New predator swaps dung for decapitation

[muriel_volestrangler]

A lifetime of dining on dung might seem like a raw deal, but the taste of toxic millipedes doesn't sound much better. None the less, scientists have discovered the first instance of a dung beetle who has abandoned the traditional faeces feast, preferring to decapitate millipedes and eat their insides. These extraordinary findings were captured on night vision camera, and published today in the Journal Biology Letters.
...
Working in the rainforest of Peru, the team set up over 1,000 traps containing different treats to tempt the beetles, including a traditional menu of dung, fungus and fruit as well as millipedes. Some of the millipedes were alive and healthy, others injured or dead, to see which - if any - the beetles preferred. They found D. valgum went exclusively for the millipedes, preferring them living, yet injured. As dung beetles rely on their sense of smell to find food, this finding could be due to a defensive smell produced by millipedes under attack. Stronger smelling and easier to handle, injured individuals would be the most attractive option.

The scientists also filmed the nocturnal beetles attacking the millipedes, in order to find out how their bodies were adapted for this different diet. They noted a narrow, pointy head and sharper 'teeth' which are used to sever and even decapitate the millipedes. Dung beetles heads are usually flat and wide like a shovel in order to roll balls of dung, but D.valgum uses its evolved head to get right inside the millipede's body and feed on its insides.

This research demonstrates how small changes in an animal's physiology can lead to large changes in behaviour. The scientists believe this unique evolutionary transition was driven by competition for food and could help to explain the coexistence of so many different types of animals.

http://royalsociety.org/news.asp?id=8246

Also BBC article, with obligatory dung beetle joke: "So while they may be the butt of many jokes, it would be foolish to pooh-pooh their talents. "

http://news.bbc.co.uk/1/hi/sci/tech/7840404.stm

[frogmarch]

1. Fish got to swim, birds got to fly,

and insects, it seems, got to do one horrible thing after another. (I think it was Annie Dillard who wrote the last part.)

This research demonstrates how small changes in an animal's physiology can lead to large changes in behaviour.

I'm going to have to ponder this for a while. To put it simply, I'd always thought that for a physiological change to work, the animal should already know how to use it.

Thanks for the article snip and the link. :-)