Introduction

This document summarises the Round 1 - Initial estimates of the Fine Scale Metrics for 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”).

For each question asked in the expert elicitation, we have summarised the results. 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.

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Structural habitat metrics

The next series of visualisations relate to structural habitat metrics.

Structural habitat metrics describe the finer scale structural elements of a species’ habitat and how the various features are arranged in space. For example, some species may need access to bare ground for nesting to be able to successfully occupy a habitat patch. This would be a structural requirement.

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Preferred % cover of rocks

Access to rocky substrate may relate to things such as habitat refugia, basking sites for reptiles, or food resources (for aquatic species). What percentage cover of rocky substrate is required for an area to be preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 5 0.0 50 Decision is based on results of study looking at artificial rock placement in NTG in SE Australia (Palmer et al. in press). PTWL are typically only found in rocky grasslands with rock cover between 10-50% (Wong et al. 2011). GED in monaro region appear more reliant on rocks than GED in the ACT (from memory, . 75 Grassland_reptiles percent_rocks Initial
19 0 0.0 10

Start of this refers to bare ground - assume this just a mistake?

Rocks perhaps not integral to grassland reptiles in ACT. Grassland Earless Dragons are not heavy users of rocks here, unlike osbornei in Cooma region. Other species like brown snakes and small skinks will of course use gaps/burrows into rocky areas, but they survive in grasslands without rock too.

CEMP says grasslands benchmark for rock cover = 0-2.8% 		80 Grassland_reptiles percent_rocks Initial
28 25 10.0 80 rocks provide cover and basking habitat 60 Grassland_reptiles percent_rocks Initial
42 25 0.0 50 Lower estimate is for pure grassland species like the earless dragon, and upper estimate is from my experience in finding Aprasia (the species that would use the most rocks of the target species). To incorporate good habitat for all these species is hard so I’m going for the mean value. 85 Grassland_reptiles percent_rocks Initial
46 35 10.0 60 I am largely basing this off the Monaro experience. I appreciate T. lineata habitat has less rock cover and therefore less reliant on this habitat variable than T. osbornei. Equally D. impar are more confined to rockless grassland in the ACT whereas they do well in both rocky basalt sites and grass only sites in the Monaro. A. parapulchella nonetheless is significantly reliant on surface rock within their range in the ACT. 75 Grassland_reptiles percent_rocks Initial
48 5 1.0 25

Not sure scale here. Also don’t think this is something done by expert. Look at the natural rock cover at grasslands with different evolutionary history.

Geology will influence whats natural and not in this space.

Also this question is so scale dependent. Scale of reserve, polygon plot. Scale influences answer. 		80 Grassland_reptiles percent_rocks Initial
68 10 5.0 40 Reptiles vary substantially in their optimum level of rock coverage. Some lizards like Aprasia are have a dependency on them whereas others like Canberra Earless Dragons would not appear to require them at all (cf T.osbornei). Another factor is the nature of the rocks. Are they shallow as say required by A.parapulchella? 20 Grassland_reptiles percent_rocks Initial
69 40 0.0 75 This metric varies a great deal. I.e. for PTWL the required cover should generally be above 10%, however most sites supporting SLL and GED in the ACT have little or no rock cover. 80 Grassland_reptiles percent_rocks Initial
Aggregated 18 3.2 49 NA 69 Grassland_reptiles percent_rocks Aggregated

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Preferred % cover of bare ground

Access to bare ground may relate to things such as nesting sites (for burrowing or fossorial species) or spaces to hunt. What percentage of ground needs to be bare ground for an area to be preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 5 0.0 20 Decision is based on ideal thatch cover for maintaining NTG ecological condition and therefore habitat for NTG reptiles (Howland et al. in prep). GED and PTWL typically only occur in areas with high floristic value. GED require greater inter tussock spaces than SLL and PTWL. 70 Grassland_reptiles percent_ground Initial
19 20 5.0 25

Grasslands benchmark for bare ground (currently used by offsets team in benchmarks for management) = 10-20%

