Science for Saving Species Research findings factsheet Project 1.2 Use of artificial habitat in herpetofauna (reptile and amphibian) monitoring In brief Background Wildlife conservation managers Effective wildlife management negatively influence the results need effective survey methods to depends on a detailed knowledge of of long-term monitoring programs be able to detect and understand where species are to be found, their as a consequence. species population trends over preferences for habitat and if their time. Common methods of Another concern with active populations are going up, down or surveying both ground based and searches, particularly on large spatial are stable. Determining this depends arboreal herpetofauna (reptiles studies in modified landscapes, is on selecting an appropriate survey and amphibians) include active how to ensure the standardisation technique that can provide robust searches and checking around of survey methodology across study information on the presence and and under artificially placed sites with different habitat elements. abundance of species. habitat, such as railway sleepers, A lack of standardisation can make corrugated iron and roofing tiles. There are well established methods the meaningful comparison of for surveying reptile and amphibian sites difficult. This research tested and abundance and movement patterns compared herpetofauna One solution to the issue of in terrestrial environments. However, detection rates from active standardising the survey of they are often labour-intensive searches with the detection rates herpetofauna is to deploy artificial methods such as installing pitfall at common types of terrestrial habitat. In the past, the most and funnel traps, or time- artificial habitat and at novel commonly deployed artificial habitat consuming active searches. arboreal artificial habitat across has been terrestrial (ground based), the Endangered box gum grassy Active searching is a method of resulting in low detection rates for woodlands of temperate south- searching available habitat for arboreal (tree-dwelling) species. eastern Australia. herpetofauna by, for example, peeling Our recent research also deployed back bark, lifting slabs or fragments a new technique – artificial bark Our findings demonstrate that of rock, turning logs, or raking habitats to assist detection of combining active searches with through leaf litter. These methods arboreal herpetofauna. the use of a range of artificial can damage these fragile parts of the habitat (timber railway sleepers, Bark study - artificial bark. Image: Daniel Florance landscape if care is not taken, and corrugated iron and artificial bark) repeat-visit, long-term monitoring of yielded the highest detection the same sites may eventually destroy rates for herpetofauna. critical microhabitat and reduce the Using artificial habitat can also overall quality of habitat for fauna. address common survey issues of For example, damaged bark may standardisation of methodologies take a tree years to replace. Such for landscapes that do not damage can also effectively reduce contain the same range of the amount of available searchable habitat elements. habitat in future surveys, and What we did We established survey sites within yellow box (Eucalyptus melliodora) box gum grassy woodland in and Blakely’s red gum (E. blakelyi). New South Wales and Victoria. A 20-minute active search of natural Sites were located on private habitat was undertaken at each site, land and stock reserves, and in which included raking through leaf conservation reserves and state litter, lifting logs and surface rocks, forests. Each site consisted of and inspecting exfoliating bark of a 200 m x 50 m search area. mature trees. An additional 5 minutes At each site we placed two arrays was spent at each site inspecting of artificial habitat 100m apart, artificial terrestrial refuge arrays. which consisted of: To test terrestrial artificial habitat, Terrestrial habitat - four 1.2m each site was surveyed every two timber railway sleepers, four years, for between four years and terracotta or concrete roofing 19 years. We conducted 5808 tiles and two stacked sheets of site visits during the study. corrugated roofing iron. To test arboreal artificial habitat, Christinus marmoratus on artificial bark. In a separate study we also each site was surveyed annually Image: Daniel Florance investigated the efficacy of artificial for 4 years. bark at a subset of survey sites. What the research We compared the herpetofauna looked like Arboreal bark habitat - non-toxic, detection and abundance survey closed-cell foam attached to the results from the artificial habitat arrays This research set out to test and trunks of the dominant eucalypt with the results of the active