SUPPLEMENT TO BIRDS OF ESSEX COUNTY lOJ 



hawk as black as a Crow and with long pointed wings was seen by me flying over 

 the dunes at Ipswich. At one point over a pine grove it poised for a moment like 

 a Sparrow Hawk with rapidly moving wings. It disappeared behind the dunes 

 and I did not see it again. It could have been none other than a Black Gyrfalcon. 



158 [356a] Falco peregrinus anatum Bonap. 



Duck Hawk. 



Not uncommon transient visitor (winter). May 12 to 24; August 17 to 

 October 20 (December 16, January 19). 



The January 19 record is of a bird seen in 1913, at Ipswich Beach by Mr. J. 

 H. Baker and myself. The December 16 record is an interesting one. I was at 

 the beach at Ipswich on this date, in 1906, and saw a Duck Hawk fly out from the 

 dunes and scale over a flock of Scoters on the ocean. It then turned about and 

 disappeared among the dunes. The Scoters appeared not a whit disturbed and 

 paid no attention to their very transient visitor. On relating the incident to Mr. 

 Brewster and expressing my surprise at the action or rather lack of action on the 

 part of the Scoters, he assured me that ducks on the water were not afraid of a 

 Duck Hawk as this bird strikes them only in the air, while the reverse is the case 

 with the Bald Eagle. 



The May 12 record is for 1907, at Essex, and as it is of interest I copy my 

 notes as written at the time : " Noticed a commotion among some Crackles and a 

 fine blue Duck Hawk, apparently a female from its size, appeared. It flew over 

 at a considerable height and then tipped quickly from side to side and fell down 

 behind some trees soon to reappear with another hawk which I saw was a Marsh 

 Hawk. The two circled about high up, the upper one frequently falling rapidly 

 as if to strike the lower who would then turn over to grapple, although as far as 

 I could see they never actually touched each other. This was repeated again and 

 again, sometimes one and sometimes the other the aggressor. The white rump 

 and long tail of the Marsh Hawk easily distinguished it from the Duck Hawk 

 with its blue back and peculiar head-markings. They finally disappeared from 

 sight, still circUng and striking." This was apparently a case of play between 

 individuals of two species. 



Under the Pectoral Sandpiper I have described the killing of one of these 

 birds by a Duck Hawk in the marsh at Ipswich. As the hawk flew off, the 

 victim was carried in the talons below and then extended out behind. The whole 

 thing was done in the twinkling of an eye so that it was difficult to realize what 

 had happened. 



