ECONOMIC RELATIONS OF OUR BIRDS. 
457 
(12) Size and activity of the bird. The larger and the more active a bird is 
the greater will be the amount of food which it requires, and, consequently, 
other things being equal, the more beneficial, or the more injurious, it will be. 
It is by no means, however, the largest bird which is the most serviceable. Dimin¬ 
utive proi^ortions are, in many cases, quite as desirable as their opposites. It is the 
smallness of the Tennessee Warbler which makes it prolitable for it to feed upon 
plant lice; and it is the same quality, together with its agility, that enables the 
Chickadee to hang back downwards from the leaves of the outermost sprays of 
trees, that it may feed upon those small larvae and other insects which can only 
be obtained by the larger and more clumsy species with difficulty. These small 
and agile birds perform, therefore, a distiii'^t work in protecting the terminal 
foliage of forest trees. 
(13) Whether the bird is or is not gregarious in its habits. It is not necessary 
that birds should be “united in troops more or less considerable ” that they may 
be of material service. On the contrary, insectivorous birds can hardly be gre¬ 
garious, at least to any considerable extent, for feeding purposes, while it is the 
gregarious habits of many graminivorous birds which lends to them their chief 
noxious quality. Not that they would eat any less grain if they did not unite 
in such large troops, but that their injury would be more evenly distributed, 
causing each man to bear his share of the expenses incident to bird life, as he 
has received his share of the profits. Did our Blackbirds spread out over the 
country at large instead of uniting in such large troops, the amount of grain 
which they would consume, though just as great as it is at present, would be 
drawn from so many sources that the quantity taken from each would be so 
small as to be almost inappreciable. Birds having gregarious habits, unless they 
perform some special and important work, should not be encouraged to an equal 
extent with other birds; and this point should be looked to especially, when it is 
proposed to introduce a foreign species. 
(14) The siciftness and dexterity of the bird ujjon the icing. The swifter and 
the more dextrous an i isectivorous bird is, which captures prey upon the wing, 
the more efficient it is, provided other things ai’e equal. If it feeds extensively 
upon parasitic insects, it becomes more dangerous, as it is better able to capture 
its prey. Among rapacious birds the swiftest winged Hawks are to be looked 
upon as the most dangerous; and, if any of these birds are to be extirpated, 
those which are best able to capture mature birds should succumb first. Extreme 
swiftness of flight is not necessarily possessed by those Hawks which are to hold 
in check injurious mammals. 
(15) The disposition of the bird. When different species of birds are to be 
associated closely together, as is the case in many cities, and as we hope will be 
more extensively the case in orchards, and in the vicinity of dwellings, only 
those, as a rule, which will live together in harmony should be encouraged. At 
least, a tyrannical, overbearing bird should not be permitted to drive away from 
our dwellings more useful species. 
(16) The value of the bird as food for man. Birds whose size an 1 flesh make 
them valuable as food for man have that much in their favor to offset whatever 
injury they may do. But birds may be too valuable as insect-destnu^ers to 
justify their being killed as game. The Prairie Chicken and Quail should be 
stricken from our list of game birds, at least for the present, and the Meadow¬ 
lark, Killdeer, and Field Plover should not bo destroyed under any consideration, 
until after they assume an abundance far beyond what they have with us at 
present. The last three species are almost exclusively insectivorous throughout 
their stay with us, and they affect meadows, pastures, and cornfields where 
