The broad-headed snake is greatly dependent on sandstone rocks for shelter, and is therefore under significant threat from the collection of sandstone rocks, or ‘bushrocks’, which are increasingly being used for garden decoration (2) (3) (4). As well as removing essential shelter sites for the snake, this reduces the available shelter for its prey and for the spiders and insects on which its prey depends (2) (3). Rock collectors also sometimes deliberately kill snakes (2).
Since the broad-headed snake inhabits areas with a high human population density, its habitat has been subject to wide-scale degradation, and its populations have become fragmented. Although it does occupy national parks, illegal rock collection has persisted in these areas, particularly alongside roads and trails (2).
The broad-headed snake is very selective about the sites it inhabits, and will not dwell in rocks exposed to too much sunlight or that are too wobbly. This complicates its conservation, as it makes efforts to improve the habitat through adding rocks an unlikely solution (2) (6). It also makes the broad-headed snake particularly sensitive to any disturbance of surface rocks (3).
Threats to the woodland areas occupied by the broad-headed snake in summer may also negatively affect this species. Altered fire regimes may affect prey availability and reduce the tree hollows in which the broad-headed snake shelters, while forestry activities can disturb the woodland habitat and remove the large, hollow trees this snake prefers (2) (3).
Illegal collection is also likely to be having a serious impact on the broad-headed snake population, with recent changes to the laws on reptile-keeping potentially exacerbating the problem (3) (11). Non-native foxes and cats may also be predating this species (2) (3).
The slow growth and reproduction of the broad-headed snake, together with its fidelity to specific sites and the low dispersal rates of juveniles, make this species particularly vulnerable to human disturbance and less likely to colonise new areas (2) (3) (7) (9).