BIRDS OF ESSEX COUNTY. 239 



Plum Island Rivers. Another and smaller stream beats its way slowly over the 

 sand dunes, keeping constantly on the lookout for forage, to the thickets of 

 Castle Hill. The third stream spreads out to the westward over the marshes 

 of the Essex and the Castle Neck Rivers, many continuing on between the hills 

 over the canal which connects the waters of the Essex and the Ipswich Rivers. 

 These early morning flights are less direct than are the return flights at night, 

 for the birds are evidently hungry and on the lookout for food. Those that 

 are bound for a distance, however, fly nearly straight and at a considerable 

 height, unless the wind is strong. The gunner, concealed in his blind in the 

 marshes on the lookout for Ducks, often measures the efificacy of his blind by 

 observing the distance at which the wary Crow sheers off. 



The winter roosts of the Crows at favorable places along the coast of 

 Essex County, as in the Ipswich dunes, the pine thickets of Cape Ann, and the 

 Essex and Gloucester pine woods, are of course of insignificant size when com- 

 pared with the roosts farther south, between latitude 35° and 40° N., in New 

 Jersey, Pennsylvania, Maryland, and the District of Columbia,' where some- 

 times 300,000 Crows gather together. It is difficult to estimate the numbers 

 of Crows that spend the nights in the Ipswich dunes in winter, and the numbers 

 vary greatly, but from various observations I should judge that there were often 

 not far from 500 birds. At Annisquam and Gloucester the numbers reach 

 into the thousands. 



Although the Crows generally roost in the thickets of pitch pine, of which 

 there are two of some acres in extent in the sand dunes, on several occasions 1 

 have found the freshly fallen snow trampled down in the lee of the bushes, and 

 showing evidence of the birds having passed the night there, crowded together. 

 The bushes themselves as well as the neighboring pine trees were covered with 

 snow, not displaced as it would be if the Crows had roosted among them. 

 There is one place in the dunes about four acres in extent where there are no 

 trees and but few bushes. Here, in winter, Crows' pellets are always numerous. 



The Crows, even within the radius of a few miles, do not all roost in the 

 same place, and they change the roost with varying conditions. There is a small 

 patch of white pines and a few cedars on the southerly side of Heartbreak Hill, 

 Ipswich, where the trees are crowded together over a space of only about half 

 an acre. To this grove the Crows gather from all sides in winter, beginning to 

 come in an hour or more before sunset. They swing around rapidly so as to 

 head up into the wind just to the leeward of the grove, and then gracefully 



' W. B. Barrows and E. A. Schwarz : The Common Crow of the United States, Bull. no. 6, 

 U. S. Dept. Agriculture, Div. of Cm. and Mamm., 1895 ; see also C. L. Edwards: Winter Roosting 

 Colonies of Crows, Amer. Joum. of Psychol., vol. 1, p. 436, 1888. 



