1 82 MEMOIRS OF THE NUTTALL ORNITHOLOGICAL CLUB. 



79. Circus hudsonius (Linn.). 

 Marsh Hawk. Frog Hawk. 



Common transient vi.sitor in .spring and autumn, formerly breeding in our locality. 



SEASONAL OCCURRENCE. 



March i, 1871, one taken, Cambridge, W. Brewster. 



March 20 — November 10. 

 November 29, 1S93, one female seen (Concord), W. Brewster, 



NESTING DATE. 



June 5, 1875, nesfi and four eggs,' Waltham, W. Brewster. 



Marsh Hawks are wide-roving birds at all seasons, and the occasional 

 appearance of one in May or June does not necessarily indicate that it has a nest 

 near the place where it may happen to be seen. For this reason the actual dis- 

 covery of the nest is essential to establish the fact of breeding. I know of but 

 one locality within the Cambridge Region where the nest has ever been found, 

 'viz., Rock Meadow. Here I took a set of four eggs on June 5, 1875, and a sec- 

 ond, comprising the same number, on June 11, 1877, while a third set of foiu- 

 was taken on June 7, 1879, by Mr. H. M, Spelman. These eggs are all in my 

 collection. All three nests were built within a yard or two of the same spot, 

 on a little meadow island covered with wild rose bushes and other low shrubs. 

 My attention was first drawn to this nesting place by the behavior of the birds. 

 On May 21, 1875, I repeatedly saw the male rise to a great height above the 

 meadow island and then return to it by a succession of short, nearly vertical, 

 downward swoops, each of which terminated in a graceful upward turn. While 

 making these plunges he uttered a dry, cackling kef-kep-kep-kep-kep. The final 

 drop carried him into the bushes, where he usually remained some time before 

 mounting into the air for another descent. Marking the spot where he invari- 

 ably disappeared, I approached it unseen, under cover of a neighboring thicket, 

 on the morning of May 24, when I found the pair of Marsh Hawks there. 

 They were very noisy, calling to one another almost incessantly. The note 

 which both birds used on this occasion, a shrill, squealing qiicc, quee, quee, was 

 new to me at the time and I have never heard it since. During the hour or 



' No. 2176, collection of William Brewster. 



