ground storey vegetation (grasses, rushes, forbs, sedges; < 0.5m height). What is the percentage of the ground layer vegetation which needs to be native to provide suitable habitat for this taxon group?

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	100	1	100	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. I think structure can be just as important as composition. Delma impar is far more tolerant of non native species than the dragon or snake. I have found them in grasslands with 100% introduced species. However occupancy is greatest when more of the composition is native, this is in part because it suggests less disturbance.	80	Grassland_reptiles	native_ground	Initial
27	100	0	100	I think the structure is more important that the species. As long as the structural complexity is there, species should use it. However, we should strive to only use native species.	50	Grassland_reptiles	native_ground	Initial
28	50	0	100	Many common species can thrive in invasive grass if allowed to grow long enough, snakes are a good example. However, Canberra’s threatened grassland reptiles require specific native grasses to live. My scales are very large to account for all species.	90	Grassland_reptiles	native_ground	Initial
29	80	5	100	Again, it would be best if the ground level vegetation (grasses) were native, but many grassland species cope well in introduced grasses (particularly in urban areas).	60	Grassland_reptiles	native_ground	Initial
30	100	25	100	I assume best and upper estimate is going to be 100% for potentially all taxa.	80	Grassland_reptiles	native_ground	Initial
31	50	50	80	EPBC defines that a grassland must have at least 50% native cover to be considered a native grassland - less than this is not considered to be a viable communtiy (and native understorey is considered irretrivable). Given we have local grassland specialist species, I would say that a native cover of at least 50% is required and achievable but the aim should be higher depending on what species you are trying to create connectivity for (e.g. Delma impar would tolerate more exotic ground layer, whereas a Grassland Earless Dragon would need a more intact native ground layer). Ideally, 100% native would be a goal, but unlikely to be achieved particularly in urban areas.	80	Grassland_reptiles	native_ground	Initial
32	80	50	100	According to the EPBC act, it need to be at least 50% native vegetation to be considered a grassland. Ideally 100% would be great but even species such as D. impar (threatened species) seem to do fine with weed species in their habitat and will readily use them as refuge sites.	90	Grassland_reptiles	native_ground	Initial
33	75	50	100	My experience has been that the native proportion of the grassland habitat needs to be quite high for many grassland reptiles (e.g. Grassland Earless Dragon, Pink-tailed Worm-Lizard). However, this is not the case for others. For example, in my experience I have found that the native vs. exotic composition of a grassland/pasture has little influence on the suitability or carrying capacity for the Striped Legless Lizard. Provided the structure is suitable (i.e. mod-high herbage mass with defined tussock structure) then the composition of the groundstorey vegetation is not of apparent importance.	70	Grassland_reptiles	native_ground	Initial
35	40	10	80	Varies a lot with species. T.lineata requires open space and grassland tussocks. Too dense is as much a problem as too low.	60	Grassland_reptiles	native_ground	Initial
36	75	25	90	There is variability amongst grassland reptiles in terms of veg cover requirements.	70	Grassland_reptiles	native_ground	Initial
37	100	0	100	I have observed grassland reptiles in areas which are completely native dominated and those which are dominated by exotic grass species. The structure of the grass matters more than the species it would seem.	90	Grassland_reptiles	native_ground	Initial
38	80	50	100	Other ground cover metrics also important for reptiles (bare ground, leaf litter etc). I am assuming ground cover not ground vegetation in this estimate	50	Grassland_reptiles	native_ground	Initial
39	70	20	100	Most need natives.	80	Grassland_reptiles	native_ground	Initial
Aggregated	77	22	96	NA	73	Grassland_reptiles	native_ground	Aggregated

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Minimum height of ground layer vegetation

This metric relates to the average height (excluding seed stalks or other reproductive structures) of grasses, sedges, rushes, forbs and other ground layer vegetation. It might affect things like the availability of food sources (e.g. grass seeds) or opportunities for small animals to escape from predators. What is the minimum height of ground layer vegetation that provides suitable habitat for this taxon group?

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	15	2.0	25	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. T. osbornei prefers a mosaic of slightly open ground for foraging and tussocks for shelter. They are less tolerant of too much extensive cover.. D. impar are less fussy and can still be found where grass cover may be too dense for dragons. The snake is similar.	65	Grassland_reptiles	min_height_ground	Initial
27	40	0.0	100	Should provide enough shelter for reptiles to thermoregulate, forage, and avoid predation.	60	Grassland_reptiles	min_height_ground	Initial
28	30	15.0	50	Although I don’t have mowed-grass depth measured specifically, I rarely see species larger than a Lampropholis occupying mowed grass.	90	Grassland_reptiles	min_height_ground	Initial
29	15	5.0	25	It is probably more important to have a mix of long, and shorter, grass. The longer grass is particularly important around shrubs, logs, and the base of rocks. But then shorter grass is needed for basking sites.	40	Grassland_reptiles	min_height_ground	Initial
30	5	3.0	7	Minimum vegetation height threshold for various ACT grassland values	85	Grassland_reptiles	min_height_ground	Initial
31	5	4.0	6	Based on studies and extensive work by Brett Howland and others, the average grass height for grassland to promote biodiversity and support a range of fauna (including threatened grassland reptiles) in the ACT is 5-12cm. Some species have preferences within this, and so this can be accounted for with heterogeneity in the grass sward. Common species like Shinglebacks and Eastern Brown Snakes may be less affected by this metric, however generally prefer some level of grass cover for camouflage and so would likely be comfortable within this range also.	95	Grassland_reptiles	min_height_ground	Initial
32	5	4.0	6	Based on published work by Brett Howland	90	Grassland_reptiles	min_height_ground	Initial
33	20	10.0	30	It has been my experience that grassland reptiles require at least 10 to 30 cm of groundlayer vegetation to permit them to move around safely. Less than this cover they tend to suffer high levels of predations and thereby undergo population decline. Examples of this are where populations are observed to crash during drought and/or overgrazing.	75	Grassland_reptiles	min_height_ground	Initial
35	20	10.0	50	Will vary substantially with species.	50	Grassland_reptiles	min_height_ground	Initial
36	7	5.0	10	Estimates are based on SLL observations - Howland research suggests that variability in height/structure is important.	70	Grassland_reptiles	min_height_ground	Initial
37	7	1.0	20	There has been quite a bit of research undertaken in the ACT around the habitat preferences of grassland reptiles as it relates to grassy ecosystem management. A couple of relevant papers or publications are attached.	80	Grassland_reptiles	min_height_ground	Initial
38	5	3.0	5	See ACT Gov grassland guidelines	70	Grassland_reptiles	min_height_ground	Initial
39	10	5.0	30	Data	80	Grassland_reptiles	min_height_ground	Initial
Aggregated	14	5.2	28	NA	73	Grassland_reptiles	min_height_ground	Aggregated

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Maximum height of ground layer vegetation

