35. Spizaetus cirrhatus

No. 35. Spizaetus Cirrhatus, Gmel.

The Crested Hawk-Eagle.

I know nothing of the nidification of this species, nor am I likely I fear to do so, until observers generally learn to discriminate it better.

With the exception of 4 specimens recently received from Mr. R. Thompson, every skin yet sent me as belonging to S. Cirrhatus (S. Cristatellus, Tem.) has proved on close examination to pertain to S. Nipalensis.

Blyth as already quoted (No. 34. q. v.) tells us, that " even the large and very conspicuously distinguished S. Nipalensis, Hodgson, is considered by Professor Sohlege, to be merely a variety of his Cirrhatus." Had Schlegel said that Nipalensis was only the adult of the bird commonly received as Cirrhatus, he would have been perfectly correct. I have seen, and possessed specimens, of the so-called Cirrhatus, from Ceylon, the Puchmurree Hills, Etawah and Kumaon, and these were all unmistakably immature examples of L. Nipalensis, as was proved by comparing them with young ones captured in the Himalayas, whose parents were known and whose nests had been watched.

Dr. Jerdon has not described the young of Spizaetus Nipalensis. This I have done at Length, and my descriptions and measurements will I hope throw some light upon the matter.

It is these immature Nipalensis that are always mistaken for Cirrhatus; the mature birds no one, who knows both species (Prof. Schlegel must excuse me, but it is a fact,) can possibly confound together.

In Cirrhatus, the upper surface of the adult is considerably lighter than in Nipalensis, and the feathers, of the head, nape, and upper back are comparatively light brown, centred more or less broadly, with dark brown ; while in the adult Nipalensis there is scarcely a trace of paler edgings in the feathers of the head, and none in those of the upper back. In Cirrhatus, the cheeks, and ear coverts are pale brown, each feather with a very narrow central dark brown stripe, while in the same parts in Nipalensis, the blackish central stripes occupy nearly the whole feather. In Cirrhatus, the breast and upper abdomen are pure white, each feather with a huge broad, dark brown central stripe on the terminal half. The whole of the lower abdomen, vent, lower tail coverts, sides, flanks, and tibial plumes are nearly uniform umber brown, without in the adult, even a trace of white mottling. In Nipalensis on the other hand the whole of the breast, except the extreme upper portion, the sides, flanks, abdomen, vent, lower tail coverts, and tibial plumes, are deep umber brown, paling on the abdomen and towards the vent, every where broadly, regularly and conspicuously, transversely barred with white; the bars being broadest and least numerous on the sides and body, and narrowest and most numerous on the tibiae. The axillaries of the fully adult Cirrhatus are of a pale umber brown slightly darker towards the centre, without a trace of bar or mottling, while the axillaries of Nipalensis are broadly and conspicuously barred with white.

The crests in these two species are excessively similar; quite as long in one as in the other, both black and more or less conspicuously tipped with white, but really, with this exception, no two birds of the same genus, can well be more unlike each other than are the perfect adults of Cirrhatus and Nipalensis.

I should mention also another difference which will I think be found constant; viz. in the bandings of the tail. In Cirrhatus and Limnaetus, the space between the broad terminal bar and the next one is always considerably broader than the terminal bar itself, while the succeeding bars are generally narrower than the interspaces. In Nipalensis on the other hand the first space is narrower, or, at any rate, not broader, than the terminal band, while the succeeding spaces are narrower than the bars. Moreover there is a greater contrast in colour between the bars and interspaces and a somewhat sharper definition of these in Nipalensis, than in the other two species.

From the adult of Caligatus, Cirrhatus is at once distinguished by the long, black white edged, or in some only white tipped, crest. A rudimentary crest, more or less elongated, is doubtless met with in some specimens of Caligaetus, but it is never more than half the length of that of Cirrhatus, and very frequently altogether wanting.

The young of Cirrhatus undoubtedly closely resemble those of Nipalensis. But where the sexes have been ascertained, the much greater size of the wing would alone enable us certainly to separate the birds. In Cirrhatus, the wing of the female, averages according to my experience, 17.62, while in no instance have I found the wing to exceed 18 inches ; the male appears to have the wing on an average 16.5. The smallest male Nipalensis that I possess, or have measured, measured 17.75, and I have now in my Museum a female, whose wing measures 19.5.

Besides the difference in size, there is another little difference which appears to me to be constant and which would alone enable us to separate either Cirrhatus or Caligatus at any stage, from Nipalensis. I say appears to me, because I have only had an opportunity of closely examining nine specimens of Nipalensis, six of Cirrhatus, and about a dozen of Caligatus. In all these, the distinction I am about to point out held good ; whether it does so universally is for other ornithologists to determine. In Cirrhatus and Caligatus, the feathering of the foot ends, more or less, above the division of the toes. In some specimens fully an eighth of an inch of the foot is left bare, in others the feathering especially of the centre portion of the foot, comes down all but level with the division of the toes. In Nipalensis on the other hand, the feathering runs distinctly down the middle toe, reaching furthest down exteriorly; so that in some specimens fully, and in all nearly, one-half of the outer portion of the first joint, of the mid toe, is plumed.

