Thursday, March 15, 2012

Parasitos de las golondrinas


Somewhat strangely, I was waiting for dinner here a couple nights ago watching TV and on came a show about parasites… narrated by a former Brown post-doc. I find parasites fascinating and thus I was somewhat excited when I encountered the first blowflies, Philornis sp., on the swallows this year. I know little about these parasites, though last year we found they were not lethal to most of the swallows, though they left scars.

Nine-day old Tachycinete stolzmanni with parasites on foot and neck.

They seem to attach to non-feathered skin, I have found most on the legs/feet with the remainder on the neck /belly. Interestingly, I also trapped two adult swallows in one nest that had a missing and a deformed toe, respectively. Without any other explanation, I assume this is the consequence of a blowfly when a chick… completely healed of course. Supporting this, when I removed the large engorged individual from the chick’s foot as seen in the picture above the toe was flaccid and pale and perhaps dead. 

The nice juicy one in the middle full of blood is the one from the foot in the pic above.

 
There is an interesting story of this genus of parasite “invading” the Galapagos and causing all sorts of harm to the radiation of Darwin’s Finches… just another problem in the terrible saga of Galapagos invasions. This is also the first time this genus, widespread in the New World, has been documented in an avian host in Peru – it is known from a whole host of other South American countries.

Foot of male stolzmanni showing deformed toe (nearest)

Foot of female (mate of above) showing missing toe on right foot

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