SLL happy on low end of bare ground 0-5%, species like GED need much more inter-tussock spacing and higher bare ground up to 25%. 		80 Grassland_reptiles percent_ground Initial
28 30 10.0 60 can provide habitat for basking, digging nests, ease of movement through the environment 60 Grassland_reptiles percent_ground Initial
42 5 0.0 20 In my experience with these species they do not utilise bare ground and aren’t commonly found in habitats with consistent bare ground. 90 Grassland_reptiles percent_ground Initial
46 25 10.0 65 GED require bare ground for basking, foraging and movement and are more reliant on this habitat variable than the other threatened reptile species. 70 Grassland_reptiles percent_ground Initial
48 10 5.0 25 On average areas with 5 to 20% bare appear to support higher diversity. However, above 5 may disfavour some, and under 10 disfavour others. 90 Grassland_reptiles percent_ground Initial
68 15 6.0 30 This is quite measurable for tympos (unpublished); 60 Grassland_reptiles percent_ground Initial
69 25 0.0 40 Again, this varies greatly by taxon - in my experience I have found that SLL do not require bare ground, however GED decline when sites grow rank and there is insufficient bare ground. 80 Grassland_reptiles percent_ground Initial
Aggregated 17 4.5 36 NA 75 Grassland_reptiles percent_ground Aggregated

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Preferred % cover of grass thatch (dead, unattached grass)

Grass thatch is the layer of dead plant material that develops between the zone of green vegetation and the soil surface. We consider dead grass to be thatch once it is no longer attached to the parent plant. Grass thatch can be beneficial for some species (e.g. providing habitat for nesting) but detrimental for other species (e.g. obstructing movement). What percentage cover of grass thatch is consistent with an area being preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 30 10.0 60 Decision is based on ideal thatch cover for maintaining NTG ecological condition and therefore habitat for NTG reptiles (Howland et al. in prep). 70 Grassland_reptiles percent_thatch Initial
19 10 10.0 20

Benchmark for grasslands (currently used in management) = 10-20%

GED seem to struggle greatly in lots of thatch, snakes and SLL not perturbed. 		80 Grassland_reptiles percent_thatch Initial
28 50 10.0 80 can provide cover, shade, or variability in the habitat which may be beneficial to certain species 50 Grassland_reptiles percent_thatch Initial
42 10 0.0 20 Brown snakes would utilise piles of dead grass temporarily, but I am unsure if any of these species would be deterred from too much grass thatch. 40 Grassland_reptiles percent_thatch Initial
46 30 10.0 70 Thatch is good but too much will impede movement of GED. 70 Grassland_reptiles percent_thatch Initial
48 5 2.0 10 Thatch is usually negatively related to reptile diversity and abundance. However, some level is probably beneficial. 90 Grassland_reptiles percent_thatch Initial
68 0 0.0 20 Low thatch for Aprasia/Tympanocryptis 50 Grassland_reptiles percent_thatch Initial
69 25 10.0 40
70 Grassland_reptiles percent_thatch Initial
Aggregated 20 6.5 40 NA 65 Grassland_reptiles percent_thatch Aggregated

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Preferred depth of grass thatch (cm)

The definition of grass thatch here is consistent with the previous question, however this question focuses on the depth of the grass thatch layer. What depth of grass thatch is consistent with preferred habitat for this taxon group? Consider the most appropriate depth of grass thatch in centimetres.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 0.5 0.0 2.0 Decision is based on ideal thatch depth for maintaining NTG ecological condition and therefore habitat for NTG reptiles (Howland et al. in prep). 70 Grassland_reptiles thatch_depth Initial
19 0.5 0.0 1.0 Grasslands benchmark currently used for management = <1 cm depth 80 Grassland_reptiles thatch_depth Initial
28 5.0 1.0 10.0 unsure about this, variable thickness is probably more likely in the environment 40 Grassland_reptiles thatch_depth Initial
42 5.0 0.0 30.0 Again not too sure but I suspect some of the smaller specialist species would be deterred from heavy layers of grass thatch, but brown snakes would enjoy it (upper estimate). 50 Grassland_reptiles thatch_depth Initial
46 2.0 1.0 5.0 Whilst good for cover, too extensive thatch depth can impede ability to forage 70 Grassland_reptiles thatch_depth Initial
48 0.5 0.0 0.5 No evidence in data I hae collected that this resource is important for lowland grassland reptiles. Complete absence probably an issue. 90 Grassland_reptiles thatch_depth Initial
68 0.0 0.0 5.0 Low confidence but thatch generally seems to be a hindrance 20 Grassland_reptiles thatch_depth Initial
69 15.0 2.0 30.0
70 Grassland_reptiles thatch_depth Initial
Aggregated 3.6 0.5 10.4 NA 61 Grassland_reptiles thatch_depth Aggregated

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Preferred % cover of leaf litter

