the cape may warbler (setophaga tigrina) is a species of new world warbler .
it breeds in northern north america .
its breeding range spans all but the westernmost parts of southern canada , the great lakes region , and new england .
it is migratory , wintering in the west indies .
this species is a very rare vagrant to western europe , with two records in britain as of october 2013. the english name refers to cape may , new jersey , where george ord collected the specimen later described by alexander wilson .
this species was not recorded again in cape may for another 100 years , although it is now known as an uncommon migrant there .
this bird is a small passerine and mid-sized new world warbler .
length can vary from 12 to 14 cm (4.7 to 5.5 in), wingspan is 1922 cm (7.58.7 in), and body mass can range from 9 to 17.3 g (0.32 to 0.61 oz) .
among standard measurements , the wing chord is 6.1 to 7.3 cm (2.4 to 2.9 in), the tail is 4.3 to 5 cm (1.7 to 2.0 in), the bill is 0.9 to 1.2 cm (0.35 to 0.47 in) and the tarsus is 1.7 to 1.9 cm (0.67 to 0.75 in) .
the summer male cape may warbler has a brown back , yellowish rump and dark brown crown .
the underparts are yellow , streaked black , giving rise to the bird's scientific name .
the throat and nape are bright yellow and the face is striking chestnut with a black eyestripe .
there is a narrow white wing bar .
other plumages resemble washed-out versions of the alternate-plumaged male's , lacking the strong head pattern .
the yellowish rump and at least indications of the white wing bar are always present .
this species is insectivorous and lays larger clutches in years when spruce budworm is abundant .
it picks insects from the tips of conifer branches or flies out to catch insects .
the cape may warbler also feeds on berry juice and nectar in winter , and has , uniquely for a warbler , a tubular tongue to facilitate this behavior .
the breeding habitat of this bird is the edges of coniferous woodland .
cape may warblers nest in dense foliage near the trunk of the tree , commonly a black spruce , and lay 49 eggs in a cup nest .
this species can lay the largest clutch of any new world warbler , probably in response to increases in the numbers of spruce budworm during outbreaks .
the song of the cape may warbler is a simple repetition of high tsi notes .
the call is a thin sip .
this bird usually sings from high perches .
