Why is the broad headed snake endangered

The maximum dispersal distance of juveniles of approximately six months of age, in a study of spatial ecology and movement of the Broad-headed Snake, was m.

The Broad-headed Snake occupies discrete home ranges in woodland habitat. The mean home range size of snakes in woodland was 3. Male home ranges did not overlap, and all snakes actively avoided sharing space with other Broad-headed Snakes over time. Individual snakes show a high degree of site fidelity. Individuals often return to the same area of woodland each year, and some individuals have been captured under the same rock in successive years.

Clearance of habitat has resulted in fragmentation and isolation of populations. High levels of human visitation and associated habitat disturbance threaten remaining populations Cogger et al.

The disturbance and removal of rocks used as retreat sites has the greatest effect on snake abundance. The rocks preferred by both snakes and their gecko prey are similar in diameter, thickness and underlying substrate to the rocks preferred by 'bushrock' collectors.

The amount of rock disturbance through overturning, piling up, removal or smashing has an impact on the abundance of snakes as well as on geckos preyed on by the snakes Shine et al.

Also, rock collectors may deliberately kill snakes Cogger et al. Broad-headed Snakes were collected in large numbers from the s to the s for pets H. Cogger in Shine et al. Bushfires may pose a threat to snake populations through altering the availability of hollows and prey, or endangering snakes when occupying hollows NSW NPWS The species requires shelter rocks that receive high levels of solar radiation.

Local increases in vegetation density could result in increased shading of retreat sites, potentially rendering them thermally unsuitable. It is likely that fire deterrence since European arrival has led to an increase in vegetation density and this may have contributed to the decline of the species, however this is yet to be objectively demonstrated Pringle et al.

The presence of beak marks on the occasional snake indicates that predatory birds may prey on the species J. Webb, personal observation in Pringle et al.

The snakes are extremely selective with respect to the physical properties of their retreat sites and studies have found that they are reluctant to shelter under wobbly, ill-fitting rocks. This means moving "new" rocks into ideal locations to augment the habitat is probably not a viable option Pringle et al.

However Velvet Geckos readily utilise pavers placed in sunny positions with small crevices between pavers and the rocky substrate, so prey availability could be increased through use of concrete pavers. Cutting of overhanging branches and clearing of understorey weeds in areas deemed important for the species could be an important management option.

Specifically, this pruning could be aimed at vegetation to the west of the cliff tops, particularly where trees from below the cliff are growing up to shade the crucial cliff edges. Such targeted management would confer the greatest amount of thermal benefit to snake habitat whilst causing minimal disturbance to the surrounding area Pringle et al. It is also recommended that locked gates be placed on fire trails in Morton National Park to protect existing populations Webb et al c.

Report to the Department of Environment and Heritage. Cogger, H. Reptiles and Amphibians of Australia - 6th edition. Cameron, R. Eggler The Action Plan for Australian Reptiles. Survey guidelines for Australia's threatened reptiles.

EPBC Act survey guidelines 6. Downes, S. Prey odour influences retreat-site selection by naive Broadheaded Snakes Hoplocephalus bungaroides. Journal of Herpetology. Goldingay, R. Between a rock and a hard place: conserving the broad-headed snake in Australia's oldest National Park. Newell Experimental rock outcrops reveal continuing habitat disturbance for an endangered Australian snake.

Conservation Biology. Krefft, G. The snakes of Australia: an illustrated and descriptive catalogue of all the known species. Broad-headed Snake, Hoplocephalus bungaroides.

Pringle, R. Shine Canopy structure, microclimate, and habitat selection by a nocturnal snake, Hoplocephalus bungaroides. Shine, R. Arboreality in snakes: ecology of the Australian elapid genus Hoplocephalus.

Fitzgerald Conservation and reproduction of an endangered species: the Broad-headed Snake, Hoplocephalus bungaroides Elapidae. Australian Zoologist. They may not occur thoughout the sub-region but may be restricted to certain areas. The information presented in this map is only indicative and may contain errors and omissions. Scientific name: Hoplocephalus bungaroides.

Conservation status in NSW: Endangered. Commonwealth status: Vulnerable. The Broad-headed Snake is generally black above with yellow spots forming narrow, irregular cross-bands. Other yellow scales may link these cross-bands laterally to form a straight or zigzagged stripe along the body. These cross-bands help distinguish it from the similar-looking but harmless juvenile Diamond Python.

Its head is flattened on top and distinct from the body. The belly is grey or greyish-black. The average length is about 60 cm, with a maximum of around cm.

Distribution The Broad-headed Snake is largely confined to Triassic and Permian sandstones, including the Hawkesbury, Narrabeen and Shoalhaven groups, within the coast and ranges in an area within approximately km of Sydney. Habitat and ecology Nocturnal.

Shelters in rock crevices and under flat sandstone rocks on exposed cliff edges during autumn, winter and spring. Moves from the sandstone rocks to shelters in crevieces or hollows in large trees within m of escarpments in summer.

Schlesinger, C. Choosing a rock: perspectives of a bush-rock collector and a saxicolous lizard. Biological Conservation Shine, R. Conservation and reproduction of an endangered species: the broad-headed snake, Hoplocephalus bungaroides Elapidae. Australian Zoologist The impact of bush-rock removal on an endangered snake species, Hoplocephalus bungaroides Serpentes: Elapidae.

Wildlife Research Swan, G. A field guide to reptiles of New South Wales. Reed New Holland. WallisDeVries, M. A quantitative conservation approach for the endangered butterfly Maculinea alcon. Van Oosterzee, P. Ecotourism and biodiversity conservation - two way track.

Pacific Conservation Biology 6: Webb, J. Out on a limb: conservation implications of tree-hollow use by a threatened snake species Hoplocephalus bungaroides: Serpentes, Elapidae.

A field study of spatial ecology and movements of a threatened snake species, Hoplocephalus bungaroides. Using thermal ecology to predict retreat-site selection by an endangered snake species Hoplocephalus bungaroides: Serpentes, Elapidae. Ecological characteristics of a threatened snake species, Hoplocephalus bungaroides Serpentes, Elapidae. Animal Conservation 1: Paving the way for habitat restoration: can artificial rocks restore degraded habitats of endangered reptiles?

Collectors endanger Australia's most threatened snake, the broad-headed snake, Hoplocephalus bungaroides. Oryx This content is only available as a PDF. View Metrics. Citing articles via Google Scholar. Most Read Is vegetarianism bad for the environment? Ian Wallis. Semi-vegetarianism — good for animals, good for the environment and good for humans Ian Wallis. Professional kangaroo population control leads to better animal welfare, conservation outcomes and avoids waste George R Wilson, Melanie Edwards.

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