Some species require access to leaf litter for food resources (e.g. arthropods and other invertebrate living in the leaf litter) or may require leaf litter as habitat refugia (for burrowing or fossorial species). What percentage of cover of leaf litter is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 0.0 0.0 0 0 100 Grassland_reptiles percent_litter Initial
19 0.0 0.0 0 NA shouldn’t really be in a grassland 100 Grassland_reptiles percent_litter Initial
28 10.0 5.0 40 assuming we’re targeting grassland species, there will only (should only) be scattered trees, and therefore not a great deal of leaf litter 50 Grassland_reptiles percent_litter Initial
42 0.0 0.0 10 I haven’t seen these species using leaf litter, except Hemiergis (rarely). 90 Grassland_reptiles percent_litter Initial
46 0.0 0.0 0 Leaf litter is not a significant feature of grasslands 90 Grassland_reptiles percent_litter Initial
48 0.0 0.0 20 Is this forb litter or tree litter. Forb litter probably contribute to invert community. Tree leaf litter can reasonably assume to be negative given most grassland reptiles avoided wooded areas. 90 Grassland_reptiles percent_litter Initial
68 7.0 5.0 10 Amount of leaf litter is generally low and not measured in grassland reptiles 20 Grassland_reptiles percent_litter Initial
69 20.0 0.0 40
70 Grassland_reptiles percent_litter Initial
Aggregated 4.6 1.2 15 NA 76 Grassland_reptiles percent_litter Aggregated

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Preferred % grass cover (all grasses)

The percentage cover of grass might be important for some species based on refugia sites or food resources. What percentage of grass cover is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 90 60 100 Lower estimate considers rock cover, bareground cover and thatch cover in rocky NTG habitat that typically supports PTWL, GED, and brown snakes. 70 Grassland_reptiles percent_grass Initial
19 70 50 90 Given bare ground, thatch and forb cover, around 70% grass cover but with heterogeneity in the landscape. SLL prefer more grass cover (up to 90%), whereas GED would prefer less grass cover with more bareground. 70 Grassland_reptiles percent_grass Initial
28 70 40 90 grasses should be the dominant structure for grassland reptiles 60 Grassland_reptiles percent_grass Initial
42 75 70 100 If the lack of grass cover is substituted with rocks then most of these species would benefit, but not with bare dirt. 80 Grassland_reptiles percent_grass Initial
46 50 20 75 The interspace between grass tussocks are essentially important for GED to be able to move, bask and forage. 70 Grassland_reptiles percent_grass Initial
48 60 50 90 I will email. But these measures could be obtained through review of 8 years of reptile monitoring and vegetation surveys across 8 grassland reserves. This process might be better filling in where no data exists, but where data does exist should use that. 90 Grassland_reptiles percent_grass Initial
68 80 70 95 based on tympo data (unpublished) 50 Grassland_reptiles percent_grass Initial
69 60 30 95 As per previous metric, this varies greatly between taxa. 80 Grassland_reptiles percent_grass Initial
Aggregated 69 49 92 NA 71 Grassland_reptiles percent_grass Aggregated

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Preferred % invasive grass cover (e.g. Wild oats, Chilean Needle Grass, Serrated Tussock, African Love Grass)

It is possible/likely that a component of total grass cover in the urban space will be comprised of highly invasive grass species. These species can monopolise grassy areas and impact on ground layer structure and function for many species. What is the percentage cover of invasive grasses which is consistent with preferred habitat for this taxon group? This metric might be used to trigger invasive plant management regimes, or identify priority areas for restoration, as some examples.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 5 0.00 50 Decision based on grassland richness being greatest in higher quality native grasslands. Invasive grass species form dense monocultures and significantly alter habitat structure and complexity. 80 Grassland_reptiles percent_invasive Initial
19 20 0.00 50 NTG requires at least 50% native cover. Ideally not much invasive grasses would be good, but not plausible. Species like SLL can persist in invasive grasses, and recorded in areas of high density Serrated Tussock (they could handle a higher %, but not preferred). 60 Grassland_reptiles percent_invasive Initial
28 40 0.00 80 probably depends more on the grass structure than the species 40 Grassland_reptiles percent_invasive Initial
42 20 0.00 100 I believe grassland dragons and legless lizards have strict associations with native grass (lower estimate) but Brown snakes and blue tongues can happily thrive in invasive grass communities (upper estimate). 90 Grassland_reptiles percent_invasive Initial
46 1 1.00 100 GED and SLL can still be found to occur where 100% of the grass cover is exotic. 80 Grassland_reptiles percent_invasive Initial
48 10 0.00 20 Most species appear to tolerate some level of weed infestation. 80 Grassland_reptiles percent_invasive Initial
68 5 0.00 10 Too much deviation from NTG is unlikely to work well 50 Grassland_reptiles percent_invasive Initial
69 20 5.00 50
75 Grassland_reptiles percent_invasive Initial
Aggregated 15 0.75 58 NA 69 Grassland_reptiles percent_invasive Aggregated

