ECONOMIC RELATIONS OF OUR BIRDS. 
445 
to perform. Few birds, and certainly no snake, can be more serviceable, as in¬ 
sect destroyers, than these animals. The facility with which some snakes climb 
trees, and the stealthiness with which all may approach tlieir prey upon the 
ground, give them great advantage over birds during the breeding season. That 
the common striped snake will devour even large mature birds, when it can ob¬ 
tain them, is proved by an instance wliich came under my observation last sum¬ 
mer. On returning to camp, after a morning’s excursion, a large striped snake 
was seen in the act of swallowing a Downy Woodpecker, which, with several 
other birds, had been thrown upon the ground after its stomach had been re¬ 
moved for examination. Only the tail feathers were protruding from the snake’s 
mouth and all of the feathers were intact. The same snake liad already swal¬ 
lowed a full-grown Catbird, with its entire plumage, and having only its stomach 
removed. The fact that a snake is sufficiently strong to seize and hold large 
toads and frogs indicates that they are abundantly able to hold any of our 
common birds, provided they come within their grasp. 
Although ten or more species of our birds prey to some extent upon snakes, 
these birds are either destructive to other bii-ds, or to frogs and toads, or to both; 
it does not follow, thei*efore, that their services sliould be retained simply be¬ 
cause they are destructive to snakes. Snakes, owing to their slow movements, 
are much more easily controlled by direct means than most other animals. 
(5) A bird renders a service when it feeds upon insects tvhich are injurious or 
destructive to usef ul animals, plants or materials, and which are not extensively 
destructive to noxious forms of life. It is in the destruction of the members of 
this group that birds are chiefly serviceable, not only because insects are among 
the most prolific and the most destructive forms of life with which we have to 
contend, but because their small size and their habits make it very difficult to 
oppose them by any direct means. While, as entomologists have claimed, the 
most potent checks against these animals are among the members of their own 
class, yet, that these are not adequate to our needs, is conclusively proved by 
the results which have invariably followed from the wholesale slaughter to 
which birds have been subjected from time to time in diffei’ent counti’ies. 
Wherever the English Sparrow, the bird so much decried in our country of late, 
has been exterminated in Europe, noxious insacts are said to have followed in 
such abundance that it has not only been gladly reinstated, but is now protected 
because it accomplishes what parasitic and predaceous insects are unable to do. 
When it is argued that birds feed indiscriminately upon beneficial and noxious 
insects, it should be observed that predaceous insects do the same, and that 
parasites have their parasitic foes. 
Birds are insignificant in numbers when compared with the abundance of 
parasitic and predaceous insects, but their larger size, their active habits, their 
longer lives, the greater facility with which they move about, and the greater 
range of country over which they roam, go far toward compensating for smaller 
numbers. It should be added, also, that birds, either in one place or in another, 
are consuming insects throughout the year, while, in the temperate zones, pre¬ 
daceous and parasitic insects do nothing during one-half of that time. No insect 
is so large but that any bird may destroy it while it is passing through one or 
more of its stages, and few are so small as not to attract the attention of many 
of our birds. The Wliite-Bellied Swallow captures on the wing plant-lice and 
flies, smaller than the wheat midge. The Purple Fincli, and some of the War¬ 
blers, feed extensively upon plant-lice. Chalcidian and otlier parasitic flies, less 
than a tenth of an inch long, have been taken from the stomach of several of 
