Eurasian Tree Sparrow

Species: Eurasian Tree Sparrow, Passer montanus, or ETSP (sometimes called the European Tree Sparrow). Both sexes look alike. The adult has a reddish brown crown separated by a narrow white color, and prominent black spot on cheeks, short black bib, and trim build. The House Sparrow is larger, chunkier (larger head) and has a small white spot over the eye. However, ETSP can hybridize with House Sparrows (HOSP). Hybrid males and females are different from each other (like HOSP). Note: protected in Illinois.

Distribution: 20 birds were introduced in 1870 in Lafayette Park, St. Louis MO by a bird dealer who imported them from Germany. Unlike HOSP, the ETSP has not spread far beyond eastern Missouri, west-central Illinois and southeastern Iowa - perhaps because it is less aggressive, or due to competition with HOSP. One bluebirder noted that after trapping and reducing the local HOSP population, ETSPs started to take over, although they did not appear to be aggressive. They tend to stay in woodlands, cultivated and abandoned fields and farms, and parks near human habitation. Like HOSP, they tend to be around human habitation, are gregarious, largely non-migratory, and socially monogamous.

Diet: Grains, weed and grass seeds, insects during breeding season and fruit (e.g., mulberry)

Nesting Behavior: Secondary cavity nester. Not aggressive or pugnacious like the HOSP, but may attempt to claim a box used by another bird (e.g., chickadee).

Nestboxes: Does not compete well with HOSP for nestboxes unless the opening is <29 mm (<1.142 inches).

Monitoring: No information available.

Nesting Timetable (typical):

• Nest site selection: The male selects a nest site between March and June. Holes are at least 3.3 feet above the ground (e.g., in a hollow fence post) to 32 feet in trees or buildings, or in dense foliage between 6.5 - 32 feet. Also nests on wall beams of barns and other outbuildings. Seen nesting near other ETSPs and HOSP.
• Nest construction: Grasses, forbs, lined with feathers. Nest construction is done by both sexes, and takes about 5 days. Nest is a domed structure of loosely intertwined (not woven) stems of dried grass, straw, pine needles, rootlets and a few sticks surrounding a cup lined with softer materials such as feathers, fur, flower parts, waste paper, bits of cloth, string, and green leaves. Entrance is on side. May fill box to top. Nest materials are mostly gathered from the ground near nest site.
• Egg laying: 1 day to 3 weeks after nest completion. 4-7 eggs, 0.8" long, white to pale gray, heavily marked with dark brown (sometimes purplish or grayish) spots/small blotches/speckles, darker than a House Sparrow. Markings usually concentrated around broad end. Smooth, slightly glossy. Great variation in size, shape, and color.
• Incubation: 10-15 days (11.6 average), usually begins day last egg is laid.
• Hatching: Later season or larger clutches may take longer to hatch.
• Development: Nothing to note.
• Fledging: 12-14 days (typically 14). Adults may feed fledglings for 1-2 weeks afterwards.
• Dispersal: Nonmigratory.
• Number of broods: First brood around April 20. May have two-three, starting the next clutch about a week after fledging.

References and More Information:

• Birds of North America, Peterson Western Birds Nests, The Birders Handbook
• House Sparrow Biology
• House Sparrow Control
• Photos below courtesy of John Curran
• Nest and Egg ID (with links to species biology and photos of nests, eggs and young) for other small cavity nesters
• YouTube video of male ETSP
• YouTube video of ETSP in nestbox, being fed by parents

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