As above, but this time please describe the maximum height of ground layer vegetation that provides suitable habitat for this taxon group? It might affect things like the ability of a species to effectively move through ground layer vegetation, or find suitable burrowing sites, or access to solar radiation.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	30	25	50	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum.	65	Grassland_reptiles	max_height_ground	Initial
27	60	10	100	Different species will require different vegetation structural complexity, but if grass is too tall/thick, it will block basking opportunities.	40	Grassland_reptiles	max_height_ground	Initial
28	40	20	60	I can’t remember average height of native grass species around Canberra, but some smaller reptile species will avoid thick tall grassland as they can’t thermoregulate.	50	Grassland_reptiles	max_height_ground	Initial
29	50	25	75	As per the last question, it has more to do with the placement of the vegetation, and the variation in height throughout the urban landscape, rather than the maximum height per se.	40	Grassland_reptiles	max_height_ground	Initial
30	12	10	15	Maximum vegetation height threshold for various ACT grassland values. Not sure how these variables will help with this process given they are so seasonal.	85	Grassland_reptiles	max_height_ground	Initial
31	12	10	15	Based on studies and extensive work by Brett Howland and others, the average grass height for grassland to promote biodiversity and support a range of fauna (including threatened grassland reptiles) in the ACT is 5-12cm. Some species have preferences within this, and so this can be accounted for with heterogeneity in the grass sward. Common species like Shinglebacks and Eastern Brown Snakes may be less affected by this metric, and generalist snakes may utilise high biomass for travelling through or shelter, but would likely be comfortable within this range also.	95	Grassland_reptiles	max_height_ground	Initial
32	13	10	15	Based on published work by Brett Howland	90	Grassland_reptiles	max_height_ground	Initial
33	50	40	70	Habitat suitability for many grassland reptiles declines when the grass sward gets too high. This is likely due to the effects of shading on thermoregulation, prevention of hunting, difficulty in finding mates etc.	70	Grassland_reptiles	max_height_ground	Initial
35	20	10	50	Based mainly on T.lineata - unpublished work by Hons student - Emily Stringer also radiotelemetry (Stevens et al.)	60	Grassland_reptiles	max_height_ground	Initial
36	25	20	40	Refer to previous comment.	70	Grassland_reptiles	max_height_ground	Initial
37	25	15	60	Different people measure grass differently, and hence some larger values might also be possible. In general though, small grassland lizards will not be commonly found in very long grass due to a lack of access to warm sunny spots. They also tend to be dark, moist and cold (although this might be associated with more insects for predatory species).	50	Grassland_reptiles	max_height_ground	Initial
38	15	12	20	See ACT grassland guidelines	50	Grassland_reptiles	max_height_ground	Initial
39	25	20	40	data from grassland work	80	Grassland_reptiles	max_height_ground	Initial
Aggregated	29	17	47	NA	65	Grassland_reptiles	max_height_ground	Aggregated

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Non-structural habitat metrics

The next series of visualisations relate to non-structural habitat metrics.

This section asks questions regarding the non-structural elements which dictate habitat suitability for each taxon group. These includes things such as the amount of light which is tolerable at the time the species is active, or appropriate thermal conditions.

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Maximum tolerable night-time light levels

This metric relates to the maximum tolerable light level which is associated with suitable habitat for this taxon group. It relates to the amount of artificial light provided at night in the urban environment (e.g from streetlights, or buildings). For some species, artificial light may disrupt foraging behaviours, mate finding behaviours, or circadian rhythm.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0.1	0.1	10	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. Irrelevant to diurnal species. Lighting should not exceed what occurs naturally. Most nocturnal species are less active during the full moon. So I would assume anything brighter than that would not be suitable for nocturnal species especially smaller ones at risk of predation.	60	Grassland_reptiles	night_light	Initial
27	0.1	0.0	10	Nocturnal animals require darkness, and if too much light is present throughout the night from artificial sources, the behaviors of animals will likely change.	60	Grassland_reptiles	night_light	Initial
28	4500.0	4000.0	5000	Very hard to comment on as little studies done on diurnal reptile responses to night urban lighting, but gecko’s seem to do really well. I don’t think many diurnal reptiles would be affected as they shelter deep during the night.	40	Grassland_reptiles	night_light	Initial
29	0.0	0.0	0	Virtually all grassland reptiles are diurnal, and therefore night time lighting levels are unlikely to be particularly imporatnt for most species.	90	Grassland_reptiles	night_light	Initial
30	0.1	0.1	5	I assume the best maximum night-time level would be equivalent to a full moon given this would be the natural maximum night-time light level.	85	Grassland_reptiles	night_light	Initial
31	0.0	0.0	0	There do not appear to be many studies into the effects of artificial light on diurnal and nocturnal reptiles in Australia. the ACT has both diurnal species (e.g. dragons, skinks and our large Elapid snakes) and nocturnal species (e.g .geckos, and nocturnal snakes like the Dwyers Snake). Some species could benefit (such as geckos) or some may be perturbed by the light (such as dragon species which appear to be more sensitive to light). Obviously artificial light is known to directly affect the ecology and physiology of animals, or impact the habitat indirectly. I found a few resources on Anole lizards, but couldn’t find any local papers (other than a general guide to light pollution for wildlife) that look at species other than mammals and marine turtles.	0	Grassland_reptiles	night_light	Initial
32	0.0	0.0	0	I’m not aware of any studies done specifically for grassland reptiles on this topic. However from my experience, agamid species do seem to stress with increased light level at night.	0	Grassland_reptiles	night_light	Initial
33	0.0	0.0	0	I don’t know whether night-time light levels impact grassland reptiles.	0	Grassland_reptiles	night_light	Initial
35	0.0	0.0	0	I have no experience of the impact of night light on grassland reptiles.	0	Grassland_reptiles	night_light	Initial
36	0.0	0.0	0	Thermal conditions are likely the most important non-structural metric for grassland reptiles.	0	Grassland_reptiles	night_light	Initial
37	0.1	0.0	1	I would assume that reptiles would spend the night nestled into leaf litter or some other structure and so would be shaded from the light, unless they were nocturnally active. But I don’t know the answer to this question!	5	Grassland_reptiles	night_light	Initial
38	2.0	1.0	10	I dont know of any evidence for this.	20	Grassland_reptiles	night_light	Initial
39	3.0	0.0	5	Based on interferrign with rest and huntign effiency of predators.	60	Grassland_reptiles	night_light	Initial
Aggregated	346.6	307.8	388	NA	32	Grassland_reptiles	night_light	Aggregated

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Maximum tolerable surface temperature

This metric relates to the maximum surface temperature which is associated with suitable habitat for this taxon group. Surface temperature is the temperature which a laser thermometer would record if it was pointed to the ground. This metric is likely to be relevant to small terrestrial species, such as reptiles.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	40	35	60	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. Dragons can tolerate much higher temperatures than most other reptile species. Nocturnal species would have a much lower threshold. I have sadly witnessed small nocturnal reptiles shrivel up and die on contact with hot sand around 50 C. With the exception of arid adapted agamids not many reptile species will be out and active when the ground is too hot to touch..	60	Grassland_reptiles	surface_temp	Initial
27	35	30	45	Many reptiles can bask in very hot temperatures as long as there is suitable shade scattered around. This metric is hard to quantify.	50	Grassland_reptiles	surface_temp	Initial
28	50	25	60	Reptiles are very efficient at thermoregulating and will actively avoid surfaces that are too hot. Some litter-dwelling species may suffer from higher heat. We have unpublished data showing tiger snakes maintaining their prefered body temperature by sheltering in grass while the surface temps reach above 60C.	70	Grassland_reptiles	surface_temp	Initial
29	40	35	45	The critical thermal maximum for most lizard and snake species is in the low 40s. Thus, the maximum surface temperature should not exceed 40 degrees throughout the majority of the habitat.	95	Grassland_reptiles	surface_temp	Initial
30	50	40	55	These numbers will vary greatly depending on whether it is assumed the animal is active or sheltering. I have assumed the animal is sheltering. If they were active on the surface then I would bring my estimates down 10oC	60	Grassland_reptiles	surface_temp	Initial
31	40	35	45	I have provided estimates based on my knowledge, field observations of reptiles and studies on Delma impar and Grassland Earless Dragons. For Delma: “Observations on captive animals suggest that the species is most active in the morning and early afternoon, and prefers high temperatures for activity and basking (ground temperatures up to 45°C)”. For Tympanocryptis: body temperatures between 16 and 45°C at Canberra (Nelson 2004). Provided there is shelter and a reptile can seek shelter once reached optimal body temperature, they can withstand and will choose to bask at these very high temperatures.	80	Grassland_reptiles	surface_temp	Initial
32	40	35	50	These temperatures are based on anecdotal evidence. I often through the year will take a thermo gun into the field just as a bit of an interest of mine to see what ground temperatures certain areas get to (helps in mimicking environments in captivity). Many of these reptiles will happily bask at 35-45 and grasslands provide adequate refuge once it peeks 50+	80	Grassland_reptiles	surface_temp	Initial
33	45	30	55	I have observed grassland reptiles basking on and comfortably traversing surfaces that are quite hot (i.e. around 45-50 degree dark roof tiles and asphalt). However, it is unlikely that these species would tolerate ambient surface temperatures this hot.	70	Grassland_reptiles	surface_temp	Initial
35	30	10	39	Temperatures experienced in natural temperate grasslands are as high as 72oC in the sun. Most reptiles will not tolerate temperatures much hotter than 40. Minimum meastured for T.lineata is 10 - maximum 39 - unpubl data	70	Grassland_reptiles	surface_temp	Initial
36	35	30	40	In relation to SLL, Saleeba et al (2020) measures temperatures under roof tiles but does not measure the temperature of the soil surface. Monitoring data indicates the presence of SLL when the under-tile temperature ranges from15 - 40 deg C.	10	Grassland_reptiles	surface_temp	Initial
37	45	35	60	It’s been a fair while since I measured the surface temperature during reptile surveys, but I understand the ground gets quite hot and can be tolerated by grassland reptiles so long as they can escape it to a cooler area if they need to.	20	Grassland_reptiles	surface_temp	Initial
38	50	40	75	Some research on this for grassland earless dragons but some not ever published - but see attached paper by Nelson and Cooper. Grassland surface temperature recorded at 70 degrees on 35 degree day. However, burrows and vegetation can mediate the effect of surface temperature so tolerance depends on shelter availability and length of intolerable temperatures	50	Grassland_reptiles	surface_temp	Initial
39	38	35	45	Studies on thermal tolerance.	90	Grassland_reptiles	surface_temp	Initial
Aggregated	41	32	52	NA	62	Grassland_reptiles	surface_temp	Aggregated

