Betsy and Tweeters,



I answer the email for Seattle Audubon, and, coincidentally, I just got two messages from others with white chickadees in the yard. These birds are leucistic, meaning that they have abnormally pale plumage due to a lack of melanin. Here is a fuller explanation of leucism:



http://www.bto.org/volunteer-surveys/gbw/gardens-wildlife/garden-birds/behaviour/plumage/leucism



There has been a population of leucistic Black-capped Chickadees in the Seattle area for many years. I had several visiting my Queen Anne yard in 2004 and banded several more in Shoreline in 2004 and 2006. Every year, I get a few reports in the Audubon email of leucistic chickadees, juncos, and other species. These birds can range from having just a few white feathers to being almost completely white. Though leucistic birds are at a disadvantage (as mentioned in the link above), the genetic mutation for leucism seems to persist, and we continue to see leucistic chickadees here in small numbers.



Rachel Lawson

Seattle

rwlawson at q.com





From: tweeters-bounces at mailman1.u.washington.edu [mailto:tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Betsy Gilbert Swart
Sent: Monday, January 12, 2015 2:21 PM
To: tweeters at u.washington.edu
Subject: [Tweeters] 'Albino' chickadee in Ballard?



This weekend I watched an unusually white chickadee in our urban Seattle garden. It

's white cheeks extended behind to cover much of its back. Anybody else seen this one or anything like such a variant?

~Betsy Swart



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