Introduction

This document summarises the Round 1 - Initial estimates of the ACT Urban Habitat and Connectivity Project expert elicitation for amphibians 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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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
74 5.0 0 100 Realistically, travel between trees for tree species (e.g Litoria peronii) would be highly dangerous in the city, especially in busier areas so the shorter the travel distance the better. 50 Amphibians tree_canopy Initial
76 0.0 0 0

These questions don’t nicely align with the ecological requirements of frogs. Some species in the region need some trees (Litoria pernoii) but other don’t (Crinia signifera). The key thing for frogs, is the presence of suitable breeding habitat. If there are no breeding habitats, then the terrestrial environmental (trees and ground layer) are irrelevant.

The best source of information on habitat requirements for species that occur in the local region is: Westgate, M. J., B. C. Scheele, K. Ikin, A. M. Hoefer, R. M. Beaty, M. Evans, W. Osborne, D. Hunter, L. Rayner, and D. A. Driscoll. 2015. Citizen science program shows urban areas have lower occurrence of frog species, but not accelerated declines. PLoS ONE 10:e0140973.

This study specifically looks at habitat requirements for frog species in the Canberra urban and peri-urban environment. 		0 Amphibians tree_canopy Initial
77 10.0 0 1000 This is tricky. Some species show no preference for canopy (Upes, crinia), whereas others do (Lit per). Species diversity will be maximised by having some canopy cover, however. I consider the following species as urban/potentially urban: Cri sig, Cri par, Lim tas, Lim dum, Lim per, Lit ver, Lit per, Neo sud. Aspirational: Lit aur Resource: Hoefer and Starrs (2016). One pond fits all. Report to Waterwatch, Ginninderra Catchment Group 50 Amphibians tree_canopy Initial
78 20.0 0 100 Important for some tree frogs. Bark, leave litter dead wood provide important refuge areas as well as habitat for prey. 0 Amphibians tree_canopy Initial
79 0.0 0 0 Most of these species do not have much direct affinity with trees, but are more strongly influenced by other vegetation characteristics including the logs and litter that trees produce. Other frog species not in this region can be more influenced by trees and some of the tree frogs are somewhat influenced by trees 80 Amphibians tree_canopy Initial
80 0.0 0 0 There are no tree canopy specialist frogs in Canberra and although forest cover would be indicative of better habitat structure for providing cover for frogs, it is likely to not be very important for dispersal between wetlands. 95 Amphibians tree_canopy Initial
Aggregated 5.8 0 200 NA 46 Amphibians 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
74 20 5.0 100 I don’t believe its entirely necessary for trees to be native but I have found a preference for natives in my fieldwork 50 Amphibians native_trees Initial
76 0 0.0 0

These questions don’t nicely align with the ecological requirements of frogs. Some species in the region need some trees (Litoria pernoii) but other don’t (Crinia signifera). The key thing for frogs, is the presence of suitable breeding habitat. If there are no breeding habitats, then the terrestrial environmental (trees and ground layer) are irrelevant.

The best source of information on habitat requirements for species that occur in the local region is: Westgate, M. J., B. C. Scheele, K. Ikin, A. M. Hoefer, R. M. Beaty, M. Evans, W. Osborne, D. Hunter, L. Rayner, and D. A. Driscoll. 2015. Citizen science program shows urban areas have lower occurrence of frog species, but not accelerated declines. PLoS ONE 10:e0140973.

This study specifically looks at habitat requirements for frog species in the Canberra urban and peri-urban environment. 		0 Amphibians native_trees Initial
77 80 0.0 100 I don’t believe nativeness is a particularly relevant, although I have generally caught Lit per associated with Casuarinas and young Eucs close to the water’s edge. In general should prefer native species regardless. Shedding of bark (Eucs) etc to create habitat for frogs. 50 Amphibians native_trees Initial
78 70 30.0 100 trees important for some tree frogs, not so much for ground dwelling frogs, however debris, dead wood, leave litter etc provide important habitat, as well as habitat for prey 0 Amphibians native_trees Initial
79 0 0.0 0 As trees are not a strong driver of these frogs abundance/ presence at a site, the nativeness of trees is not a strong metric for this group 80 Amphibians native_trees Initial
80 0 0.0 0 Native vegetation is likely important for frogs, but trees not so much. 90 Amphibians native_trees Initial
Aggregated 28 5.8 50 NA 45 Amphibians native_trees Aggregated

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Preferred distance between mature trees

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
74 20 5.0 100 The distance needs to be large enough so the trees can actually grow to maturity but not too far that it becomes too big a risk for frogs to travel. 50 Amphibians mature_trees Initial
76 0 0.0 0

These questions don’t nicely align with the ecological requirements of frogs. Some species in the region need some trees (Litoria pernoii) but other don’t (Crinia signifera). The key thing for frogs, is the presence of suitable breeding habitat. If there are no breeding habitats, then the terrestrial environmental (trees and ground layer) are irrelevant.

