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 badly 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, but 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 alsu 
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 foot of smull 
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 berries 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. Doubtless 
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 berries of sumac and 
poison ivy, and, disgorging the seeds afterward, of course spreads 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 remainder of a single species of beetle, 
Telephorus bilineatus. 