searches compare the efficacy of using species in these woodlands, of natural habitat at these sites. artificial habitat – terrestrial and arboreal – and active searches to Bark study site. Image: Daniel Florance detect herpetofauna (frogs and reptiles). There had been very little previous research focussed on this topic, so we were keen to address the knowledge gap with field testing and surveys. We consider that our results are relevant to any long-term ecological monitoring programs that include herpetofauna. We compared long-term results for detecting herpetofauna species in artificial terrestrial and arboreal habitat with the results of active searches of natural habitat. The research was conducted in the Endangered box gum grassy woodlands of temperate south-eastern Australia, but has relevance to herpetological surveys more broadly. Key findings The results show that artificial habitat is effective for the detection 4.0 of many species of herpetofauna. Our key finding was that active searches combined with terrestrial 3.0 artificial refuges detected the highest diversity of herpetofauna 2.0 species. However, both methods detected supplementary species. Mean abundance 1.0 Of all artificial habitat, timber railway sleepers were the most effective 0 for detecting frog species while Terrestrial Active Bark roofing tiles were the least effective. refuges searches refuges In particular timber refuges were Survey method effective for detecting several burrowing species, whereas active Mean abundance (95% credible interval) of the southern marbled gecko, Christinus marmoratus, searches were effective for detecting using three different survey methods between 2013 and 2016 habitat generalists. Combining The most effective detection This demonstrates the suitability of active searches with surveys at the method for this species was artificial the material for short- to medium- terrestrial timber railway sleepers bark. Artificial bark habitat detected term use. Longer-term studies may yielded the highest detection of an average of 132 times more require a more robust material, amphibians across sites. individuals of the gecko than did and this needs further testing. Over the study period we detected terrestrial artificial refuges, and 20 More marbled geckos were detected 3970 individuals from 18 frog times more individuals than were on larger trees (mean diameter species. The spotted marsh frog found during active searches. = 78cm). Therefore, larger trees (Limnodynastes tasmaniensis) with thick bark located in timbered was the most abundant species, The closed-cell foam material used areas, regardless of the tree species accounting for 67.75% of all as artificial bark in this research was investigated (Blakely’s red gum and observations. Frog detection rates weather-resistant in field conditions. yellow box), may be the best trees were also positively associated Damage caused by birds and to target for artificial-bark installation. with above average rainfall. invertebrates was evident on some foam, but this did not prevent reptiles Marbled geckos took some time to Corrugated iron was up to five from using it. The foam remained initially colonise artificial bark, but times more effective for detection viable throughout the four-year by 12 months after installation the of reptile species than tiles or deployment period. detection rates were stable. timber, and a combination of active searching and corrugated iron provided supplementary species detections, yielding the highest species richness. Terrestrial artificial habitat and active searches were not effective for detecting arboreal species, such as the southern marbled gecko (Christinus marmoratus). RIGHT: Artificial substrates - terrestrial array. Image: Daniel Florance Further Information Michael, D.R., Blanchard, W., Scheele, B.C. and Lindenmayer, D.B. (2019). Comparative use of active searches and artificial refuges to detect amphibians in terrestrial environments. Austral Ecology, 44, 327-338. https://doi.org/10.1111/aec.12677 Michael, D.R., Florance, D., Crane, M., Blanchard, W. and Lindenmayer, D.B. (2018). Barking up the right tree: comparative use of arboreal and terrestrial artificial refuges to survey reptiles in temperate eucalypt woodlands. Wildlife Research, 45, 185-192. https://doi.org/10.1071/WR17117 Michael, D.R., Cunningham, R.B., Donnelly, C.F. and Lindenmayer, D.B. (2012). Comparative use of active searches and artificial refuges to survey reptiles in temperate eucalypt woodlands. Wildlife Research, 39, 149-162. https://doi.org/10.1071/WR11118 Recommendations Herpetofauna detection and amphibians, corrugated iron for given area as the time required to census surveys can be improved terrestrial reptiles and artificial inspect refuges is considerably