No. 2. Vultur Calvus, Scop.
The Indian King Vulture.
Breeds from the latter end of January to the middle of April; but, so far as my experience goes, by far the majority lay in March. In fact, as a rule, this bird hardly begins to lay until every G. Bengalensis has hatched off.
I once found a nest with a fresh egg in November, but this was a most exceptional case. The nest I have invariably found on trees. It is said, Dr. Jerdon remarks, to breed on inacessible cliffs; but at Ajmere, where on the Taragurh hill, there are numerous suitable precipices, many of which are occupied by Gyps Indicas, I found a pair, the only ones I met with, breeding on a large Peepul tree at the foot of the hill. As far as my experience goes, the nests are always on large trees, commonly on the very top of Peepul (Ficus Religiosas) and Banian (Ficus Indicus) trees, at least 30 or 40 feet from the ground. Mr. W. Blewitt, however, informs me that he obtained an egg of this bird on the 20th February, from a large nest, (constructed of Acacia twigs and lined with leaves and straw) placed on the top of a Keekur bush (A. Arabica), in the Dhoona Beer near Hansie, at a height of about 13 or 14 feet only, from the ground. I have never found two pairs breeding near each other. The tree they commonly select is one standing altogether apart, in the middle of some Dhak (Butea Frondosa) jungle, or waste place ; but I have taken their eggs from trees, belonging to groups situated in cultivated land, and on the 1st March, 1867, I found a nest, (from which I shot the female and took the egg,) on a Peepul tree, situated right in the centre of the village of Deopoora, zillah Mynpooree. The nest is a huge flat platform, more often oval or oblong than circular, chiefly composed of sticks, varying from one inch to half an inch in diameter, loosely put together, but still from their aggregate weight and the manner in which they interlace, forming a very solid structure. They always have a lining towards the centre, often of numerous strips, from 6 to 10 inches long and from 1 to 3 broad, of the fan leaves of the Toddy palm, (Borassus Flabelliformis), but not uncommonly of Peepul, Banyan or Neem (Melia Azedirukhta) leaves, or of slender twigs of these trees to which the leaves are attaohed.
The nest varies from 2 1/2 to 4 feet in length and breadth and is often more than a foot in thickness. Though I have no positive proof of it, native hunters assure me that, when not molested, they breed year after year during long periods in the same nest, and the materials of one nest that I demolished, weighed over 8 Indian maunds (over 6 hundred weight) and proved to have at least 3 distinct layers and to have been used many times. As however I know that this bird sometimes, (like Ketupa Ceylonensis, vide infra) takes possession of old nests of Haliaetus Leucoryphus (of which bird there were several pairs in the neighbourhood) I cannot be certain, that these vultures had really, as the nest seemed to indicate and the villagers declared, bred in this same nest during many successive seasons.
They lay a single egg; I have heard it asserted that they sometimes lay two, but of the numbers of nests that I have personally examined, I never found one that contained more than a single egg or a single young one, and in upper India, I feel quite sure that one is the normal number.
The eggs, when first laid, are usually a nearly unsullied pale greenish white, but as incubation proceeds, they become greatly stained and discolored by the droppings of the parent bird. I have taken only one egg at all marked, and this showed numerous very faint dingy purplish streaks and spots, but possibly higher coloured examples may occur.
In shape, the eggs vary from rather long ovals to nearly spheres; but the normal type I consider to be a round oval.
The texture is moderately fine, the shell very strong and as a rule glossless, but I have found eggs with a faint gloss.
The egg-lining is green.
The eggs vary in size from 3.5 to 3.2 in Length, and from 2.8 to 2.45 in breadth: of 24 eggs measured, the average length and breadth was 3.34 and 2.6.
Mr. W. Blewitt tells me that, besides the nest already alluded to, he found no less than 7 nests of this Vulture, in the neighbourhood of Hansee, between the 6th and 24th March; each contained a single egg. Four of the eggs were quite fresh, two partly incubated, and one ready to hatch off, those taken on the 22nd and 24th March, being quite fresh. Two nests were not above fourteen feet from the ground, and no nest, (this is not a part of the country where trees run high,) was above 25 feet from the ground. Two were on Keekur trees, two (the two low ones) on old Heense shrubs (Capparis Aphylla) and three on Peepul, Burgot and Seeshum trees. The nests varied from 19 to 25 inches in diameter, and from 5 to 8 inches in thickness, and were all dense masses of thorny twigs of the Ber (Zisyphus Jujube) Khyr (Acacia Catechu) and Keekur (Acacia Arabica). They were fined, some thickly, some thinly, with leaves or straw, and in one the egg was regularly bedded in leaves and straw. This is not altogether in accordance with my own experience ; but in this, as in other cases, Mr. Blewitt sent me all the eggs, and more than one of the parent birds, and there can be no doubt as to the accuracy of his observations. The same gentleman took a fresh egg of this species, as late as April 13th, 1868. The nest was placed upon a Peepul tree, at the height of about 30 feet from the ground, measured about 16 inches in diameter by 6" in depth, and was composed of Keekur twigs, lined with fine straw and a few leaves. This was also in the Hansee district.
