420 Roosevelt Wild Life Bulletin 



fringe the shores of the lakes, streams and swamps at the lower 

 levels. In the older woodlands the birch grows to a commanding 

 height. Its fruit is a small, scaly, conelike catkin, which ripens 

 in midsummer and clings to its place until late autumn. The yellow 

 birch (Betula lutea) predominates in the forest farther back from 

 waterlines, preferring dryer situations than its relative. 



The small conelike catkin of the birch contains many flat seeds 

 arranged along a stubby axis, which begin to ripen about the middle of 

 July. Thereafter the birches receive visits from the Crossbills, which 

 appear to know when the seeds are ready and frequent the trees 

 irregularly as long as the supply of seeds lasts. During the last 

 week of July the birch banquet is at its best, and at that time the 

 crop on some trees in favored localities is thoroughly harvested. 

 As a rule the calls of these birds can be heard when the}" are seeking 

 the seed-bearing trees, but they are quite silent when feeding, or 

 merely give utterance to a faint quit. In the season of 1916 four 

 tall white birches were producing seeds on the campus at Barber 

 Point. They bore plentifully, and I estimated that their crop 

 sufficed for about three Crossbills a month, but other birds also 

 visited them during that time and foraged there. Doubtless in many 

 places the seed-bearing white birches were not visited so persistently 

 and their seeds were permitted to remain until later in the season, 

 forming a reserve supply. In the latter part of July Goldfinches, 

 usually in pairs, also visit the birch trees for a part of their daily 

 fare. On the ground under such a seed-bearing tree, can be seen 

 in late summer the sprinkled small green scales of the catkins torn 

 apart by the birds. Another visitor, later in the summer, is the Purple 

 Finch. The birches also provide food for autumnal migrants and 

 winter visitors. In describing the Red-poll in winter Dr. ITearns 

 remarks ('80, p. 11) that "the swamps of birch trees that they 

 inhabited, and on whose seeds they fed, were absolutely swarming 

 with them. So great were their numbers that the supply of birch 

 seeds soon gave out, and then they scattered over the entire region, 

 feeding largely upon the seeds of the alder, and of various weeds." 

 The same ornithologist also asserts that in winter the Goldfinch 

 and the Tree Sparrow feed largely on birch seeds. 



A very interesting relationship exists between the Yellow-bellied 

 Sapsucker and the birches. The Sapsucker is a true woodpecker ; 

 but unlike its fellows it has developed a taste for sap and also the 

 live inner bark, more especially that of the birch but also of most 

 other forest trees. The Sapsucker drills a horizontal row of holes 

 around a tree trunk, and later another row so arranged that one hole 

 stands directly above another in the two series. From time to time 

 additional openings are made in like manner, with the effect of 

 vertical rows as well as horizontal, between which the sapwood 

 becomes so injured that the tree is virtually girdled, or at least 

 wounded in a way to induce premature decay. These holes, only 

 deep enough to penetrate to the sapwood, become cavities in which 

 sap accumulates in small drops, and the Sapsucker regularly visits 



