l82 MEMOIRS OF THE NUTTALL ORNITHOLOGICAL CLUB. 



79. Circus hudsonius (^Linn.). 

 Marsh Hawk. Frog H.mvk. 



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



SEASON.\L OCCURREN'CE. 



March 1, 1 87 1, one taken. Cambridge, W. Brewster. 



March 20 — November 10. 

 November 29, 1893, one female seen (Concord), W. Brewster. 



NESTING DATE. 



June 5, 1S75, nesti and four eggs.i 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- 

 coven,- 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 four 

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

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

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

 My attention was first drawn to this nesting place by the beha\-ior 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. WTiile 

 making these plunges he uttered a dry, cackling kep-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 verj' noisy, calling to one another almost incessantly. The note 

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

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



•No. 2176, coUection of WiDiain Brewster. 