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Maximum tolerable ambient temperature

This metric relates to the maximum ambient temperature which is associated with suitable habitat for this taxon group. Ambient temperature is the temperature which a mercury thermometer would record if it was suspended in the air out of direct sunlight (e.g. in the shade). This metric is likely to be relevant to larger terrestrial species, such as kangaroos, as well as arboreal species such as birds and bats.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	30	30	37	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. Dragons can tolerate much higher temperatures than most other reptile species. Nocturnal species would have a much lower threshold. In general survey guidelines for active hereptofauna searches are that they are not conducted when the temperature is above 30 degrees as most reptile species will seek shelter when the temp increases above 30 C.	65	Grassland_reptiles	ambient_temp	Initial
27	38	35	45	This greatly depends on the thermal heterogeneity of the site. If suitable shade is plentiful, reptiles should be able to bounce shuttle between hot and cool microhabitats even if the ambient temperature is quite hot.	50	Grassland_reptiles	ambient_temp	Initial
28	31	20	42	The species evolved around Canberra so I feel the summer average would be accurate. I gathered these numbers from BOM summer maximums.	70	Grassland_reptiles	ambient_temp	Initial
29	38	35	40	As per my last comment, this relates to the critical thermal maxima for most species.	70	Grassland_reptiles	ambient_temp	Initial
30	42	35	45	see previous comment	50	Grassland_reptiles	ambient_temp	Initial
31	35	28	38	I have provided estimates based on my knowledge of captive reptiles and field observations of reptiles. From guidelines for Delma impar “Shelter sites should be checked when ambient temperatures do not exceed 28 deg”. Again, if there are adequate shelter sites, reptiles can withstand high ambient temperatures for a time. On warm summer days, they could reach optimal body temperature quickly in warm ambient temperatures without basking for long periods, go hunting, then retreat to a shelter site without overheating.	80	Grassland_reptiles	ambient_temp	Initial
32	35	29	38	Based on anecdotal evidence - for example, as a snake catcher I tend to notice our call rates drop for snake sightings once the ambient temperature gets to 29-30+. Surface temperature can be much hotter than the ambient (I have recorder over a 20 degree difference) and it is these surface temps that most grassland reptiles influenced by.	80	Grassland_reptiles	ambient_temp	Initial
33	40	35	45	Based on field observations that grassland reptiles usually seek shelter during temperatures above 35 degrees.	75	Grassland_reptiles	ambient_temp	Initial
35	35	15	39	Based on detailed observations of T.lineata. Most species would have to be underground beyond these temperatures.	60	Grassland_reptiles	ambient_temp	Initial
36	37	35	45	Based on the findings of Saleeba - voluntary maximum temperature was 37 deg C. Note that grassland reptiles utilise soil cracks and rock shelters to avoid extreme heat. These are readily available in Victoria but my not be such a significant feature in the ACT.	50	Grassland_reptiles	ambient_temp	Initial
37	42	27	47	Again, would depend on the presence of appropriate habitat which enabled them to escape the heat if they needed to. If this occurred, and they had to cut feeding short or similar, prolonged heat waves could become problematic for these species. Papers by Lyn Nelson and Chloe Sato show some thermal tolerances for grassland reptiles (couldn’t attach here)	40	Grassland_reptiles	ambient_temp	Initial
38	40	38	50	Based on Grassland earless dragon work by Nelson and Cooper but this is not exactly what they looked at	80	Grassland_reptiles	ambient_temp	Initial
39	32	30	38	For reptiles to be basking, active etc. Need clarify on what this refers to as they can obviously escape extreme heat. Its how long it lasts that is the issue.	80	Grassland_reptiles	ambient_temp	Initial
Aggregated	37	30	42	NA	65	Grassland_reptiles	ambient_temp	Aggregated

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Habitat patch size and typical dispersal distances

The next series of visualisations relate to habitat patch size and typical dispersal distances.

This section asks questions regarding habitat patch sizes and typical dispersal distances for your selected taxon group.

Habitat patch size is explored for both core habitat (where the species lives full time) and corridors (areas the species might move through when dispersing, or when moving between connected habitat patches). Dispersal capability covers how far a species will typically move within and between habitat patches (e.g. within a home range), as well as how far they typically will move during a major dispersal event, e.g. when migrating or dispersing to a new home range.

The answers to these questions will help us to understand how far apart different patches of habitat can be whilst still being connected for a taxon group, as well as what the aspirations should be in terms of the total extent of connected habitat at the landscape or regional scale to facilitate typical dispersal patterns for the species. Below, we ask you to provide your upper, lower and best estimates for a range of metrics related to patch size and movement behaviour.

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Minimum suitable core habitat patch width

This metric relates to the minimum dimensions of an area which could be considered suitable core habitat for the taxon group. By core habitat, this would mean the area was able to provide all resources required by the species, including food, shelter, mates, etc.

For example, for a small mammal, the edge effects associated with a narrow strip of suburban woodland nestled between two rows of residential blocks may prevent it being classified as suitable core habitat. For an aquatic species, a stream may need to be some minimum width to provide sufficient core habitat for the species to move around in. If a core habitat patch in this instance is considered to have a rectangular shape, what would be the minimum width of the shorter side, regardless of how long the longer side might be?