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Preferred % native forb cover

Native forbs include any flowering ground-layer plant, that is not a grass, sedge or rush. They may provide habitat structure or food resources. What percentage cover of native forbs is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 2 0.0 5 Higher quality grasslands have high diversity and abundance of native forbs and are more likely to support a greater range of habitat types. That is, forb rich grasslands typically support a greater level of heterogeneity. 60 Grassland_reptiles percent_forb Initial
19 10 0.0 20 ACT veg benchmarks for grasslands say 4-17%, CEMP 0-18.5%. I see this metric as more of a reflection of the quality of grassland, rather than direct impact on reptile species. May not be any forbs in some grasslands occupied (e.g. Native Pasture). 60 Grassland_reptiles percent_forb Initial
28 20 5.0 40 some forbs mixed in to the grasses would add some heterogeneity 40 Grassland_reptiles percent_forb Initial
42 10 0.0 10 Without evidence, I suspect many of these species would not use and be displaced by large non-grass plants. 80 Grassland_reptiles percent_forb Initial
46 25 1.0 65 Presence of a good diversity and abundance of forbs would imply that the site is not overgrazed (and therefore not too bare) but also not over dominated by grass and hence too dense. 70 Grassland_reptiles percent_forb Initial
48 25 0.0 50 See previous comments. 80 Grassland_reptiles percent_forb Initial
68 20 10.0 30 Low confidence 10 Grassland_reptiles percent_forb Initial
69 15 2.0 30
75 Grassland_reptiles percent_forb Initial
Aggregated 16 2.2 31 NA 59 Grassland_reptiles percent_forb Aggregated

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Preferred % exotic broad leaf cover (e.g. thistles)

Exotic broad leaf plant species (such as thistles or pigweed) make up the majority of the non-native ground layer plants which are not grasses, sedges or rushes. They may exclude native vegetation from growing in the ground layer or alter habitat structure. What percentage cover of exotic broad leaf plants is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 5 0.00 20 NA 80 Grassland_reptiles percent_broad Initial
19 30 0.00 30 CEMP benchmark = 0-27.8% 60 Grassland_reptiles percent_broad Initial
28 5 0.00 25 small amount may be ok, but you wouldn’t want them to dominate the grassland 40 Grassland_reptiles percent_broad Initial
42 5 0.00 20 Same as previous question. 80 Grassland_reptiles percent_broad Initial
46 10 1.00 50 I hate thistle 75 Grassland_reptiles percent_broad Initial
48 10 0.00 30 Few if any areas don’t have broadleaf cover above 5%. 70 Grassland_reptiles percent_broad Initial
68 5 0.00 10 Invasiveness is high so even small stands will be damaging. 30 Grassland_reptiles percent_broad Initial
69 10 0.00 20
70 Grassland_reptiles percent_broad Initial
Aggregated 10 0.12 26 NA 63 Grassland_reptiles percent_broad Aggregated

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Preferred total length of coarse woody debris (>10cm diameter incl. snags, stumps)

Coarse woody debris (CWD) refers to fallen dead trees and the remains of large branches on the ground in forests, grasslands and in aquatic ecosystems. Here we define CWD as being greater than 10 cm in diameter and including snags (aquatic) and tree stumps. CWD provides structure and refugia within a terrestrial habitat and changes physical and hydraulic properties in aquatic systems. CWD needs to be considered when managing forests for biodiversity but also for managing fire risk. What is the preferred total length of coarse woody debris required in an area to be preferred habitat for this taxon group? Consider the total length in metres in a one-hectare patch.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 0 0.00 0 0 100 Grassland_reptiles cwd_length Initial
19 0 0.00 0 NA grassland species 100 Grassland_reptiles cwd_length Initial
28 6 1.00 20 not really sure if length really matters, might be more useful to think of density or number of snags/logs in an area 40 Grassland_reptiles cwd_length Initial
42 1 0.00 2 Most of these species wouldn’t use any woody debris, but blue tongues and brown snakes can shelter under larger debris if it is wide enough. I doubt many of these species would use CWD with diameters <30cm. 80 Grassland_reptiles cwd_length Initial
46 0 0.00 0 Not relevant to grassland specialists 90 Grassland_reptiles cwd_length Initial
48 0 0.00 5 I’m in grassland reptiles I think. Otherwise sorry filled out wrong survey 80 Grassland_reptiles cwd_length Initial
68 5 0.00 5 Habitat to some, shelter for predators to others 30 Grassland_reptiles cwd_length Initial
69 100 0.00 300
75 Grassland_reptiles cwd_length Initial
Aggregated 14 0.12 42 NA 74 Grassland_reptiles cwd_length Aggregated

