4 
RELATIVE FERTILITY OF BIRDS AMD INSECTS. 
The majority of our native birds have but one 
brood of young in the course of the year: a few have 
two or three. In the case of the smaller insect-eat¬ 
ing birds, the number of eggs to a brood is, on an 
average, not more than five. Some of the larger 
birds, as the various Gallinm, lay from five or six to 
twenty eggs to a brood. On the other hand, the 
reproductive energy of insects is truly marvellous. 
It is said that a single pair of grain-weevils have pro¬ 
duced six thousand young b'-tween April and August. 
The common varieties of aphides or plant-lice, which 
are found on almost all kinds of plants, are produced 
in spring from eggs laid the season before; and 
through the summer only females are developed. At 
the last of the season, males and females both appear; 
and eggs are laid for the brood which hatches early 
in the spring. Reaumer says that one individual in 
Black-billed Cuckoo. C . ery . hrophthalmus . (Scansores.) 
one season may become the progenitor of six thou¬ 
sand millions. The silk-worm moth produces about 
five hundred eggs; the great goat-moth about one 
thousand ; the tiger-moth one thousand six hundred; 
the female wasp at least thirty thousand. There is 
a species of white ants, one of which deposits not 
less than sixty eggs a minute, giving three thousand 
six hundred in an hour. How, then, shall this enor¬ 
mous mass of insects be kept in check ? What shall 
prevent them from overrunning the country, destroy¬ 
ing the crops, and devastating the land ? 
FOOD OF BIRDS. 
Various causes operate to check the undue in¬ 
crease of insects; and the chief of these is the appe¬ 
tite and instinct which a wise Providence has given 
to birds. If the number of eggs produced by insects 
is wonderful, the number destroyed by a single bird 
is no less so. Audubon says a woodcock will eat its 
own weight of insects in a single night. Dr. Brad- 
lev says that a pair of sparrows will destroy three 
thousand three hundred and sixty caterpillers in a 
week. We saw the parent bird visit a young purple 
martin on a church-spire opposite our window five 
times in as many minutes, each time with an insect. 
A brood of partridges will nearly exterminate the 
denizens of an ant-1 1 111 in a couple of days. . A\ ood- 
peckers are constantly employed in lidding the 
orchards of insects and their eggs, which they skil¬ 
fully discover under the pieces of dead bark.. 
ins, through the spring and summer, are continually 
hunting for worms and grubs which they find con¬ 
cealed under the surface of the ground. We re¬ 
cently noticed a common cliipping-sparrow capture a 
moth; and,upon depriving her of it, we found it to be 
that of the common apple-tree caterpillar (Clisio- 
campa Americana ), so destructive to the orchards of 
New England. To check the excessive increase of 
O 
Upper fig. Wood-Pewee. Contopus virens. Lower fig. 
King-bird. T. ccirolinensis. (Insessores.) 
insects is evidently the great task which birds are 
intended to perform. Did they have no other office 
save to cheer and encourage humanity with their 
beautiful plumage and song, and to typify a purer 
and more ethereal existence to us creatures who 
“ grovel here below,” even then they would deserve 
the favor of every Christian and every poet; but 
when the useful is.combined with the beautiful,’ and 
a practical value is added to an elevating symbol 
they command the interest of every one, and their 
protection becomes a matter of consequence to all. 