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	200	100	400	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. Regarding dragons on average my monitoring transects are at least 200m apart. We can identify individuals based on dorsal patterns. I occasionally retrap individuals at the same transect over 2-3 years but I have never had them turn up at transects other than their original ones. They don’t disperse much or have large home ranges so they can persist in small areas. Delmas and Parasuta are capable of travelling further so by virtue of scale they would require proportionally larger minimal core patches but I don’t have data for this. Other than based on the size of the fragmented ‘island’ patches of reserves I have found them in.	60	Grassland_reptiles	min_width_core	Initial
27	30	20	70	Depending on the length dimension, I think many species, especially small lizards and skinks could survive in pretty narrow patches.	40	Grassland_reptiles	min_width_core	Initial
28	500	100	1000	Very little home range data available for most of the species in the Canberra. Unsure how far an Aprasia moves, but large elapids can easily cover a kilometer.	60	Grassland_reptiles	min_width_core	Initial
29	20	10	25	Many grassland reptile species can live in relatively small habitat patches. Whilst it would be ideal to have larger habitat patches, species can occur in smaller patches.	60	Grassland_reptiles	min_width_core	Initial
30	40	20	40	I assume the upper and best estimate should be the same given bigger will always be better with this variable.	25	Grassland_reptiles	min_width_core	Initial
31	0	0	0	This is highly variable - some threatened species would require a much wider patch to avoid edge effects, or those with a large home range such as an Eastern Brown Snake, whereas animals like blue tongues could exist in a small area between houses in suburbia. I am not confident to make an estimate.	0	Grassland_reptiles	min_width_core	Initial
32	0	0	0	This is incredibly difficult to answer as this would vary greatly depending on the species as they will all have different average home range sizes.	0	Grassland_reptiles	min_width_core	Initial
33	15	10	20	Based on observations of grassland reptiles persisting in at least the short to medium in strips of grassland/pasture retained along roadsides in the ACT and region (e.g. small Striped Legless Lizard populations persisting in patches along Well Station Drive).	80	Grassland_reptiles	min_width_core	Initial
35	5000	500	20000	These sizes would be appropriate for smaller grassland specialists and not for larger more general like brown snakes, bluetongues, shinglebacks.	80	Grassland_reptiles	min_width_core	Initial
36	20	10	50	Road and rail corridors continue to support SLL - need to consider habitat suitability of adjacent properties.	50	Grassland_reptiles	min_width_core	Initial
37	15	5	500	I think this would vary greatly for different species. Some species likely have very small home ranges and so would undertake all of their core activities in a small area, so long as there were no edge effects (e.g. skinks in a garden). Other species may be more sensitive and hence only persist in larger areas (e.g. D. impar) where habitat is more intact - although D. impar are known to occur in high densities in small (21ha) degraded sites. Large species such as snakes would likely use larger home ranges also.	20	Grassland_reptiles	min_width_core	Initial
38	400	300	500	Based on existing Grassland earless dragon habitat	60	Grassland_reptiles	min_width_core	Initial
39	300	100	500	Basd on SLL habitat use and home range	60	Grassland_reptiles	min_width_core	Initial
Aggregated	503	90	1777	NA	46	Grassland_reptiles	min_width_core	Aggregated

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Minimum suitable corridor habitat patch width

This metric relates to the minimum dimensions of an area which could be considered suitable habitat for the taxon group to move through, e.g. between different patches of ‘core’ habitat, or when dispersing (e.g. as a sub-adult looking for a new home range). Corridor habitat would need to provide all resources required by the species to effectively move through the urban space, e.g. suitable perch sites for birds, suitable protection from predation for mammals and reptiles.

For example, for a small mammal, the edge effects associated with a narrow strip of suburban woodland nestled between two rows of residential blocks may prevent it being classified as suitable core habitat, but it might be sufficient habitat to facilitate movement through the area. For an aquatic species, a stream may need to be some minimum width to provide sufficient core habitat for the species to move around in, however the same species may be able to navigate a narrow culvert if just being used as part of a movement corridor. If a movement corridor in this instance is considered to have a rectangular shape, what would be the minimum width of the shorter side, regardless of how long the longer side might be?

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	200	100	300	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. Regarding dragons on average my monitoring transects are at least 200m apart. We can identify individuals based on dorsal patterns. I occasionally retrap individuals at the same transect over 2-3 years but I have never had them turn up at transects other than their original ones. They don’t disperse much or have large home ranges so they can persist in small areas. Delmas and Parasuta are capable of travelling further so by virtue of scale they would require proportionally larger minimal core patches but I don’t have data for this. Other than based on the size of the fragmented ‘island’ patches of reserves I have found them in.	65	Grassland_reptiles	min_width_corridor	Initial
27	5	2	10	Many species can navigate through relatively small corridors, like fence rows or tree rows.	80	Grassland_reptiles	min_width_corridor	Initial
28	7	5	10	If suitable habitat reptiles should happily move through a small width.	70	Grassland_reptiles	min_width_corridor	Initial
29	20	10	25	As per my previous comment.	50	Grassland_reptiles	min_width_corridor	Initial
30	10	2	10	I assume the upper and best estimate should be the same given bigger will always be better with this variable.	25	Grassland_reptiles	min_width_corridor	Initial
31	50	10	100	This is highly variable - some threatened species would require a much wider area with suitable habitat (with cover in between) to avoid edge effects and disturbance, whereas those with a large home range and ability to move longer distances (and are gnerally less perturbed by suburban barriers) such as an Eastern Brown Snakes are happy to move through either small grass strips alongside footpaths or larger areas with ease.	60	Grassland_reptiles	min_width_corridor	Initial
32	50	2	100	Variable depending on the species. These are imply based on areas that I have seen reptiles pass through in a suburban environment.	50	Grassland_reptiles	min_width_corridor	Initial
33	10	5	20		80	Grassland_reptiles	min_width_corridor	Initial
35	200	20	10000	These values are for small specialist grassland lizards - based on genetic evidence for T.lineata, A.parapulchella, and NZ grassland skinks that shows poor dispersal over even moderately small distances of inhospitable habitat. I know of no evidence that measured the width of corridors and their relationship to connectivity in this group.	80	Grassland_reptiles	min_width_corridor	Initial
36	10	5	50	Very limited data regarding dispersal.	50	Grassland_reptiles	min_width_corridor	Initial
37	25	5	50000	It would probably depend on the edge effects. So long as it was good habitat, not shaded, suitable resources a narrow strip would probably facilitate movement between larger, better quality habitat patches.	30	Grassland_reptiles	min_width_corridor	Initial
38	100	50	200	Dont know any data behind this	20	Grassland_reptiles	min_width_corridor	Initial
39	20	15	30	Based on SLL movement	70	Grassland_reptiles	min_width_corridor	Initial
Aggregated	54	18	4681	NA	56	Grassland_reptiles	min_width_corridor	Aggregated

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Typical dispersal distance when seeking new home range/territory