Preferred % cover of floral resources

Floral resources refer to flowering plants which might provide food resources throughout the entire forest column (i.e. ground layer to canopy). What is the preferred percentage cover of floral resources in an area at any one time which is associated with preferred habitat for this taxon group? You might consider the percentage cover across a one-hectare patch if it helps, or another scale if that makes more sense to you. We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 0 0 0 0 100 Grassland_reptiles percent_floral Initial
19 0 0 0 I am not sure about this metric. 1 Grassland_reptiles percent_floral Initial
28 10 0 20 a little may be ok, but you would still want the dominant group to be grasses 40 Grassland_reptiles percent_floral Initial
42 0 0 0 I don’t think this is necessary for these reptiles. 60 Grassland_reptiles percent_floral Initial
46 0 0 0 I don’t think this is relevant to grasslands so much. 90 Grassland_reptiles percent_floral Initial
48 0 0 0 Grasslands 80 Grassland_reptiles percent_floral Initial
68 0 0 0 Unsure about this metric 1 Grassland_reptiles percent_floral Initial
69 75 40 95
60 Grassland_reptiles percent_floral Initial
Aggregated 11 5 14 NA 54 Grassland_reptiles percent_floral Aggregated

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Preferred number of flowering species (floral resource diversity)

A diversity of flowering plants throughout the entire forest column (i.e. ground layer to canopy) provides food resources across time and space. What is the preferred number of flowering species in an area at any one time for the habitat to be preferred for this taxon group? Consider the preferred number of flowering species across a one-hectare patch. We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 20 1.0 30 Higher floristic diversity indicates higher habitat heterogeneity and availability of resources for all grassland taxa. 60 Grassland_reptiles min_flower_sp Initial
19 0 0.0 0 Unsure here, reptiles eat insects so likely important. 1 Grassland_reptiles min_flower_sp Initial
28 10 5.0 25 diversity may be good as long ass they dont take over the grassland 40 Grassland_reptiles min_flower_sp Initial
42 0 0.0 0 Same as previous. 80 Grassland_reptiles min_flower_sp Initial
46 0 0.0 0 Not relevant to grasslands beyond an indication of good forb diversity and hence indication of not too much grazing pressure 90 Grassland_reptiles min_flower_sp Initial
48 60 20.0 100 This scale does not match any that we measure so hard to estimate. 80 Grassland_reptiles min_flower_sp Initial
68 0 0.0 0 Uncertainty high 1 Grassland_reptiles min_flower_sp Initial
69 10 2.0 15
75 Grassland_reptiles min_flower_sp Initial
Aggregated 12 3.5 21 NA 53 Grassland_reptiles min_flower_sp Aggregated

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Minimum temporal availability of floral resources

A diversity of flowering plants throughout the entire forest column (i.e. ground layer to canopy) provides food and other resources across time. What is the minimum temporal availability of floral resources in an area for the habitat to be suitable for this taxon group, in terms of the number of months per year? (e.g. a score of 6 would indicate that flowering plants were available for at least 6 months of the year, although not necessarily continuously). We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 4.0 1.0 6.0 Minimum estimate based on a single grass species flowering period. Upper estimate stretches from early Spring to late summer. Best estimate includes spring and early-mid summer. 60 Grassland_reptiles temp_floral Initial
19 3.0 3.0 6.0 Grasslands usually flower at least from Sept/Oct-Dec. Some seasons they flower longer (e.g. La Nina) 40 Grassland_reptiles temp_floral Initial
28 3.0 0.0 6.0 not sure 20 Grassland_reptiles temp_floral Initial
42 0.0 0.0 0.0 Same as previous. 80 Grassland_reptiles temp_floral Initial
46 0.0 0.0 0.0 Not relevant to grassland specialists 99 Grassland_reptiles temp_floral Initial
48 6.0 3.0 9.0 Don’t get this question. 80 Grassland_reptiles temp_floral Initial
68 0.0 0.0 0.0 Uncertainty high 1 Grassland_reptiles temp_floral Initial
69 4.0 2.0 6.0
60 Grassland_reptiles temp_floral Initial
Aggregated 2.5 1.1 4.1 NA 55 Grassland_reptiles temp_floral Aggregated

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Preferred % cover of shrub layer (0.5-3m height)

