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Scientists use data gathered by citizen scientists to learn more about birds and to conduct studies on particular species or specific birding behaviors. One study produced by scientists from Audubon and the Cornell Lab of Ornithology used the Christmas Bird Count data to learn about the irruptive behavior of pine siskins. Irruptive behavior is when birds will travel to a different, more southerly winter location than normal, often because the standard food supply has collapsed. It turns out that pine siskins irrupt every other year, but when they irrupt, sometimes they travel east and sometimes they will head west, alternating between the two sides of the continent. We don't understand why that is, but now we know what to look for.
Scientists have also used the data to chart some population trend lines for birds such as the American kestrel. Kestrels, like other hawks and other predatory birds experienced a significant population decrease when DDT was used extensively. After DDT was banned, the kestrel population had been recovering until 1997 when there was a new drop-off in the numbers spotted. The theory for the latest drop-off is that they have been affected by the pesticides that target their prey (large insects and rodents) and the loss of habitat as farmlands and open pastures are turned into developments.
When you are counting birds, it is always a thrill to see one of the more unusual species for a locale. Since the banning of DDT, Portland has had nesting Peregrine falcons and bald eagles within the city limits, which is really nice by my book. So it is not too surprising that one of my best birds for a CBC was a juvenile bald eagle flying overhead.
This year, the scientists are looking for data on the types and numbers of birds common to the boreal forest and where they were found during the CBC. They will match up data from this year's count with the work going on with the Boreal Songbird Initiative (http://www.borealbirds.org/) to understand how the boreal birds are faring.
Anyone can participate in a Christmas Bird Count. If you don't have much practice with identifying birds, you can contribute by watching for any movement and pointing it out to the leader of the group (extra eyes are a big help) or by being responsible for recording the birds seen. (This can be a challenge for some species like crows in Oregon which always seem to number more than one can accurately count.) You can also participate by watching birds that come to your feeders on the day the CBC is going on in your neighborhood.
To find out more about the Christmas Bird Count visit, http://www.audubon.org/birds/cbc/ . While there you can also discover what types of birds have been spotted in your neighborhood and review the historical records that are available for the counts all the way back to the first CBC in 1900.
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