Monday, February 16, 2009

Rare Leucistic Sabiá (Thrush) in Brazil

My cousin, Antonio, lives in São Paulo, Brazil. He just sent me this link to a female SABIÁ (a common Brazilian bird in the thrush family) exhibiting leucistic feathers. As a result, the males are rejecting her, and she can’t find a mate. The reporter also mentions that the white feathers make the bird more susceptible to predation because it has no camouflage.

Click here for a link to a video showing the bird (it’s in Portuguese, but you don’t need to speak the language to understand the meaning of the video).

On the Project FeederWatch site, you can find a nice explanation about plumage variations and the difference between albinism and leucism:
Albinism is a genetic mutation that prevents the production of melanin in the body. Leucism is a genetic mutation that prevents melanin from being deposited normally on feathers. Leucism is rare in birds, and albinism is extremely rare. From 2000-2006, Project FeederWatch participants reported fewer than 1000 leucistic birds. Given that participants report about 5.5 million birds each season, the percentage of leucistic birds is very, very small.

Typically birds with abnormally white feathers do not survive long because they are so much more visible to predators. Those that do survive may have trouble attracting a mate. Consequently, the mutated genes that cause albinism and leucism are less likely to be passed on to a new generation.

4 comments:

Kallen305 said...

Will have to check this out later. For some reason my computer won't allow me to play videos yet again......Hmmmmmm. I love seeing the birds of South America so look forward to seeing it once I figure this out. ;o)

Roy said...

Interesting. I've never seen either an albino bird or a leucistic one. Thanks for the lesson.

Shellmo said...

That's too bad she can't get a mate - poor thing!!

Kelly said...

...I know...poor thing :-(