Relation of Summer Birds to Western Adirondack Forest 431 



tions are made apparently by juvenile birds in late summer, and 

 in many cases the aspens immediately' begin to show signs of sick- 

 ness and die in the fall. 



The Fire Cherry and the Birds. The most characteristic ele- 

 ment of the cleared and burned tracts, especially where dry, is the 

 fire cherry or bird cherry (Primus pennsylvanica). It is chiefly 

 associated with the aspens, birches, maples and willows, all in the 

 sapling stages. The fire cherry grows in clumps, and at its best 

 in the western Adirondack region may become ten to fifteen feet ?n 

 height. It forms no part of the original dense woods, but follows 

 the clearing of the forest, particularly in openings that have been 

 swept by fire. It produces a small red fruit, the fleshy part of 

 which is thin and sour, in clusters that begin to ripen by the end 

 of the third week of July ; and for the following month or so these 

 natural cherry orchards are favorite resorts for birds. After the 

 middle of August, heavy rains are likely to beat off the fruit. It 

 appears that the fire cherry is the most important source of sum- 

 mer bird food in the Adirondacks, as it is also a good foraging 

 ground for the insect hunters. 



The Mountain Ash and the Birds. This tree (Pyrus americana) 

 does not usually attain more than the tall sapling stage. It grows 

 best along the rocky shores of lakes, ponds and streams, or on the 

 edges of bogs and swamps. It produces small berry-like fruit, in 

 showy clusters ripening in the fall and remaining in place as a late 

 autumn supply for various species of resident and migrating birds 

 after the summer fruits have served their turn. Some birds leave 

 their summer habitat as soon as their young are fairly well able to 

 care for themselves, while others linger as long as there is suitable 

 food and the weather not too severe. With the latter group the moun- 

 tain ash berries are an important food, and also with such migrating 

 birds as travel southward in a leisurely way, enjoying the bounties 

 of nature as they go. These berries are the principal fare of Robins 

 in the fall, but the supply is soon. exhausted, as the birds are loath to 

 leave a locality where there is an abundance of the fruit. The 

 Catbird until late in the fall also skulks among the coverts where 

 mountain ash berries abound. Eaton ('14, p. 10) tells us that a 

 crop of mountain ash berries attracts flocks of Cedar Waxwings 

 and Pine Grosbeaks ; and that the Purple Finch shows a preference 

 for these fruits in winter. This tree is one of many species tapped 

 by the Yellow-bellied Sapsucker for its sap. 



From this brief sketch it appears that each species of forest tree 

 exerts its own particular influence upon bird life ; and to some de- 

 gree each component of a vegetation association is effective in 

 attracting one or another of the group of birds recognized to be 

 closelv related to it. One element alone, as a pure stand of beech 

 or a grove of maples, exerts but slight influence on bird life; but 

 such an element combined with others may become an influence of 

 vital importance. 



