[nialltkeogh]

Hi all,

This morning I was watching the local pair of Robins feeding their fledged young in my back garden near Cabinteely, Co. Dublin.

One of the adults was preening quite close to the back door and I could see with the naked eye that there was something in its bill whilst it was preening.

On closer inspection through binoculars I could clearly see that the bird had a live (and wriggling!) millipede in its possession and was seemingly using it as an aid.

I can only imagine that the Robin was agitating the Millipede so as to induce the release of a defensive secretion (hydrogen cyanide?) which in turn may kill mites or other parasites. Millipedes give off a strong smell when handled and I'm sure this is secretion that the Robin was after.

Similar behaviour is well documented in preening Starlings and Jays which use formic acid released by ants.

This certainly wasn't a mutual or commensal relationship. As soon as the Robin was finished with the millipede, it ate it!!

Has anybody noted this behaviour in Robins or other species before?
Do any other birds use millipedes?

Regards,
Niall

[Capercaillie71]

Originally Posted by nialltkeogh

Has anybody noted this behaviour in Robins or other species before?
Do any other birds use millipedes?

In a word, yes!

Here's a link to a paper about the practice. Apparently benzoquinones are the chemicals that are released.

http://www.springerlink.com/content/n7mg767vk8007521/

In the references from the above article there is a 1992 'British Birds' note on Robins 'anting' with millipedes.

[KnockerNorton]

There is also some evidence that chickadees/tits may use insect/invert' secretions around their nest entrance to deter predators or parasites.

Good observation though.

[nialltkeogh]

Cheers for the info and link,

Turns out I have that BB article in my collection.

Regards,
Niall