448 
ECONOMIC RELATIONS OF OUR BIRDS. 
It will probably be far within the limits of *tnith, if it is assumed that the 
avex'age number of birds observed per mile represents only one-half the actual 
number which existed on each square mile at the time it was crossed. At this 
rate the bird population of Jefferson would be 66 per square mile, while that of 
the vicinity of Ithaca would be 114 per square mile. This would give for Jeffer¬ 
son county a total bird population of 80,096, and for an equal area in the vicinity 
of Ithaca, 51,984. At the rate of 66 per square mile, an area somewhat less than 
that of our state would have a population of 8,565,000. 
From the stomach of a Passenger Pigeon were taken nine full-grown black 
crickets, and four grasshoppers over an inch long, together with two large cater¬ 
pillars and one harvestman. From the stomach of a young Partridge, less than 
a week old, were taken thirteen caterpillars, seven harvestmen and one grub; 
from that of a Night-hawk wei'e taken five small grasshoppers, eight large 
square-shouldered hemiptera, and ten scorpion bugs, none of which were less 
than three-fourths of an inch long. Nine grammes of insect debris were taken 
from the stomach of another Night-hawk. Three Golden-winged Woodpeckers 
had in their stomachs, respectively, 255, 220, and 200 ants. In the stomach of a 
Hairy Woodpecker were found the remains of eleven gi’ubs of long-horned beetles 
and thirteen measuring worms. A Pewee, Sayornis fuscus, had in its stomach ten 
ichneumon flies, averaging over half an inch long, five small moths and one caddis 
fly. The actual amount of food which the above species eat during the day, if 
we except the Night-hawk, is probably more than three times that which was 
found in their stomachs. Fifty insects of the average size would certainly'bo a 
small daily allowance for the average bird. One hundred and twenty days is 
less than the time our summer residents are with us. At the rate assumed, each 
bird would consume 6,000 insects. This would give as the aggregate number of 
insects consumed by the birds calculated to occupy an area equal to that of our 
state, the enormous total of 21,384,000,000. Add to this amount the work which 
these birds do in their soutliern homes, and we have a low estimate of the influ¬ 
ence they exert over insect life. 
It should be borne in mind that less than half of our summer residents are 
included in the table, and tliat nothing whatever has been said in regard to the 
birds of passage which sweep the state twice every year. 5 h) insects which 
these birds eat will more than compensate for whatever other food those birds 
which have entered into our computation may consume. 
(6) A bird does us service when it feeds upon noxious mollusks. In damp 
climates, such as exist in many parts of Europe, mollusks often become very 
abundant and very destructive to garden and field products. In the United 
States, however, but little injury from them appears to have been thus far 
realized; and in a climate like ours, but little apparently need be anticipated. 
The fact, however, that slugs have occasionally made destructive raids upon 
strawberry patches, should put us sufficiently on our guard to look into their 
possibilities for evil before we attempt to drive off or destroy their natural 
enemies. It may be remarked here, in passing, that a species of Limax, common 
in the grass at Ithaca, N. Y., has several times been seen feeding upon ripe 
cherries that had fallen from the trees. Whether, as many slugs are known 
to do, this species will in damp days ascend the trees to feed, is a question 
worthy of study. 
Mollusks, and other animals as well, may be, at times, extremely injurious 
even when, so far as their food is concerned, they are practically harmless. That 
terrible disease known as “fluke-rot” or “ water-rot,” which has destroyed in a 