The mid-storey or shrub layer provides structure for nesting, refugia from predators and food resources for many species. This could be related to the amount or complexity of structure the species group prefers or is tolerant of in its preferred habitat, or some other feature of the species groups’ general biology or life history. This metric considers the percentage cover across a one hectare patch.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 0.0 0.00 0.0 0 100 Grassland_reptiles percent_shrub Initial
19 10.0 0.00 10.0 EPBC benchmark for grasslands = <10%, Grassland reptiles don’t rely on shrubs for use, but could make use of them if available. 60 Grassland_reptiles percent_shrub Initial
28 10.0 0.00 30.0 some scattered shrubs would provide shelter, basking areas, etc. 40 Grassland_reptiles percent_shrub Initial
42 1.0 0.00 5.0 I don’t think these species like or require shrubs. 80 Grassland_reptiles percent_shrub Initial
46 1.0 1.00 5.0 Shrubs are not a typical feature of grasslands. 90 Grassland_reptiles percent_shrub Initial
48 0.0 0.00 10.0 Shrubs not part of grasslands. 80 Grassland_reptiles percent_shrub Initial
68 0.0 0.00 5.0 For some species in NTG shrubs are likely to be a negative 50 Grassland_reptiles percent_shrub Initial
69 0.0 0.00 10.0
80 Grassland_reptiles percent_shrub Initial
Aggregated 2.8 0.12 9.4 NA 72 Grassland_reptiles percent_shrub Aggregated

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Preferred % tree canopy cover (per ha)

The tree canopy provides structure (such as shade), habitat and resources for a range of species. Tree canopy cover may influence how a 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 accounts for the availability of canopy cover from exotic and native tree species in the environment, as well as both young and mature trees (> 3m height). Consider the percentage cover across one hectare patch.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 0.0 0.00 0 0 100 Grassland_reptiles percent_canopy Initial
19 0.0 0.00 10 EPBC benchmark for grasslands = <10% 80 Grassland_reptiles percent_canopy Initial
28 5.0 0.00 20 canopy cover should be minimal in a grassland 40 Grassland_reptiles percent_canopy Initial
42 2.0 0.00 10 Many of these species don’t need tree cover. 80 Grassland_reptiles percent_canopy Initial
46 1.0 1.00 10 Canopy cover is not a typical feature of grasslands. Shade can be an impediment to basking. 90 Grassland_reptiles percent_canopy Initial
48 0.0 0.00 10 grassland 80 Grassland_reptiles percent_canopy Initial
68 0.0 0.00 0 Tree layer providing bird perches and shading - generally a negative for grassland reptiles 70 Grassland_reptiles percent_canopy Initial
69 10.0 0.00 20
80 Grassland_reptiles percent_canopy Initial
Aggregated 2.2 0.12 10 NA 78 Grassland_reptiles percent_canopy Aggregated

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Physical chemical properties

The next series of visualisations relate to physical chemical properties.

Physical chemical properties mostly relate to the aquatic environments or soil.

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Preferred soil moisture content

Soil moisture content is the total amount of water, including the water vapor, in the soil. Soil moisture influences the vegetation species present and can affect burrowing and feeding activity of some fauna. This metric seeks to determine the preferred soil moisture content for the taxon group.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 30 10.0 60 Best estimate is based on approximate average soil moisture index for spring/early summer in canberra region. Lower estimate is a dry year and upper estimate is a wet year. 60 Grassland_reptiles soil_moisture Initial
19 0 0.0 0 I don’t have any expertise here, but is likely important as it relates to grass, forb and invertebrate community etc. 1 Grassland_reptiles soil_moisture Initial
28 20 1.0 40 not sure how to quantify this one, or what cracking soil would constitute on a % scale 10 Grassland_reptiles soil_moisture Initial
42 10 5.0 40 A quick browse of the literature and I couldn’t find any soil moisture specifications for the species that frequently use soil (e.g. Hemiergis and Tympanocryptis) but I highly suspect these species need a certain level of soil moisture. Unsure how much this is. 20 Grassland_reptiles soil_moisture Initial
46 50 30.0 80 Educated guess only. Moisture is particularly important to ensure deposited eggs do not desiccate in burrows. 50 Grassland_reptiles soil_moisture Initial
48 0 0.0 0 Don’t get this metric being included. 1 Grassland_reptiles soil_moisture Initial
68 5 5.0 10 I have never measured this but soil moisture is generally low. 30 Grassland_reptiles soil_moisture Initial
69 20 10.0 30
30 Grassland_reptiles soil_moisture Initial
Aggregated 17 7.6 32 NA 25 Grassland_reptiles soil_moisture Aggregated

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Habitat function and risk management

The next series of visualisations relate to habitat function and risk management.

