215 
immature bird, in a condition of plumage exactly corresponding with the young of H. novce zealandice. 
This circumstance, together with the great difference in size between the male and female, led me, 
among others, to the conclusion that the two birds were referable to one and the same species *. 
Dr. Otto Finsch (Journal fur Ornithologie, 1867, p. 317) expressed his belief that//, brunnea was 
the female of H. novce zealandice — a decision based (as he has since informed me) on Forster’s account 
of the bird; but in a subsequent paper (oj). cit. 1870), referring to my observations on the subject, 
he adopts the view of its being the young of that species, quoting, at the same time, Dr. Haast’s 
opinion to the contrary. In Captain Hutton’s ‘ Catalogue 5 f only one species is admitted, the 
author remarking that it is very variable in size, and that “ a large male can be distinguished from a 
small female by its more slender legs, which are 06 of an inch in circumference in the male, and 0'8S 
of an inch in the female.” On the other hand, several excellent local observers have always held that 
they could distinguish a larger and a smaller species, the former differing in some of its habits from 
the common Bush-Hawk, and frequenting the open country in preference to the woods. Mr. Gurney 
also called attention to the subject in a letter to ‘The Ibis’ (1870, p. 535), in which he gave the 
dimensions of various examples that had come under his notice. Of these, the small specimen of 
H. brunnea , in the Nortvich Museum, marked ? (measuring 1 4' 5 inches in total length, wing 0 • 2 5 ) , 
is, no doubt, as Mr. Gurney suggests, incorrectly labelled; for I have never met with so small an 
example of that sex ; and it must be confessed that conclusions based on a mere examination of 
skins, in the absence of a positive determination of the sex, are very unsatisfactory. 
It will be seen, on reference to the measurements I shall give in treating of the smaller species, 
that the sexes differ very much in size, the female, as is always the case with members of this family, 
being the larger bird. The fact that a male of the present species (of which the sex was carefully 
ascertained by Dr. Haast) was actually larger than the female of H. brunnea appeared to me 
sufficient of itself to warrant a specific separation. Having, however, brought with me to England 
good examples of both forms for illustration in my former edition, I compared them with the fine 
series of specimens in the British Museum (about twenty in number) and with Forster’s original 
drawings, and came to the conclusion that there were in reality two distinct species, closely resembling 
each other in plumage in both the young and adult states, but differing appreciably in size. In this 
examination I was kindly assisted by Mr. J. H. Gurney, an ornithologist who, as is well known, 
has made Birds of Prey his special study ; and as he entirely concurred in the conclusion arrived at, 
I felt that I could publish it with some degree of confidence. 
Mr. Sharpe afterwards pointed out (Ibis, 1873, p. 327) that the name of Falco brunneus of Gould 
had been preoccupied by Bechstein, who thus called the common Kestrel of Europe, and that conse- 
quently our small bird, if allowed to be distinct from II. novce zealandice , must bear another title. He 
considers that this should be Hieracidea australis (Iiomb. & Jacq.) ; but it seems to me that this is 
only a synonym of the older species and that the right name to fall back upon for the former is 
Falco ferox of Peale. In his official catalogue of the Accipitres in the British Museum, under the 
generic name of Ilarpa, he not only gives 11. australis the precedence, but commits (as I venture to 
think) the further error of making it a “ subspecies,” or constant variety, of H. novce zealandice. 
The two birds are either specifically distinct or they belong to one and the same species. 
Professor Hutton contributed to ‘The Ibis’ for October 1879 a table of measurements for the 
purpose of showing that there existed only one species; but in my reply to that paper (Ibis, 1881, 
p. 453) I pointed out that his argument was quite inconclusive, inasmuch as “ his ? specimen B gives 
a wing-measurement only -25 of an inch longer than that assigned by me to the female of the smaller 
species.” 
* Tide Trans. N.-Z. Instit. vol. i, p. 106 (1868). 
t ‘ Catalogue of the Birds of New Zealand,’ by F. W. Hutton, Geol. Survey of N. Z. (1871). 
