174 
YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 
towns its colonies are so large that the resulting damage it inflicts 
upon fruit trees in spring is very great. It is fond also of all the 
small fruits, and in some regions the damage to fruit as the result 
of its attacks is considerable. 
There is yet another field for the exercise of this pest’s pernicious 
activity. Its aggressive and meddlesome disposition and its habit 
of acting in concert enables it to overpower and drive away many of 
our native birds, which before its advent were as numerous about 
dwellings as they were welcome. 
The house wren, the bluebird, the phoebe, and certain swallows are 
the chief sufferers from the aggressive warfare waged by the sparrow. 
Even that excellent fighter, the purple martin, is unable to long resist 
the persistent attacks of a united colony of sparrows, since, when 
unable to overcome the martin in open warfare, the sparrows enter 
the nests during the absence of the owners, kill the helpless young, 
and pitch out the eggs. The result is that not only are the above- 
named species and other small birds driven away from the localities 
they used to inhabit, but their numbers have steadily diminished and 
must continue to do so because of their inability to find other suitable 
breeding places. Thus the sparrow has usurped the places about our 
homes by right belonging to our own birds, and its increase has 
been at the expense of native American species, with the result that 
a number of highly important useful species have been replaced over 
large areas by a single destructive one. Not only should all aid and 
comfort be withheld from this foreign invader, but a concerted effort 
should be made to reduce its numbers and to exterminate it wherever 
and whenever possible. 
Cranes and herons.— Some of our birds are neither insect eaters 
nor vegetable eaters. Some of the hawks and owls, as is well known, 
live chiefly upon flesh, while the cranes, herons, storks, and king¬ 
fishers live largely upon fish, crustaceans, and frogs. By eating 
small fish which are the fry of valuable kinds or serve as their food, 
these birds do more or less harm, as the fish breeder, whose ponds are 
invaded, knows well enough. So also their habit of eating frogs is 
injurious. 
But while thus injurious to some extent in certain localities where 
their pernicious activity may necessitate reprisals, cranes and herons 
do good service in the destruction of small rodents, especially meadow 
mice and pocket gophers. As in other cases the relation of these 
birds to the community varies according to circumstances, and they 
are to be dealt with accordingly, bearing in mind, so far as possible, 
the good to the community as a whole and not solely individual 
interests. 
