Notes from the Station

Species: Bewick’s Wren
Most recent capture date: 12/24/2022
Earliest capture date: 5/15/2022
Age: about 8 months old

Notes: This youngster’s bill is Not Right: instead of the upper and lower mandibles meeting at one point, the lower mandible is too short and the upper mandible is too long and slightly decurved. His bill has been like this since we first saw him in May, which is a good sign: clearly he has figured out how to use it well enough to survive, so as long as it doesn’t get any stranger, he should be okay. We have caught him about once a month since May, and I’m always a little surprised he’s survived – but on this latest capture he was quite fat, so I can probably stop worrying about him!

Species: House Finch
Most recent capture date: 12/24/2022
​Sex: Male

Notes: Our third House Finch from that date, sporting the least-common of the colors we see: gold!

Species: House Finch
Most recent capture date: 12/24/2022
​Sex: Male

Notes: The second of our three House Finches on that date, this one showing off a classic dusty rose hue. (This color could easily show up on a Purple Finch, but several traits including bill length assure us that this is a House Finch.)

Species: House Finch
Most recent capture date: 12/24/2022
Earliest capture date: 1/19/2022
Age: at least one year old
​Sex: Male

Notes: We caught three male House Finches on 12/24, nicely spanning the range of male House Finch colors we see in our area. This fellow is a nice reddish-orange. I’ll post the other two in the following posts.

Species: Yellow-rumped Warbler, Audubon’s subspecies
Most recent capture date: 1/4/2023
Age: at least two years old

Notes: The banding station is located next to Coyote Creek, and includes a managed floodplain that catches creek overflow to prevent flooding in less-convenient places. This means that when we get lots of rain, we flood, and banding has to be put on hold for the safety of both birds and people. So far in 2023 we have managed to band for only one half-morning, during which we processed just five birds, including this warbler. Yellow-rumped Warblers of both subspecies are a late winter staple bird for us, and we’re especially excited to see them this year because we recently secured a grant to fund a research project about them.

Species: Bushtit
Most recent capture date: 11/26/2022
Earliest capture date: 11/20/2019
Age: at least three years old
​Sex: Male

Species: Ruby-crowned Kinglet
Most recent capture date: 11/27/2022
Age: about six months old
​Sex: Male

Species: American Goldfinch
Most recent capture date: 11/20/2022
Age: about six months old
​Sex: Male

Notes: American Goldfinches used to be one of the most common captures at CCFS, but they have declined precipitously, to the point where we captured none of them at all in 2018-2021. The cause for that decrease is an ongoing mystery. We have plenty of their favorite seeds growing, which our local Lesser Goldfinches enjoy eating. The Breeding Bird Survey has found that American Goldfinch populations are decreasing overall, but not nearly as quickly as the local drop we have seen.

Species: Golden-crowned Sparrow
Most recent capture date: 11/26/2022
Earliest capture date: 11/23/2019
Age: three years old

Notes: Most Golden-crowned Sparrows that we see in the winter have understated, golden-brown and dark brown crowns. This bird’s striking black and gold regalia would be a clue that they are an older bird even if we didn’t have our capture history information to tell us that they are three years old.

Species: Swamp Sparrow
Most recent capture date: 11/12/2022
Age: about six months old

Notes: Swamp Sparrows live in the eastern half of North America, except for a little strip of wintering habitat along the west coast. This individual is only the seventh of their species that we have banded, and the first we have seen since 2016. (If you’re struggling to see what sets this fellow apart from our common Song Sparrow, note the nearly-unstreaked breast and blinding charisma.)