This metric describes how far dispersing individuals from this taxon group will travel, usually to find a new home range or territory. This metric assumes the availability of continuous habitat.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	100	60	200	I am only answering with reference to Tympanocryptis osbornei. Regarding dragons my monitoring transects are 60m long and I have recaught the same individuals across the length of the transect but not at transects 200m away. Distances for D. impar and P. flagellum would be larger but I have no data for this.	65	Grassland_reptiles	disperal_distance	Initial
27	300	30	800	This is really species/group/size specific. Something like an arboreal skink or gecko maybe have a very small home range of only a few trees (20m), whereas something like a red-bellied black snake may travel a few kms throughout the year.	60	Grassland_reptiles	disperal_distance	Initial
28	150	50	1000	Very little known for reptiles.	30	Grassland_reptiles	disperal_distance	Initial
29	50	20	100	Most grassland reptile species would have relatively low dispersal abilities, and generally would not be moving large distances throughout the landscape.	60	Grassland_reptiles	disperal_distance	Initial
30	30	3	50	The lower value reflects the possibility of a mgmt trail forming a barrier to dispersal.	25	Grassland_reptiles	disperal_distance	Initial
31	50	10	1000	Very hard to say, its varies widely and a lot of grassland reptiles (particularly threatened species) have not been studied in this regard, and this is “recommended future research”. For GED, it appears that perhaps it is just “tens of metres”, while brown snakes can likely disperse more widely. I have taken an educated guess, but am not confident in my estimates.	50	Grassland_reptiles	disperal_distance	Initial
32	50	10	2000	I do not know of any papers specifically on grassland reptiles in regards to how far they will move to establish a new home range. My answer is simply based of anecdotal evidence of how far young T. scincoides may move in suburbia and to the extreme of how far I have had P. textilis move after translocation.	50	Grassland_reptiles	disperal_distance	Initial
33	150	20	300		60	Grassland_reptiles	disperal_distance	Initial
35	500	10	50000	Maximum dispersal distances in continuous habitat: P.vitticeps are in 10s of km. T.osbornei in 10s of km, T.lineata in 100s of metres but larger continuous habitat does not exist, A.parapulchella 10s of km	60	Grassland_reptiles	disperal_distance	Initial
36	100	20	400	Genetic data (Maldonado et al.) suggest dispersal is less than 400m for SLL. Recapture data indicates very restricted movement.	60	Grassland_reptiles	disperal_distance	Initial
37	30	3	1000	This will vary for different species. For small skinks, dispersal is likely less than 50m. Large species such as snakes may move much further to find a new home range. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-294X.2008.03951.x https://conbio.onlinelibrary.wiley.com/doi/abs/10.1111/j.1523-1739.2005.00161.x	30	Grassland_reptiles	disperal_distance	Initial
38	600	30	2000	Most data on movement is not for dispersal. This will vary widely according to species. These values do not include snakes	70	Grassland_reptiles	disperal_distance	Initial
39	60	50	100	HOme range studies on GEd and SLL	80	Grassland_reptiles	disperal_distance	Initial
Aggregated	167	24	4535	NA	54	Grassland_reptiles	disperal_distance	Aggregated

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Typical movement distance within established home range/territory

This metric describes how far an individual typically moves within a suitable habitat patch. It could be considered as the distance between the centre and the edge of a home range or territory.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	60	20	100	I am only answering with reference to Tympanocryptis osbornei. My unpublished data is similar as what has been found for the Canberra Earless Dragon. Stevens, T. A., M. C. Evans, W. S. Osborne, and S. D. Sarre. 2010. Home ranges of, and habitat use by, the grassland earless dragon (Tympanocryptis pinguicolla) in remnant native grasslands near Canberra. Australian journal of zoology 58:76-84.	75	Grassland_reptiles	movement_within	Initial
27	300	50	800	This estimate will not cover range restricted animals like arboreal skinks or geckos, or large travelling snakes, but should cover most of the general small/medium sized reptiles.	50	Grassland_reptiles	movement_within	Initial
28	100	20	500	Very little known and hard to quantify in small reptiles. We have tracked tiger snakes moving as little as 20m in 6 weeks to 800m in three days, and that’s a large elapid so must be a lot shorter from small species.	40	Grassland_reptiles	movement_within	Initial
29	10	2	50	Some species of grassland reptile can have a permanent home site, and rarely venture too far from this burrow, crevice, log etc. The home ranges of most species is generally extremely small.	70	Grassland_reptiles	movement_within	Initial
30	10	5	20	Based on memory of SLL movement distance	25	Grassland_reptiles	movement_within	Initial
31	0	0	0	Very difficult to ascertain - again, some species have large home ranges (e.g. brown snake), while others can be small (e.g. Blue tongue - they often live their whole life in one backyard, and this year I found the same individual in the grassland under the same tile as last season). There have been some radiotracking studies done on Delma impar, Tympanocryptis lineata, and Eastern Brown Snakes (e.g. A radiotelemetric study of movements and shelter-site selection by free-ranging brownsnakes (Pseudonaja textilis, Elapidae) and some people in the group will likely be more familiar with these estimates.	0	Grassland_reptiles	movement_within	Initial
32	0	0	0	All species will be different and you would need to refer to different radio tracking studies per species for this. Also, it this how far they move daily? weekly? monthly? annually? female vs male? Time of year? An animal is likely to use all of it home range to some capacity other wise the space would not be considered apart of their home range.	0	Grassland_reptiles	movement_within	Initial
33	100	10	200	This metric will vary greatly between grassland reptiles. For example, mark-recapture studies of Striped Legless Lizards using roof tiles across 12 week spring periods have found that individuals rarely travel more than 10 metres during a season (being their most active time of year), however tracking studies of Grassland Earless Dragons using fluorescent dye has recorded individuals of this species moving a couple of hundred metres within suitable habitat.	80	Grassland_reptiles	movement_within	Initial
35	100	100	500	Shinglebacks, T.lineata, P.vitticeps are in this ballpark.	80	Grassland_reptiles	movement_within	Initial
36	15	2	50	Recapture data for SLL.	70	Grassland_reptiles	movement_within	Initial
37	20	6	200	Again, varies depending on the size of the animal. Small movements within habitat for grassland reptiles such as small skinks and delma (often found under the same tile in a 20x25m distance grid) but known to move between tiles 10m apart. Snakes would be more.	20	Grassland_reptiles	movement_within	Initial
38	20	10	2000	A few papers have looked at movement in grassland and woodland reptiles. Varies by species and dispersal events not necessary distinguished	80	Grassland_reptiles	movement_within	Initial
39	50	20	150	Base don on GED and SLL average	70	Grassland_reptiles	movement_within	Initial
Aggregated	60	19	352	NA	51	Grassland_reptiles	movement_within	Aggregated

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Typical capacity for movement outside of suitable habitat (in the absence of a physical barrier)

This metric aims to quantify how far this taxon group can or will typically move outside of areas mapped as suitable habitat. For example, a kangaroo might be able to cross a road, even though a road is not classified as suitable habitat, so long as there are no wildlife exclusion fences. A cockatoo might be able to move across a suburb between one suitable woodland habitat patch and another.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	20	2.0	100	I am answering with reference to Tympanocryptis osbornei, Delma impar and Parasuta flagellum. I don’t think T. osbornei would move out of suitable habitat or away from cover. You never see them in the open. D. impar have been recorded moving at least 20m in a day. (Kutt 1992). So it stands to reason that they could move at least a days length out of suitable habitat in a single movement. Kutt, A. (1992). Microhabitat selection and mobility of the Striped Legless Lizard, Delma impar. Hons. Thesis. University of Melbourne. Parkville, Victoria: Department of Zoology, University of Melbourne. P. flagellum is the most capable of moving longer distances but I have no data on this. Just impressions based on what I’ve observed in the field of similar sized elapids.	65	Grassland_reptiles	capacity_movement	Initial
27	5	2.0	10	Barriers like roads make it difficult to successfully navigate across.	60	Grassland_reptiles	capacity_movement	Initial
28	40	0.0	100	Aprasia and grassland earless dragons would not attempt to cross a road, I suspect. Snakes and large skinks will but they don’t appear comfortable when doing so.	50	Grassland_reptiles	capacity_movement	Initial
29	10	0.0	25	Most grassland reptile species would be unlikely to be able to travel long distances across unsuitable habitat.	50	Grassland_reptiles	capacity_movement	Initial
30	5	3.0	20	Lower estimate assume most spp could move over a mineral earth mgmt trail; upper estimate assumes most spp couldn’t move over a large hwy; and best assumes could move across a single lane road.	25	Grassland_reptiles	capacity_movement	Initial
31	0	0.0	0	Large local Elapid species will regularly move outside of suitable habitat when moving around the landscape, blue tongue species and other generalist are likely to do this also. Delma impar are known to use sub-optimal habitat in the absence of more preferable native habitat as the structure is more important for them, whereas specialists like Grassland Earless Dragons and fossorial species are unlikely to move outside of suitable habitat.	0	Grassland_reptiles	capacity_movement	Initial
32	200	0.0	2000	Not all reptile species, such as small delma or earless dragons would do well to cross an open road. However, larger species would/do just fine. As mention previously, I have recorded a P. textilis move 2.3KM through a suburban environment (even though I consider this to be suitable habitat for this particular species, but we are talking about native environments which is why I have mentioned it).	60	Grassland_reptiles	capacity_movement	Initial
33	10	5.0	20	Based on field observations that grassland reptiles rarely move out side of suitable habitat.	80	Grassland_reptiles	capacity_movement	Initial
35	100	0.0	200	Radiotelemetry data on T.lineata shows some forays into unsuitable habitat of a few metres (Stevens et al). More generalised species like P.textilis, T.rugosa, P.barbata could go further if there is some vegetation.	40	Grassland_reptiles	capacity_movement	Initial
36	10	2.0	20	Unsure	20	Grassland_reptiles	capacity_movement	Initial
37	3	0.0	30	For most species, I don’t think they would move very far from cover - particularly if the surface was very hot. Snakes can and often do cross roads however, so can larger skinks. In general I’m thinking of smaller species and so have provided a smaller best estimate.	40	Grassland_reptiles	capacity_movement	Initial
38	100	0.0	500	Depends largely on what you are considering to be not habitat and the species. Grassland earless dragon will move through non native grass but not much else. Other species have broader tolerances.	40	Grassland_reptiles	capacity_movement	Initial
39	5	2.0	15	Studies show cant cross roads.	80	Grassland_reptiles	capacity_movement	Initial
Aggregated	39	1.2	234	NA	47	Grassland_reptiles	capacity_movement	Aggregated

