BIRDS OF THE CAMBRIDGE REGION. 



393 



about two thousand birds resorted nightly, at the height of the season, to the 

 Maple Swamp. In either 1873 or 1874 they deserted this place and formed 

 another roost in a similar piece of swampy woods on the northern side of the 

 Fresh Pond Marshes, near where Little River joins Alewife Brook, and 

 partly within the confines of Arlington. This roost was many times more 

 populous than the earlier one, for it included, in addition to the whole 

 Cambridge contingent, a great number of birds drawn from the neighboring 

 portions of Arlington and Belmont. Indeed, at the height of its prosperity it 

 sometimes sheltered, if my notes may be trusted, upwards of twenty-five thou- 

 sand Robins. It was frequented until 1876 when the woods were cut down. 



On August 25, 1884, I discovered a Robin roost on the dividing line 

 between Belmont and Waltham, just above the upper pond in the Beaver Brook 

 Reservation. It then contained an imposing number of birds — "thousands," 

 according to my notes. Judging by counts and estimates made by Mr. Walter 

 Faxon, the number of Robins which visited it in 1889 must have sometimes 

 reached a total of eight to ten thousand. There are good reasons for believ- 

 ing that it was originally formed of the scattered legions from the Little River 

 roost — distant less than three miles in an air line to the eastward. 



I have had no report of the Beaver Brook colony for ten or twelve years 

 and I am by no means sure that it is still in existence. Indeed I have reason 

 to suspect that the Robins which frequent Arlington and Belmont now roost 

 somewhere to the westward of Great Meadow, for I saw them flying in that 

 direction by hundreds on the evening of September 26, 1901. 



In 1 88 1 and for some twelve years later most if not all of the Robins 

 which bred in Cambridge and its suburbs roosted in Norton's Woods, where 

 careful estimates, made by Mr. C. F. Batchelder in July, 1890, aggregated as 

 high as fifteen hundred birds. Mr. Batchelder tells me that our Cambridge 

 Robins ceased to resort to these woods in 1894 or 1895. Late in June, 1902, 

 they began assembling every evening — to my infinite surprise — in some 

 ancient lilacs which form a dense and rather extensive thicket in the garden 

 immediately behind our house. At first there were not more than twenty or 

 thirty birds, but their numbers rapidly increased until by the close of the sum- 

 mer we often counted as many as four or five hundred. 



The first Robins returned to our garden on March 12 of the following 

 spring. The gardener reported that upwards of fifty birds assembled at the 

 roost the next evening, and that they flew into and about the thicket of lilacs as 

 if preparing to spend the night there, but that all of them departed before it had 

 become quite dark. The same thing came under my own observation a few 

 evenings afterwards, and also on several occasions towards the end of the month. 

 I was absent from Cambridge during most of April, but on the evening of the 

 29th I saw twenty-five or thirty Robins settle themselves for the night in the 



