Exciting Cooper’s Hawk Chase



In October last year, I spotted a Cackling Goose among the 500+/- Canada Geese on a pond near my home in Woodbury.  Formerly considered a subspecies of the abundant Canada Goose lineage, Cackling Geese were designated as a separate species by the American Ornithologists’ Union in 2004.  They are considered a rare Fall migrant through New England, and are often confused with the smaller races of the Canada Goose. (see Sibley, December 2014, for a full discussion of this identification challenge http://www.sibleyguides.com/2014/12/cackling-ish-geese/)  

                           Cackling Goose (right) Compared to Canada Goose
 
Anyway, that’s not what this post is about.  While looking again for the Cackling Goose the next day, I noticed splashing around the outskirts of the goose flock.  I caught sight of a Belted Kingfisher but quickly realized it was not diving for fish, but trying to escape a pursuing Cooper’s Hawk, loudly rattling in apparent panic.  The chase ranged around the 5 +/- acre pond for several minutes with the hawk appearing to attempt to drive the kingfisher into the water several times.  The hawk soon gave up and the kingfisher landed on a floating swim raft to recover.  
                              The Chase is On...

                               Complete with Bemused Observers

According to historic and contemporary descriptions, as well as personal observations, Cooper’s tend to chase and eat medium sized birds, up to chicken size.  Larger birds identified as Cooper’s’ prey in The Birds of North America (http://bna.birds.cornell.edu/bna/species/075/articles/foodhabits) includepoultry, Ring-necked Pheasant, Ruffed Grouse, Bobwhite Quail, Least Bittern, American Crow, Rock Pigeon, [and] various blackbirds…” 

While Belted Kingfishers fall into this range, the hunting technique here varies from the typical ambush in the woods that we are familiar with for this species.  According to the species account in The Birds of North America, Coopers typically rely on concealment and use “a series of brief perch-and-scan episodes to find prey” but also “they are known to hunt from higher flight, stooping on prey in open habitat.”  Apparently data are limited, but the account makes no specific mention of hunting over open water, although open fields are used.

Teddy Roosevelt, however, did observe this behavior.  "In the East, by the way, I have seen the same trick of hovering over the water where a flock of ducks had disappeared, performed by a Cooper's hawk. He had stooped at some nearly grown flappers of the black duck; they all went under water, and he remained just above, grasping at any one that appeared, and facing them to go under without getting a chance to breathe.  Soon he had singled out one, which kept down a shorter and shorter time at each dive; it soon grew exhausted , was a little too slow in taking a dive, and was grasped in the claws of its foE." (Theodore Roosevelt, Hunting Trips of a Ranchman. The Modern Library, New York. Orig. Pub. 1885) 

    Eventually, Everyone Goes Back to Where they Were

I wasn’t sure which bird to root for, but it was exciting to watch.

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