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Barriers to movement

The next series of visualisations relate to barriers to movement.

This is the final section of this survey. This section asks questions regarding barriers to movement in the urban space, which might be represented by vertical barriers (fences, walls, buildings, gutters), water barriers (lakes, streams, rivers), substrate barriers (e.g. concrete or bitumen) or barriers relating to the use of an area by people (traffic, pedestrians). By quantifying these barriers we can use remote sensing data to identify their location in the urban environment and demonstrate functional habitat fragmentation.

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Maximum crossable extent of paved surface (incl. concrete drains)

This metric aims to capture the distance this taxon group can move across a paved surface, e.g. concrete or bitumen. Examples might include bike or pedestrian paths, roads and driveways, concrete drainage channels, tennis courts, car parks, etc. For reptiles, for example, a taxon group may choose this substrate as a basking site but not be able to move a long distance due to the lack of suitable habitat cover to protect from predation. For fish, platypus or turtles, there may be some maximum distance a species can move through an artificial waterbody (e.g. a concrete drainage channel) between naturalised pools or streams.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	7.0	5.0	20	I’m only basing this off the width of a typical road which for most larger grassland reptiles such as blue tongues and snakes seems to be enough of an impediment if roadkill is anything to go by.	65	Grassland_reptiles	paved_surface	Initial
27	5.0	3.0	10	Lack of shelter and potential for extreme heat would deter a lot of species.	50	Grassland_reptiles	paved_surface	Initial
28	5.0	0.0	30	Rarely have ever seen or heard of a reptile in the middle of a large area of open concrete.	80	Grassland_reptiles	paved_surface	Initial
29	20.0	5.0	50	Most grassland reptiles species would be able to utilise paved surfaces as basking sites. However, very few would be able to disperse long distances across paved surfaces due to their exposure to predators.	60	Grassland_reptiles	paved_surface	Initial
30	5.0	3.0	10	see previous comment	25	Grassland_reptiles	paved_surface	Initial
31	5.0	0.0	15	Larger species have the ability to travel more quickly over open non-grassed areas like paths and road, and some reptiles will even actively seek out these areas for basking. Large elapids can be more confident and have been seen to traverse over open paved areas. On the contrary, animals like Delma are highly unlikely to move outside of grassed areas (in 6 seasons of snake catching, I have once been called to a Delma impar inside a daycare kitchen, well within the building). I think paved areas of around 5 m or less gives more lieklihood that an animal such as a Delma may be able to cross it, given there was appropriate grass structure either side.	50	Grassland_reptiles	paved_surface	Initial
32	5.0	0.0	100	I have seen species cross shopping centres carparks but these are usually the larger, better suburban adapted species. Most, would make it across a footpath or possibly a road but I would find it hard to believe more specialised species such as Aprasia would do so.	50	Grassland_reptiles	paved_surface	Initial
33	1.0	0.5	4	My experience has been that grassland reptiles very rarely venture beyond the boundary of their grassland habitat. If they do then it is generally only for a short distance. Examples of this are that species such as the Striped Legless Lizard and Grassland Earless Dragon will usually not cross well-established gravel driveways and certainly won’t cross a sealed road. I have however known these species to traverse farm tracks where the wheel ruts are cleared (approx. 1m wide) but there is a strip of grass retained down the middle.	80	Grassland_reptiles	paved_surface	Initial
35	20.0	10.0	100	Even larger more generalised species will be reluctant to cross large expanses of paved area without cover. Genetic evidence for T.lineata show that major highways are complete barriers (Colley 2021).	50	Grassland_reptiles	paved_surface	Initial
36	4.0	2.0	10	Mixed evidence. Instances where SLL appear to be incapable of crossing 2m wide gravel track but other instances of the species being found in the middle of road, backyards etc.	60	Grassland_reptiles	paved_surface	Initial
37	17.0	2.0	300	It would depend on other factors, like surface temperature and predation risk, but in the absence of those issues I think reptiles could cross a fair distance of paved surface if they wanted to (they probably wouldn’t want to).	30	Grassland_reptiles	paved_surface	Initial
38	10.0	0.0	100	This will depend on species, temperature, traffic etc	30	Grassland_reptiles	paved_surface	Initial
39	2.0	0.0	3	Cant cross roads	80	Grassland_reptiles	paved_surface	Initial
Aggregated	8.2	2.4	58	NA	55	Grassland_reptiles	paved_surface	Aggregated

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Maximum crossable height of vertical structures

