the myrtle warbler (dendroica coronata coronata) is a small new world warbler .
this passerine bird was long known to be closely related to its western counterpart , audubon's warbler , and at various times the two forms have been classed as separate species or grouped as yellow-rumped warblers , dendroica coronata .
the two forms most likely diverged when the eastern and western populations were separated in the last ice age .
in north america , the two forms are now again officially recognized as conspecific .
the myrtle warbler has a northerly and easterly distribution , with audubon's further west .
it breeds in much of canada and the northeastern usa .
it is migratory , wintering in the southeastern united states , eastern central america , and the caribbean .
it is a rare vagrant to western europe , and has wintered in great britain .
the summer male myrtle warbler has a slate blue back , and yellow crown , rump and flank patch .
it has white tail patches , and the breast is streaked black .
the female has a similar pattern , but the back is brown as are the breast streaks .
the myrtle can be distinguished from audubon's warbler by its whitish eyestripe , white (not yellow) throat , and contrasting cheek patch .
their trill-like songs , nearly indistinguishable , consist of a 34 syllable "tyew-tyew-tyew-tyew", sometimes followed by 3 more "tew"'s .
the call is a hard check .
its breeding habitat is a variety of coniferous and mixed woodland .
myrtle warblers nest in a tree , laying 45 eggs in a cup nest .
these birds are insectivorous , but will readily take wax-myrtle berries in winter , a habit which gives the species its name .
experienced birders recognize myrtle warblers with the naked eye by their flycatcher-like habit of making short flights from their perch in search of bugs .
they form small flocks on migration or in winter .
