Like pretty much anyone else writing about this, I’m in it for the headline. Well, maybe 30% for the headline — this is also just freaky natural history. A paper in Biology Letters reports that great tits (Parus major — basically big chickadees) will hunt and eat hibernating bats [$-a] if they can’t find other food sources.
The paper reports on ten years of recorded bat-eating by a population of great tits in Hungary, capped by two years of systematic observations and a couple simple experiments. Are the tits hunting bats because other food is scarce? The authors put out birdseed and bacon near the bat cave, and observed that the birds killed many fewer bats. Do the tits use audio cues to find their prey? The authors played a tape recording of bats calling, and watched as the birds oriented to the sound and approached the speaker. There are also a number of grisly photos of tit-killed bats.
This is really the kind of work that attracts most field biologists to science in the first place — a wild, interesting observation that provides an excuse to do some really unusual (and thorough) birdwatching. More complicated science will follow, I hope, like an estimate of the selective advantage this new food source provides to the birds. But it all starts with an incredible story.
You might want to count your fingers after hand-feeding a great tit. Photo by joyrex.
Estok, P., Zsebok, S., & Siemers, B. (2009). Great tits search for, capture, kill and eat hibernating bats Biology Letters DOI: 10.1098/rsbl.2009.0611