24 



BULLETIN 171, U. S. DEPARTMENT OF AGRICULTURE. 



some pulp may have been of cultivated fruit. The most important 

 vegetable food of the bluebird is wild fruit. The maximum quan- 

 tity is eaten in December, when it amounts to 57.64 per cent. Janu- 

 ary comes next, but after that month the amount decreases rather 

 abruptly to zero in May. Xo fruit, either wild or domestic, was 

 found in the 58 stomachs taken in that month, but after that time 

 the amount taken increases rapidly to its maximum in December. 

 The average for the year is 21.85 per cent. At least 38 species of 

 wild fruits were identified and probably more were present but not 

 recognizable. The fruit-eating period of the bluebird is not in sum- 

 mer when the fruit is fresh on the tree, but from October to Febru- 

 ary, inclusive, during which months three-fourths of its fruit eating 

 is done. From this it appears that fruit is really the winter food of 

 the bluebird, tiding it over until insects are again abundant and 

 taking the place of seeds eaten by so many birds at this season. 



Seeds, however, are eaten by the bluebird, but only occasionally 

 and sparingly. Apparently taken in spring, fall, and winter when 

 nothing better offers they average for the year only 0.67 per cent. 

 There is nothing to fear from the bluebird on the score of its eating 

 grain, for this food was found in only two stomachs, one taken in 

 January and the other in July. The first contained two kernels of 

 wheat and nothing else, and in the second was found what appeared 

 to be the ground-up pulp of wheat ; the total percentage for the year 

 is 0.32 per cent. 



Under the head of miscellaneous vegetable food are included the 

 seeds of sumac, both the harmless and poisonous kinds : the seeds of 

 the bayberry; and a little indeterminate vegetable refuse and rub- 

 bish. The average for the year is 7.84 per cent, but for the five 

 months from October to February these constitute a very fair pro- 

 portion of the food. At this time of year seeds of the poison ivy, the 

 poison sumac (in Xew England called dogwood), and the other 

 sumacs are usually abundant and seem to be relished by many winter 

 birds. 



Following is a list of the various articles of vegetable diet identi- 

 fied in the stomachs of eastern bluebirds and the number of stomachs 

 in which found : 



Eed cedar (Juniperus virginiana) _ 15 



Panic grass (Panicum sp.) 3 



Pigeon grass ( Chcetochloa sp.) 1 



Wheat (Triticum vulgaris) 1 



Asparagus berries (Asparagus offi- 

 cinalis) 1 



False Solomon's seal (Smilacina 



racemosa) 2 



Green brier (Smilax oona-nox) 1 



Hound-leaved brier (Smilax ro- 



tundifolia) 1 



Cat brier (Smilax sp.) 1 



Bayberry (llyrica carolinensls) 28 



Hackberry (Celtis occidentalis) 12 



Southern hackberry (Celtis missis- 



sippiensis) 3 



Mulberry (Morus sp.) 2 



Mistletoe berries (Phoradendron 



flavescens) 8 



Sorrel (Rumex sp.) 1 



Smart weed (Polygonum^.) 2 



Amaranth (Amaranthus sp.) 1 



