No. 28. Aquila Naevia, GMEL.
THE SPOTTED EAGLE.
The Spotted Eagle breeds commonly throughout the Oudh and Rohilcund Terai, the Dhoon and the northern portion of the Saharunpoor district, (and probably in many other suitable localities) but I have never myself had the good fortune to see or take a nest. My friend, Capt. Marshall, R. E., furnishes me with the following note on the nidification of this species.
" Builds in the Saharunpoor district in the end of May and beginning of June. The nest is commenced about the end of April and the young are hatched by the middle of June.
" The nest is placed in a fork near the top of a large tree, about thirty-five or forty feet from the ground. All that I have found, have been in the line of trees along the bank of the Eastern Jumna Canal, on the outside ones farthest from the water, and always in Sheesum trees. I found four nests, one with young (on the 10th June) and three with eggs on the 22nd of May and 3rd and 11th of June. All the eggs were hard set. The nest is a large circular platform-like structure of sticks, with a few dead leaves in the egg receptacle, but no other lining. I noticed no remains of food in any of them. The diameter of the whole nest was about twenty inches, and the interior depth about two inches. I have never found more than one egg in any nest; the egg now before me is a perfect, but very blunt oval; of a slightly yellowish white ground, somewhat profusely spotted and blotched with rather faint yellowish brown, and a pale washed-out purplish brown, which latter colour greatly predominates; the egg is absolutely glossless."
An egg which I owe to Capt. Marshall's kindness, is a broad oval in shape, and has a greyish white ground, richly blotched and spotted with pale purple. This egg is somewhat larger in every way than that figured by Mr. Hewitson; it has no gloss, and when held up against the light, the shell, as in all these Eagles, is a bright sea-green.
This egg and the one above described by Capt. Marshall, measure respectively 2.7 X 2.2 and 2.5 X 1.96.
The egg figured by Mr. Hewitson from Mr. Wolley's collection, measures 2.44 by 2.02.
Without pretending to dogmatize in regard to a matter which I have not by any means fully investigated, I am inclined to think, that the ohanges of plumage in this species, have not yet been satisfactorily determined.
There are two supposed races of this bird, one the western, or smaller form, A. Naevia, Gmel. and the other the eastern and robuster form, A. Clanga, Pallas. Now whether this latter be really a form of Naevia, or whether as I suspect, it really represents the second stage of A. Imperialis (q. v.) it seems certain to me that our bird is the feebler or eastern form, the true Naevia of most European authors. Further on I shall give exact, and more or less detailed, measurements, and descriptions taken from eleven fresh speci¬mens of this species, but I wish first to premise that, accord¬ing to my views, this Eagle has three well marked stages of plumage.
1st. The buffy, or buffy fulvous.
2nd. The purple brown, white spotted.
3rd. The uniform deep brown stage.
In all these stages, where the sexes have been ascertained, this species can at once be separated, by its much smaller size, from, A. Imperialis, while from A. Fulvescens, it may be distinguished ; first, by its invariably barless tail; secondly by its more silky, and soft plumage, and thirdly by its rounder nostrils.
The utmost confusion seems to prevail amongst some, at least, of the continental ornithologists as to this, and kindred species. Radde, I find, boldly uniting A. Naevia, A. Naevioides, A. Clanga, A. Bifasciata, and A. Fulvescens. The best of it is, that the measurements and descriptions (such as they are) that he gives, clearly prove to me that with one exception, his supposed Naevias are all forms of A. Imperialis, more or less intermediate, (because killed in April and May) between the four stages described by me when dealing with that species.
That Bifasciata is a form of Imperialis is I think certain.
That Naevia is utterly distinct from Naevioides and Fulvescens is equally certain.
That Fulvescens, Fusca, and Punctata, are one and the same, is beyond doubt; but whether these are, or are not, distinct from Naevioides is yet doubtful, though I incline to believe them so.
That our common upper Indian Spotted Eagle is identical with that of western and southern Europe, the true Naevia, figured by Yarrel, the detailed dimensions and descriptions given further on, will, I believe, sufficiently establish.
