Learning from past designs: improving amphibian fences using an adaptive management approach

John Gould; Alex Callen; Gregory Knibb; Rachael Donelly; Kate Schmahl; Cassandra Maynard; Samantha Sanders; Frank Lemckert; Colin McHenry

doi:10.1071/WR23007

REVIEW (Open Access)

Previous Next Contents Vol 51(1)

Learning from past designs: improving amphibian fences using an adaptive management approach

John Gould

^A ^* , Alex Callen ^A , Gregory Knibb ^A , Rachael Donelly ^A , Kate Schmahl ^A , Cassandra Maynard ^A , Samantha Sanders ^A , Frank Lemckert ^B and Colin McHenry ^A

+ Author Affiliations

- Author Affiliations

^A Conservation Science Research Group, University of Newcastle, Callaghan, NSW, Australia.

^B Eco Logical Australia Pty Ltd, Newcastle, NSW, Australia.

^* Correspondence to: john.gould@newcastle.edu.au

Handling Editor: Adam Stow

Wildlife Research 51, WR23007 https://doi.org/10.1071/WR23007

Submitted: 19 January 2023 Accepted: 8 June 2023 Published: 30 June 2023

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Fences have been widely used to exclude, manage, or monitor both native and invasive amphibian populations. Given that fences are artificial barriers that impact animal movements within the landscape, it is critical they do not allow for unwanted movement or lead to unintended animal welfare risks. We have carried out a literature review to identify features that have been used for amphibian fences, as well as aspects of fence design, installation, and maintenance that have limited their effectiveness. We also describe our own application of adaptive management to amphibian exclusion fences, in which we detected flaws and improved features, and monitored the effectiveness of these changes. Based on an exploration of the literature and our experiences, we found several key attributes to fences that must be considered when created for amphibians, including height, lip barriers, underground barriers, support frameworks, gates, seams, clearance zones, and moisture refuges. We found that studies commonly do not detail all of these aspects of their fences, and that few openly describe flaws in the design, installation, and subsequent maintenance of their fences. This is potentially concerning because it may limit chances to make improvements to fence designs that are specific for amphibians. We subsequently provide considerations and recommendations for each key fence attribute, along with maintenance and monitoring advice. These take into account intended fence purpose, desired fence permeability, and project constraints for a variety of amphibian types, life histories, and developmental stages. They are intended to be used by managers to assist in designing an effective fence for their target species. Some of our recommendations to reduce animal welfare risks are to minimise the use of: (1) fence materials that could cause abrasion injuries, (2) dry substrates that could lead to desiccation, (3) geofabrics that could lead to entanglement, and (4) fence aprons that animals could easily become trapped under. This is likely to be a valuable guide for practitioners who are required to install amphibian fences and for policy makers who prescribe fences for mitigation. This guide is applicable for projects managing threatened native species, as well as invasive species, such as the cane toad (Rhinella marina).

Keywords: amphibian, artificial barriers, cane toad, exclusion fence, fence design, landscape engineering, management tool, population management, terrestrial dispersal.

References

Allaback ML, Laabs DM (2002) Effectiveness of road tunnels for the Santa Cruz long-toed salamander. Transactions of the Western Section of the Wildlife Society 38/39, 5-8.
| Google Scholar |

Anson JR (2018) Predator proofing for conservation: an AWC perspective. Australian Zoologist 39, 352-358.
| Crossref | Google Scholar |

Aresco MJ (2005) Mitigation measures to reduce highway mortality of turtles and other herpetofauna at a north Florida lake. Journal of Wildlife Management 69, 549-560.
| Crossref | Google Scholar |

Arntzen JW, Oldham RS, Latham DM (1995) Cost effective drift fences for toads and newts. Amphibia-Reptilia 16, 137-145.
| Crossref | Google Scholar |

Bager A, Fontoura V (2013) Evaluation of the effectiveness of a wildlife roadkill mitigation system in wetland habitat. Ecological Engineering 53, 31-38.
| Crossref | Google Scholar |

Beebee TJC (2013) Effects of road mortality and mitigation measures on amphibian populations. Conservation Biology 27, 657-668.
| Crossref | Google Scholar |

Bennett AF (1991) Roads, roadsides and wildlife conservation: a review. In ‘Nature conservation ii: the role of corridors’. (Eds DA Saunders, RJ Hobbs) pp. 99–117. (Surrey Beatty and Sons: Chipping Norton, Australia)

Beranek CT, Maynard C, McHenry C, Clulow J, Mahony M (2021) Rapid population increase of the threatened Australian amphibian Litoria aurea in response to wetlands constructed as a refuge from chytrid-induced disease and introduced fish. Journal of Environmental Management 291, 112638.
| Crossref | Google Scholar |

Bergen SD, Bolton SM, Fridley JL (2001) Design principles for ecological engineering. Ecological Engineering 18, 201-210.
| Crossref | Google Scholar |

