thorn-apple, and mountain ash trees in such a way as to form girdles of punctures, 

 sometimes 2 feet or more in breadth (up and down), about the trunks and 

 branches. * * * The holes, which are sometimes merely simple punctures, 

 and sometimes squarish spaces (multiple punctures) nearly half an inch across, 

 are placed so near together that not infrequently they cover more of the tree than 

 the remaining bark. Hence, more than half of the bark is sometimes removed 

 from the girdled portions, and the balance often dries up and comes off. There- 

 fore it is not surprising that trees which have been extensively girdled generally 

 die, and mountain ash are much more prone to do so than either apple or thorn- 

 apple trees, due, very likely, to their more slender stems. This is the only one 

 of the woodpeckers that does much of any harm to trees. 



The Yellow Warbler {Dendrolca aestlva aestiva) 

 By Herman C. DeGroat 



Length, little more than 5 inches. Mostly yellow, breast and belly streaked 

 with reddish brown. 



Range : North America, breeding generally throughout its range south to 

 California, New Mexico, Missouri and northern South Carolina; winters in 

 Central and South America. 



The "yellow bird," or wild canary, as it is sometimes called, is one of the 

 commonest of the warbler tribe, and ranges over a vast extent of territory, being 

 found here and there from ocean to ocean. Unlike some of its relatives, it 

 prefers open thickets, especially of willows, to thick woodland, and often builds 

 its pretty nest by the roadside or in garden shrubbery. Though not an expert 

 musician, the yellow warbler sings early and often, and in zeal makes up what 

 it lacks in quality of voice. Because its nest is easily found by the initiated, this 

 warbler is often victimized by the infamous cowbird and is forced to bring up 

 one. or even two, young cowbirds in place of its own rightful progeny. It is 

 pleasant to be able to record the fact that sometimes the clever warbler knows 

 enough, — how it knows it is another matter,- — to evade the unwelcome responsi- 

 bilities thus thrust upon it, and builds a platform over the alien €.gg and then 

 continues its domestic affairs as originally planned. Indeed cases are on record 

 when two cowbirds' eggs have been found in a nest, each covered up by a separate 

 layer of nest material. If this is not intelligence of a high order, how else can 

 we characterize it? The food of this warbler consists almost exclusively of 

 harmful insects, including the black olive scale. 



The yellow warbler reaches the northern states about May 1st, having made 

 a long journey by easy stages from Mexico and Central America, where it winters. 

 It leaves again for the South early in September. Many persons confuse it with 

 the goldfinch, which may be easily known by its black wings and crown. These 

 are entirely distinct species. 



214 