About Etawah, the native fowlers call this the " Bhaour Gidh." I rather suspect that these birds pair in the air. Just before the breeding season, a pair may be seen to tower, and then, one apparently getting on the back of the other, both come with plunges and flappings of the wings nearly to the ground, when separating they sail away slowly towards some large tree where they both rest. Mr. R. Thompson and myself have observed something very similar in the Lammergeyer. Perhaps this is only ante-nuptial play and is not the real consummation of matrimony. As regards the colour of the neck, legs and conspicuous bare thigh patch (which last Dr. Jerdon does not notice) I have remarked that it becomes much brighter, and more vivid, towards the breeding season, and is always at this time brighter in the male than in the female.
The head of the young bird (which latter has the black of the adult everywhere replaced by a more or less dark brown) is pretty thickly covered with down, (that of the adult is bare) and looks almost like a miniature V. Monachus. In its oval narines too, Calvus approximates to the round ones of Monachus, so different from the slit-like nostrils of our 4 species of Gyps, Vultur Occipitalis of S. Africa is a sort of representative of Calms, but in this species, to judge from the specimen in my valued friend Colonel Tytler's museum, (to which I owe many opportunities of comparing foreign and Indian types,) the adult always retains the down on the head as in Monachus. The narines in this bird (Occipitalis) are more oval than in Calvus, but all 3 species are closely related to each other, and the genus Otogyps scarcely appears to me worthy of retention.
Gyps Indicus (verus) and Gyps Bengalensis may doubtless give place to this bird in feeding; but it is our bird that has to give way, when it comes into the company, as I have so often seen it, of V. Monachus and G. Fulvescens (nobis, No. 3 bis).
The following are exact dimensions taken from several specimens. Length, 30 to 33. Expanse, 80 to 88. Weight, 8.5 lbs. to 11 lbs. Wing, 22.5 to 24; the third primary is the longest, the first is from 2 to 3 inches shorter, and the second from 2 to 4. Tail of 14 feathers, from 9.8 to 11. Tarsus, 4.3 to 4.6. The greatest length of the foot is from 7 to 8 inches, the greatest width, 5 to 5.5; the mid toe from 3.4 to 3.8; its claw along curve from 1.3 to 1.5, hind toe, 1.2 to 1.45 ; its claw along curve, 1.5 to 1.68; inner toe, 1.25 to 1.6; its claw along curve, 1.6 to 1.75. Bill, straight from edge of cere to point, 1.9 to 2; ditto along curve, 2.3 to 2.55; from gape, 2.6 to 3; width at gape, 1.8 to 1.95; height at margin of cere, 1 to 1.1, length of cere, 0.9 to 1.15. The olosed wings fall short of the end of the tail by 2 to 3.25. The lower tail coverts by from 3 to 5.5.
Mr. Salvin, I think, tells us how a young Gyps Fulvus devoured a half pound pot of arsenical soap, without seeming much the worse for its indigestible meal, the following remarks by Captain Hutton tend to show that Vultures generally are but little liable to injury from poisonous food. He says, " There is a curious fact which applies not only to all these Vultures, but likewise to Leptoptilus Javanicus our rain Adjutant, which it may be as well to record. In order to procure good specimens of Mammalia, I have occasionally been in the habit of placing out a carcass of some large animal, well poisoned with Strychnia, and have thus procured Foxes, Jackals, Leopards, Bears, Kites, Jays, Crows and Aquila Imperialis, but never in any instance was a Vulture or an Adjutant affected, although greedily devouring the flesh of the poisoned carcass. The eagles ate greedily for about five minutes, scarcely more, then they suddenly ceased, but instead of flying off, they stood as if rooted to the ground, and then fell prone with outstretched neck and half open wings upon the spot where they had stood; after a few convulsive croakings and gaspings they were dead. The Vultures after feeding, either soared away or sat upon the neighbouring trees, yet none ever fell, as did the smaller birds, nor did they appear to be in the least affected. A medical officer at Dehra told me he had observed the same in regard to the Adjutant above mentioned. The natural way to account for this is, the power of such foul feeders to resist the effects of things that would poison most other animals ; feeding as do the vultures upon the most putrid and disgusting substances, they may be said habitually to feed upon poison. I found, however, that deer, such as the Kakur and Goral, which are any thing but foul feeders, could eat poisoned bread without being affected by the drug, so that the matter seems to require further investigation. Aquilae Imperiales do not touch the putrid entrails in which the vultures delight, but confine themselves to the solid and non-poisonous flesh, so that they might well be supposed not to possess the same power of resisting poison rubbed into their food."