BIRDS OF THE CAMBRIDGE REGION. 



137 



where food is abundant and where it is not too much molested. In the Fresh 

 Pond region it has been very much more numerously represented within the past 

 decade than it was thirty or forty years ago, despite the disappearance of most 

 of the woods and thickets which it formerly frequented and the rapid multiplica- 

 tion of houses and human population. In the earlier days we seldom met with 

 more than two or three breeding pairs in any one summer, but in May, 1896, 

 Mr. O. A. Lothrop found no less than ten nests containing eggs or young within 

 a space of about an acre in the Maple Swamp. There were almost if not 

 quite as many there the following spring, but most of the eggs were taken by 

 boys, and the birds have since nearly ceased to frequent the place. It is excep- 

 tional for them to form a colony of this kind for, unlike most Herons, they are 

 not habitually gregarious at any season. Their local increase, which began 

 about 1885 and reached its maximum ten or twelve years later, was due, no 

 doubt, to one or another of the changes in the physical and vegetal condition of 

 the swamps, that occurred during this period ; such changes, for example, as the 

 partial submergence, at every season, of the region lying to the north and west 

 of the Glacialis, or the excessive multiplication and wide dispersion of the cattail 

 flags over this semi-flooded area. 



In midsummer, after their young had become strong of wing, our Cam- 

 bridge Green Herons were once accustomed to feed in the early morning and 

 late afternoon — as well as at all hours of the day when the weather was lower- 

 ing — in the salt or brackish marshes along Charles River. We used to see 

 them constantly in the month of August, passing and repassing low over Brattle 

 Street at various points between Sparks Street and Mount Auburn. They all 

 returned to their roosts in the Fresh Pond Swamps at evening, when the last 

 stragglers sometimes met the first flights of Night Herons moving in the oppo- 

 site direction. Within the past two or three years both species have nearly 

 ceased to visit the Charles River Marshes. 



As nearly as I can ascertain, they feed at the present time chiefly in the Fresh 

 Pond Marshes, at Great Meadow, and about the shores of our larger ponds. It 

 is probable that some of them resort to the salt marshes near Revere Beach and 

 perhaps also to the fresh-water meadows along the Concord River opposite Bed- 

 ford, for these localities lie within easy flight (for Herons) of the Cambridge Re- 

 gion, and both, I believe, are still frequented by the birds in summer. 