This metric aims to determine how much of a vertical structure will impede movement by this taxon group. For example, turtles may not be able to climb up a steep roadside curb, however for a gecko a vertical structure equivalent to a multi-storey building may not be prevent movement. Birds may be able to cross vertical barriers of any height, unless they are flightless.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0.30	0.01	0.80	Most grassland reptiles can’t climb. Snakes are limited by the lengths of their own bodies.	80	Grassland_reptiles	max_height_building	Initial
27	0.40	0.20	1.00	This would exclude species like arboreal geckos, which should be able to climb any height, and some non-climbing species like blue tongue lizards, which may struggle to climb over a road side curb. However, most snakes, skinks, and dragons should be able to climb fairly well over rough surfaces. The roughness of the barrier would be an important consideration.	50	Grassland_reptiles	max_height_building	Initial
28	0.03	0.00	40.00	Geckos enjoy the urban walls, an Aprasia could not climb one. Most species in Canberra aren’t good climbers.	90	Grassland_reptiles	max_height_building	Initial
29	1.50	1.00	5.00	Most grassland reptile species are terrestrial, and not great climbers. They would be able to traverse relatively low vertical barriers, but would be less likely to move across barriers that were more than 2 m high.	60	Grassland_reptiles	max_height_building	Initial
30	0.20	0.10	1.00	most grassland reptiles seem to be reasonable climbers??????	25	Grassland_reptiles	max_height_building	Initial
31	0.20	0.10	1.00	Geckos in our region (Eastern Stone and Marbled) have setae, so are able climb most structures and so that should not be a barrier. However, other species like dragons and snakes may not be able to climb over say a smooth Colorbond fence. I have witnessed a snake go approx 1 m up a colorbond fence that had snake-proof mesh between the bottom of the fence and ground level, find a small gap, and push its way through. Small animals could go under vertical structures, as often snakes and blue tongues and other creatures do when there are even tiny gaps between the bottom of the fence. If a structure is solid to the ground with no gaps underneath, and is smooth, I have provided estimates based on this. If it was a structure such as a mesh fence, then it could be higher as dragons can get leverage and climb this. Also, a mesh fence could be a barrier to a bearded dragon who could try to go through and get stuck, whereas a legless lizard or snake could slip straight through.	60	Grassland_reptiles	max_height_building	Initial
32	1.00	0.10	1.80	These estimates greatly depend on what these structures are made of, not just the species attempting to cross. For example, agamid species such as P. barbata could easily scale a tall wooden fence but can’t climb a colorbond fence. In many cases there are ways around, underneath or through structures for slimmer terrestrial reptiles but I have answered these as if it was a sealed wall.	60	Grassland_reptiles	max_height_building	Initial
33	0.20	0.10	0.30	Based on field observations with pitfall traps and other similar survey methods. Mature individuals of many grassland reptiles (e.g. Delma spp., Grassland Earless Dragon) can readily escape from 20cm deep pitfall traps, however they very rarely escape from 30 cm deep, and never from 40cm deep. Generally, pygopodids can climb over a barrier that is less than 2/3rds of its total length.	70	Grassland_reptiles	max_height_building	Initial
35	0.30	0.10	1.00	Depends on the surface and the species.	50	Grassland_reptiles	max_height_building	Initial
36	20.00	10.00	30.00	SLL capacity to jump and climb. Depth of pit-fall buckets and height of drift-fences.	70	Grassland_reptiles	max_height_building	Initial
37	0.01	0.00	0.50	I’ve seen skinks climb small vertical surfaces, but not very high (gecko’s being an exception). Snakes can also climb over barriers, however legless lizards may not be able to. On average I’d say the capacity to overcome a solid vertical barrier (depending on what is is made from) would be quite low. Chasing skinks as a kid, they fell off things easily!	70	Grassland_reptiles	max_height_building	Initial
38	0.40	0.20	1.00	This would also depend on the surface of the vertical structure	5	Grassland_reptiles	max_height_building	Initial
39	0.01	0.00	0.01	Guess	60	Grassland_reptiles	max_height_building	Initial
Aggregated	1.89	0.92	6.42	NA	58	Grassland_reptiles	max_height_building	Aggregated

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Minimum passable gap dimensions (e.g. 50mm in chain link fence)

This metric aims to quantify the size of a gap which would allow passage of this taxon group through what would otherwise be a barrier (e.g. a fence, or a culvert). For example, an antechinus might be able to pass through a chain link fence, however a turtle may not.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	0.15	0.10	0.20	No comment	75	Grassland_reptiles	gap_dimensions	Initial
27	0.06	0.02	0.10	This should only exclude large species groups like Pagona, Tiliqua, or turtles.	70	Grassland_reptiles	gap_dimensions	Initial
28	0.07	0.01	0.10	Many of the species are small and need those big gaps!	90	Grassland_reptiles	gap_dimensions	Initial
29	0.20	0.10	1.00	Depending on the substrate, some barriers might represent a considerable barrier to some grassland reptile species.	35	Grassland_reptiles	gap_dimensions	Initial
30	0.02	0.01	0.03	Most grassland reptiles are pretty small	50	Grassland_reptiles	gap_dimensions	Initial
31	0.10	0.01	0.10	This is quite variable, a hatchling snake or Delma could pass through a tiny gap, whereas a Larger elapid would need a larger gap (but not too large, they compress their bodies well. A large bearded dragon would need a larger gaps due to their scalation and head width. I assume turtles (which would need a bigger gap) are covered in the aquatic reptile group.	80	Grassland_reptiles	gap_dimensions	Initial
32	0.10	0.00	0.10	This estimate I have made is based from hatchling P. textilis to adult male P. barbata.	100	Grassland_reptiles	gap_dimensions	Initial
33	0.08	0.01	0.10	This metric depends greatly on the species. For example, a mature Striped Legless Lizard can pass through mesh with <1cm holes, however a mature Bearded Dragon would require >7cm holes to pass.	75	Grassland_reptiles	gap_dimensions	Initial
35	0.10	0.05	0.10	This depends on being able to find the gap.	60	Grassland_reptiles	gap_dimensions	Initial
36	0.01	0.01	0.01	SLL can pass through very small gaps. Escapes from tiny holes in seams of reptile bags.	100	Grassland_reptiles	gap_dimensions	Initial
37	0.20	0.05	100.00	Most grassland reptiles would be able to fit through a 20cm gap if it was at ground level.	90	Grassland_reptiles	gap_dimensions	Initial
38	0.10	0.02	0.10	Depend on species size	80	Grassland_reptiles	gap_dimensions	Initial
39	0.01	0.01	0.02	animal size	60	Grassland_reptiles	gap_dimensions	Initial
Aggregated	0.09	0.03	7.84	NA	74	Grassland_reptiles	gap_dimensions	Aggregated

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Maximum crossable extent of water body

This metric aims to quantify the distance this taxon group can move across a permanent waterbody. In some instances, larger species such as kangaroos may be readily able to navigate a small stream by hopping from one side to the other, however the same might not be possible for a small grassland reptile.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	1.00	1.00	100	Snakes don’t have trouble swimming. Waterways would be a complete impediment to grassland earless dragons and larger bodied skinks such as shinglebacks and blue tongues. Some smaller reptiles might be able to swim across a very insignificant stretch of water but not a creek or river.	90	Grassland_reptiles	max_waterbody	Initial
27	1.00	0.00	2	Small skinks will likely be blocked from crossing water bodies, however, some snakes and medium size reptiles may be able to swim across short distances. This excludes species like turtles.	50	Grassland_reptiles	max_waterbody	Initial
28	1.00	0.00	3	Of all Canberra reptiles I’d consider snakes being the only taxon that would choose to swim. Water skinks will as well.	100	Grassland_reptiles	max_waterbody	Initial
29	1.00	0.00	2	Most grassland reptiles have relatively poor swimming abilities, and therefore even relatively small water bodies represent sizeable dispersal barriers to species.	70	Grassland_reptiles	max_waterbody	Initial
30	1.00	1.00	5	We know the Molonlgo river has formed a barrier to dispersal for PTWL and therefore assume grassland reptiles are not big swimmers.	25	Grassland_reptiles	max_waterbody	Initial
31	0.00	0.00	0	I am unsure if a Grassland Earless Dragon would be able to cross a permanent water body at all (even say 10 cm), but potentially. Blue tongues are not great swimmers but can float and make it over a small water body. Snakes are excellent swimmers and can traverse large distances over water.	0	Grassland_reptiles	max_waterbody	Initial
32	0.00	0.00	0	I am aware of certain grassland reptile species being able to swim rather well but I have no evidence to suggest that other species such as T. lineata can swim at all.	0	Grassland_reptiles	max_waterbody	Initial
33	1.00	0.00	2	I believe that grassland reptiles will avoid traversing a waterbody of any width. However, I have observed Striped Legless Lizards swimming quite proficiently through flooded grassland/pasture to reach non-flooded areas.	50	Grassland_reptiles	max_waterbody	Initial
35	1.00	1.00	20	Some snakes can swim reasonable distances, small grassland lizards generally will not.	50	Grassland_reptiles	max_waterbody	Initial
36	2.00	1.00	5	Unknown for SLL.	10	Grassland_reptiles	max_waterbody	Initial
37	0.00	0.00	50	Most small skinks I wouldn’t think would be able to cross water, however snakes can swim in floods so they are a different story.	20	Grassland_reptiles	max_waterbody	Initial
38	0.00	0.00	0	Depends on species, some could cross small bodies	70	Grassland_reptiles	max_waterbody	Initial
39	0.00	0.00	1	No evidence for swimming	80	Grassland_reptiles	max_waterbody	Initial
Aggregated	0.69	0.31	15	NA	47	Grassland_reptiles	max_waterbody	Aggregated

