41. Polioaetus ichthyaetus

No. 41. Polioaetus Ichthyaetus. HORSF.

THE EASTERN WHITE TAILED EAGLE.*

This species generally, I believe, lays in January ; but in the valleys of Kumaon and Gurhwal, where it is, I know, far from uncommon, it is said to lay as late as April.

It builds, invariably, as far as I have yet observed, on large trees, situated on the bank of some river, or in the immediate proximity of some considerable piece of water. It constructs its own nest, returning like the Golden Eagle, year after year, to the same spot, and each year adding fresh materials, so that the nest, a very large one to begin with, grows in time to an enormous size, reminding one of Wilson's descriptions of those of the Osprey. Stout sticks, and small branches mingled with twigs and grass roots, are the principal materials, but weeds and coarse grass help to fill up the interior, in which, as in the case of Bonelli's Eagle and others, a thin layer of green leaves is commonly spread, for the eggs to rest on. The eggs are normally three in number; but I have twice seen only two eggs in a nest, in both cases fully incubated. The only egg that I now possess, (which I owe to Captain Cock,) is a broad and very perfect oval in shape. In texture, it is rough and pitted, but it nevertheless has a slight gloss. It is a perfectly unspotted egg, and though in places somewhat soiled and discoloured, must, when fresh, have been a nearly, pure, milk white. Held up against the light, the shell is even a darker green than that of H. Leucoryphus, in fact it is almost black. Whether this character is general, or peculiar to the single specimen I now possess, I cannot of course decide. I have had many of these eggs in former years; but I did not then, unfortunately, collect specimens.

Five eggs, of which I have recorded measurements, varied from 2.72 to 2.8 in Length, and from 2.1 to 2.15 in breadth.

Captain Cock sends me the following note : - : " The nest of Polioaetus Ichthyaetus is a very large structure of sticks, in fact the biggest nest that I have known of. I found one on the top of a high thorn tree, on the banks of a river. When I first visited the nest, it was empty, but the bird was sitting on the tree near it. I again visited the nest about a fortnight later, and found three eggs in it. The nest was about 5 1/2 feet in height, about 4 1/2 in diameter, and but slightly hollow. There were a quantity of leaves in the nest quite fresh. The leaves belonged to some small shrub (the leaf itself was a very small one) and were evidently placed there to make a softer bed for the eggs. The birds had built in the same tree for an immense time, but at length the tree was blown down, and they built on the next biggest tree to it, and have continued for the last few years to nidificate there. The eggs were dirty white, similar in shape and size to the one sent to you (above described.) The birds did not exhibit any anger when their eggs were taken, but the female flew round and round a few times." Captain Unwin remarks,

" I found a nest of Polioaetus Ichthyaetus in the neighbourhood of Huzara on the 27th February, 1869. The nest was situated in a large, Tulip tree, about 35 feet from the ground. It was built of sticks, stubble, weeds, and coarse grasses, and was about 2 1/2 to 3 feet in diameter. It contained two young birds. The villagers stated, that the old birds arrived every year, about November. The probable age of the young was four or five weeks; they were unable to fly, though one was is commonly spread, for the eggs to rest on. The eggs are normally three in number; but I have twice seen only two eggs in a nest, in both cases fully incubated. The only egg that I now possess, (which I owe to Captain Cock,) is a broad and very perfect oval in shape. In texture, it is rough and pitted, but it nevertheless has a slight gloss. It is a perfectly unspotted egg, and though in places somewhat soiled and discoloured, must, when fresh, have been a nearly, pure, milk white. Held up against the light, the shell is even a darker green than that of H. Leucoryphus, in fact it is almost black. Whether this character is general, or peculiar to the single specimen I now possess, I cannot of course decide. I have had many of these eggs in former years; but I did not then, unfortunately, collect specimens.

Five eggs, of which I have recorded measurements, varied from 2.72 to 2.8 in Length, and from 2.1 to 2.15 in breadth.

Captain Cock sends me the following note : - : " The nest of Polioaetus Ichthyaetus is a very large structure of sticks, in fact the biggest nest that I have known of. I found one on the top of a high thorn tree, on the banks of a river. When I first visited the nest, it was empty, but the bird was sitting on the tree near it. I again visited the nest about a fortnight later, and found three eggs in it. The nest was about 5 1/2 feet in height, about 4 1/2 in diameter, and but slightly hollow. There were a quantity of leaves in the nest quite fresh. The leaves belonged to some small shrub (the leaf itself was a very small one) and were evidently placed there to make a softer bed for the eggs. The birds had built in the same tree for an immense time, but at length the tree was blown down, and they built on the next biggest tree to it, and have continued for the last few years to nidificate there. The eggs were dirty white, similar in shape and size to the one sent to you (above described.) The birds did not exhibit any anger when their eggs were taken, but the female flew round and round a few times." Captain Unwin remarks.

