Hi All
this question was prompted by a friend who sent me a photo of a 'natural' ie non-anthropogenic egg-laying site for grass snakes that was recently discovered in a local park - it was in the bowl of a tree, where the process of decomposition was presumably generating some warmth.
It prompted me to wonder what proportion of egg-laying sites for grass snakes (and other species, like Aesculapians) are anthropogenic and what are more 'natural' - in other words, how dependent are grass snakes on humans in this regard? In the UK we tend to find most sites in compost heaps etc, but of course this is because of observer bias - we see snakes near these structures and sure enough that's where we find clutches of eggs and hatchlings. A valuable conservation technique is to construct these heaps in areas with grass snakes present - or is it? is a lack of egg-laying sites really a limiting factor for grass snakes in an otherwise 'optimal' habitat? Of course, it will vary with location and human presence, but I would like to know in a 'typical' rural habitat whether grass snakes are really so dependent on artificial sites as is sometimes assumed...
So I wonder if anyone knows of research into this question? I guess you would have to track female grass snakes (maybe using radio telemetry) ahead of their oviposition to get an unbiased view of site selection for egg laying in a variety of habitats / locations / even in different countries?? Any information gratefully received, as ever
Cheers
Will