ECONOMIC RELATIONS OF OUR BIRDS. 
555 
125. Cyanocitta gristata (Linn.), Strickl. BLUE JAY. Group III. 
Class b. 
The Blue Jay is distributed throughout the state, but, like the Robin, is far 
more abundant in settled than in unsettled portions. It is a summer and winter 
resident, but less abundant in the latter than in the former season. Groves, 
fields, villages, and the vicinity of dwellings are more frequented than wood¬ 
lands; and although it is an arborial species, it is much upon the ground in quest 
of food. Occasionally it extracts insects from the crevices of the bark on the 
trunks of trees. When unmolested it becomes more and more familial’, and 
keeps closer to dwellings; and during the winter, particularly, they crowd into 
villages to feed upon the crumbs from the kitchens. It is so like the Common 
Crow in very many of its traits, that much which has been said of that bird ap- 
phes equally well to this. Its smaller size, however, renders it less dangerous to 
other birds as a class, and better fitted to do service in destroying insects. Did 
not the destruction of the eggs and young of other birds appear to be a general 
trait rather than an individual peculiarity of the Blue Jay, it would be necessary 
to throw but little restraint over it. As it is, it must be held within narrow lim¬ 
its. The Jay is not an especially valuable bird to agricultural interests when 
compared with other species. From the first of August until the first of April, 
two-thirds of the year, not more than one-tenth of its food consists of insects, 
and during the rest of the year, less than two-thirds of it consists of this ma¬ 
terial. During August, September and October, about one-tenth of its food con¬ 
sists of grain and other useful products, and it is not especially destructive to 
the seeds of weeds; while during May and June it is known to feed to a consid¬ 
erable extent upon the eggs and young of other birds. 
Dr. Brewer, however, in speaking of this species in “ Birds of North America,” 
says: “The Jay is charged with a propensity for destroying the eggs and young 
of the smaller birds, and has even been accused of killing fuU-gi’own birds. I 
am not able to verify these charges, but they seem too generally conceded to be 
disputed. These are the only serious grounds of complaint that can be brought 
against it, and are more than outweighed ten-fold by the immense service it 
renders to man in the destruction of his enemies. Its depredations on the gar¬ 
den or farm are too trivial to be mentioned.” He also says: “ Dr. Kirtland has 
also informed me of the almost invaluable services rendei'ed to farmers in his 
neighborhood, by Blue Jays, in the destruction of caterpillars. When he fii’st 
settled on his farm, he found every apple and wild cherry-tree in the vicinity 
disfigured and denuded of its leaves by the larvae of the Clisiocavipa Ameri¬ 
cana, or tent-caterpillar. The evil was so extensive that even the best farmers 
despaired of counteracting it. Not long after the Jays colonized upon his place 
he found they were feeding their young quite extensively with these larvae, and 
so thoroughly that two or three years afterwards not a worm was to be seen in 
the neighborhood; and more recently he has searched for it in vain, in order to 
rear cabinet specimens of the moth.” 
I insert this quotation because it illustrates so well the great danger of over¬ 
estimating the real service which any particular bird may render at a given 
time. In the first place, it is by no means certain, from what Dr. Kirtland says, 
that the disappearance of the tent-caterpillar from his neighborhood, at the 
time he mentions, was in any marked degree due to its destruction by the Blue 
Jay. It is a well known fact that the tent-caterpillar, and very many other 
noxious insects, may be very abundant in a given locality for a few years and 
then suddenly disappear almost entirely, when birds could have had no very 