Whether A. Clanga is a true species, or whether Pallas like Radde, ignorant of the four-fold change of plumage in A. Imperialis, obtained specimens of this latter, between the 1st and 2nd, and 2nd and 3rd stages, and to these gave the name of Clanga, I cannot decide, but I am strongly disposed to think that this is the real origin of the supposed more robust form of A. Naevia.
The absolutely unbarred tail, is at all ages, characteristic of the Spotted Eagle ; I can show a sequence of some forty odd birds, from the pale buff, to the deepest umber or liver brown, not one of which exhibits a trace of barring on the tail; while per contra, I can show a still larger series of Fulvescens, every bird in which (except three in which the tails are terribly abraded and bleached), shows unmistakable barrings on the centre tail feathers. Besides this, the difference in the texture of the plumage, (that of Fulvescens being comparatively stiff, harsh, and thin, that of Naevia, soft, silky, and dense) in the strength of the bills, feet and legs, and in the shape of the nostrils, suffice to separate these two species conclusively. Both go through, it is true, not very dissimilar changes of plumage, and individuals of both races may be found so similar in general appearance, that even good figures of them might wholly fail to prove them different, but a mere glance at the tails, the first touch almost of the plumage, or a comparison of the bills, nostrils and feet (supposing the sexes to be known) would unmistakably show how distinct they were.
Naevia, with us, at any rate, is a bird frequenting moist localities. Where large jheels abound, or where canal irrigation is extensively resorted to, there Naevia (in upper India at any rate) is very common, but in the dry sandy plains, which occupy so vast a portion of the surface of Continental India, this species is extremely rare.
A remarkable fact as to change of geographic distribution, resulting from modification of the physical aspect of a country by human industry, came under my own notice in connection with this species. The Etawah District between Cawnpore and Agra, belonged essentially to the dry sandy class. For years I shot through this district without ever obtaining a single specimen of the Spotted Eagle. After a time the Granges Canal, with innumerable, minor channels was opened out through the district. Huge tracts . came under irrigation. A year or two passed away, when suddenly one day, shooting with Mr. Brookes, along the canal, we found the Spotted Eagle common. Subsequently, numerous specimens were obtained at various localities in the district in the neighbourhood of the canal. I thought I might possibly have overlooked this species in past years; but this seemed unlikely, because winter and summer I daily had one or two men out shooting, and even had I always passed it over, one or other of them must have killed it. However, this matter was set at rest, by several Aheriahs, (native hunters and bird-catchers by caste), spontaneously pointing out this bird to me, as having only appeared in the district during the last two years. This species has always been plentiful in the Dhoon and the northern portion of the Suharunpoor District, in which the Granges Canal has its origin, and there can be little doubt that as the canal, year by year, was opened out further and further, developing tracts suited to their tastes, the Spotted Eagles (whose favourite food with us is unquestionably* frogs,) rapidly followed its course.
This bird, generally sits in a very slouching kite-like fashion, across a branch, half way up a tree. Fulvescens, on the other hand, more commonly sits bolt upright, in the centre of the very top of a tree; so that, when looking from a distance, you see his head and half his body, against the clear sky above the very top of the tree, while when close to the tree, you cannot see him at all. Imperialis too, often adopts a similar position.
If Clanga be a true species, and not a form of Imperialis, as I cannot help suspecting, it is curious that the true Naevia should occur in India and western Europe and Clanga in Palestine. Mr. Tristram (Ibis, 1865) tells us, that the Spotted Eagle is " much more common in winter than in summer on the plains. We observed it only two or three times in the Lebanon in spring. Mr. Gurney has pronounced a specimen I showed to mm, to belong to the large form described by Pallas as Aquila Clanga. I found one nest in a tree, between Nazareth and Caiffa."
I now give, in a tabular form, exact measurements of eleven specimens. These are not perhaps well chosen, but they are all I have by me, and they were all recorded from the fresh bird, with the utmost care.
