Tracking Pine Siskin Movements
Every few years FeederWatchers record a large movement of Pine Siskins into the lower 48 states. When siskins appear after a long absence, many FeederWatchers wonder where these gregarious finches came from and, following the winter, where do they go?
The 2008-09 irruption
Pine Siskins made a dramatic showing at feeders during the 2008-09 FeederWatch season. We heard from FeederWatch participants like Marion Kinney of Somerville, New Jersey, and Kaye Johnson of Sperryville, Virginia, who had Pine Siskins at their feeders for the first time. Other participants were seeing unusually large flocks of these birds. Shirley Robinson of Rhinelander, Wisconsin, wrote, “Pine Siskins were everywhere. I have so many this winter, I have been filling my five thistle sacks every day.”
Pine Siskins are an irruptive species, which means that these birds move in irregular patterns in winter. Although siskins can be found in most parts of the U.S. and Canada any winter, they visited a higher proportion of feeders during the 2008-09 winter and their flock sizes were larger. Pine Siskins were reported at 24.4% of Project FeederWatch sites continent-wide in 2007-08, compared to 50% of sites in 2008-09. The average flock size during the 2007-08 winter was 11.7, and it was 15 during 2008-09.
FeederWatch data do an excellent job of demonstrating shifts in the distribution and abundance of birds, but to find where, for example, siskins seen in Alabama went, we need to identify and follow individual birds. Fortunately, millions of birds are marked with uniquely numbered leg bands in North America each year, providing a rich source of information for tracking individual birds. Banding is conducted by trained, licensed bird banders, many of whom are citizen scientists who volunteer their time to help study bird populations. These efforts are organized by federal wildlife agencies in the U.S. and Canada through an international banding program.
In order to track movements in Pine Siskins, we acquired records from the U.S. Bird Banding Laboratory for all 31,004 siskins banded in the U.S. and Canada between September 2008 and July 2010. Of the 31,004 siskins banded, 46 birds were recaptured or found dead at a later date with the band number, location, and date of encounter reported to the Bird Banding Lab. Birds were encountered as soon as 3 days and as long as 438 days after banding.
Mapping the initial banding location and point of recovery for these siskins revealed stark and interesting patterns as birds from different regions appeared to come from different source populations. Five birds banded in the southern states during the winter of 2008-09 were subsequently encountered nearly due north.
A different pattern was recorded for birds banded in the northeast, as these birds moved west across the continent. Three of these northeast-to-northwest birds were recovered more than one year after being banded and appear to have spent two consecutive winters on opposite sides of the continent! For instance, a siskin that was initially banded in central New York State in April 2009 was found on Vancouver Island, British Columbia, in April 2010. A similar pattern was recorded for a siskin banded in central Pennsylvania in April 2009. It was later encountered in western Washington State in June of 2010.
In summary, it appears as though the siskins that moved into the south central and southeastern states were birds that came from and returned to the north-central portion of North America, while those moving into the northeastern U.S. and southeastern Canada were western in origin.
How to report a banded bird
If you encounter a bird with a numbered leg band, be sure to record the band number, the species (if known), your location, and the date, and call toll-free 1-800-327-BAND (2263) from anywhere in Canada or the United States.
Your observations will provide valuable information about bird movements, and the Bird Banding Lab will provide you with feedback about when and where the bird was banded.
Identifying Pine Siskins
When seeing Pine Siskins for the first time, they can be hard to identify. Sometimes they mix with a flock of American Goldfinches, which are similar in size, shape, and behavior, making them hard to notice unless you look closely. When seen alone, they look very much like female House Finches. Pine Siskins have brown streaks like House Finches, but they are smaller and have small bills. Pine Siskins also have a touch of yellow in their wings, but that can be hard to see, especially at a distance.
Brighter individuals have more yellow, and when siskins spread their wings and tail, the yellow is more easily seen. You can learn more about Pine Siskins on the Cornell Lab’s All About Birds web site.
As often happens in birds that feed and roost in tight flocks, there have been outbreaks of Salmonella reported in some Pine Siskin flocks. Salmonellosis is caused by a bacteria belonging to the genus Salmonella. It is a common cause of mortality in feeder birds, but the symptoms are not always obvious. Sick birds may appear thin, fluffed up, and may have swollen eyelids. They are often lethargic and easy to approach. Some infected birds may show no outward symptoms but are carriers of the disease and can spread the infection to other birds.
Salmonellosis is primarily transmitted by fecal contamination of food and water by sick birds, though it can also be transmitted by bird-to-bird contact. Occasionally, outbreaks of the disease cause significant mortality in certain species.
If a sick bird comes to your feeder, minimize the risk of infecting other birds by cleaning your feeder area thoroughly. If you see several diseased birds, take down all your feeders for at least a week to give the birds a chance to disperse. Salmonella strains found in birds can be dangerous to humans, so do not handle any sick or dead birds, and be sure to wash your hands thoroughly after handling feeders.