FOOD HABITS OF SOME WINTER BIRD VISITANTS. 3 



EVENING GROSBEAK (Hesperiphona vespertine). 



. (Plate I.) 



The large beak and the contrasting plumage of yellow, black, and 

 white make the evening grosbeak an easily recognized species. 

 Breeding in the western United States and Canada, during the 

 winter it is occasionally seized with a wandering impulse which 

 carries it east to New York, Pennsylvania, and adjacent States. 

 Usually, however, it chooses to spend this season in the West, 

 wandering over the country in flocks of varying numbers. 



For the study of the food habits of this grosbeak, 127 stomachs 

 collected in 14 States and Canada were available. Of these 88 were 

 taken in the winter months (October to March, inclusive), or at 

 the time when the birds commonly appear about human habitations. 

 The remaining 39 were taken in summer. 



Winter food. — Ornithologists who have been fortunate enough to 

 observe this interesting bird report that the chief elements in the 

 diet are various kinds of wild fruit, seeds of ash, maple, box elder, 

 and conifers, and buds. Except for this last item these observa- 

 tions are verified by stomach examination. No buds were found 

 in the stomachs, and this seems to indicate that the bud-eating habit 

 is not so general as has been supposed. It is worthy of note that 

 about 50 stomachs taken in Ontario in the winter of 1889-90, and 

 examined by various members of the Canadian Institute, contained 

 no buds. 2 it was found that seeds of several different trees and 

 shrubs constituted the food supply of the birds while they re- 

 mained in that locality. 



No trace of animal matter was found in the 88 winter stomachs, 

 seeds and fruit constituting the entire contents. Seeds of wild 

 fruits formed 39.63 per cent: winged seeds (maple, ash, and box 

 elder), 37.96 per cent; coniferous seeds, 14.5 per cent; and miscel- 

 laneous seeds, mast, and rubbish, the remainder. The most im- 

 portant seeds of wild fruits in the food for this period were cherry 

 pits {Primus), found in 23 stomachs and amounting to 17.48 per 

 cent of the total food; dogwood (Cornus), identified in 63 stomachs, 

 13.77 per cent; mountain-ash (Sorbus), taken from 13 stomachs, 

 3.82 per cent; and snowberry {Symphoricarpos) in 11 stomachs, 

 forming 1.77 per cent of the food of the 88 birds. Of the winged 

 seeds, ash seeds (Frcwinus) were found in 4: maple {Acer) in 

 30; and box elder {Acer negundo) in 13 stomachs. Juniper berries 

 had been eaten by 14 birds, and seeds of other conifers by 13. 



The nature of the contents of certain stomachs of this species 

 gives a vivid idea of the shearing or crushing power of the beak. 

 The seeds of cherries were broken easily and a whole one was rarely 

 found. The flattened seeds of snowberry were split longitudinally 

 in nearly everv case. 



Summer food.— The food for the summer season, as determined 

 by an examination of 39 stomachs, is 20.82 per cent animal and 79.18 

 per cent vegetable matter. 



The vegetable food was of much the same character as that taken 

 during the winter season. Seeds of wild fruits are 37.87 per cent 

 of the food for the summer compared with 39.63 per cent during 



Trans. Canadian Inst., vol. o, p. 124, 1S91-92. 



