Determining the impacts of conservation fencing on woma pythons (Aspidites ramsayi)

Joshua Magro; Reece Pedler; John Read; Rebecca West

doi:10.1071/WR24163

RESEARCH ARTICLE (Open Access)

Previous Contents Vol 51(12)

Determining the impacts of conservation fencing on woma pythons (Aspidites ramsayi)

Joshua Magro

^A ^* , Reece Pedler

^A , John Read

^A ^B and Rebecca West

^A

+ Author Affiliations

- Author Affiliations

^A Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW Sydney, NSW 2052, Australia.

^B School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5000, Australia.

^* Correspondence to: joshua.magro@cdu.edu.au

Handling Editor: Pablo Ferreras

Wildlife Research 51, WR24163 https://doi.org/10.1071/WR24163

Submitted: 2 October 2024 Accepted: 21 November 2024 Published: 9 December 2024

Abstract

Context

Fenced conservation reserves are an effective management tool for the conservation of many threatened species. However, conservation fencing is known to inadvertently affect non-target species, ranging from barrier effects to direct mortality. There is a paucity of information on the negative impacts of fencing on reptiles.

Aims

Using the woma python, a species of conservation significance, this research aimed to improve our knowledge of how reptiles interact with fences.

Methods

The spatial ecology of womas was explored in relation to fencing at the Wild Deserts project partnership site, a rabbit-, cat- and fox-proof fenced area of Sturt National Park in arid Australia. A 6-year dataset of opportunistic observations of womas at the study site were analysed for demographic, spatial and temporal patterns in woma fence interactions. Nine adult pythons were radiotracked over a year to assess space use in relation to fencing.

Key results

Twenty-two per cent of all opportunistic woma observations at the site were mortalities associated with entanglements. All 20 entanglement deaths were in 30-mm netting despite 50-mm netting comprising lower segments of 21% of the fence network. Fencing encounters were greatest in dune habitats and during summer and autumn. Fence crossings were infrequent among telemetered pythons and most encounters did not result in entanglement, with four of the nine individuals recorded to have crossed the fence successfully, despite one mortality.

Conclusions

Thirty-millimetre netting, particularly in areas of netting overlap, represents an entanglement risk to womas.

Implications

This research is applicable to the management of conservation fences and can be extended to other large snake and reptile species. The impacts of small-aperture netting on large snakes and other non-target species should be considered in the planning phases for conservation fencing and mitigation strategies should be sought in the planning phases where possible. Large-aperture netting is preferable to 30-mm netting for pythons, where exclusion of rabbits is not necessary. However, larger netting apertures may disproportionately affect other non-target species such as bearded dragons.

Keywords: entanglement, fence, home range, mortality, radiotelemetry, reptile, safe haven, snake.

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