The best source of information on habitat requirements for species that occur in the local region is: Westgate, M. J., B. C. Scheele, K. Ikin, A. M. Hoefer, R. M. Beaty, M. Evans, W. Osborne, D. Hunter, L. Rayner, and D. A. Driscoll. 2015. Citizen science program shows urban areas have lower occurrence of frog species, but not accelerated declines. PLoS ONE 10:e0140973.

This study specifically looks at habitat requirements for frog species in the Canberra urban and peri-urban environment. 		0 Amphibians mature_trees Initial
77 100 0.0 1000 Not sure that mature trees play much of a role. I associate Lit per with both large and small trees. What seems to matter more is how close they are to the water’s edge. 10 Amphibians mature_trees Initial
78 20 3.0 50 One pond fits all? report has shown that the distance to woodlands over 10ha are important for a range of species and greater distance is a good predictor for lower species richness. 0 Amphibians mature_trees Initial
79 0 0.0 0 Mature trees do provide some important resources for this group, but other variables are much more important 80 Amphibians mature_trees Initial
80 0 0.0 0 NA 95 Amphibians mature_trees Initial
Aggregated 23 1.3 192 NA 39 Amphibians mature_trees 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
74 1.0 0.0 10 A continuous ground layer would be ideal as it protects them from the elements and predators. 50 Amphibians ground_layer Initial
76 0.0 0.0 0

These questions don’t nicely align with the ecological requirements of frogs. Some species in the region need some trees (Litoria pernoii) but other don’t (Crinia signifera). The key thing for frogs, is the presence of suitable breeding habitat. If there are no breeding habitats, then the terrestrial environmental (trees and ground layer) are irrelevant.

The best source of information on habitat requirements for species that occur in the local region is: Westgate, M. J., B. C. Scheele, K. Ikin, A. M. Hoefer, R. M. Beaty, M. Evans, W. Osborne, D. Hunter, L. Rayner, and D. A. Driscoll. 2015. Citizen science program shows urban areas have lower occurrence of frog species, but not accelerated declines. PLoS ONE 10:e0140973.

This study specifically looks at habitat requirements for frog species in the Canberra urban and peri-urban environment. 		0 Amphibians ground_layer Initial
77 0.0 0.0 50 Majority of frogs show some affinity to complexity of habitat in the ground layer. Large expanses of bare ground etc considered to be a negative trait - increased exposure to predation etc. See Starrs and Hoefer (2016) for species-level associations with rocks, logs etc in the riparian zone 50 Amphibians ground_layer Initial
78 10.0 5.0 50 ground layer without vegetation provides very high predation risk for frogs, as well as higher risk of drying out while moving across this area 0 Amphibians ground_layer Initial
79 8.0 4.0 20 This group can tolerate short distances of gravel and bitumen etc. 70 Amphibians ground_layer Initial
80 10.0 5.0 40 I have observed many of these species on roads on rainy nights or out foraging on mowed grass patches. Most would probably not venture great distance from some ground cover though. 70 Amphibians ground_layer Initial
Aggregated 4.8 2.3 28 NA 40 Amphibians 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
74 100 20.0 100 Amphibians are very sensitive to toxins which may be produced/released by non natives. 70 Amphibians native_ground Initial
76 0 0.0 0

These questions don’t nicely align with the ecological requirements of frogs. Some species in the region need some trees (Litoria pernoii) but other don’t (Crinia signifera). The key thing for frogs, is the presence of suitable breeding habitat. If there are no breeding habitats, then the terrestrial environmental (trees and ground layer) are irrelevant.

The best source of information on habitat requirements for species that occur in the local region is: Westgate, M. J., B. C. Scheele, K. Ikin, A. M. Hoefer, R. M. Beaty, M. Evans, W. Osborne, D. Hunter, L. Rayner, and D. A. Driscoll. 2015. Citizen science program shows urban areas have lower occurrence of frog species, but not accelerated declines. PLoS ONE 10:e0140973.

