The first heavy snowfalls of the winter often bring large flocks of American Tree Sparrows to bird feeders. This bird is commonly mistaken for the smaller Chipping Sparrow, but the two species look quite dissimilar in the winter. The American Tree Sparrows central breast spot, bi-colored bill, and large size are unique among the species. Plump and long-tailed, American Tree Sparrows are busy visitors in winter backyards and weedy, snow-covered fields across southern Canada and the northern United States. Hopping up at bent weeds or even beating their wings to dislodge seeds from grass heads, they scratch and peck the ground in small flocks, trading soft, musical twitters. Come snowmelt, these small rusty-capped and smooth-breasted sparrows begin their long migrations to breeding grounds in the tundra of the far North.
Cool Facts (credit: allaboutbirds.org)
- Misleadingly named by European settlers reminded of Eurasian Tree Sparrows back home, American Tree Sparrows are ground birds. They forage on the ground, nest on the ground, and breed primarily in scrubby areas at or above the tree line.
- American Tree Sparrows need to take in about 30 percent of their body weight in food and a similar percentage in water each day. A full day's fasting is usually a death sentence. Their body temperature drops and they lose nearly a fifth of their weight in that short time.
- Like many songbirds, American Tree Sparrows synchronize hatching and fledging so all of the chicks join in the foraging pretty much together. Although the female lays only one egg per day until she's got 4 to 6 eggs (and may even skip a day between eggs), the chicks hatch within hours of each other and may not even hatch in the order their eggs were laid.