oil gland
Posted by carol m on March 8, 2007
Q: We have cormorants on our lake in the winter and we also explain to students that they have they wings stretched out to dry as they don't have oil on them like other birds. Yesterday a student asked if there were other birds who also don't have the oil gland to use in spreading this substance on their wings.
Thanks.
Carol Miserlian
State: Texas
A: Well actually, cormorants do have an oil gland (so do Anhingas) but for some reason, their plumage is wettable anyway and this is why they need to dry their plumage. Those species that do NOT have an oil gland (uropygial gland) include the Ostrich, Emu, cassowaries, bustards, frogmouths, and some parrots, pigeons and woodpeckers.
I haven't been able to find any recent studies on the oil gland function but from what I've been able to find, the function in all birds is just not well understood - still much to learn. Thanks for asking.
John Wiessinger ( March 8, 2007)