Beetling About in a diverse habitat again

I’ve been away for most of the last two months, so apologies for the hiatus. 

In the last episode I talked about how the range of dung beetle species at any one site can tell us something about the habitats and animals present. That’s the theory anyway. And I mentioned that my Honours student was sampling four different areas of urban bushland in the Manly-Mosman area, using three different baits (bandicoot, wallaby and possum) and non-baited traps. The idea was to see if a particular poo was particularly attractive to a particular dung beetle and therefore whether relictual mammal populations supported relictual dung beetle populations.

We stuffed up slightly, because we assumed that the officially listed bandicoot population on North Head meant that bandicoots only occurred there. Unfortunately, it was not true – they are fairly common suburban animals throughout the Manly-Mossman area, so that was one supposedly isolated mammal population that went out the window. 

And brush-tailed possums are also found everywhere. However, wallabies are only found in two reserves in that area, so they seemed mostly likely to give us some interesting results.

Multiple traps were put out four times in each reserve, from November to February. We looked at all beetles that came to the traps, not just dung beetles. Altogether there were 90 different species of beetle in the traps, with about 17 showing a clear preference for dung, including nine different kinds of dung beetles.

I can’t give detailed results, because my student hasn’t published them. However, we did find that different dung beetles favoured different poo types, including one species which only occurred in wallaby dung in the two reserves where wallabies occurred. Which suggests that extinction of the wallabies would lead to extinction of the beetle.

Thanks again to Matilda Rosas for comments and information, and to Symbio Zoo for poo.