As in the case with Imperialis, so here, one of my reasons for believing in the specific identity of all the various forms hereafter to be described, (and the dimensions of whose representatives, I am now about to give) is the close structural resemblance of all these latter in every minute detail.
Length, 26.5 25.5 26.0 27.75 27.5 27.88 26.75 27.5 28.0 28.5 27.5
Expanse.... 61.0 63.0 64.0 67.0 68.0 69.0 69.5 68.0 69.0 72.0 73.0
Weight in lbs.... 3.94 3.38 3.81 3.5 3.56 3.81 3.56 4.16 4.19 4.2 3.98
Wing,...... 19.26 19.0 19.75 19.5 20.0 20.5 20.0 20.75 21.0 20.5 21.0
Which primary the longest, 4th 4th&5th 5th 4th 4th&5th 4th 5th 4th 5th 4th 4th
By how much other Primaries fall short of longest 1st 4.13 3.88 3.75 4.13 4.63 4.0 4.88 4.63 4.5 3.9 4.5
2nd 1.5 1.19 1.25 0.88 1.38 1.75 1.88 1.38 1.5 1.6 0.9
3rd 0.5 0.38 0.41 0.13 0.5 0.43 0.38 0.38 0.7 0.2 0.37
Length of tail from vent.... 10.63 11.0 11.0 11.75 11.6 12.0 11.6 12.0 12.0 12.2 11.5
By how much longest feathers exceed shortest, 1.18 1.13 1.0 1.13 1.13 1.0 1.0 1.0 1.1 1.2 1.3
Tarsus, 4.06 8.94 3.92 3.5 4.25 4.0 3.94 4.0 3.8 3.82 4.0
Foot, greatest length 5.5 5.25 5.3 5.75 5.63 6.0 5.38 5.63 6.0 5.88 5.7
Ditto, greatest width, ....... 4.75 4.75 4.68 5.0 4.88 5.25 4.5 5.0 5.07 6.0 4.65
Mid toe 2.19 2.13 2.17 2.13 2.25 2.44 2.22 2.'44 2.5 2.37 2.5
Its claw, along curve, 1.25 1.25 1.3 1.25 1.25 1.19 1.13 1.13 1.38 1.25 1.25
Hind toe..... 1.13 1.13 1.1 1.13 1.13 1.19 1.09 1.19 1.16 1.08 1.15
Its claw, along carve, 1.66 1.5 1.6 1.63 1.56 1.31 1.44 1.56 1.75 1.38 1.5
Inner toe, 1.21 1.3 1.28 1.4 1.43 1.5 1.4 1.52 1.51 1.49 1.5
Its claw, along curve, 1.4 1.37 1.38 1.42 1.53 1.63 1.4 1.61 1.6 1.47 1.37
Bill, straight, including cere,. 1.81 1.88 1.9 1.97 1.88 2.0 1.94 1.81 1.94 1.94 1.9
Ditto, along curve, ditto ditto, 2.25 2.25 2.27 2.38 2.31 2.47 2.38 2.38 2.37 2.4 2.5
Ditto, from gape, 2.28 2.63 2.7 2.38 2.31 2.38 2.49 2.38 2.44 2.4 2.3
Ditto, width at gape, 1.69 1.75 1.76 1.75 1.75 1.88 1.69 1.88 1.89 1.78 2.0
Ditto, height at margin of cere, 0.66 0.69 0.7 0.69 0.72 0.75 0.69 0.72 0.78 0.72 0.75
Length of cere, 0.69 0.75 0.73 0.75 0.75 0.75 0.69 0.66 0.69 0.78 0.75
Distance by which the closed wings fall short of end of tail,. 1.0 0.5 Nil. 0.88 0.88 end of tail. 0.25 beyond end of tail. 0.25 0.25 Nil. 0.2
Distance by which lower tail coverts fall short ditto 3.25 3.5 3.6 3.63 3.5 3.5 3.0 3. 25 3.75 4.0 3.9
DESCRIPTION. I first take No. 1 male, as fairly typical of the first stage of Plumage.
