The field sparrow (Spizella pusilla) and the American tree sparrow (Spizella arborea) are two similar-looking bird species that belong to the sparrow family Passerellidae. At a quick glance, they may appear identical to an untrained eye. However, upon closer inspection, there are several key differences between these two species in terms of appearance, voice, habitat, range, and behavior.
Quick Identification Tips
Here are some quick tips to distinguish between a field sparrow and an American tree sparrow:
- The field sparrow has a reddish-brown cap, gray face, and unstreaked breast.
- The American tree sparrow has a rusty cap, black cheek spot, and streaked breast.
- The field sparrow’s song is a sweet, melodic trill. The tree sparrow’s song is a buzzy trill.
- The field sparrow prefers brushy fields. The tree sparrow likes weedy fields.
- The field sparrow’s range centers on the eastern and central US. The tree sparrow is widespread across Canada and the northern US.
Appearance
While both sparrows are small, streaky brown birds, approximately 5.5-6.5 inches in length, the field sparrow has distinguishable reddish-brown markings on its head and an unstreaked gray breast and belly. The American tree sparrow has a rusty brown cap, black cheek spot or “ear patch”, and a streaked breast and belly. In flight, the field sparrow shows a brown back with dark streaks, while the tree sparrow shows a brighter rusty back.
Field Sparrow
- Reddish-brown cap
- Gray face
- Bright pink bill
- Unstreaked gray breast and belly
- Brown back with dark streaks
American Tree Sparrow
- Rusty brown cap
- Black cheek spot (“ear patch”)
- Yellowish bill
- Streaked breast and belly
- Brighter rusty brown back
Voice
The songs and calls of these two sparrows are distinct and can aid identification.
The field sparrow delivers a high-pitched, melodic trill that speeds up and slurs at the end. Its call is a distinctive “pink” note.
The American tree sparrow has a buzzier, more musical trill that is lower-pitched and slower than the field sparrow’s song. Its call is a soft “dit.”
Habitat
Field and tree sparrows utilize different types of habitats during breeding season:
- Field Sparrow: Brushy fields, overgrown pastures, shrublands, forest edges
- American Tree Sparrow: Tundra, boreal forest, weedy fields
Field sparrows prefer to nest in dense shrubs and thickets, while tree sparrows nest on the ground amongst grasses and weeds.
In winter, both species frequent open fields, grasslands, and marshes. Field sparrows mainly winter in the southern US, while tree sparrows winter across the northern US south to Texas and the Southeast.
Range
The breeding and year-round ranges of these species differ considerably:
- Field Sparrow: Breeds in the eastern and central US. Winters in the southern US.
- American Tree Sparrow: Breeds in Alaska, Canada, and the northern US. Winters across southern Canada and the northern US.
Species | Breeding Range | Winter Range |
---|---|---|
Field Sparrow | Eastern and central US | Southern US |
American Tree Sparrow | Alaska, Canada, northern US | Southern Canada, northern US |
Behavior
Some key behavioral differences between these species include:
- Nesting: Field sparrows nest off the ground in shrubs. Tree sparrows nest on the ground.
- Foraging: Field sparrows mainly eat insects and seeds. Tree sparrows eat a wider variety of insects and seeds.
- Flocking: During migration and winter, tree sparrows form large nomadic flocks while field sparrows form smaller groups.
- Migration: Field sparrows are short-distance migrants. Tree sparrows migrate longer distances.
In summary, field sparrows stick to brushy habitat near their nesting areas year-round and form small flocks. Tree sparrows are more nomadic and communal outside the breeding season, migrating further and flocking in large numbers.
Conclusion
While the field sparrow and American tree sparrow may appear similar at first glance, they can be reliably distinguished by their markings, songs, preferred breeding habitat, range, and behavior. The field sparrow is a rusty-capped brushland species of the central and eastern US. The tree sparrow is a rusty-capped tundra breeder that winters across southern Canada and the northern US in large flocks. Understanding these key differences is helpful for properly identifying these two common North American sparrow species.