4 LIFE-HISTORIES OF BIRDS 



are migratory and generally caused over the 

 woodland regions of our country; insectivorous, 

 but like many other insect-feeding birds, feed con- 

 siderably upon berries and such like. Although 

 not strictly gregarious, some, the robin for exam- 

 ple, collect in troops during feeding, or migrate in 

 companies. They are all vocal, and some exquisitely 

 melodious, as the wood-thrush. 



Turdus migratorius. Linn. 



Scarcely any of our ordinary species is so abun- 

 dant in Eastern Pennsylvania as the Robin, which 

 is the subject of the present sketch. Within a circle 

 of country scarcely exceeding one half-mile in 

 diameter, sixty families have been frequently ob- 

 served. In one particular instance, at least six 

 occupied nests were noticed upon an acre of ground, 

 besides a few of the cat bird, wood-thrush, song 

 and tree sparrows, making fifteen in all. In the 

 month of February small flocks of a dozen and 

 even more have been observed on open grounds, 

 flying from tree to tree, doubtless the scenes of 

 past associations. In the small valleys among the 

 hills of the romantic Wissahickon, where the pier- 

 cing winds and drifting snows of winter do scarcely 

 visit, many of these birds discover comfortable 

 shelter. We venture this opinion for the following 

 reason: On certain warm days in February, which 

 remind us of jhe genial days of April, small flocks 

 have often been seen by the author in such situa- 

 tions. These could hardly have migrated from 



