brewer's sparrow (spizella breweri) is a small , slim species of american sparrow in the family emberizidae .
this bird was named after the ornithologist thomas mayo brewer .
adults have grey-brown backs and speckled brown crowns , both with dark streaks , and a pale eye-ring .
their wings are brown with light wing bars and the underparts are pale grey .
their bill is pale with a dark tip and they have a long notched tail .
they are similar in appearance to the clay-colored sparrow (s .
pallida) but do not have a pale stripe on the crown or grey neck patch .
the male sings to defend a nesting territory .
the song is a long varied mix of notes and trills .
males have 2 distinct types of songs - classified as short and long songs .
there are two distinct subspecies:these birds migrate to the southwestern united states south to central mexico .
these birds forage primarily in shrubs or in low vegetation , but also on the ground .
they mainly eat insects in summer with seeds becoming a more important part of the diet at other times of the year .
they usually forage in flocks outside of the breeding season , sometimes with other sparrows .
the female typically lays 3 to 4 eggs (up to 5) in a cup nest in low shrubs .
brewer's sparrow has decreased in some parts of their range .
causes are not well understood , but it is suspected that the decline is due at least in part to destruction of sagebrush habitat .
additional information on resource use and limitation during the wintering season is desperately needed .
when the timberline sparrow was still considered a good species , brewer's sparrow was classified as near threatened by the iucn .
however , as only entire species are evaluated for the iucn red list , following the merger the entire population of s .
breweri is classified as species of least concern .
