| backyard birding |

providers for their offspring. Color may also indicate

which birds are the healthiest. While he was a graduate stu- dent, Kevin McGraw, now a professor of evolutionary and systems biology at Arizona State University, examined the potential connection between bright feathers and good health in this species. During winter, he initiated a study of 60 temporarily captured male goldfinches. One group of the birds had a stomach parasite that weakened them; the other group did not have the para- site.When all of the goldfinches later grew their breeding plumage, the sick individuals were a much duller yellow. Under any circumstances,

molting into these summer col- ors is taxing and time-consum- ing for goldfinches. It may be one reason why this species breeds late in the season, usually not beginning in earnest until mid-July. One benefit of their slow start: Cowbirds, which parasitize other species’ nests, usually have finished laying their eggs by the end of June. During breeding season,

goldfinches seldom defend a territory and may even nest in loose colonies. The female builds her compact nest in a shrub or small tree, usually sheltered under a canopy of leaves. She lays three to six bluish white eggs and incubates

DRESSED IN winter colors, a male goldfinch (left) braves the cold in Colorado. During spring in North Carolina, another male (right) undergoes its seasonal molt to breeding plumage.

them by herself, while her mate brings food to the nest. On the surface, it appears to be a peaceful scene of domestic bliss. But Tarvin and his colleagues have discovered that all of the youngsters in a nest are not necessarily the offspring of the female’s mate. “Some of the young are sired

by the male that raises them, and some by the guy next door or even the one down the road,” says Tarvin. “In our study area, we found 30 percent of the nests have young with different fathers.” And when

Enticing Goldfinches Is Easy Just about anyone who feeds birds in a yard during winter discovers that goldfinches seldom come by ones and twos but instead often by the dozens. During summer, the birds visit back- yards as well, although usually in smaller numbers. Niger (also called thistle) seed is their favorite, but the birds also devour black oil sunflower seeds. Goldfinches are not particularly picky about the type of feeder they will eat from. Gardeners also can lure them by growing native sunflowers, thistles, goldenrod, coreopsis, elm and alder. These plants are important sources of food, and female goldfinches use thistledown to line their nests.

| 14 | NATIONAL WILDLIFE

providers for their offspring Color may also indicate

which birds are the healthi While he was a graduate st dent, Kevin McGraw, now professor of evolutionary an systems biology at Arizona State University, examined potential connection betwee bright feathers and good health in this species. Durin winter, he initiated a study 60 temporarily captured ma goldfinches. One group of t birds had a stomach parasit that weakened them; the ot group did not have the par site.When all of the goldfinches later grew their breeding plumage, the sick individuals were a much duller yellow. Under any circumstances,

the nestlings are about two weeks old, the female some- times abandons them, leaving her mate to raise the youngsters alone while she begins a second brood with another male, pre- sumably a colorful one. Once the breeding season

winds down, goldfinches begin to lose their brilliance and some people mistake them for spar- rows.Most of the birds migrate to more southern climes and spend the winter jostling at feeders or foraging in over- grown fields and abandoned pastures. But when the days start to lengthen inMarch and April, bright flecks of yellow begin appearing on their plumage, and they morph once again into the bright birds of summer.

South Carolina writer DOREEN CUBIE sees goldfinches regularly

in her NWF-certified wildlife habitat.

molting into these summer c ors is taxing and time-consu ing for goldfinches. It may b one reason why this species breeds late in the season, usu not beginning in earnest unt mid-July. One benefit of the slow start: Cowbirds, which parasitize other species’ nest usually have finished laying their eggs by the end of June During breeding season,

goldfinches seldom defend a territory and may even nest loose colonies. The female builds her compact nest in a shrub or small tree, usually sheltered under a canopy of leaves. She lays three to six bluish white eggs and incub

Enticing Gold Just about anyone who feeds b come by ones and twos but ins yards as well, although usually favorite, but the birds also dev picky about the type of feeder native sunflowers, thistles, gold sources of food, and female go

| 14 | NATIONAL WILDLIFE

LEFT, DANN ZIEGLER; RIGHT, STAN H. LEWIS