igo Bird -Lore 



throughout the winter, and evidences of joy and conviviality in the 

 midst of December. 



SUGGESTIONS FOR THE MONTHS' STUDY 



Food and Distribiili'on. — Observe relation between the food supply, as it is con- 

 trolled by temperature, and the departure of the last migrants (see preceding articles). 

 Compare the food of migratory, summer-resident birds with that of winter birds ; the 

 former being insect- and fruit-eaters, the latter, seed- or flesh-eaters. Note variation 

 in the food of certain birds, such as the Flicker, Bluebird and Robin, which, insec- 

 tivorous in summer, later subsist on fruit, including winter berries, and are thus some- 

 times found throughout the year as far north as Massachusetts. Are these birds 

 represented by the same individuals at all seasons ? What permanent residents are 

 resident in the strict sense of the word ? During the winter the relation between food 

 and distribution is especially marked, a failure of the food-supply at the north occasion- 

 ally bringing us great numbers of boreal birds. (See Fisher and Loring, Evening 

 Grosbeaks in New York, ' Forest and Stream,' XXXIV, 1890, p. 64 ; Brewster, Evening 

 Grosbeak in New England, Ibid. , p. 44 ; Butler, ' Some Notes Concerning the Even- 

 ing Grosbeak,' 'The Auk,' IX, 1892, p. 238; Brewster, 'A Remarkable Flight of Pine 

 Grosbeaks,' 'The Auk,' XII, 1895, p. 245; Chapman, 'The Season's Flight of Cross- 

 bills,' Bird-Lore, II, 1900, pp. 25, 59.) 



The presence of food may induce birds which generally winter further south to 

 remain through the winter. A small flock of Doves passed the winter at Englewood, 

 N. J., feeding exclusively, as far as was observed, on the grain in a pile of chaff from 

 buckwheat, winnowed in the field. Myrtle Warblers are common at the same locality 

 during the winter when there is an abundance of bayberries, but when there are no 

 berries there are no Warblers. 



Observe how the daily wanderings of flocks of Juncos, Tree Sparrows, etc., are 

 governed by food. Are these flocks composed of the same individuals ? Have they a 

 regularly frequented roosting place ? Note the roosting habit of Crows (see Stone, 

 Bird-Lore, I, 1899, 177). 



Food thus exerts so great an influence on a bird's range at this season, when the 

 supply may be limited, that we may govern at least the local distribution of birds by 

 supplying them with proper food. (See Torrey, in this number of Bird-Lore; Daven- 

 port, in Lange's ' Our Native Birds ; ' Merriam, ' Birds of Village and Field ;' Bird-Lore, 

 I, 1899, pp. 19. 55. 185.) 



Ecofiomk Value of IVinler Birds. — At this season, Hawks and Owls, by destroying 

 harmful rodents. Sparrows, by eating the seeds of injurious weeds, and Creepers, Wood- 

 peckers, Nuthatches, Chickadees and Golden Kinglets, by devouring the eggs and larvae 

 of insects, are of inestimable benefit to man. (See Weed, ' Winter Food of the Chicka- 

 dee, ' publications of the New Hampshire Agricultural Experiment Station, Durham, 

 N. H.; Forbush, Mass. Crop Rep. for July, 1895, pp. 20-32; Beal, 'Food of Wood- 

 peckers," Bull. No. 7, Biological Survey, U. S. Dept. of Agriculture;* Judd, 'Birds as 

 Weed Destroyers,' Yearbook of Dept. of Agriculture* for i8g8, pp. 221-232; Fisher, 

 'Hawks and Owls in Relation to Agriculture.') 



Bird-Census. — The comparatively small number of birds present during the win- 

 ter, together with the absence of foliage, except on coniferous trees, make it possible 

 to estimate the number of individuals occupying a given area. Such estimates are not 

 only of interest in themselves, but they are of assistance in determining the economic 

 value of birds. (See beyond, 'A Christmas Bird Census. ') 



*For all government publications apply to the Supt. of Documents, Washington, D. C. 