" I found a nest of Polioaetus Ichthyaetus in the neighbourhood of Huzara on the 27th February, 1869. The nest was situated in a large, Tulip tree, about 35 feet from the ground. It was built of sticks, stubble, weeds, and coarse grasses, and was about 2 1/2 to 3 feet in diameter. It contained two young birds. The villagers stated, that the old birds arrived every year, about November. The probable age of the young was four or five weeks; they were unable to fly, though one was pushed outside the nest. I subjoin the dimensions* and a brief description of one of these young birds which I took from the nest. Later, while watching the tree, through a glass, from a distance of some 150 yards, I saw one of the old birds arrive, with & fish, I should think nearly 2 lbs. in weight, in its claws."

Horsfield (Zool. Res. in Java) tells us of this species, that " their nest was built on the top of a large tree, and was constructed in a rude manner, of branches of trees. The branches which were placed on the exterior, were more than an inch in diameter: the inside was lined with small twigs. It was irregularly round, and very slightly excavated.."

My friend, Mr. Thompson, writes to me from Gurhwal that these birds " breed from March to May. The nest, which is a large structure of small sticks and twigs loosely put together, is usually placed in a tree at a convenient distance from the water, and at no great height from the ground, I have found their nests on the Kosilla river, at Oomta Dabee, in the Patlee Dhoon, on the Ramgunga river; Kotree Dhoon on the Sunnai river; and lastly above Hurdwar on the river Ganges. They lay from two to three large white eggs, smaller than those of Haliaetus Fulviventer. Three appears to be the normal number of their eggs. During the breeding season, the birds utter at intervals, a loud yet plaintive cry, especially whenever one of them approaches the nest whilst the other is sitting in it. The male during this time is assiduous in his attentions, and the meeting of the pair on his return from fishing excursions always appears to call forth fresh cries. About the middle of April the eggs are laid, and are hatched during the following month. These birds are generally distributed over the rivers and larger streams of the Sub-Himalayas, remaining on them throughout the year."

Mr. Blyth had the following note in the Ibis for 1865; " Haliaetus Lineatus, Gray (Hardwicke's Ill. Ind. Zool.) is erroneously assigned in the Ibis, (1863, p. 23) to the young of Milvus Govinda, it being decidedly the young of Pontoaetus Ichthyaetus (Horsf.) in abraded, spotted plumage; for the young of this bird, and of M. Govinda are quite similarly speckled."

This does not exactly agree with Captain Unwinds descrip¬tion, recorded on the spot from a live young one, taken from the nest to sit for his portrait, and for my part I am inclined to -believe, that H. Lineatus, Gray, is the young not of this species, but possibly of the next, H. Leucoryphus. This species occurs not only all over India, Burmah and Malay, but also as we learn from Mr. Wallace* (Ibis 1868) in Sumatra (Wall) and Borneo. (Mus. Lugd.) .

* I am obliged to add the word " Eastern" to the English name given by Dr. Jerdon, because the " White Tailed" Eagle, or Sea Eagle, is the name by which a very different species, the European, H. Albicilla, is universally known.

It is probable that the object of laying the eggs on green leaves, is to secure a certain amount of moisture for the shells.

Eggs artificially hatched, have, we know, to be daily sponged with a moist cloth. Great numbers of birds leave their eggs for a short time about sunrise, to feed in grass and jungle, and return all " dewy breasted" to their nests, so that I have taken Pea-fowls' eggs, quite wet from this cause. But how is sufficient moisture secured for eggs laid, like those of the Sand-grouse, on the bare, absolutely dry sand, whose parents feed in the dryest ground, (never, even when they drink, wetting their feathers in the slightest) and return dry-breasted to their eggs ?

* Expanse, 64 inches; wing 17; length 25; tail 8.25 ; bill at gape, 3.5 ; Tarsus 3.5.

Description - : Irides dark brown ; cere brownish; gape and orbital skin, pale yellow; legs and feet pale yellowish white ; bill and claws horny black; lores naked and whitish, thinly covered by blue hairs. Plumage, above, dark brown, primaries and tail blackish, 3rd and 4th quills longest, Secondaries on inner web pale fulvous, slightly speckled with dusky. Beneath of a somewhat lighter brown throughout.

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: 
41. Polioaetus ichthyaetus
Book Author: 
Allan Octavian Hume
CatNo: 
41
Year: 
1869
Page No: 
239
Common name: 
Eastern White Tailed Eagle
M_ID: 
3074
M_CN: 
Grey-headed Fish Eagle
M_SN: 
Haliaeetus ichthyaetus
Volume: 
Vol. 1
id: 
12466

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