16 



BULLETIN 1249, U. S. DEPARTMENT OF AGRICULTURE. 



Betulaceae — Continued. 



Alnus sp. (alder) 103 



Polygonaceae. 



Erioyonum sp 40 



Polygonum punctatum (smart- 

 weed) 1 



Polyyonmn sp. (smartweed) — 55 

 Chenopodiaceae. 



Clienopodium album (lambs- 

 quarters) 30 



Clienopodium sp. ( goosefoot ) _ 132 

 Amaranthaceae. 



Amaranthus sp. (pigweed) 65 



Portulacaceae. 



Portulaca oleracea (purslane)- 7 

 Brassicaceae. 



Campe sp. (wintercress) 4 



Rosaceae. 



Rubus sp. (blackberry) 1 



Vacciniaceae. 



Gaylussacia sp. (huckleberry) _ 1 

 Verbenaceae. 



Verbena sp 1 



Menthaceae. 



Nepeta cat aria (catnip) 29 



Caprifoliaceae. 



Viburnum sp. (blackhaw) 7 



Ambrosiaceae. 



Ambrosia elatior (ragweed). 18 



Ambrosia sp. (ragweed) 189 



Asteraceae. 



Bidens sp. (Spanish needles) _ 1 



PINE SISKIN (Spinas pinus). 



(Plate III). 



The pine siskin is another species best known to the people of 

 the United States as an irregular winter visitor. Its dull streaked 

 plumage and goldfinch-like night are more or less familiar to ob- 

 servers throughout the country, though it is more common in the 

 Northern States. It breeds chiefly in the great belt of coniferous 

 timber of the Canadian Zone, which lies almost wholly beyond the 

 borders of the United States, except in the mountains. In this 

 country it breeds in northern Minnesota and Michigan, and in the 

 mountains as far south as North Carolina in the East and to the 

 Mexican border in the West. 



For a study of the food of the pine siskin 291 stomachs from 20 

 States, the District of Columbia, and Canada were available. Of 

 these, 266 were collected during the months from October to May, 

 inclusive, this being the season during which the species is most 

 common in this country; only 25 were taken during the remainder 

 of the year. 



Winter food. — Examination of stomachs taken during the win- 

 ter months shows that seeds of conifers, alder, birch, and of weeds 

 of various kinds are the principal food of the pine siskin at this 

 season. Seventy stomachs contained coniferous seeds to the extent 

 of 23.28 per cent of the season's food. Siskins, in common with 

 many other seed-eating birds, usually make an entire meal on a 

 single food, and consequently seeds of conifers constituted 100 per 

 cent of the contents of nearly all stomachs in which they occurred. 

 Forty-eight birds were found to have eaten birch or alder seeds 

 practically to the exclusion of all other foods. In many stomachs 

 distinction between these two kinds of seeds could not be made 

 in the fragmentary condition in which they were usually found. 

 Of the winter's food 18.69 per cent consisted of seeds of these two 

 plants. Seventy-six birds had eaten weed seed, which comprised 

 24.58 per cent of the season's food. In the Eastern States ragweed 

 (Ambrosia elatior), found in 27 stomachs, was most commonly 

 taken, while in California 28 birds had eaten seeds of groundsel 

 (Senecio). Various other seeds were occasionally taken but rarely 

 in any quantity. 



