BIRDS OF THE CAMBRIDGE REGION. 219 



and on May 22, 1900, I found a female in our garden. The latter bird spent 

 the entire day on one of the larger branches of an old apple tree where it was 

 surrounded by a mob of noisy and excited Robins who apparently mistook it for 

 an Owl. 



114. Chordeiles virginianus (Gmel). 



NiGHTHAWK. 



Common transient visitor during migrations and rare summer resident, at least formerly. 



SEASONAL OCCURKENCE. 



April 23, 1895, one seen, Cambridge Region, W. Faxon. 



May 15 — September 25. 

 October 5, 1868, one seen, Fresh Pond, W. Brewster. 



NESTING DATES. 



June 5 — 15. 



Nighthawks continue to visit the Cambridge Region in undiminished num- 

 bers at their times of migration.^ About the middle of May or a little later 

 they may be found singly, by day, roosting on the ground in rocky pastures, on 

 the branches of large pines or oaks in the woods, and of apple trees in the 

 orchards, sometimes near houses and occasionally even in our city gardens ; 

 at evening, when twilight is falling and when the warm, moist air is laden 

 with the fragrance of blossoming fruit trees, we often see the birds passing over- 

 head on their way northward. During the return migration, which takes place 

 in the latter part of August or early in September, they are still more numerous 

 or at least conspicuous, appearing about sunset, evening after evening, in strag- 

 gling companies containing from six or eight to fifteen or twenty birds each, and 

 attracting general attention by their graceful yet erratic manner of flight. The 

 members of these flocks, although scattered more or less widely and apparently 

 absorbed in feeding, move onward steadily, if rather slowly, in the same gen- 

 eral direction, ordinarily towards the south or southwest. At first they fly at 

 rather high altitudes, but, as the daylight wanes, they descend to just above the 

 tops of the trees or houses, and finally, when the landscape has become nearly 



1 They have been comparatively scarce during the past two years owing, it is thought, to heavy 

 rains which occurred in the summer of 1903 and which are known to have caused widespread destruc- 

 tion among the Swallows and other birds or similar feeding habits. 



