xl 
I N T 11 0 D U C T I O N. 
Genus Nauclerus. 
The single species of this form is remarkably different from all the other Kites. Its more slender 
structure, lengthened wings, and long forked tail indicate that it possesses vast powors of flight, and that it 
would experience but little difficulty in making a transit from its native eountry to even very distant shores, 
when circumstances force it to leave its own. 
30. Nauclerus eurcatus. 
Swallow-tailed Kite. 
This bird is so strictly American that I have not given a figure of it ; notwithstanding it has been killed 
at least five times in our islands, the earliest of these occurrences having been at Ballachulish, in Argyle- 
shire, in 1772, since which others have taken place at Wensleydale, at Farnham, in Cumberland, and 
on the Mersey. 
Subfamily CIRCIN.K. 
The Harriers, comprising numerous species, are so widely dispersed over the face of the globe as to 
warrant the use of the term universal with reference to their distribution. In each of the five great divisions 
of the globe one or other of the seventeen known species are to be found. In Europe there are four, three 
of which inhabit and breed in Britain. In habits and economy they do not resemble the Falcons, the 
Buzzards, or the Kites, but assimilate somewhat to the Strigidse, or Owls. Their actions, indeed, are peculiar 
to themselves ; and their great flapping wings render them conspicuous objects when flying over a marsh or 
the sunny side of a moor, with keenly searching eyes, in pursuit of their food, which varies with the nature 
of the locality. If in the fen, reptiles, from the snake to the newt, are captured and eaten, as are frogs and 
insects ; at the breeding-season young Snipes, Moorhens, or other nestlings are fortunate if they escape 
their scrutinizing eyes. They nest chiefly on the ground, and lay four or five white eggs. Their flight is 
somewhat laboured and flapping. 
Ornithologists have divided the Harriers into five different genera ; and even the three which inhabit 
Britain have each received a separate generic title, a procedure which may seem superfluous to some 
persons ; but before placing his veto upon it each objector should have all the known species before him, 
when he would perceive that the great Marsh-Harrier, with its brown plumage, differs considerably from 
the slender ash-coloured bird with its barred tail, and both from the uniformly coloured and stouter-built 
Hen-Harrier. Knowing how strong the feeling is against the multiplication of generic terms, I have in this 
work retained them all in the genus Circus. 
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