This section asks questions regarding habitat function and risk management for your selected taxon group.

These metrics describe what sorts of risks need to be managed within habitat areas to retain habitat function. The responses to these questions will aid in the identification, design and restoration of habitat patches and connectivity corridors in the urban space, provide an evidence base for policy decision making, and set thresholds for management intervention.

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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Preferred noise levels (during active period)

Anthropomorphic noise may impact on habitat suitability for native fauna by creating disturbance or interrupting communication pathways. This metric seeks to determine the level of anthropomorphic noise preferred by the taxon group. Sources of noise might include commercial or residential areas, traffic, or other human based sources. This metric should be based on the long-term ambient noise level during the day, and exclude short-term sounds, such as cars backfiring in a parking lot. Noises such as school bells, concerts, or sirens would all contribute to the mean noise level.

Decibels: 0 threshold of human hearing, 20 quiet room, 60 busy street, 80 loud radio, 100 subway train, 110 industrial noise, 120 jet plane take-off, 130 gun shot. Remembering that decibels are described on a logarithmic scale.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 20 0.0 120 No idea 50 Grassland_reptiles noise_level Initial
19 20 0.0 60 I don’t have expertise here. SLL and GED (and other species) are in places with busy roads nearby, planes flying overhead etc. Obviously a lower level of noise is preferred, but they seem to cope. Brown snakes and skinks seem pretty OK with most levels of noise, being found in urban areas too. 40 Grassland_reptiles noise_level Initial
28 20 0.0 40 wild places often have surprisingly high background noises (birds, wind, etc) 40 Grassland_reptiles noise_level Initial
42 50 20.0 100

A recent review found reptiles can respond and acknowledge industrial noise levels: https://link.springer.com/chapter/10.1007/978-1-4939-8574-6_7

But I suspect many of these species would adjust to regular noises once they learn they are not threatening. 		90 Grassland_reptiles noise_level Initial
46 0 0.0 0 I don’t think this is especially relevant to grassland reptiles beyond the possible disturbance of vibration created by noise 80 Grassland_reptiles noise_level Initial
48 20 0.0 60 Don’t know. Assume high noice bad 60 Grassland_reptiles noise_level Initial
68 0 0.0 0 I have no data on this 1 Grassland_reptiles noise_level Initial
69 20 0.0 60
75 Grassland_reptiles noise_level Initial
Aggregated 19 2.5 55 NA 54 Grassland_reptiles noise_level Aggregated

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Minimum tolerable fire interval

Fire can impact on habitat suitability either by influencing core habitat structural elements (such as ground and mid-storey complexity) or by causing direct mortality to individuals or populations. This metric seeks to determine the minimum tolerable fire interval (assuming low-moderate intensity burns on a patchy sub-hectare scale) before there is an impact on resident species. The assumption is that fire is applied during the active period for the species (e.g. during daylight hours on a warm day for grassland reptiles). We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 60 24 60 Best estimate is based on ideal fire interval for grasslands to promote floristic diversity and habitat heterogeneity and therefore resource availability (Williams, Marshall and Morgan 2015?)). 70 Grassland_reptiles fire_interval Initial
19 0 0 0 Think this is super variable, depends on grassland community type too. Not confident making an estimate before the discussion. Some may be OK on regular basis, if only small, cool burns in some areas with opportunity to escape the fire. This is also very site dependent. 1 Grassland_reptiles fire_interval Initial
28 24 12 60 not very familiar with the fire tolerances of these species 20 Grassland_reptiles fire_interval Initial
42 0 0 12 A bit unsure about the scale of this metric (I put 0 as never burns) but none of these species like fire. 12 Grassland_reptiles fire_interval Initial
46 60 24 120 Fire (particularly in lieu of grazing) can be an important tool in controlling veg biomass. For grasslands its application would mainly be applied following significant growth seasons e.g. post La Nina, but not during drought conditions. 70 Grassland_reptiles fire_interval Initial
48 10 0 50

5 to 10 years appear compatible. No fire may be bad, every 3 years likely bad based on a few studies.

