Parasite?

[Adams Serra]

Hey John, is that bug on the bird some type of parasite?

[John Chardine]

Adams- This is an insect called a feather or chewing louse in a group called Mallophaga. It is indeed a parasite- more correctly an ecto-parasite meaning is stays outside the body. Feather lice eat feather material and pose no threat to their host so long as the numbers on any one bird don't get too high. Notice how the body is elongated and they have strong, short legs to hold on to feathers. Their shape allows them to hide in amongst the plumage and avoid being preened off by the bird. Lice tend to be found on the bird's head because birds cannot preen there. Paired males and females sometimes preen each other ("allopreening") around the head for this reason. Another method dark birds use to rid themselves of lice is to expose their plumage to the hot sun. This has been shown to heat their plumage up to temperatures that are lethal to the lice. Lice are wingless and so have to crawl on and off their hosts. As "birds of a feather flock together", i.e., species tend to stick to themselves, lice tend to move to another host of the same species rather than a different one. Over the course of evolutionary history this has produced an association between certain host species and certain lice. Some species of birds have feather lice that are very specific to their species are are found on no other.

Well done seeing this!

PS- attached image is of a Northern Gannet feather louse

[Axel Hildebrandt]

I assumed the little bug on the chick is an ant. Could it be a louse, too?

[Adams Serra]

Hi John,
Thank you for the great lesson. I appreciated.

Adams

[Steve Maxson]

I assumed the little bug on the chick is an ant. Could it be a louse, too?

Hi Axel. Though it's hard to tell for certain, I would vote for an ant in this photo. The feather lice that I've seen up close tend to have bodies that are flattened from top to bottom. This one's body appears chunkier - like an ant. It also seems rather large for a bird the size of a snowy plover (see how small the louse is in Adams original photo). Anyway, that's my 2-cents worth. :) Any other opinions?