Search results
Results from the WOW.Com Content Network
The first flightless bird to arrive in each environment utilized the large flightless herbivore or omnivore niche, forcing the later arrivals to remain smaller. In environments where flightless birds are not present, it is possible that after the K/T Boundary there were no niches for them to fill. They were pushed out by other herbivorous mammals.
An audio recording of a house sparrow. The house sparrow (Passer domesticus) is a bird of the sparrow family Passeridae, found in most parts of the world. It is a small bird that has a typical length of 16 cm (6.3 in) and a mass of 24–39.5 g (0.85–1.39 oz).
Early settlers called it the "swamp sparrow", no doubt because of its colouration. [14] The tail feathers are thin, dark brown, and spine-like. The birds reach a length of 18 cm (7 in) ― as measured from tip of beak to end of tail. However, almost half of that is tail. [14]
The juveniles are browner overall with pale tips to the upperpart feathers and is spotted with grown below rather than barred and the rump feathers have only the tips white, and shows dark. In adults the bill is black, the long legs and long toes are yellow, the cere is yellow and the eyes are deep yellow; in juveniles have a yellowish-green ...
Being a member of Emberizoidea, New World sparrows have only nine easily visible primary feathers on each wing (they also have a 10th primary, but it is greatly reduced and largely concealed). [7] Despite their name, not all of the New World sparrows resemble the typical image of a sparrow.
For a sparrow, the Cape sparrow is strikingly coloured and distinctive, and is medium-sized at 14–16 cm (5.5–6.3 in) long. [3] Adults range in weight from 17 to 38 grams (0.60–1.34 oz). [4] The breeding male has a mostly black head, but with a broad white mark on each side, curling from behind the eye to the throat.
The yellow-browed sparrow is a small American sparrow, measuring 13 cm (5 in) in length, [9] with a mass between 14.5 and 19 g (0.5 and 0.7 oz). [10] Sexes are similarly plumaged, though males average very slightly larger than females. [2]
The Cassin's sparrow is a fairly large, plain, grayish sparrow that lacks conspicuous markings. In flight, the long, roundish tail is obvious and the white tips of the tail feathers are sometimes apparent. This species is most easily identified by its distinctive song and dramatic skylarking behavior during the breeding season.