This study specifically looks at habitat requirements for frog species in the Canberra urban and peri-urban environment. 		0 Amphibians native_ground Initial
77 0 0.0 0 Not overly confident, but not sure that nativeness plays a huge role. Complexity and nature of groundlayer structure I perceive to be more important than species composition. 25 Amphibians native_ground Initial
78 70 20.0 100 large clumps of tussock-like grasses provide important habitat for frogs. non native plants often have different growth characteristics and do not attract native invertebrates (mobile frog food) in the same way as native species 0 Amphibians native_ground Initial
79 30 0.0 50 Structure of vegetation is likely more important that nativeness. Little known impact of ground vegetation nativeness. Structure and vegetation associated with water bodies is more important for this group 50 Amphibians native_ground Initial
80 60 5.0 90 Structure is likely to be the most important element of vegetation requirements for amphibians, although it is difficult to say what proportion of weed species could replicate native vegetation. Certainly, some frog species are found to shelter weeds. Although weed species tend to change the overall wetland structure and can choke wetlands out. 25 Amphibians native_ground Initial
Aggregated 43 7.5 57 NA 28 Amphibians 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
74 5 3.0 10 I honestly don’t have a good answer for this. I think its important that there is enough height for individuals to rest under but I don’t think an actual specific height is important. 20 Amphibians min_height_ground Initial
76 15 10.0 30 Frogs need some level of ground layer vegetation for shelter, to avoid predation and to help movement 75 Amphibians min_height_ground Initial
77 10 0.0 50 Starrs and Hoefer (2016) - suggests that mowing is detrimental to frogs (but confounded with large woody debris, so not overly robust, and note the analysis on species richness is problematic, so not to be relied on). Excess bare ground may lead to increased exposure, predation etc. Managing for a mosaic the best solution given diversity of preferences among species and life history stages. 1 Amphibians min_height_ground Initial
78 50 20.0 100 wide mowing buffers have been shown to increase frog diversity and abundance as it provides important habitat, good invertebrate fauna, cooler temperatures and helps retain moisture for longer. Mowing itself kills frogs. one pond fits all… 0 Amphibians min_height_ground Initial
79 6 5.0 10 This varies between species. Some species require more cover but other species, like the spotted grass frog, thrive in shorter cover. 80 Amphibians min_height_ground Initial
80 100 5.0 100 Some very small frogs (e.g. Crinia) can likely move through short grass comfortably. Most would require higher/thicker vegetation. 80 Amphibians min_height_ground Initial
Aggregated 31 7.2 50 NA 43 Amphibians 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
74 5 0 10 Similar to my previous comment, as long as there is cover I don’t think the specifics are important. 20 Amphibians max_height_ground Initial
76 70 40 100 For frogs, the issue is more about the density of ground layer vegetation. If it’s too thick, movement could be impeded. 75 Amphibians max_height_ground Initial
77 50 10 100 Excess groundcover likely to limit sunlight etc, probably not ideal. Managing for a mosaic is probably ideal to provide for diversity of preferences among species and life history stages etc. Note that Lit per readily use perches, but other species (eg. crinia) don’t use the vertical structure. 1 Amphibians max_height_ground Initial
78 50 30 100 I am not aware of adverse effects of increased heights of ground layer on frogs 0 Amphibians max_height_ground Initial
79 30 25 50 Little is known about this metric 40 Amphibians max_height_ground Initial
80 0 0 0 I don’t think maximum height of vegetation would matter to frogs, there is no upper limit. 0 Amphibians max_height_ground Initial
Aggregated 34 18 60 NA 23 Amphibians max_height_ground Aggregated

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Preferred distance between emergent vegetation

This metric relates to the spatial distribution of emergent vegetation in waterways, which may affect things like the availability of perch sites for dragonflies, or the availability of anchoring points for frog spawn. This metric considers the availability of both exotic and native vegetation in the environment. The answer to this question will give an equivalent score to something like “percentage vegetative cover”, which might be a more familiar (but harder to map) version of this metric.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
74 1.0 1 5 Just based off fieldwork observations. Even less than 1m would be good too. 50 Amphibians emergent_veg Initial
76 40.0 10 100 this is important for some frog species but not others. Ideally, within a given section of water way/wetland/dam you will have a diversity of aquatic and emergent vegetation for different species. 60 Amphibians emergent_veg Initial
77 2.0 0 100 Starrs and Hoefer (2016) found some species (eg Lim per) show affinity to thick stands of emergent macrophytes. When I think of this, Im thinking either large stands of Phragmites, or Juncus etc. Lit ver, Lim tas happily sit amongst emergent veg for calling. Excess gaps likely to lead to increased predation etc. 10 Amphibians emergent_veg Initial
78 3.0 1 5 no idea about this- how to measure what an emergent plant is- you look at the entire plant or just at each stalk?? lots of frog species prefer the presence of emergent vegetation, which is often in a clump along the edge of a waterway. other species do not rely on emergent veg as their spawn sinks to the floor of the waterway/pond 0 Amphibians emergent_veg Initial
79 1.0 1 3 I am not sure I understand this question. is it asking for distance between clumps of emergent veg, or between stems? 20 Amphibians emergent_veg Initial
80 10.0 5 20 NA 50 Amphibians emergent_veg Initial
Aggregated 9.5 3 39 NA 32 Amphibians emergent_veg Aggregated

