Detective Work

Back in October when I visited the Bay Area in California I was tickled to get some nice photo opportunities featuring Golden-crowned Sparrows. I don't get many chances at these (they rarely vagrate into Colorado) so seeing them and hearing their vocalizations was very cool. One that was perching cooperatively at the Palo Alto Baylands sported a band- sweet! As I was editing the pictures I realized that I could make out lots of numbers, so I enlisted the help of some bander friends of mine who knew their way around banding codes. From the various angles, they figured out that only the first number of each sequence was missing (?###-?####). With that information, there was a chance of figuring out the exact number (for example, the first number in the prefix was likely a 0, 1, or 2 based on the band size that Golden-crowned Sparrows take, and from that sequence, perhaps only one of the used band numbers in the 5-digit suffix was from a Golden-crowned Sparrow.) From there I chatted with a very helpful person at the USGS Patuxent Wildlife Research Center Bird Banding Lab (the national clearinghouse for bird banding information), who couldn't come up with a match at the time but promised to look into it. Look into it she did, and I got an email today that they were able to nail down the band number and the information on the bird, which I then formally submitted on the band reporting site. Turns out the bird was banded on 15 April 2008 within a few hundred meters of where I saw it on 10 October 2008. In the intervening months it migrated north, as Golden-crowned Sparrows breed near treeline in Brittish Columbia, Yukon, and Alaska. Then it came back again to its wintering territory at sea level on the southern San Fransisco Bay area- nice round trip and very tight site fidelity!