Huia...

[shkrobius]

I've recently heard of an extinct New Zealand bird called Huia. Apparently, this bird was the only known example of sexual division of foraging labor based on monogamous marriage other than H. sapiens (male hunters - female gatherers). Male Huias had short bills for breaking wood in search of insects, whereas female Huias had very long, curved bills for exploring crevices. Between them, they cooperatively foraged for food as a couple. It is said that the bird died of grief if you killed its mate.

Now the Huia's gone, and we are quite alone...

http://www.notornis.org.nz/free_issues/Notornis_43-1996/Notornis_43_1_19.pdf
http://www.k-state.edu/bsanderc/2001wsgb.pdf