Thursday, 3 December 2009

Ant-icipation

Grey-headed robins (Heteromyias albispecularis) are the number one visitors to the bird bath. They are enthusiastic bathers and, once in place, are difficult to shift, as a Macleay's honeyeater discovered.





The robins often exhibit active 'anting' behaviour, in which they pick up one or more ants in their beaks and rub the insects over their feathers. Many species of birds also do this. It was thought that formic acid squirted by the distressed ants cleaned up feather-munching lice and mites and got rid of bacteria and fungi. But, it turns out, the volume and concentration of formic acid isn't sufficient to do the job. Instead, it is likely that birds like the grey-headed robin are actually disarming the ants prior to feeding on them. A beakful of formic acid is just too pungent but half a beakful is piquant.



5 comments:

Lulu Stader said...

Brilliant stories, and the picture of the robin squawking at the honey eater is just delightful. Fantastic!

Dave Coulter said...

I like a shot of formic acid after dinner myself ;)

Snail said...

The robins are birds with very definite ideas about how things should go.

I wish that shot of the honeyeater were a bit sharper. I had to shoot through a window in late afternoon light. Still, you take what you can get!

Dave, I think it helps the dinner go down nicely.

desertnutmeg said...

That is absolutely fascinating! I wonder if any North American birds do this-will have to go do some research....

Snail said...

Scrub jays (or is it Steller's jays? I've forgotten which one) definitely do it. I think a range of passerines engage in this behaviour.

There's also passive anting, in which they stretch out on an ant nest and let the little biters swarm all over them. That doesn't sound like much fun to me.