( 896 ) 
MARSH HAWK. 
FALCO cYANEUS, Linn. 
PLATE CCCLVI. 
Wiru ease and elegance of flight, guided by an uncommon acute~ 
ness of what I would call short-sightedness, the Marsh Hawk, like an 
experienced gleaner, ranges over the wide extent of the prairie. The 
pure white of the hind part of the female’s back, and the pale blue of 
the male, attract your eye so long as the pair remain within sight. The 
diligence and industry which they exhibit remind you of the search of 
a well-trained pointer. 
This species visits the greater part of the United States. Dr Ricu- 
ARDSON procured some specimens in latitude 65° north, and Dr Towns- 
END found it on the plains of the Columbia River, as well as on the 
extensive prairies bordering on the Missouri. I have met with it in 
Newfoundland and Labrador on the one hand, in Texas on the other, 
and in every intermediate portion of the country. 
In the Fauna Boreali-Americana, Mr Swarnson has published an ex- 
cellent paper relating to such birds as have and have not been consi- 
dered as identical with this bird and the European one bearing the same 
name, I perfectly agree with that gentleman when he says that * the 
typical structure of the wing in the present group must unquestionably 
be that most prevalent among the species. It must, however, be re- 
membered, that even this character is subject to variation, according to 
the age and perhaps the locality of the bird, and that it must not be in- 
sisted upon with too much rigour.” I regret that this learned ornitho- 
logist did not introduce the word sex into the above well-founded re- 
mark, as in the sexes of birds, as well as in individuals of different 
ages, remarkable differences are often observed. 
It is to Montacu that we are indebted for our first knowledge of 
the differences that exist between the male and the female of the Euro- 
pean Hen Harrier, with which Witson believed the Marsh Hawk of 
America to be identical. ‘The Prince of Mustcnano, in his continuation 
of Wilson’s American Ornithology, also considered these birds as the 
same ; although he has since altered his opinion. For my part, having 
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