Tuesday, April 9, 2019

Chestnut-backed Chickadee

As you probably noticed in my last few bird blogs, the Federal and State authorities have authorized me to band birds here in Washington. I am grateful for these permits, since they can be difficult to obtain. Despite our living among 175 moving boxes, I did open a single net in my backyard. The first bird banded in Washington was this Chestnut-backed Chickadee.

The second bird banded was a Black-capped Chickadee. Erika and I wondered how these two similar birds coexist. Chestnut-backed Chickadees forage higher in trees than do Black-capps and are more restricted to conifers. Chestnut-backed also forage more often on the upper sides of leaves and branches. Finally, Black-capped Chickadees employ more feeding strategies than do Chestnut-backs (Dahlsten et al. 2002).

Chestnut-backed Chickadees are found from southern Alaska to southern California. In the last 50 yeas, this range has expanded a bit into the central Sierra Nevada and suburban areas in eastern San Francisco Bay. Ornithologists can not explain these changes (Dahlsten et al. 2002). 

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