Admitting that the young of both Nipalensis and Cirrhatus do generally so resemble each other, that, although the practised eye will at once separate specimens, it is difficult to express the difference by any verbal descriptions, I yet think that the difference in size, coupled with the difference of the pluming of the feet, just noticed, is sufficient to enable even a tyro to discriminate between them.

To some practised ornithologists, this detailed demonstration that Cirrhatus and Nipalensis are different, will seem superfluous and they may be tempted to exclaim in Cornish fashion " Who said they wor'nt! do you wish to argue, you beggar ?" but I can assure them, that in India, the majority of our field ornithologists, not only fail to discriminate between the young of Cirrhatus and Nipalensis, but actually disbelieve (as I did at one time myself) in the existence of any distinct species, S. Cristatellus vel Cirrhatus.

I cannot here do better than quote the remarks of Mr. R. Thompson, who, without any communication on tins subject with me, scarcely a year ago sent me the following - :

" Jerdon does not give a description of the young state of L. Nipalensis, but from his description of the early and later state of L. Cristatellus, (S. Cirrhatus,) I am inclined to think that he has mistaken L. Nipalensis for it; any how, his descriptions hold correct for the young and somewhat later stages of L. Nipalensis. The long occipital crest nearly five inches long, deep black, tipped with white, is exactly it. The L. Niveus (S. Caligatus) though sometimes with the crest, has it not so long, nor is it black, but a dark brown, edged on the upper margin with earthy white. Jerdon's description of the young state of L. Cristatellus is positively precise with the actual state of the young L. Nipalensis, excepting that beneath, this latter is not pure white, but a very light rusty with some few black centre markings."

" Last year I obtained two authenticated live specimens of the young L. Nipalensis. Photographs of these birds were sent to Mr. Hume. I have now a live one in the second stage of plumage, which would agree with Jerdon's adult L. Cristatellus only that it is very light ferruginous below, instead of pure white, as in adults of the L. Niveus." Later, Mi. Thompson after further opportunities of observation, altered his opinion and writing from Jubbulpoor in May 1869, he says, " I have got a couple of skins of Limnaetus Cristatellus, just as Dr. Jerdon describes it and I feel with him that the two races (L. Niveus and Cristatellus) are distinct. The cries of both birds are precisely similar and no ordinary observation would enable one to point out where the difference lies; but this, as Dr. J. says, will be found in the long black crest pointed white, which is always present. I have seen several, all with the black, white tipped, full crest. I only found one nest, which contained a half fledged young one, which I took and kept for some days till the heat killed it. Young as it was, the little wretch used to seize and clutch hard a chicken offered to it."

Mr. R. Thompson also says, " S. Caligatus is the bird which holds sway in the lower forests. In the Himalayas it is succeeded by S. Nipalensis; but in the more open country in the lower plains, there occurs a small semi-crested Eagle, the minature of S. Caligatus, which Jerdon nowhere describes. My specimen was shot in the act of feeding on a grey horn bill which it had chased and killed. It was not Astur Trivirgatus. It had the tarsi well feathered to the toes. The skin was sent home."

Can this bird be the F. Lathami of Tickell, referred to by Jerdon ? and is this by any chance S. Nanus of Wallace, Ibis, 1868, page 14 ? I wish some one would procure and send me specimens of this supposed dwarf Hawk Eagle. It has been repeatedly mentioned to me by sportsmen, but I have never felt sure that the young of Hieraetus Pennatus was not really what they referred to, although when shown specimens of this, I have on two occasions been told, that their bird had shorter wings and a longer tail.

It is noteworthy that Blyth remarks, that Cirrhatus never attains the black Plumage. Wallace, however, who gives as habitats of the species, Java, Penang, Sumatra, and Borneo, says, " My specimen from Java is nearly black, and that from Penang very white underneath."

To judge, however, from his synonymes, he refers to the species which I have given as S. Caligatus, and it may happen, that the Cirrhatus of some authors, is no other than S. Caligatus, while of other and specially Indian authors, the Cirrhatus is only the young of Nipalensis.

BookTitle: 
My Scrap Book
Reference: 
Hume, Allan Octavian, ed. My Scrap Book: Or, Rough Notes on Indian Oology and Ornithology. Vol. 1. 1869.
Title in Book: 
35. Spizaetus cirrhatus
Book Author: 
Allan Octavian Hume
CatNo: 
35
Year: 
1869
Page No: 
206
Common name: 
Crested Hawk Eagle
M_ID: 
2723
M_CN: 
Changeable Hawk-Eagle
M_SN: 
Nisaetus cirrhatus
Volume: 
Vol. 1
Term name: 
id: 
12519

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