Date: 5/29/18 3:18 pm
From: Adam Lewis (sbfledgling) <aj.lewis...>
Subject: [sbcobirding] Phainopepla Yardbird Update
I saw the first Phainopepla April 29. The number increased through May 12 when 10 were counted, 8 in a Mimosa tree and 2 in the Pineapple Guava under it. According to Lehmann’s BOSBC this is a candidate for the largest Phainopepla sighting in Santa Barbara County. The number of birds has fallen off as the flowers are consumed and age out but I saw one as late as yesterday (May 28).  I took a number of photos which enticed me to attempt to ID sex and age.  What follows are my thoughts based on two references.  I appreciate any feedback if you think I got it wrong. 
Of the ones I caught on camera some are obvious adults in ‘Definitive Basic plumage’. The others are first year birds but none have the yellow gape or dark iris of the juvenile (good picture of one here https://www.flickr.com/photos/151398845@N06/35231649935/ ( https://www.flickr.com/photos/151398845@N06/35231649935/ ) ). From the description of the Phainopepla Nitens in Birds of North America on-line and the monograph “ Postjuvenal Molt and the Appearance of Sexual Characters of Plumage in Phainopepla Nitens ” (Alden Miller, 1933) the first year birds are in ‘Basic I plumage’ (postjuvenal molt). Assignations have been added to some of the individuals shown in https://www.flickr.com/photos/sbfledgling/albums/72157668938377388 ( https://www.flickr.com/photos/sbfledgling/albums/72157668938377388 )  

Of note is the varied appearance of the first-year males. One has roughly a 50/50 mix of brown and black feathers (PHAINOPEPLA 2) and another is almost entirely black but having white edges (PHAINOPEPLA 10). Miller says this white edging appears only in first year males. The two references state feather color in the first year males depends on the sexual maturity when the feathers grow out, i.e., body chemistry. Since the maturation of the male changes during its first year it follows that some feathers can grow black and some brown. Additionally, the pied appearance of PHAINOPEPLA 2 lasts for a few months until it molts again and grows its all-black adult feathers.

Phainopeplas breed in the Sonoran Desert of Arizona approximately February through April. When it gets hot they depart for the California coastal plain where breeding occurs approximately May – Jul. Since the Goleta birds are not juveniles but older it seems likely they were bred in Arizona not Santa Barbara.  

Prof. Glenn Walsberg, a principal author of the species account in the Birds of North America on-line has seen the photos and made instructive comments. He concurs these yard birds most likely bred in the Sonoran Desert and pointed me to the Miller monograph. I appreciate his time.

Adam Lewis
Goleta

 
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