0 the prothonotary warbler (protonotaria citrea) is a small songbird of the new world warbler family .
1  it is the only member of the genus protonotaria .
2 the prothonotary warbler is 13 cm long and weighs 12.5 g .
3  it has an olive back with blue-grey wings and tail , yellow underparts , a relatively long pointed bill and black legs .
4  the adult male has a bright orange-yellow head; females and immature birds are duller and have a yellow head .
5  in flight from below , the short , wide tail has a distinctive two-toned pattern that is white at the base and dark at the tip .
6 it breeds in hardwood swamps in extreme southeastern ontario and eastern united states .
7  it winters in the west indies , central america and northern south america .
8  it is a rare vagrant to western states , most notably california .
9 it is the only eastern warbler that nests in natural or artificial cavities , sometimes using old downy woodpecker holes .
10  the male often builds several incomplete , unused nests in his territory; the female builds the real nest .
11  it lays 37 eggs .
12 the preferred foraging habitat is dense , woody streams , where the prothonotary warbler forages actively in low foliage , mainly for insects and snails .
13 the song of this bird is a simple , loud , ringing sweet-sweet-sweet-sweet-sweet .
14  the call is a loud , dry chip , like that of a hooded warbler .
15  its flight call is a loud seeep .
16 these birds are declining in numbers due to loss of habitat .
17  they are also parasitized by the brown-headed cowbird (molothrus ater), or outcompeted for nest sites by the house wren (troglodytes aedon) .
18  it is listed as endangered in canada .
19  the species persists in protected environments such as south carolina's francis beidler forest currently home to more than 2,000 pairs , the densest known population .
20 this bird was named after prelates in the roman catholic church known as the protonotarii , who wore golden robes .
21  it was once known as the golden swamp warbler .
22 the prothonotary warbler became known in the 1940s as the bird that , in front of the house un-american activities committee , established a connection between whittaker chambers and alger hiss .
23  chambers had testified that hiss enjoyed bird-watching , and once bragged about seeing a prothonotary warbler .
24  hiss later testified to the same incident , causing many members to become convinced of the pair's acquaintance .
25 this bird is mentioned in a sand county almanac by aldo leopold as the " ewel of my disease-ridden woodlot", "as proof that dead trees are transmuted into living animals , and vice versa .
26  when you doubt the wisdom of this arrangement , take a look at the prothonotary .
27 " john james audubon's painting of a prothonotary warbler is the third plate in his birds of america .