Bode M, Wintle B (2010) How to build an efficient conservation fence. Conservation Biology 24, 182-188.
| Crossref | Google Scholar |

Boyle SP, Dillon R, Litzgus JD, Lesbarrères D (2019) Desiccation of herpetofauna on roadway exclusion fencing. The Canadian Field-Naturalist 133, 43-48.
| Crossref | Google Scholar |

Chang Y-H, Wu B-Y, Lu H-L (2013) A study on the use of ecological fences for protection against Polypedates megacephalus. Ecological Engineering 61, 161-165.
| Crossref | Google Scholar |

Cherney DN (2011) Securing the free movement of wildlife: lessons from the American west’s longest land mammal migration. Environmental Law 41, 599-617.
| Google Scholar |

Crawford N, Endlein T, Pham JT, Riehle M, Barnes WJP (2016) When the going gets rough – studying the effect of surface roughness on the adhesive abilities of tree frogs. Beilstein Journal of Nanotechnology 7, 2116-2131.
| Crossref | Google Scholar |

Darcovich K, O’Meara J (2008) An olympic legacy: green and golden bell frog conservation at Sydney Olympic Park 1993-2006. Australian Zoologist 34, 236-248.
| Crossref | Google Scholar |

Dodd CK, Jr (1991) Drift fence-associated sampling bias of amphibians at a Florida sandhills temporary pond. Journal of Herpetology 25, 296-301.
| Crossref | Google Scholar |

Dodd CK, Jr, Barichivich WJ, Smith LL (2004) Effectiveness of a barrier wall and culverts in reducing wildlife mortality on a heavily traveled highway in Florida. Biological Conservation 118, 619-631.
| Crossref | Google Scholar |

Eco Logical Australia (2017) Green and golden bell frog plan of management – Arncliffe. Prepared for NSW Roads and Maritime Service. Eco Logical Australia.

Emerson SB, Diehl D (1980) Toe pad morphology and mechanisms of sticking in frogs. Biological Journal of the Linnean Society 13, 199-216.
| Crossref | Google Scholar |

Florance D, Webb JK, Dempster T, Kearney MR, Worthing A, Letnic M (2011) Excluding access to invasion hubs can contain the spread of an invasive vertebrate. Proceedings of the Royal Society B: Biological Sciences 278, 2900-2908.
| Crossref | Google Scholar |

Forman RTT, Alexander LE (1998) Roads and their major ecological effects. Annual Review of Ecology and Systematics 29, 207-231.
| Crossref | Google Scholar |

Forman RTT, Sperling D, Bissonette JA, Clevenger AP, Cutshall CD, Dale VH, Fahrig L, France RL, Goldman CR, Heanue K, Jones JA, Swanson FJ, Turrentine T, Winter TC (2003) ‘Road ecology: science and solutions.’ (Island Press: Washington, DC, USA)

Forti LR, Pontes MR, Augusto-Alves G, Martins A, Hepp F, Szabo JK (2022) Data collected by citizen scientists reveal the role of climate and phylogeny on the frequency of shelter types used by frogs across the Americas. Zoology 155, 126052.
| Crossref | Google Scholar |

Gould J (2023) Tree frog exclusion zone fencing. figshare, Online resource. 10.6084/m9.figshare.22817459

Hamer AJ, Lane SJ, Mahony MJ (2002) Management of freshwater wetlands for the endangered green and golden bell frog (Litoria aurea): roles of habitat determinants and space. Biological Conservation 106, 413-424.
| Crossref | Google Scholar |

Hayward MW, Kerley GIH (2009) Fencing for conservation: restriction of evolutionary potential or a riposte to threatening processes? Biological Conservation 142, 1-13.
| Crossref | Google Scholar |

Hels T, Buchwald E (2001) The effect of road kills on amphibian populations. Biological Conservation 99, 331-340.
| Crossref | Google Scholar |

Hertwig I, Sinsch U (1995) Comparative toe pad morphology in marsupial frogs (genus Gastrotheca): arboreal versus ground-dwelling species. Copeia 1995, 38-47.
| Crossref | Google Scholar |

Homyack JD, Giuliano WM (2002) Effect of streambank fencing on herpetofauna in pasture stream zones. Wildlife Society Bulletin 30, 361-369.
| Google Scholar |

Hou W-S, Chang Y-H, Wang H-W, Tan Y-C (2010) Using the behavior of seven amphibian species for the design of banks of irrigation and drainage systems in Taiwan. Irrigation and Drainage 59, 493-505.
| Crossref | Google Scholar |

Hughes DF, Green ML, Warner JK, Davidson PC (2021) Evaluating exclusion barriers for treefrogs in agricultural landscapes. Wildlife Society Bulletin 45, 305-311.
| Crossref | Google Scholar |

Jehle R, Arntzen JW (2000) Post-breeding migrations of newts (Triturus cristatus and T. Marmoratus) with contrasting ecological requirements. Journal of Zoology 251, 297-306.
| Crossref | Google Scholar |