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Percentage of emergent vegetation which needs to be native

This metric relates to the composition of the emergency aquatic vegetation. What is the percentage of the emergent aquatic vegetation which needs to be native to provide suitable habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
74 70 30 100 Estimates 40 Amphibians native_emergent Initial
76 20 0 50 There is little to no evidence that I am aware of on this topic. I have seen most of the frog species from the local region breeding in dams with almost entirely non-native vegetation. 60 Amphibians native_emergent Initial
77 0 0 0 I don’t believe the species are dependent on native species, rather they are just dependent on the structure that emergent veg provides. 10 Amphibians native_emergent Initial
78 80 30 100 ?? 0 Amphibians native_emergent Initial
79 70 0 90 I dont know if any one has ever looked at this. Emergent vegetation is important but most surveys dont look at native vs non native emergent veg 20 Amphibians native_emergent Initial
80 60 20 80 NA 50 Amphibians native_emergent Initial
Aggregated 50 13 70 NA 30 Amphibians native_emergent Aggregated

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Distance found from a permanent waterbody

This metric enables mapping of the potential distribution for those species which are tied in some way to a permanent waterbody. This might be a small species which is semi-aquatic (e.g. some frogs, turtles) or a larger species which relies on permanent water to drink (e.g. some birds and mammals). How far will this taxon group be found from permanent water?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
74 25 10 1000 Many species require permanent water bodies for successful reproduction, especially species that have long/slow metamorphic stages (from tadpole to adult). Non-permanent water bodies can cause tadpoles to die before reaching maturity or can cause them to mature faster leading to smaller adult body size ultimately reducing their survivability. 80 Amphibians waterbody Initial
76 0 0 0 The vast majority of frogs in the local area will preferentially breeding in semi-permanent/ephemeral waterbodies. They don’t need permanent water. That said, many species will breed in permanent dams. But these are not essential 0 Amphibians waterbody Initial
77 1000 50 10000 Frogs generally found in the landscape, well away from water. Constantly moving through the landscape. Need to accept that many frogs are quite ‘terrestrial’ but dependent on water for reproduction. 50 Amphibians waterbody Initial
78 30 5 500 frogs only need open water for breeding. Outside of the breeding season the move into the surrounding landscape, into ditches, under bark, leave litter or rocks, where temperatures stay cooler and evaporation stays low. some species can be found quite a distance away from any permanent water body during these times. However, these refuge areas need to be very well connected to the waterway . 0 Amphibians waterbody Initial
79 800 600 1400 Frog abundance drops as distance to water body increases. Some frogs can be found in very terrestrial areas however. 70 Amphibians waterbody Initial
80 50 20 500 This is a very understudied area, but for some species we have good records of them being at least 500 m from the nearest water body (e.g. Uperoleia), although we have almost no information on how long this would be for. Others rarely venture from the water’s edge (e.g. usually within 10 metres of riparian zone). 60 Amphibians waterbody Initial
Aggregated 318 114 2233 NA 43 Amphibians waterbody 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
74 0.1 0.10 10.0 This metric is very important and amphibians are primarily nocturnal, or at least most active at night. Given this, please take my answers with a grain of salt simply because of my lack of knowledge on Lux. 50 Amphibians night_light Initial
76 0.0 0.00 0.0 This is not something I know anything about and the 0 values reflect this, rather than the fact that I don’t think it’s important. 0 Amphibians night_light Initial
77 0.1 0.01 1.0 Not confident at all. Not familiar with any research on this specific topic. Many exhibit increased movement/reproductive behaviour at night so presumably light levels are important. 1 Amphibians night_light Initial
78 99.0 99.00 99.0 no idea about this 0 Amphibians night_light Initial
79 20.0 1.00 300.0 A few papers have found negative effects of ALAN on frog development and susceptibility to stressors but I dont know of any that worked out the value range as each only tested one or two levels of light 50 Amphibians night_light Initial
80 0.1 0.05 0.5 NA 70 Amphibians night_light Initial
Aggregated 19.9 16.69 68.4 NA 28 Amphibians 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
74 21 9 35 I’ve definitely over thought this question and just put temperature ranges. It feels wrong so please feel free to omit this answer. Temperature is definitely important for amphibians. Too cold and they won’t come out and do all their froggy things (i.e. mate), too hot and they die. 60 Amphibians surface_temp Initial
76 0 0 0 Again, this is not something I know anything about and the 0 values reflect this, rather than the fact that I don’t think it’s important. 0 Amphibians surface_temp Initial
77 35 25 45 Not overly familiar with this, but being ectothermic, some reasonable predictions can be made. Research on Lit aur demonstrate that basking behaviour exists, and data for thermal tolerances probably exists. I don’t associate any of our local species that I would expect to occur in an urban context having a particularly low thermal threshold for maximum temperature. Desiccation a bigger issue. 10 Amphibians surface_temp Initial
78 24 10 30 no comment 0 Amphibians surface_temp Initial
79 28 25 35 Most frogs will shelter to varying extents unless water is present during the day to prevent desiccation, particularly during hot weather therefore will not be exposed to high surface temperatures. 20 Amphibians surface_temp Initial
80 27 25 30 This is based off temperatures we hold frogs in the laboratory and knowledge of CTmax. Some winter species, e.g. Crinia, Litoria verreauxii might require cooler maximum temperatures. 70 Amphibians surface_temp Initial
Aggregated 22 16 29 NA 27 Amphibians 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
74 21 9 35 I believe this would be similar to surface temperature. It’s important to note that there is quite a large variation between species with habitat preference (trees, desert, pond etc) playing a large role, as well as average species size. 50 Amphibians ambient_temp Initial
76 0 0 0 Again, this is not something I know anything about and the 0 values reflect this, rather than the fact that I don’t think it’s important. 0 Amphibians ambient_temp Initial
77 25 15 30 Again, dependent on humidity/desiccation. Presumably being ectothermic growth rates etc are temperature dependent, so low temperatures are bad as well as high temperatures. I’d expect a mean of 25 would be more than adequate to ensure high growth potential in most of our local species. 20 Amphibians ambient_temp Initial
78 28 25 40 no comment 0 Amphibians ambient_temp Initial
79 38 30 40 This variable interacts with the humidity, the microclimate and would vary between species. Again, frogs alter behaviour to prevent desiccation so it is not that straight forward 20 Amphibians ambient_temp Initial
80 35 30 48 At these higher temperatures many frogs would have to seek shelter and cooler spots in the environment and certainly need to hydrate. 50 Amphibians ambient_temp Initial
Aggregated 24 18 32 NA 23 Amphibians ambient_temp Aggregated

