Red Crossbill, Loxia curvirostra
Red Crossbill, male, 11/23/07, Skylawn Cemetery, San Mateo Co
Red Crossbill, female, 11/23/07, Skylawn Cemetery, San Mateo Co
I had the good luck to find this previously reported flock and have them pose for me in morning sun against a blue sky. The adult males are typically solid red, though they may also have some yellow; adult females are typically olive with varying amounts of yellow. The first-winter males are quite variable in plumage, but as I learned from Ron Thorn, who first found these birds, first-cycle birds retain their juvenal tail feathers until Spring, so these feathers should appear abraded in Fall as compared to adults' fresh ones. Another mark for first-cycle birds is buff tips to the wing coverts.

The top two birds appear to be adult male and female respectively. The third bird shows worn tail feathers as well as mixed plumage, and is presumably a first winter male. The fourth bird, though it shows some red, is mostly yellow, and while the tail feathers look fresh, it has the buff wing coverts, so is presumably a first-winter bird -- a male? The last one is mostly red, though not as solid-colored as the top one; and while the tail feathers aren't obviously abraded, it does have the buff tipped wing coverts, and so I'm presuming it is a first-winter male. Comments and corrections welcome.
Red Crossbill, first winter male, 11/23/07, Skylawn Cemetery, San Mateo Co
Red Crossbill, male, 11/23/07, Skylawn Cemetery, San Mateo Co
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