FOOD HABITS OF THRUSHES. 



17 



Red osier (Cornus stolonifera) 



Panicled cornel (Cornus paniculata) 



Dogwood unidentified (Cornus sp.) 



Huckleberries (Qaylussacia sp.) 



Three-flowered nightshade (Solatium 



triflorum) 



Nightshade unidentified (Solarium sp.)_ 

 Black twinberries (Lonicera involu- 



crata) 



Honeysuckle berries (Lonicera sp.) 



Snowberries (Symphoricarpos racemo- 



sus) 



Dockmackie (Viburnum acerifolium) 



Arrowwood (Viburnum sp.) 



Black elderberries (Sambucus canaden- 

 sis) 



Red elderberries (Sambucus pubens) 



Blue elderberries (Sambucus glauca)-- 



Tarweed (Madia sp.) 



Fruit pulp not further identified.. 



5 

 15 



1 

 17 



Food of young of russet-hacked thrush. — Before concluding the 

 discussion of this species it will be of interest to note the results 

 obtained from an investigation of stomachs of 25 nestlings of the 

 russet-back taken in June and July when the birds were from two 

 to eleven days old. These were from eight broods, ranging from 

 three to five nestlings to the brood. The percentage of animal food 

 of the young (92.60 per cent) is considerably higher than that of the 

 parent birds. 



The distribution of the animal food is as follows: Caterpillars 

 were found in every stomach but seven and aggregated nearly 27 

 per cent; beetles, including the useful Carabidse (7.7 per cent), are 

 irregularly distributed to the extent of 22 per cent ; other more or less 

 harmful species included five families of (Hemiptera) bugs, 13.8 

 per cent, viz, stinkbugs, leaf hoppers, tree hoppers, shield bugs, and 

 cicadas; ants and a few other Hymenoptera amount to 12 per cent, 

 and spiders the same. These latter were mostly harvestmen or daddy 

 longlegs (Phalangida?). The remainder (6 per cent) included a few 

 miscellaneous insects. Only three stomachs contained remains of 

 grasshoppers. Carabid beetles were eaten by the young birds to the 

 extent of 7.7 per cent, which is more than three times the amount 

 eaten by the adults, a remarkable fact when is considered that these 

 insects are very hard shelled, thus seemingly unsuited for young 

 birds. 



The vegetable food consisted of fruit (6.8 per cent), mainly black- 

 berries or raspberries, found in 11 stomachs, and twinberries in 1, 

 and two or three other items, including a seed of filaree and some 

 rubbish. From the irregular variety of food in the different 

 stomachs, it would seem that the parents make little selection, but 

 fill the gaping mouths of their young with the nearest obtainable 

 supply. 



In addition to the examination of stomach contents of nestlings 

 two nests were carefully and regularly watched, and from these it 

 was determined that the parent birds fed each nestling 48 times in 

 14 hours of daylight. This means 144 feedings as a day's work for 

 the parents for a brood of three nestlings, and that each stomach was 

 filled to its full capacity several times daily, an illustration that the 

 digestion and assimilation of birds, especially the young, are con- 

 stant and very rapid. Experiments in raising young birds have 