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Maximum tolerable water temperature (aquatic only)

This metric relates to the maximum water temperature which is associated with suitable habitat for this taxon group. Water temperature is the temperature which a mercury thermometer would record if it was pointed held under the surface of the water, out of direct sunlight. This metric is likely to be relevant to fish and other aquatic organisms, as well as species which lay eggs in the aquatic environment.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
74 22 20 30 This is quite disputed in the literature. Some studies have found that water temperature doesn’t really have an impact on amphibians while others have. I think similar to my last comment that it is a lot to do with the species and potentially the individual itself. So for example a persistent individual caller might be less impacted by water temperature as opposed to a less persistent caller or groups/duos that are calling. 40 Amphibians max_w_temp Initial
76 0 0 0 Again, this is not something I know anything about and the 0 values reflect this, rather than the fact that I don’t think it’s important. 0 Amphibians max_w_temp Initial
77 25 15 30 Given the range of variation in water temperatures in ponds/wetlands around the ACT in summer, anything in excess of ~ 30 degrees is likely to be problematic I think. Short term spikes perhaps not so bad, and tadpoles appear to be quite resilient. 20 Amphibians max_w_temp Initial
78 26 25 30 tadpole development needs warm water however, tadpoles do easily cook if water temps go above 30 degrees. in addition, deterioration of water quality, reduction in water availability and lower availability of prey items would be negatively correlated with increased water temperatures 0 Amphibians max_w_temp Initial
79 36 30 40 Dont know of research for this frog group particularly. 30 Amphibians max_w_temp Initial
80 25 20 27 Again, winter species or stream-dwelling species would likely require no more than the lower limits here. 50 Amphibians max_w_temp Initial
Aggregated 22 18 26 NA 23 Amphibians max_w_temp Aggregated

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Minimum tolerable water temperature (aquatic only)

