OP ARTS AND SCIENCES. II7 



the Saco valley, I have found a fevv each year during the breed- 

 ing season at North Conway, among the scrubby Bear Oaks 

 that grow on a certain sandy tract it an altitude only a few feet 

 above the valley (500 ft.)- During the month of August flocks 

 of these birds, sometimes numbering two or three hundred, I 

 have frequently seen at Intervale, in late afternoon, moving 

 leisurely down the Saco valley. The larger flocks often take a 

 considerable time to pass a given point, as the individual birds 

 fly quartering up and down, back and forth, so that the flock as 

 a whole swings down the valley, completely past the observer, 

 then back agasin, then down the valley once more, with each re- 

 turning swing coming back a less distance until all are passed. 

 Evidently the birds are feeding^at such times. On August 19, 

 1897, I observed a large flock of over 200 birds thus passing 

 down the Saco valley, when it finall}^ broke into two divisions, 

 one of Vi^hich moved off northward up the valley, while the other 

 continued on southward. At other times the flocks do not seem 

 to be actively engaged in feeding, but each bird, usually sep- 

 arated by a considerable space from the next, flies swiftly on 

 towards the south, as if with a distinct goal in view ; and fre- 

 quently such flocks are so scattered that barely a half dozen 

 birds are in sight at once, now a little group of two or three 

 winging its wa}^ past, to be followed shortl}^ by a single strag- 

 gler or a pair. By the end of August, their migration is prac- 

 jtically over in the White Mountains, though an occasional be- 

 lated migrant may be seen hurrying south during the first week 

 or two of September. 



Dates : (April 17, Hollis) May 11 to September 15. 



139. Cliaetura pelag'ica (Ivinn.). Chimney Swift. 



A common summer resident of the Transition area, especially 

 about the larger centers in the southern and central parts of the 

 state. In the White Mountains, a few are usually to be ob- 

 served during the summer about almost every small cluster of 

 houses, or less commonly a pair or two will be found inhabiting 

 a chimne}^ of some isolated farmhouse. At Intervale, there ap- 

 pear rarely to be more than a few pairs in any season, notwith- 

 standing the abundance of chimneys. Dr. A. P. Chadbourne 