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Tolerable vehicle traffic flow (incl. boats) during active period (day/night)

This metric aims to quantify the level of vehicle traffic (including boats in an urban waterbody) which would represent a barrier to this taxon group. The number should be based on the amount of traffic occurring during the species’ active part of the day or night. For example, an echidna may be willing and able to cross a road at night when there is little traffic, however during the day an increased traffic volume may result in the road (or rather, the traffic on the road) becoming a barrier for this species. A similar approach can be applied to aquatic and riparian species in terms of boat traffic.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	45	30.0	60	How do you account for deliberate behaviour of morons deliberately running snakes over? How do you account for reptiles that will bask on roads at certain times of day so that they are immediately vulnerable to even one vehicle? I have no data on this. Just averaging that one car a minute could provide enough of a frequency to pose risk to animals basking or slowly crossing a road.	60	Grassland_reptiles	traffic_flow	Initial
27	30	20.0	60	Slow moving species, or those that stop to bask on the road will be excluded form this estimate, and those that just sprint across.	50	Grassland_reptiles	traffic_flow	Initial
28	30	30.0	60	Reptile don’t cross roads very fast and suffer high mortality.	70	Grassland_reptiles	traffic_flow	Initial
29	5	0.0	30	For grassland reptiles, the width of the barrier (road, waterbody) is probably a larger factor than the traffic density itself.	15	Grassland_reptiles	traffic_flow	Initial
30	5	0.0	60	Wild guess	5	Grassland_reptiles	traffic_flow	Initial
31	0	0.0	0	I believe for an animals such as an Earless Dragon, any vehicle during its active period is a barrier. For animals such as large Elapids, they occasionally cross a road unscathed, but are often hit and killed or severely injured and have to be euthanased. So realistically, any vehicle traffic is a barrier.	0	Grassland_reptiles	traffic_flow	Initial
32	0	0.0	0	Light to no traffic would be best for most species. I have not seen any reptile successfully make it across a road during peak traffic. I won’t attempt to give a figure for vehicles per hour.	0	Grassland_reptiles	traffic_flow	Initial
33	0	0.0	0	Given that species from this taxon group tend not to move out their habitat and cross roads etc., I do not believe that this metric is relevant to grassland reptiles.	0	Grassland_reptiles	traffic_flow	Initial
35	5	5.0	20	Even modest traffic appear to be a barrier for T.lineata.	20	Grassland_reptiles	traffic_flow	Initial
36	6	6.0	12	No idea.	0	Grassland_reptiles	traffic_flow	Initial
37	3	0.0	12	Snakes can cross roads, but often don’t make it. Smaller species might be able to do a dash between vehicles if they were warm enough, but might not attempt it.	5	Grassland_reptiles	traffic_flow	Initial
38	2	1.0	20	Dont know of any work to inform this	3	Grassland_reptiles	traffic_flow	Initial
39	2	1.0	5	Given they cant cross roads in most cases not sure about this.	30	Grassland_reptiles	traffic_flow	Initial
Aggregated	10	7.2	26	NA	20	Grassland_reptiles	traffic_flow	Aggregated

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Tolerable pedestrian traffic flow (incl. swimming) during active periods (day/night)

This metric aims to quantify the level of pedestrian traffic (including swimmers in an urban waterbody) which would represent a barrier to this taxon group.The number should be based on the amount of pedestrians passing during the species’ active part of the day or night. A similar approach can be applied to aquatic and riparian species in terms of people swimming in a waterbody.

For example, a kangaroo may be willing and able to cross school playground at dusk in summer when there are few people about, however during winter an increased use of the school oval for organised sports in the evening may result in the grassy area becoming a barrier for this species.

Expert	Best	Lower	Upper	Comments	Confidence	Taxon	Variable	Group2
7	6	6.0	12	You’d only need one person to walk past every 10 minutes to spook something for long enough that it would hide before venturing out again. However many species can become tolerant to the presence of humans especially if they are only walking past and not towards them. Again no data on this just anecdotal observations.	65	Grassland_reptiles	pedestrian_flow	Initial
27	90	60.0	120	This greatly depends on the cover or area where the pedestrians are. I envisioned crossing a walking path.	50	Grassland_reptiles	pedestrian_flow	Initial
28	30	10.0	60	Some urban species - like Lampropholis and blue-tongues - can become tolerant of human traffic, so this influences the higher score. But I suspect many more cryptic species would not tolerate it.	60	Grassland_reptiles	pedestrian_flow	Initial
29	20	5.0	100	Grassland reptiles in urban areas can be relatively tolerant of pedestrian traffic, but this will vary depending on the habitat complexity and refuge sites that they have available to them.	20	Grassland_reptiles	pedestrian_flow	Initial
30	5	0.0	60	wild guess	5	Grassland_reptiles	pedestrian_flow	Initial
31	4	4.0	10	It really depends on the species, most reptiles will hide and actively avoid human traffic, so it would need to be low to no human traffic during the day as most grassland reptiles are diurnal (except for geckos and Dwyers Snakes).	30	Grassland_reptiles	pedestrian_flow	Initial
32	10	5.0	20	As long as the traffic is not constant, species that don’t mind being in the open for a short period will cross without issue. The issue with situations like this is that most reptile actively avoid conflict so there are likely small species would would never cross if it risked exposure to a larger animal.	10	Grassland_reptiles	pedestrian_flow	Initial
33	2	1.0	5		20	Grassland_reptiles	pedestrian_flow	Initial
35	1	1.0	5	a hunch	20	Grassland_reptiles	pedestrian_flow	Initial
36	6	1.0	12	The substrate is probably more important than the volume of pedestrian traffic.	0	Grassland_reptiles	pedestrian_flow	Initial
37	10	5.0	30	Reptiles which become accustomed to traffic, like those which live on population hiking trails or boardwalks, appear to be fairly tolerant of people but it would depend on how often they had to move and how much energy this took.	10	Grassland_reptiles	pedestrian_flow	Initial
38	2	1.0	10	I dont know any reserach to inform	40	Grassland_reptiles	pedestrian_flow	Initial
39	4	3.0	5	If frequently disturbed during peak activity would have impact	60	Grassland_reptiles	pedestrian_flow	Initial
Aggregated	15	7.8	35	NA	30	Grassland_reptiles	pedestrian_flow	Aggregated

ACT Urban Habitat and Connectivity Project - Grassland reptiles

Steph Courtney Jones, Melissa Snape, Steph Pulsford, Danswell Starrs

5 October 2021

Introduction

Shared resources

Structural habitat metrics

Preferred distance between tree canopies

Percentage of trees which need to be native

Preferred distance between mature trees

Preferred distance between mid-storey canopies

Percentage of native mid-storey vegetation

Preferred distance from ground layer vegetation

Percentage of native ground layer vegetation

Minimum height of ground layer vegetation

Maximum height of ground layer vegetation

Non-structural habitat metrics

Maximum tolerable night-time light levels

Maximum tolerable surface temperature

Maximum tolerable ambient temperature

Habitat patch size and typical dispersal distances

Minimum suitable core habitat patch width

Minimum suitable corridor habitat patch width

Typical dispersal distance when seeking new home range/territory

Typical movement distance within established home range/territory

Typical capacity for movement outside of suitable habitat (in the absence of a physical barrier)

Barriers to movement

Maximum crossable extent of paved surface (incl. concrete drains)

Maximum crossable height of vertical structures

Minimum passable gap dimensions (e.g. 50mm in chain link fence)

Maximum crossable extent of water body

Tolerable vehicle traffic flow (incl. boats) during active period (day/night)

Tolerable pedestrian traffic flow (incl. swimming) during active periods (day/night)