Feet, pale dingy yellow; claws, darkish brown; iris, pale yellowish brown. The whole lower mandible and basal half of upper mandible, greyish white, with a tinge of blue; tip of upper mandible, horny brown; cere and gape, pale dingy yellow.
Plumage. The whole head, throat, neck all round, breast, sides, abdomen, and thigh coverts, a pure buff. Most of the feathers, darker shafted, and those of the top of the head conspicuously so; a narrow dusky, ill-defined supercilium running backwards over and behind the ear coverts. Upper back and scapulars, light brown, the longest of the latter only somewhat darker, and all but these broadly margined with fulvous white, and with the margins much abraded. The middle of the back, buff, the bases of the feathers, white, and showing through. The feathers of the rump, light brown, broadly margined with buffy white and white. The upper tail coverts pure white. The tail brown, paler towards the tips, the margins of which are almost white. The lesser and median coverts, light brown each broadly margined with buff towards the base, and white towards the tip.
The greater coverts, except those of the first three or four primaries, a rather darker brown than the median, margined towards the tips with white, and those of the last three primaries margined with white the whole way up the outer webs. The first seven primaries as in the adult; but the outer webs above the emarginations a redder brown. The last three primaries not only tipped with white, but with a broad white margin all the way up the outer web. The winglet, the greater coverts of the first three primaries and the secondaries a rich umber brown, showing in some lights a purple gloss; the secondaries narrowly tipped with white. The axillaries, and the whole of the lower lesser wing coverts and median coverts, except just at the carpal joint, a warmer buff than even the breast; a sort of rufous salmon colour, I might almost call it; feathers below the vent, and lower tail coverts a slightly buffy white ; (as in the adult) longest thigh coverts, and tarsus feathers, dirty fulvous, or buffy white.
Next as typical of the second stage, I take No. 4 a female, shot at Rahun, February 20th, (the male above described, was shot at the same place, on the same date, in company with this very female).
DESCRIPTION. Feet, pale wax yellow ; claws, black above, horny brown beneath, scutae reticulate, inconspicuous, 5-4 well marked transverse scutae at the ends of the mid toes, and 4-3 at the ends of the others, inner edge of mid claw a little dilated. Irides, a rather light brown. Eye shelf and edges of lids plumbeous, lower lid nearly white, with a few tiny tufts of down. Bill, bluish grey at base of both mandibles, and horny black at tips, cere and gape pale wax yellow.
Plumage. The skin of the lores pale bluish, pretty thickly set with tiny pale brown feathers, the dark naked prolonged shafts of which at front curl upwards and outwards towards the nostrils and forehead like soft bristles. Forehead, top, and back of the head, a rather light umber brown, the feathers specially of the hind head, very narrow, sharp pointed, and paling towards the tip. From the gape, under the eye and over the ear coverts, a patch of brown lighter than the top of the head. Below this from the side of the lower mandible a slightly darker band, than either the above mentioned ear patch, or the throat, which latter with the chin, is about the same colour as the ear patch, but looks lighter, as the feathers are rather sparsely set, and allow the white bases to show through a good deal. The neck all round, upper back, scapulars, and lesser wing coverts an uniform rich umber brown, a shade darker than the top of the head; a few of the longer scapulars have a central fulvous white spot on the tips, two or three of the median scapulars on one side have a trace of the same kind of spot. Lower back and rump the same rich umber brown, but each feather with a conspicuous somewhat pear-shaped, brownish or fulvous white spot at the tip. The upper tail coverts slightly-fulvous white. The tail feathers nearly uniform blackish brown, the shafts of the basal one-third white, or whitish. Near the tips, the colour fades to a sort of sandy brown, and there is a trace of a pale tipping. The median and greater coverts much the same colour as the lesser coverts, but all the greater coverts, except the first three or four (which with the winglet are a rather darker brown still) conspicuously tipped with fulvous white, and all the longest, and a few of the other median coverts with central, fulvous white spots at the tips. The secondary greater