The American Tree Sparrow is so called 'American' because there is an Eurasian Tree Sparrow, Passer montanus. This sparrow looks very different and is rarely in North America so the only confusion would be in the name.
The American Tree Sparrow is average in size, 16 cm long. The most striking features are its light gray throat, breast and belly with a single dark spot in the centre of the breast. Note, there are no stripes on its breast. It has a gray head and nape and a rufous crown and a rufous eyeline extending posteriorly from the eye. There are rufous-buff patches on the sides of the breast and the back is streaked with black and rufous. There are two white wing bars, the upper one sometimes being indistinct. The bicoloured bill is distinctive, with a dark colour on the top and yellow on the bottom.
The American Tree Sparrow can be confused with the Chipping Sparrow or the Field Sparrow. The latter two are usually seen only in summer so the most often time you would need to be careful is in the overlapping seasons. However, there is a Field Sparrow coming to a feeder in New Brunswick this winter so it had to be differentiated from an American Tree Sparrow. The Chipping Sparrow is slightly smaller, has a rufous crown and a light gray breast and throat. It does not have the central breast spot and it does have a black eyeline which runs both posteriorly and anteriorly to the bill. It also does not have the bi-coloured bill, the bill being all black or dark gray. The Field Sparrow differs by not having the 2-toned bill or the dark central breast spot. It also has a white eyering.
I am always delighted to see the American Tree Sparrows return in the late fall. We have two coming to our feeders periodically this winter. What I love about this species is its cheerful winter presence and its beautiful song. It makes a musical high-pitched bell-like tinkle. When you become familiar with that sound you know the American Tree Sparrows are nearby. In flight they also make a tweedle-eet sound.
The sparrow shown above is a juvenile and still shows some striping on the breast. The central breast spot in clearly visible. It will reach adult plumage as the breeding season approaches.
The American Tree Sparrow breeds in our far north; Labrador, Nunavut, Northwest Territories, Yukon and Alaska. It does not breed as far north as the Arctic islands. It spends its winters in the most southerly parts of Canada including the Maritime provinces and most of the continental United States except the most southern part.
The American Tree Sparrow builds its nest low to the ground in a clump of grass or moss. The nest is made of stems, strips of bark, moss and grass and lined with feathers, fur and hair. Three to seven light blue or greenish eggs spotted with brown are laid and are incubated for 12 to 13 days by the female. This species eats seeds, insects, berries and, in summer, small flowers. It feeds by scratching on the ground but also forages from foliage and from the snow. These birds will also feed by beating tall weeds with their wings in order to cause the seeds to fall to the ground. They readily eat cracked corn, millet and sunflower seeds at feeders.
It is interesting to note that this species which is called a 'Tree' sparrow does not nest in trees and feeds from the ground. It was mistakenly named by early settlers from Europe who thought it looked like the Eurasian Tree Sparrow. Another interesting fact is the result of one study which reports that the American Tree Sparrow watches for predators using its left eye. That must mean it knows which way to orient itself in order to know what direction from which danger could come. Interesting. All in all, this beautiful winter sparrow is an interesting species.
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