CIRCUS ASSimihlS, Jard. and Selb. 
Allied Harrier. 
Circus assimilis, Jard. and Selb. 111. Orn., vol. ii. pi. 51. 
Swamp Hawk, of the Colonists. 
The Circus assimilis may be regarded as the commonest of the Harriers inhabiting- New South Wales and 
South Australia ; it also occurs, but in smaller numbers, in Van Diemen's Land. Another Harrier is rather 
abundantly dispersed over all the localities suitable to its existence in Western Australia, and it is just possible 
that they may prove to be mere varieties of each other ; if such should be the case, the whole of the southern 
portion of the coast of Australia, from east to west, must be included within the range of its habitat ; still, 
without further evidence in favour of this supposition, I should consider them to be distinct species ; and if 
this opinion is well-founded, the two species will be found to inosculate in the latitude of Spencer's and 
St. Vincent's Gulfs, as, in the collections lately forwarded to me by Mr. Harvey of Port Lincoln, I found two 
or three individuals precisely identical with those from Swan River. In size the Circus assimilis is but little 
inferior to the Marsh Harrier (^Circus (eruginosus^ of Europe, to which it offers a great resemblance in its 
habits and economy ; being generally seen flying slowly and somewhat heavily near the surface of the 
ground, evincing a partiality to lagoons and marshy places, situations which offer it a greater variety and 
abundance of food than any other ; the principal part of its food consists of reptiles, small mammalia and 
birds. I several times observed this species in the lagoons near Clarence Plains in Van Diemen's Land, as 
well as in all similar situations in almost every part of New South Wales I visited. 
I was not so fortunate as to find the nest of this Harrier, — a knowledge of its form and of the colour of its 
eggs is therefore yet to be ascertained. That it breeds in the localities in which I observed it I have little 
doubt, from the circumstance of the adults paying regular and hourly visits to the marshes in search of food, 
which was doubtless borne away to their young. Wlien in a state of quiescence, this species, like the other 
Harriers, perches on some elevation in the open plain rather than among the trees of the forest ; the trunk 
of a fallen tree, a large stone, or small hillock, being among its favourite resting-places. 
The sexes offer the usual diflferences in the larger size of the female ; the markings of that sex are also 
rather less well-defined, and have not so much of the grey colouring as the male. 
Head and all the upper surface rich dark brown ; the feathers at the back of the neck margined with 
reddish buff ; face light reddish brown ; facial disc huffy white, with a dark stripe down the centre of 
each feather ; all the under surface buffy white, which is deepest on the lower part of the abdomen and 
thighs, each feather with a streak of brown down the centre ; upper tail-coverts and base of the tail-feathers 
white ; remaining length of the tail-feathers brownish grey ; irides reddish orange ; eyelash and cere pale 
yellow ; bill dark brown, becoming light blue at the base ; tarsi greenish white ; feet bright orange ; claws 
dark brown. 
The female differs in being of a larger size and of a darker brown, particularly on the under surface, and 
in having the tail of a deeper tint and obscurely barred. 
The fisrures are about two-thirds of the natural size. 
