FeederWatchers document mass movements
of robins, siskins, and jays

More than 38 percent of FeederWatchers contributed data via the Internet in 1998-99—double the number of online contributors in the previous year. This coming year, more than 1,200 returning FeederWatchers have chosen to forgo receiving paper materials in the mail and will participate entirely online.

Lest FeederWatchers who favor pen and paper feel neglected, we hope that you will like our new Research Kit, which has been extensively revised. In addition to having a slightly different Instruction Booklet, the kit now includes a FeederWatch resource guide with more information about bird feeding and FeederWatch results. And thanks to FeederWatch sponsor Perky-Pet Products, we offer a new, larger version of our Common Feeder Birds Poster this season. Now, let’s look at some of this past season’s highlights.

Large Robin Flocks Roamed Northern Climes

This graph shows the percentage of feeders visited by Pine Siskins in the California and East Central regions. Last winter, FeederWatchers along the West Coast were treated to an irruption of Pine Siskins. In the past decade, the species tended to stage irruptions on opposite sides of the continent in alternating years, so siskins might make a big showing in the East this coming winter.

"The woods around this area produced a heavy crop of cones this year. While I saw and heard large flocks of Pine Siskins and grosbeaks in the woods during this time, hardly any were visiting my feeders," reported Gordon and Dorothy Kelly of La Tuque, Quebec. This FeederWatching couple wasn’t alone. Pine Siskins skipped most feeders in the East and instead staged an irruption on the western front.

This delighted many western FeederWatchers. "I sometimes saw as many as 100 Pine Siskins at my feeders," said Marvin Ellison of Vancouver, Washington. And Karen Buckallew of Evanston, Wyoming, observed "large flocks of Pine Siskins—between 75 and 100 birds" at her feeders early in the season, noting that "they seemed to be traveling with Evening Grosbeaks, American Goldfinches, and Red-breasted Nuthatches."

Kaye Lafreniere of Colorado Springs, Colorado, wrote, "Over 75 Pine Siskins landed in my count site at one time, but alas—it wasn’t a count day!" We sympathize with this lament. We found even larger flocks recorded in the database, including flocks of 327 in Alaska and of 240 in Washington State. But even during western invasion years, Pine Siskins can be seen at feeders of some eastern Canadians: the largest flock reported on a count day was 400 siskins in Quebec City, Quebec. If the pattern of the past decade holds true, then FeederWatchers in the East will have their turn playing host to parties of hungry Pine Siskins this coming year.

Blue Jays Headed West

For many FeederWatchers in the West, watching a "blue jay" at their feeders could mean that a Steller’s Jay has dropped by for a visit. For some western FeederWatchers, however, these "blue jays" are routinely becoming the Blue Jay itself, a common species in eastern North America.

Over the last decade, the number of Blue Jays reported by FeederWatchers in the Northern Rockies region has significantly increased. Last winter we received reports of Blue Jays, which are typically an eastern bird, from many locations even farther west, including Oregon and Washington.

This chart lists the most frequently reported species in each FeederWatch region in the winter of 1998-99. The red squares indicate species that were new to this year's top-10 list since last year. Notably, this was the first year that American Robins appeared on the top-10 list in the Northern Rockies region. The regional breakdown is shown below.

Veteran FeederWatchers know they can’t always predict which species of birds they’ll see from one year to the next. These year-to-year changes occur not just at individual feeders but across whole regions of North America. So this year’s "FeederWatch Regional Top 10" list (Figure 5, above), which tells you which birds were most frequently seen in your neck of the woods, illustrates these widespread changes when compared from one year to the next.

A quick look at the top-10 table shows a lot of gray in the upper-right-hand corner, because the regions are arranged from West (left) to East (right), and the eastern regions share many of the same top-ten species. Ecological regions in the East differ less dramatically from each other than do those in the West, so Easterners from Nebraska to New England tend to see many of the same birds. The West, however, is a land of extremes, and the resident bird life varies dramatically. As a result, bird species are not as widely distributed in the West as they are in the East and the regional top-10 lists often have very little overlap. Use the chart at left to see how the top-10 birds in your region compared with what you observed at your own feeder.

FeederWatch data clearly show long-term patterns in the abundance of certain feeder birds, some of which are presented above. For example, the Mourning Dove is declining in seven regions and increasing in the Northern Rockies region. The conclusions presented above were based on an analysis of mean group size at feeders.

Because bird populations are so variable, it’s not uncommon for species to enter and exit the top-10 lists periodically through the years. Fourteen species were new to this year’s top-10 list, species that didn’t make the list last winter (see the red squares in Figure 5). Not surprisingly, the American Robin entered the top 10 in both East and West regions this year, appearing on the California, Northern Rockies, and South Central regional top-10 lists. In fact, this is the first time the robin has shown up in the Northern Rockies top-10 list.

Inevitably, some species have to exit the top 10 to make room for new arrivals. So who left the top-10 roster this year? Notably absent were the winter finches and Red-breasted Nuthatches in the East, which staged major irruptions there in 1997–98 but were relatively quiet or irrupting in the West last year. For example, Common Redpolls fell from the top-10 list in the North Central and North Atlantic regions, and Pine Siskins fell from the Northern Rockies list. The latter finding is interesting, because Pine Siskins were irrupting into the western part of the continent. Taking a closer look, we find that Pine Siskin populations in the Northern Rockies tend to synchronize with those in the East rather than with those in the West. So a "boom" year for siskins in California is often a "bust" year for siskins in Ohio and in Alberta.

The year-to-year changes in top-10 lists may indicate that some species are highly variable in where they winter. Other annual changes, however, may be going on against a backdrop of gradual and systematic changes in abundance. Take, for example, the Mourning Dove. This bird is still ubiquitous, with a presence on the top-10 list in 10 different regions, but its numbers are declining in 7 of these regions, both East and West. The Breeding Bird Survey has also detected declines in Mourning Dove populations in some of the same areas. Although scientists don’t yet know the cause of the declines, some evidence suggests they may be related to land-use changes.

House Sparrow populations in the East have been declining for much of this century. FeederWatch data reflect this decline, as shown in the above trend graph compiled from reports in the Great Lakes region.

European Starling populations are declining in the Mid-Atlantic (above) as well as in the East Central regions. Today, FeederWatchers in these regions report 15 to 20 percent fewer birds at feeders than were reported a decade ago.

FeederWatch data also show that although starlings are holding their own over most of the East, significant population declines are occurring in the East Central and Mid-Atlantic regions. In these regions today, FeederWatchers report 15 to 20 percent fewer birds at their feeders than were reported a decade ago. In most regions of the West, starling populations are showing no apparent trend or are highly variable over time. In the Southwest, however, Feeder-Watchers have documented an increase in the number of starlings during the last decade. In this region, the number of starlings reported at feeders has increased by 35 percent over 10 years, although the percentage of feeders being visited by starlings (approximately 45 percent) has changed little.

Of course, not all bird species are declining in numbers. Some species, such as the American Robin, are being reported in greater numbers by FeederWatchers, as mentioned earlier. Other species, such as the Northern Cardinal, appear consistently stable throughout their entire range. And still other species are just plain variable in their occurrence at North American feeders: in addition to the oft-mentioned "winter finches" that invade from the Canadian north woods, the abundance of Purple Finches changes considerably from one year to the next in many regions.

We hope that these examples have shown you how your FeederWatch data can be used to detect and confirm important changes in bird populations across North America. Thanks again to all of our past and present FeederWatchers for providing us with the means to detect these important trends. We look forward to providing more long-term analyses such as this one in future issues of Birdscope.