This metric relates to the minimum water temperature which is associated with suitable habitat for this taxon group. Water temperature is the temperature which a mercury thermometer would record if it was pointed held under the surface of the water, out of direct sunlight. This metric is likely to be relevant to fish and other aquatic organisms, as well as species which lay eggs in the aquatic environment.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
74 10.0 5.0 10 See previous. 40 Amphibians min_w_temp Initial
76 0.0 0.0 5 Although there is a substantial range in the minimum water temperature that frogs in the region can tolerate, many species are OK in water down to low temperatures close to 0C 0 Amphibians min_w_temp Initial
77 4.0 0.0 10 Based on observed water temperatures around Canberra in ponds and wetlands in winter. Crinia very capable of existing at much lower temps. Others appear to shut down and are not dependent on water temps anyway. 20 Amphibians min_w_temp Initial
78 18.0 15.0 25 temperature - min and max over time or constant?? does that mean a pond that never gets warmer than xx degrees can not be seen as a habitat? this is true for most urban stormwater ponds- far too large and with too steep edges to warm up quickly in spring 0 Amphibians min_w_temp Initial
79 0.0 0.0 5 This could be taken as the temperature tolerable to tadpoles or to adult frogs, which will be different as adult frogs can avoid overly cold (or hot) water in a way tadpoles cannot. 30 Amphibians min_w_temp Initial
80 8.0 5.0 10 Being ectotherms, most frogs could tolerate fairly cold temperatures for periods of time and would mostly shut down. 50 Amphibians min_w_temp Initial
Aggregated 6.7 4.2 11 NA 23 Amphibians min_w_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
74 5 2 5 I don’t actually know the specifics, this is just a rough estimate. 40 Amphibians min_width_core Initial
76 5 1 10 No clear if this question is focused on breeding habitat for frogs or terrestrial habitat? Or connectivity between the two? See research on ‘habitat split’ and amphibians. https://www.science.org/doi/10.1126/science.1149374 75 Amphibians min_width_core Initial
77 500 100 1000 Struggled with this one. Given how mobile frogs are in the environment, in order to maintain a population long-term in any given area, I think several hundred metres would be required. Little brown jobs maybe less, so of the bigger ones maybe more? Ive estimated at the upper end to account for the fatties like Lim dum. 10 Amphibians min_width_core Initial
78 300 20 500 no comments 0 Amphibians min_width_core Initial
79 2 1 30 This depends if we are talking about terrestrial or aquatic habitat. 50 Amphibians min_width_core Initial
80 30 20 50 NA 50 Amphibians min_width_core Initial
Aggregated 140 24 266 NA 38 Amphibians 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
74 2 1.0 2 I’ve done this for both aquatic and terrestrial corridors, purely because there is rarely connectivity between permanent water bodies in cities. 20 Amphibians min_width_corridor Initial
76 5 1.0 10 Not clear if this question is focused on breeding habitat for frogs or terrestrial habitat? Or connectivity between the two? frogs can move across non-suitable habitat to get to breeding sites (e.g. across roads and urban areas). See research on ‘habitat split’ and amphibians. https://www.science.org/doi/10.1126/science.1149374 50 Amphibians min_width_corridor Initial
77 25 2.0 50 Provided suitable habitat is present, I don’t think the corridor needs to be particularly wide. I don’t know anything about the directionality of frog dispersal or migration. 10 Amphibians min_width_corridor Initial
78 25 1.0 50 wider corridors can provide a much better range of habitats, especially over long distances 0 Amphibians min_width_corridor Initial
79 2 1.0 10 Again, is this terrestrial or aquatic? 50 Amphibians min_width_corridor Initial
80 3 2.0 10 NA 60 Amphibians min_width_corridor Initial
Aggregated 10 1.3 22 NA 32 Amphibians min_width_corridor Aggregated

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Minimum suitable core habitat depth (aquatic only)

This metric relates to aquatic habitat only. As per the minimum width measurements above, what is the minimum depth of a habitat patch which would enable it to be suitable as core habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
74 1.00 0.10 1.00 I’m not sure if total depth is important, but I do know that having a shallower littoral zone with lots of veg is important. 50 Amphibians min_depth_core Initial
76 0.00 0.00 0.00 can just be damp for frogs to move through - no standing water needed 0 Amphibians min_depth_core Initial
77 0.50 0.10 1.00 Variable between species. Most I think can deal with relatively shallow water - again habitat quality and ephemerality more important than depth per se. Those with longer larval phases may be more dependent on deeper habitats - given correlation with longer persistence of water. 20 Amphibians min_depth_core Initial
78 2.00 0.50 3.00 depth provides cooler areas in summer, better protection from pond drying out etc- however, a range of depth, including steeper banks and shallow banks need to be included. 0 Amphibians min_depth_core Initial
79 0.10 0.05 0.40 Assuming this is for aquatic habitat? 60 Amphibians min_depth_core Initial
80 0.04 0.02 0.05 NA 60 Amphibians min_depth_core Initial
Aggregated 0.61 0.13 0.91 NA 32 Amphibians min_depth_core Aggregated