Jones CG (2012) Grand challenges for the future of ecological engineering. Ecological Engineering 45, 80-84.
| Crossref | Google Scholar |

Keeffe R, Blackburn DC (2020) Comparative morphology of the humerus in forward-burrowing frogs. Biological Journal of the Linnean Society 131, 291-303.
| Crossref | Google Scholar |

Labonte D, Clemente CJ, Dittrich A, Kuo C-Y, Crosby AJ, Irschick DJ, Federle W (2016) Extreme positive allometry of animal adhesive pads and the size limits of adhesion-based climbing. Proceedings of the National Academy of Sciences 113, 1297-1302.
| Crossref | Google Scholar |

Lesbarrères D, Lodé T, Merilä J (2004) What type of amphibian tunnel could reduce road kills? Oryx 38, 220-223.
| Crossref | Google Scholar |

Long K, Robley A (2004) Cost effective feral animal exclusion fencing for areas of high conservation value in Australia: a report. Department of Sustainability and Environment. Arthur Rylah Institute for Environmental Research, Victoria, Heidelberg, Melbourne, Australia.

Malt J (2012) Assessing the effectiveness of amphibian mitigation on the sea to sky highway: population-level effects and best management practices for minimizing highway impacts. Ministry of Forests, Lands, and Natural Resource Operations.

Mark Peaden J, Justin Nowakowski A, Tuberville TD, Buhlmann KA, Todd BD (2017) Effects of roads and roadside fencing on movements, space use, and carapace temperatures of a threatened tortoise. Biological Conservation 214, 13-22.
| Crossref | Google Scholar |

Matos C, Petrovan SO, Wheeler PM, Ward AI (2019) Short-term movements and behaviour govern the use of road mitigation measures by a protected amphibian. Animal Conservation 22, 285-296.
| Crossref | Google Scholar |

Mazerolle MJ, Desrochers A (2005) Landscape resistance to frog movements. Canadian Journal of Zoology 83, 455-464.
| Crossref | Google Scholar |

Mbaiwa JE, Mbaiwa OI (2006) The effects of veterinary fences on wildlife populations in Okavango Delta, Botswana. International Journal of Wilderness 12, 17-41.
| Google Scholar |

Moseby KE, Read JL (2006) The efficacy of feral cat, fox and rabbit exclusion fence designs for threatened species protection. Biological Conservation 127, 429-437.
| Crossref | Google Scholar |

Muir G (2008) Design of a movement corridor for the green and golden bell frog Litoria aurea at Sydney Olympic Park. Australian Zoologist 34, 297-302.
| Crossref | Google Scholar |

Penman T, Muir G, Magarey E, Burns E (2008) Impact of a chytrid-related mortality event on a population of the green and golden bell frog Litoria aurea. Australian Zoologist 34, 314-318.
| Crossref | Google Scholar |

Poole D (2002) Effectiveness of two types of electric fence for excluding the red fox (Vulpes vulpes). Mammal Review 32, 51-57.
| Crossref | Google Scholar |

Schlupp I, Podloucky R (1994) Changes in breeding site fidelity: a combined study of conservation and behaviour in the common toad Bufo bufo. Biological Conservation 69, 285-291.
| Crossref | Google Scholar |

Sillero N (2008) Amphibian mortality levels on Spanish country roads: descriptive and spatial analysis. Amphibia-Reptilia 29, 337-347.
| Crossref | Google Scholar |

Smith JM, Barnes WJP, Downie JR, Ruxton GD (2006) Structural correlates of increased adhesive efficiency with adult size in the toe pads of hylid tree frogs. Journal of Comparative Physiology A 192, 1193-1204.
| Crossref | Google Scholar |

Swan M (1986) The conservation ecology of Rana temporaria and Bufo bufo in Leicestershire. PhD thesis, Leicester Polytechnic.

Vos CC, Chardon JP (1998) Effects of habitat fragmentation and road density on the distribution pattern of the moor frog Rana arvalis. Journal of Applied Ecology 35, 44-56.
| Crossref | Google Scholar |

Wallander J, Isaksson D, Lenberg T (2006) Wader nest distribution and predation in relation to man-made structures on coastal pastures. Biological Conservation 132, 343-350.
| Crossref | Google Scholar |

Wells KD (2010) ‘The ecology and behavior of amphibians.’ (University of Chicago Press: Chicago, Illinois)

Woltz HW, Gibbs JP, Ducey PK (2008) Road crossing structures for amphibians and reptiles: informing design through behavioral analysis. Biological Conservation 141, 2745-2750.
| Crossref | Google Scholar |

Zug GR, Lhon WZ, Min TZ, Kyaw K, Thin T, Win H, Nyein MTD, Aung K, Tin KT (2001) Durability of silt-fencing for drift-fence arrays at a tropical site. Herpetological Review 32, 235 236.
| Google Scholar |