A few days ago I received a call about a thrush that had hit someone's window this summer and unfortunately perished from the incident. However, the careful observer saw something different on the birds leg: an metal bird band!
We met up, exchanged information, and I excitedly rushed off to query our database. Surely, this Swainson's Thrush must have been"one of ours". I was further curious by the unfamiliar prefix of the band and pondered how old the bird might be; the prefix is the first four numbers on a songbird band and a station will often go through 100s or even 1000s of bands with a particular prefix (the last 5 digits change in chronological order). This sometimes gives the bander an indication on the time period a band was used (and thus the age of the bird) or if the band is "foreign" (a bird banded by someone else).
My curiosity rose as I went through 29 years of banding data and didn't find '2771-28004'. I double checked the band number, took some measurements, checked the birds sex, and took some other notes from the specimen. My last resort was to check the inventory of every band ever issued to be used by our station. No band with the prefix 2771 had been in our inventory, which meant that...
...it was banded at different banding station or by a different research project! A foreign band!
The Bird Banding Laboratory (run by the U.S. Geological Survey, a federal agency) issues permits and bands, and maintains a records database of all birds banded in North America; it also helps connect banders to each other when birds are found (or bands are seen through binoculars or in a photo) and reported across the country. This was my only hope to find where this Swainson's Thrush "came from". I reported the band to the Bird Banding Laboratory (this is something anyone can do by going to this link).
It wasn't long until the original banding record arrived in my inbox; the Swainson's Thrush, now dead from a window collision this June, was originally banded in September of 2018 at Silver Islet, Ontario, Canada as a hatch year! That's over 3,000 miles away! At the time it was banded, it's sex wasn't able to be determined, which was a question I could now answer almost two years later for the banders at Silver Islet. It's a male! This Swainson's Thrush may have met an unfortunate end, but it's recovery has provided clues about it's life.
Banding birds is one of the ways that we have uncovered where birds go during different times of year, sometimes how quickly it takes to get there (a Swainson's Thrush we banded here in Fairbanks in 2018 flew about 900 miles in 10 days a couple years ago!), how long birds live, and other important insights that can be applied to both further our understanding of these marvelous species and pave the way to research that guides management decisions to conserve them.
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| Common Redpoll (Female) |
Today we had a beautiful clear day and captured two new species for the season, an American Green-winged Teal and a Common Redpoll. The Common Redpoll was particularly exciting because she still had a brood patch (an area of highly vascularized and featherless skin on the abdomen used to keep eggs and chicks warm) suggesting she'd just completed a breeding attempt; she also had an esophageal diverticula that appeared to be full of birch seeds.
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