coverts are conspicuously mucronate, and abraded at the tips. The second to the sixth primaries are emarginate on the outer webs, the emarginations being high up, in the second hidden by the coverts. The first to the fifth are strongly notched on the inner webs, the notches being almost equally high up. The first six primaries are blackish brown below the emarginations and notches; above they are umber brown on the outer web, and greyish, mottled with brown, on the inner web. The rest of the primaries and secondaries are tipped inconspicuously with brownish white, have the outer webs umber brown, and the inner pale greyish brown, with numerous close, rather narrow, ill-defined, brown transverse bars. The whole upper surface has, in a good light, a certain purplish gloss. Breast, sides and upper abdomen, the same rich umber brown as the neck, but each feather with a narrow, paler, somewhat sandy, central streak, these becoming larger and more conspicuous as the feathers recede from the neck; on the lower abdomen, the central streak occupies nearly the whole feather, and the feathers immediately above the vent, are wholly of this sandy brown hue. The thigh coverts are the same rich deep umber, but the longest are tipped with fulvous white, and those above them have central fulvous white spots at the tips. The whole of the feathers below the vent, and lower tail coverts, rather dirty, or slightly fulvous white. The lesser and median lower wing coverts the same rich umber brown, a few of the latter over the first few primaries with terminal fulvous spots. The larger lower wing coverts greyish brown, faintly and irregularly mottled, with greyish white. Tarsus a paler brown than the thigh coverts, mottled behind with dingy white, and with the terminal feathers in front of the same colour.
I next take No. 11, a female, as typical of the third or uniform deep brown stage. Shot on 27th December.
DESCRIPTION. Feet bright orange yellow. Irides deep brown. Cere and gape, orange yellow. Bill, blue dusky at tips. Tongue rather long and narrow, of nearly equal width throughout, obtuse ended, with conspicuous central groove.
Plumage. The whole bird a nearly uniform rich umber, or deep liver brown, the quills and tail feathers almost black, and these and the longer scapulars with a perceptible purple gloss. A narrow white tipping to the longest upper tail coverts, and a few of the feathers near the vent, a little mottled with white; no trace of white tipping or mottling to any other portion of the Plumage. The bases of all the feathers are white, but the bird is so well feathered that these nowhere show through. The brown of the head, neck and throat is slightly paler than that of the rest of the body, and the feathers of both head and nape have traces of slightly paler brown, narrow central stripes. A few of the lesser and median wing coverts, old abraded feathers, are a somewhat paler brown. I have another bird before me very similar to this one, except that the whole plumage is a still darker brown, there is no admixture of paler feathers in the wing coverts, the faintly paler centres of the hackles are almost wanting and the tarsal feathers are pure white. This I take to be the oldest form. I have seen and preserved several such, but have unfortunately failed to record measurements from the fresh bird in any of these. As far as can be ascertained from the skins, they correspond precisely with the dimensions above recorded.
In the second stage considerable variations occur. Of No. 10, a bulky looking female shot near Juggernathpoor in March, and which is decidedly in younger plumage than the one which I have described as typical, I have the following note : -
The whole bird is a lighter and duller brown, and its spots are a duller fawn or dingier fulvous white than those of the No. 4 type. There is no purple gloss. The chin is darker and more the colour of the front and top of the head, where there is little trace of the pale tippings. On the other hand, the pale brown tippings are more conspicuous on the feathers of the hind head and upper part of the neck. The breast, abdomen and sides are nearly uniform dull pale wood brown, with only here and there faint traces of the rich dark umber brown margins so characteristic of this stage. The longer thigh coverts again, are almost wholly dingy fulvous white, with only a mottling of dingy umber brown on the basal halves. Lastly, the rump is mostly a dingy fulvous, the feathers only having narrow dingy umber brown margins, which do not extend to the tips. The bird, though much nearest to No. 4, appears intermediate between it and No. 1.