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Minimum suitable corridor habitat depth (aquatic only)

This metric relates to aquatic habitat only. As per the minimum width measurements above, what is the minimum depth of a habitat patch which would enable it to be suitable as a movement corridor for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
74 1.00 0.10 1.00 Again, I’m not entirely sure, overly deep water is not needed swim/travel, however deeper water or water with protective vegetation will reduce predation from birds or terrestrial predators. 20 Amphibians min_depth_corridor Initial
76 0.00 0.00 0.00 can just be damp for frogs to move through - no standing water needed 0 Amphibians min_depth_corridor Initial
77 0.00 0.00 0.00 I perceive that most movements are undertaken by the terminal life history phase, then water depth is not a significant factor. 20 Amphibians min_depth_corridor Initial
78 0.00 0.00 0.00 frogs can hop between habitats, no need to have waterways for movement 0 Amphibians min_depth_corridor Initial
79 0.10 0.05 0.40 For aquatic habitat 50 Amphibians min_depth_corridor Initial
80 0.02 0.01 0.03 Temporary surface water or wet vegetation is likely to be enough for most frogs to move on rainy nights. 75 Amphibians min_depth_corridor Initial
Aggregated 0.19 0.03 0.24 NA 28 Amphibians min_depth_corridor Aggregated

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
74 50 5 3000 So there is quite a bit of research on this however I’m only familiar with dispersal across agriculture and wetlands, not in urban areas. I do know that the level of disturbance throughout a landscape is important (obviously) and can hinder dispersal quite significantly. It is also a lot to do with the population itself and its dynamics as well as its location in the habitat. There’s lots of different elements that come into play. Predation, temperature and other microhabitats/waterbodies along the way also have an impact. One of the biggest threats to amphibians (mainly frogs) during dispersal is desiccation. It’s very common that frogs will die of “dehydration” before reaching their destination. 50 Amphibians disperal_distance Initial
76 1500 200 4000 these estimates assume dispersal within a 1 year period 75 Amphibians disperal_distance Initial
77 250 20 1000 Not overly confident about this one - not informed by any specific empirical data. 5 Amphibians disperal_distance Initial
78 500 250 2000 arggg 0 Amphibians disperal_distance Initial
79 400 30 1000 Depends on species. Lim tas recorded to moved up to 720m in agri landscapes. 80 Amphibians disperal_distance Initial
80 500 100 2500 We have tracked and recorded some frogs moving kilometres across the landscape, e.g. Litoria aurea. Other small species might only prefer to move shorter distances, perhaps in the low hundreds of metres. 50 Amphibians disperal_distance Initial
Aggregated 533 101 2250 NA 43 Amphibians 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
74 5 1 20 Again I’m not 100% sure, but from my observations and from what I’ve read in the literature they don’t generally move too far within the home ranges unless I have to. If they’ve got a well established and safe spot they typically don’t leave it. 40 Amphibians movement_within Initial
76 100 10 500 this is a bit problematic for frogs as it depends on the spatial arrangement of terrestrial and aquatic habitat 75 Amphibians movement_within Initial
77 10 5 50 Not informed by empirical evidence. Single observation of a Psuedophrne calling from within ~ 25m radius over 3 years. 5 Amphibians movement_within Initial
78 500 50 1500 arggg 0 Amphibians movement_within Initial
79 20 0 250 Recapture data in agricultural landscape with this suite of species 80 Amphibians movement_within Initial
80 100 50 1000 NA 50 Amphibians movement_within Initial
Aggregated 122 19 553 NA 42 Amphibians 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
74 10 1 3000 Again I don’t have any solid evidence, but it’s not uncommon to see frogs crossing roads or travelling along roads to get to other habitat, especially banjo frogs and other large species. I don’t know how plausible this is for smaller species though. 20 Amphibians capacity_movement Initial
76 300 20 2000 again, for frogs, this depends on the level of habitat split between terrestrial and aquatic habitats 75 Amphibians capacity_movement Initial
77 200 20 1000 Not based on any specific empirical data 5 Amphibians capacity_movement Initial
78 50 20 100 guessed 0 Amphibians capacity_movement Initial
79 20 5 200 This depends how hostile the "“non suitable habitat”" is and how accurate we have been at defining habitat 70 Amphibians capacity_movement Initial
