BROWN HAWK; 
the breast more or less pale creamy-buff, and in some mottled with brown or 
rufous and brown, and certainly in these stages of plumage they have been 
found breeding. . . . Of course it does not follow that finding rufous and 
brown birds in company signify they are one and the same species, for how 
frequently are Elanus axillaris and E. scriptus found together ; but one cannot 
get away from the fact that intermediate forms occur, and they are certainly 
not the immature or young stage of Hieracidea orientalis. We have in the 
Australian Museum Collection specimens of the latter, from the nestling to 
the adult, but not the young stage of H. berigora. I, therefore, intend at 
present to keep the two separate, although I may not be correct in doing 
so. Look at the difference between a light and dark specimen of Nisaetus 
morphnoides : on the other hand, I have never seen a typical Hieracidea 
berigora that is sandy-brown above and almost pure white below that was 
obtained in Tasmania.” 
It will be useful, after studying this account, to revert to Gould’s 
account, which I here quote for comparison : “ This species (the Brown 
Hawk, Hieracidea berigora of Gould) is universally distributed over New 
South Wales and Tasmania, and is represented in Western and North- 
western Australia by a nearly allied species, to which I have given 
the name of H. occidentalis. In its disposition it is neither so bold nor so 
daring as the typical Falcons, but resembles in many of its habits and 
actions the Kestrels. Although it sometimes captures and preys upon birds 
and small quadrupeds, its principal food consists of carrion, reptiles, and 
insects ; the crops of several that I dissected were literally crammed with 
the latter kind of food. It is generally met with in pairs ; but at those 
seasons when hordes of caterpillars infest the newly-sprung herbage, it 
congregates in flocks of many hundreds — a fact I myself witnessed during 
the spring of 1840, when the downs near Yarrundi, on the Upper Hunter, 
were infested in this way to such an extent as to spread destruction 
throughout the entire district. By the settlers this bird is considered^ one 
of the pests of the country ; but it was clear to me whatever injury it 
may inflict by now and then pilfering the newly-hatched chickens from 
the poultry-yard is simply compensated for by the havoc it commits 
among the countless myriads of the destructive caterpillar. To give an 
idea of the numbers of this bird to be met with at one time, I may state 
that I have frequently seen from ten to forty on a single tree, so sluggish 
and indisposed to fly that any number of specimens might have been 
secured. So much difference occurs in the plumage of the H, berigora 
that the changes it undergoes require to be closely studied. Professor 
Kaup considers it and the next species to be identical, but having had 
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