Eurasian Tree Sparrow Life History

Habitat

Habitat Towns

In North America, Eurasian Tree Sparrows inhabit farms, lightly wooded areas (especially with hedgerows and bushes), villages, parks with ornamental plantings, and reedbeds along lakeshores. Along with doves, pigeons, House Sparrows, and crows, they often forage on spilled grain near grain elevators. Another requirement for them is nest cavities: they nest in crevices in old buildings, light fixtures, fence posts, or old woodpecker holes in trees). In some places they roost in cavities overnight, especially during winter.

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Food

Food Seeds

Eurasian Tree Sparrows eat grains, seeds, fruits, flowers, and invertebrates. They forage on the ground, in grasses and bushes, and in the lower parts of trees, usually by picking and gleaning. On occasion they fly after insects. Around agricultural areas they consume oats, rye, wheat, corn, sunflower, and sorghum. In spring they eat large quantities of insects and other arthropods (mites, ticks, spiders), particularly when feeding young. They also eat ripe berries, flowers, leaf buds, and new plant shoots. As plants produce seed in late summer and fall, Eurasian Tree Sparrows take fallen seeds on the ground or strip the seedhead while perched on a plant’s stalk. This species forages singly, in small groups, or in large flocks, especially after the breeding season. When foraging in grasses as a large flock, the birds in the rear of the flock fly together to the front of the moving flock in a kind of leapfrogging pattern.

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Nesting

Nest Placement

Nest Cavity

Males select the nest site, which may be any sort of cavity in a tree, building, pole, fence post, or bird nest box. Most nests are more than 3 feet and less than 30 feet off the ground.

Nest Description

Both male and female build a cup nest of grass and straw, lined with feathers, hair, cloth, string, and plant matter, which is usually set inside a large, bulky sphere of intertwined grass, straw, and roots accessed via a side entrance or tunnel. The dimensions of the nest depend in part on the size of the cavity in which it is constructed. The interior cup normally spans no more than 2 inches, but the overall nest may be up to 18 inches across and 17 inches tall.

Nesting Facts
Clutch Size:4-7 eggs
Egg Description:

White to pale gray, heavily marked with spots, small blotches, or speckling.

Condition at Hatching:

Naked and helpless.

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Behavior

Behavior Ground Forager

Eurasian Tree Sparrows form pair bonds in their first breeding season, at the age of about 1 year, and remain monogamous once paired, provided both male and female survive. (Even with these long-term pair bonds, DNA studies have revealed that 10–20% of offspring are from copulations outside the pair bond.) In spring, males sing from nest sites and display to females by fluffing the plumage, drooping and vibrating the wings and tail, bowing, and darting in and out of the nest cavity, to invite the female to inspect it. Displaying males sing or give a strange rattling call. Although this species often nests in small colonies, with nests very close to one another, males vigorously defend the nest cavity and defend the female against rivals. Males threaten rivals by opening and drooping the wings, raising and lowering the fanned tail, and mechanically rocking side to side with head raised and bill partly open. Because males and females look very similar, scientists studying this species had to color-band individuals to learn that females likewise confront and attack other females during the spring courtship period—and again during an autumn courtship period. Both male and female build the nest, incubate the eggs, and care for the young. After raising one or more broods, pairs stay together and commence an autumn courtship period very similar to the spring. Afterward, these birds gather into larger flocks for foraging and roosting. They frequently forage and roost miles away from their natal areas.

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Conservation

Conservation Low Concern

According to the North American Breeding Bird Survey, populations of Eurasian Tree Sparrow increased steeply, by an estimated 5.8% per year between 1966 and 2015. Partners in Flight estimates a global breeding population of 250 million; there is no estimate of the size of the relatively tiny North American population. Partners in Flight rates the species rate a 4 out of 20 on the Continental Concern Score, indicating a species of low conservation concern.

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Credits

Barlow, Jon C., Sheridan N. Leckie, Peter Pyle and Michael A. Patten. (2017). Eurasian Tree Sparrow (Passer montanus), version 2.1. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.

Partners in Flight (2017). Avian Conservation Assessment Database. 2017.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, USA.

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