This question can be answered with quantitative data collected in the ACT. 		80 Grassland_reptiles fire_interval Initial
68 48 0 120 Fire is probably intrinsic to maintaining vegetation structure and reducing weeds. I know of no definitive data that says what that interval should be. Low intensity burns essential. 30 Grassland_reptiles fire_interval Initial
69 24 12 48
75 Grassland_reptiles fire_interval Initial
Aggregated 28 9 59 NA 45 Grassland_reptiles fire_interval Aggregated

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Minimum tolerable mowing intervals

Mowing can impact on habitat suitability either by influencing core habitat structural elements (such as ground storey complexity) or by causing direct mortality to individuals or populations. This metric seeks to determine the minimum tolerable mowing interval (assuming mowing to 5cm height using a ride-on slasher) before there is an impact on resident species. The assumption is that mowing is undertaken during the active period for the species (e.g. during daylight hours on a warm day for grassland reptiles) and covers all accessible areas (i.e. leaves patches around fence posts and sign bases). It is also assumed that there are limited other ground-layer disturbance mechanisms (e.g. herbivore grazing) taking place in mown areas. We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 12.0 6 12 Frequent mowing has been shown to reduce SLL numbers (ACT Government unpublished data). Annual mowing of mgmt trails in early summer in ACT reserve networks has been shown to maintain vegetation condition and increase habitat heterogeneity (Smith et al. 2018). 60 Grassland_reptiles mowing_interval Initial
19 0.0 0 0 Hard to say, be good to discuss. Some areas I think shouldn’t be slashed at all (e.g. core habitat, have witnessed tail loss in SLL after slasher went through), other areas may be very regular and more just thoroughfare for some animals (e.g. snakes) so can be regular without issue. 1 Grassland_reptiles mowing_interval Initial
28 3.0 2 6 hard to say 40 Grassland_reptiles mowing_interval Initial
42 10.0 2 12 I suspect the Tympan’s and Delma will be very susceptible to this but the larger species won’t seem to mind sporadic mowing. 50 Grassland_reptiles mowing_interval Initial
46 3.0 2 12 Assuming that mowing is limited to managed areas eg adjacent to paths or road verges and around signs. Not large swathes of grassland habitat. Might only be needed during periods of significant growth eg La Nina seasons. I feel that regular mowing would deter native reptiles and lead to mortality. 65 Grassland_reptiles mowing_interval Initial
48 12.0 2 24 Mowing more than 6 times per year is known to negatively impact SLL. 80 Grassland_reptiles mowing_interval Initial
68 0.0 0 36 Mowing may be ok but impractical over large areas and the height of mowing will be critical. Some high set mowing might be plausible. 50 Grassland_reptiles mowing_interval Initial
69 3.0 2 4
75 Grassland_reptiles mowing_interval Initial
Aggregated 5.4 2 13 NA 53 Grassland_reptiles mowing_interval Aggregated

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Maximum tolerable presence of introduced predators (incl. fox, dog, cat)

Introduced predators such as cats and foxes are a major source of extinction for native Australian fauna. Domestic dogs are also known to impact on habitat suitability for native species. This metric seeks to determine the maximum number of individual foxes, cats or dogs which can persist in an ecosystem before an impact on habitat suitability is anticipated for other resident species. The metric considers the impacts of both domestic and feral animals combined and will assume ‘individuals’ are separate based on current best practice described in the literature if individual animals cannot be identified from markings alone.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
12 1.0 0.00 1.0 No idea 50 Grassland_reptiles intro_predators Initial
19 1.0 0.00 1.0 I don’t have expertise here, though given the impact of cats in particular on native reptiles I think their tolerable level will be very low (though realistically may be higher than I’d like to think in 24hr period). 40 Grassland_reptiles intro_predators Initial
28 1.0 1.00 3.0 mortality by feral/domestic predators is so high for reptiles, even a few cats can cause a lot of damage 40 Grassland_reptiles intro_predators Initial
42 1.0 0.00 1.0 The fossorial species like Hemiergis and Aprasia should not spend much time on the surface and not be impacted by these predators. But the surface basking species would be susceptible. 70 Grassland_reptiles intro_predators Initial
46 1.0 1.00 1.0 There should be no tolerable level for introduced predators. Individual predators can refine their hunting strategy to specifically target specific species/taxa. 100 Grassland_reptiles intro_predators Initial
48 0.0 0.00 1.0 Is this per camera or per camera grid. Its highly possible to get no detection in a 24 hr period even if fox and cat high. Actually 1 fox per week is probably likely in area with moderate foxes. 50 Grassland_reptiles intro_predators Initial
68 0.0 0.00 0.0 Cat predation is a constant threat and likely to increase extinction risk at any level. 50 Grassland_reptiles intro_predators Initial
69 5.0 0.00 10.0
20 Grassland_reptiles intro_predators Initial
Aggregated 1.2 0.25 2.2 NA 52 Grassland_reptiles intro_predators Aggregated