0 the myrtle warbler (dendroica coronata coronata) is a small new world warbler .
1 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 .
2  the two forms most likely diverged when the eastern and western populations were separated in the last ice age .
3  in north america , the two forms are now again officially recognized as conspecific .
4 the myrtle warbler has a northerly and easterly distribution , with audubon's further west .
5  it breeds in much of canada and the northeastern usa .
6  it is migratory , wintering in the southeastern united states , eastern central america , and the caribbean .
7  it is a rare vagrant to western europe , and has wintered in great britain .
8 the summer male myrtle warbler has a slate blue back , and yellow crown , rump and flank patch .
9  it has white tail patches , and the breast is streaked black .
10  the female has a similar pattern , but the back is brown as are the breast streaks .
11 the myrtle can be distinguished from audubon's warbler by its whitish eyestripe , white (not yellow) throat , and contrasting cheek patch .
12   their trill-like songs , nearly indistinguishable , consist of a 34 syllable "tyew-tyew-tyew-tyew", sometimes followed by 3 more "tew"'s .
13  the call is a hard check .
14 its breeding habitat is a variety of coniferous and mixed woodland .
15  myrtle warblers nest in a tree , laying 45 eggs in a cup nest .
16  these birds are insectivorous , but will readily take wax-myrtle berries in winter , a habit which gives the species its name .
17  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 .
18  they form small flocks on migration or in winter .