Of another, I say, No. 5, female resembled No. 4 closely, but there was a much richer purple gloss on the whole upper surface, which also was somewhat darker; the ear patch was not so light, the spots on the scapulars and lower back and rump were larger and more conspicuous, and in the case of the scapulars far more numerous. The upper back and base of the neck behind, of uniform colour in the first, have in this specimen terminal, central buffy spots. The pale tippings to the feathers of the head were far more conspicuous, every one of the median wing coverts had its terminal spot, and most of the lesser have also a minute buffy white linear spot, or speck at the tip. There was somewhat less white about the upper tail coverts. Below, the surface generally darker and the central streaks lighter and far more strongly marked. A patch of feathers on the breast, a sandy brown, (though not so pale as the central streaks of the lower feathers) only narrowly margined with the deep umber brown. There was rather more white about the tarsus above the foot. The pale tipping of the tail feathers was also more conspicuous.
No. 3 male, was an older bird, intermediate between the second and third stages, " not a speck or spot on back of neck, upper back, shoulders, lesser and median wing coverts, except at the very tips of the longest of the latter. None of the quills, except the last three primaries with more than the faintest trace of pale tippings, only a few minute specks on the scapulars. Scarcely any pale centering to the breast feathers, and far less of this on the abdomen than in any of the preceding" (viz. Nos. 2, 4, 5 - : 10).
Further I may add that No. 2 male, and No. 6 female, were identical in plumage with No. 4, though No. 2 was smaller and No. 6 a little larger. No. 7, a female, the smallest obtained, was much the same type as No. 5 as regards the amount of spotting ; in other respects differed from Nos. 2, 4 and 6, but little. The longer thigh coverts were, however, almost wholly fulvous white, the spots being so large as to occupy nearly the whole surface of the feathers. Nos. 8 and 9 were between No. 7 and Nos. 2, 4 and 6) the throats and breasts being perhaps a purer and darker brown.
In all the specimens of the first and second stages of plumage that I have examined, the ovaries and testicles have been so little developed, as to render the discrimination of the sexes, a matter requiring care and a magnifying glass. In all specimens of the third stage of plumage, they have been well developed.
I think I ought to note, that my valued friend, Mr. Brookes, differs from me as to the first stage described, really pertaining to this species. He believes it to be distinct. For my part, the exact structural correspondence, the possession of more or less intermediate forms, and the fact that in a part of the country where the Spotted Eagle is common, these pale buff birds were pointed out by native fowlers, as the young of the species, incline me to the opinion already expressed of the specific identity of the two forms.
Mr. C. Farman, in the Ibis for 1869 gives the following particulars in regard to the nidification of the Spotted Eagle in Bulgaria.
"In the spring of 1865, I observed a nest of this bird placed on an Ash tree overhanging the stream at the southern entrance of the Pravidy valley : it was more neatly put together than most of the Eagles' nests, and was warmly and softly lined with the blossoms of the Ash tree; it contained one young bird just hatched, and two eggs already cracked by the young birds within. On the edge of the nest were the two fore legs of a Leveret."
* Vide Ibis, 1867.
" The other day, half-way up Apis Hill, on a white patch caused by a heavy landslip, I observed what I took to be a black tree stump ; but a shining white spot on it excited my wonderment. As we ascended the mass of coralliferous debris, the stump-like object took wing, and slowly napped away amid the hoots and grunts of several monkeys that were sporting on the hill side. I then saw that it was an adult Imperial Eagle (Aquila heliaca,) the white spot being one of the conspicuous shoulder patches this bird carries in the mature Plumage."
* These, with us in India, are not like ploughed fields at home. Here ridge and farrow together barely exceed 5 inches, as a rule.
* Dr. Bree lays stress upon the number of transverse scuta on the ends of the toes ; it will be seen from this and subsequent descriptions that this is variable in the extreme, even in the two feet of the same bird, and can therefore, in no way be relied upon, as a specific character.
* I have unfortunately not preserved a record of the contents of the stomachs in more than thirteen cases. In eleven of these " Frogs and Toads, chiefly small" are recorded. One I shot in the act of eating part of the liver of an Antelope we had killed, and one had eaten a Rat.