LAND BIRDS. 589 



24 to September 10, and was last seen October 12." As a rule he con- 

 siders it "the most common woodland migrant in autumn." In Wisconsin, 

 according to Kumlien and Hollister "It is usually an extraordinarily- 

 abundant migrant, especially in the fall, at some seasons far outnumbering 

 any other species. * * * No authentic record of it as a summer 

 resident, although it is at times common, even in the southern counties, 

 by August 15th." 



From three independent sets of observations it seems fairly certain 

 that this species occasionally nests in the higher or more northern parts 

 of the state. Mr. Walter M. Wolfe found young just able to fly, near 

 Beulah, Benzie county, August 4, 1906. He writes: "I secured one 

 adult, then a young bird too Ijadly mutilated for identification, and finally 

 another young bird that clearly settled the case." Mr. Gerard A. Abbott, 

 of Chicago, writes us under date of October 2, 1906: "The Tennessee 

 Warbler was seen in Oscoda county, Mich., late in June 1906, l)ut no nests 

 were discovered, though they were certainly breeding." Mr. Norman 

 A. Wood, of Ann Arbor, writes: "None of our party saw this warbler 

 [the Tennessee] at the Porcupine Mountains (Ontonagon Co.) during 

 the month we were there, July 13 to August 15, 1904. Our earliest 

 record at Isle Royale was on August 2, 1905, at Siskowit Bay. We did 

 not see any at the northeast end of the island in July, but it was not a 

 favorable place for them to breed, so I am sure a few bred on the island, 

 as the migrants did not seem to come until about August 15, and the 

 greatest number on August 30." 



The bulk of the species is believed to nest far north, even within the 

 Arctic Circle. Several nests were taken in June 1901 in Cariboo, British 

 Columbia, by Mr. Allan Brooks, and are described by J. Parker Norris in 

 the Auk, Vol. XIX, pp. 88-89. The eggs are there described as somewhat 

 different from the other members of the genus in being spotted with a few 

 larger red brown spots in addition to the usual fine markings, and also 

 with a number of spots of light lilac. The eggs averaged about .60 by 

 .46 inches. The nests were placed on the ground at the ft)ot of small 

 bushes and arched over by dry grass. 



The food of this species is of peculiar interest because it is one of the 

 few warblers which have proved to be destructive to fruits in a peculiar 

 way. The Tennessee Warbler is known to puncture ripe or ripening 

 grapes and to suck the juice, thereby causing the decay of the ])erries so 

 punctured and attracting yellow-jackets, bees and other nectar-loving 

 insects so that whole clusters are sometimes ruined. This work was long 

 attributed to orioles, catbirds and various other species, but has now been 

 definitely fixed on the present species and cannot be denied. Doul)tless 

 in some cases the damage so done is considerable, but usually the birds 

 are so scarce that the amount of fruit damaged is absolutely insignificant. 

 Like numerous other warblers this species eats the ])erries of sumac and 

 poison ivy, and, disgorging the seeds afterwai'd, of course spi'eads these 

 poisonous plants. Except for these two habits the bird is undoubtedly 

 beneficial, since its food consists mainly of insects, among which are immense 

 numbers of leaf-destroying forms, and in particular, plant-lice and the minute 

 leaf-rollers and other forms which few but the warblers capture. Prof. 

 Forbes examined a single stomach of this species taken in 1882 in an 

 orchard overrun with canker worms and found that four-fifths of its food 

 consisted of canker worms and the i-emaindei- of a single siiocies of beetle, 

 Telephorus hilinealus. 