80 25 10 100 NA 60 Amphibians capacity_movement Initial
Aggregated 101 13 1067 NA 38 Amphibians 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
74 10 10 200 I’m not entirely confident on this one so it’s just an estimate. 20 Amphibians paved_surface Initial
76 100 20 300 extrapolation from observations that frogs readily cross 3 lane highways 75 Amphibians paved_surface Initial
77 10 3 50 Frogs seem to have no qualms with crossing roads at night when conditions are good (wet). Appears that 3m of concrete/road is not a significant barrier. 10 Amphibians paved_surface Initial
78 50 20 100 as before 0 Amphibians paved_surface Initial
79 10 5 80 I dont know any research to back this up. This will also depend on timing and traffic etc 50 Amphibians paved_surface Initial
80 20 10 100 On a rainy night, many species could cross at least some distance. 60 Amphibians paved_surface Initial
Aggregated 33 11 138 NA 36 Amphibians 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
74 0.05 0.01 0.1 Realistically this is just a curb. 20 Amphibians max_height_building Initial
76 2.00 0.10 20.0 treefrogs can climb and so this isn’t much of an issue for them. But the ground frogs can’t get over even small vertical surfaces, hence my big range 75 Amphibians max_height_building Initial
77 0.10 0.05 1.0 Highly variable between species. Little brown jobs don’t appear to be much of climbers, whereas tree frogs seem capable of scaling almost any vertical surface. Based my estimates on what I perceive a crinia could deal with. 10 Amphibians max_height_building Initial
78 10.00 0.00 10.0 guessed 0 Amphibians max_height_building Initial
79 1.00 0.10 10.0 This depends on the species. Litoria species will have better ability to climb vertical structures than grass frogs 70 Amphibians max_height_building Initial
80 0.20 0.10 20.0 I am quite confident that for some small ground-dwelling frogs, vertical barriers beyond about 20 cm would become difficult to cross. Climbing tree species can scale large trees. 90 Amphibians max_height_building Initial
Aggregated 2.22 0.06 10.2 NA 44 Amphibians max_height_building 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
74 20 20 100 Again this depends on the species and the specifics of the water body. 50 Amphibians max_waterbody Initial
76 30 10 100 this isn’t known for the frog species from this region. They generally avoid lakes though 50 Amphibians max_waterbody Initial
77 10 5 50 If you incorporate tadpole movement abilities, it might be a bit wider. I perceive some are inclined to swim relatively large distances but most stick to shallow water. Water depth may be an important factor in determining this. Eg. if lots of emergent/floating veg, perhaps can traverse much larger water bodies, than if they are deep open water = fish food. 10 Amphibians max_waterbody Initial
78 50 20 200 frogs will swim along the edges as long as good habitat is provided 0 Amphibians max_waterbody Initial
79 1000 800 5000 I am not certain about this metric 20 Amphibians max_waterbody Initial
80 250 100 1000 All local native frogs can swim, although most would likely not choose to swim great distances. 90 Amphibians max_waterbody Initial
Aggregated 227 159 1075 NA 37 Amphibians 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
74 1 1.0 10 I wasn’t overly sure how to answer this because I think it varies between aquatic and terrestrial habitat. It would be significantly less in water. 10 Amphibians traffic_flow Initial
76 20 5.0 80 frogs often have a strong urge to get to a breeding site, so if weather conditions are suitable, they try cross roads despite traffic, but many can be killed by vehicles 50 Amphibians traffic_flow Initial
77 10 1.0 50 More than 50 cars per hour and the mortality rate on the road may get to be excessive. 1 Amphibians traffic_flow Initial
78 0 0.0 0 0 0 Amphibians traffic_flow Initial
79 30 10.0 100 I dont know any evidence to inform this 20 Amphibians traffic_flow Initial
80 12 6.0 30 NA 70 Amphibians traffic_flow Initial
Aggregated 12 3.8 45 NA 25 Amphibians 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
74 2 2.0 4 I genuinely have no idea 10 Amphibians pedestrian_flow Initial
76 0 0.0 0 No estimate provided as I can’t think of situations where this is an issue for frogs 0 Amphibians pedestrian_flow Initial
77 100 10.0 500 Frogs seem relatively robust to human intrusion, but I don’t know about sub-lethal impacts etc. 10 Amphibians pedestrian_flow Initial
78 0 0.0 0 0 0 Amphibians pedestrian_flow Initial
79 40 10.0 400 Unlikely to be high swimming activity at night. 20 Amphibians pedestrian_flow Initial
80 12 6.0 20 NA 40 Amphibians pedestrian_flow Initial
Aggregated 26 4.7 154 NA 13 Amphibians pedestrian_flow Aggregated