I 
ECONOMIC RELATIONS OF OUR BIRDS 459 
and tliere are few fields but what have at least a few trees standing in them. In 
the portion of Jefferson county where the notes were taken, the country is 
nearly level, with gentle undulations, and is traversed by Rock and Bark rivers. 
These streams draw a sharp line between prairie and openings on one side, and 
heavy maple timber on the other. Marshes trend along the streams, and shallow, 
reedy ponds are common. Compared with the vicinity of Ithaca, the farms are 
larger, the houses less numerous, the orchards smaller, the woods larger, and few 
trees stand in the cultivated fields. 
Route I led from a point about one-half a mile north from Bark river out and 
across cultivated fields, through two small groves, across a marsh near Cold¬ 
spring Pond, and then again across cultivated fields. Routes II and III each led 
east from Rock river, north of Jefferson, alternately through pieces of heavy 
timber, and across dry cultivated fields. Route IV led from the Crawfish west, 
ui^on the prairie southwest of Aztalan, traversing dry treeless fields, and lead¬ 
ing through two small oak groves. Route V extended from the buildings of 
Cornell University west across the valley, leading through a pasture, through the 
north end of the city, through the swamp, and u^d the railroad, bordered by cul¬ 
tivated fields on one side and by tangled thickets on the other. Route VI led 
directly east from the campus to Varna, and then southwest along the line of 
the railroad. On this trip only cultivated fields were crossed and one small 
piece of woods passed through. Route VII led up the valley from Ithaca along 
the east side, and then across to Enfield Falls. On this tramp we passed in turn 
along the railroad, bordered with small scattered thickets on both sides, across 
the Inlet, through low fields, and then past cultivated fields and small pieces of 
woods. Route VIII lay ten miles east of Ithaca, and led from McLean off to 
the southeast of Dryden, and then through Dryden to Freeville. A branch of 
Fall Creek was crossed twice, and with the exception of a small marsh near 
Freeville, only dry cultivated fields and small pieces of woods were passed. 
It should be observed that the notes taken in Jefferson county were obtained 
after the breeding season, while those taken at Ithaca were made din ing the 
breeding season before the young birds had, to any extent, left the nests. The 
difference in the times of observation in the two localities will doubtless com¬ 
pensate largely for the difference 'in topographical featiu*es. For instance, the 
Bobolinks observed on trip VIII were, with two exceptions, all males, so that 
the figures probably show but about one-half the actual number of birds of this 
species which were thei*e at the time. 
The table, as it stands, indicates that notwithstanding the fact that the vicinity 
of Ithaca has been much longer under cultivation, and that it is more thickly 
settled, its bird population is more than a third larger, so far as the number of 
individuals is concerned, than that of Jefferson county. Whether this gi-eater 
abundance is due more to the influence of man than to natural topographical 
features, the table does not appear to prove, for it is deceptive in regard to this 
point in several respects. 
(.3) What birds, if left to themselves, are likely to become most abundant as 
the country grows older. Before we can safely interfere with the restraints 
which nature has imposed upon bird-life, we must know the facts in regard to 
this point, because it can hardl}^ be supposed that the different si)ecies will con¬ 
tinue to hold the same relative proportions to one another that they now do if 
their enemies should be removed. If the birds in the table to which we have * 
had occasion to refer are classified under the four heads. Fruit-eaters, Fly¬ 
catchers, Seed-eaters and Insect-eaters, the average number of individuals ob¬ 
served per mile during the eight trips, considered collectively, will be found to 
be approximately as follows: 
