THE GREAT FOREST EAGLE.
IN the penultimate number of the This Mr. W. R. Ogilvie Grant relates the story of what is perhaps the most interesting ornithological discovery of recent years. Mr. John Whitehead, a naturalist who has de- voted much time to the exploration of the different islands of the Philippine group, had formed, among other collections of birds made in this region, a series of those inhabiting the island of Samar. This collection was lost at sea near Singapore, and in order to replace it and restore the lost link in his chain of examples of " island life" in this little-known region, he once more set out from Manilla in 1896 and estab- lished himself again in the woods of Samar. In doing so he had no other choice than to become one of the inhabitants of the tropical forest. Samar is all forest, and there was no more escape from it than there is from the desert or the steppe for those who elect to travel in Arabia or Central Asia. The great tropical forest which belts the world is very much the same, whether in Central America, or the Amazons, or the islands of the Malay Archipelago. Its peculiarity from the human point of view is that life goes on on two levels. There is an upper story and a basement. The basement is the ground, on which by the strict law of the forest no creature is supposed to live at all, except perhaps the few species of forest swine which, with various differences of form, haunt the great forests in America and in the Malay Archipelago. But of all ground-dwelling creatures which venture into this "crypt" of the tropical forest, man is at the greatest disadvantage. He walks beneath a roof of foliage so lofty that he can scarcely distinguish the forms of the branches which support its leaves, supposing that there were light sufficient to use his sight to good purpose. But the tops of the giant trees are so dense that light scarcely penetrates, and the would-be explorer of the forest, and discoverer of new species of birds and beasts, finds that be has to tread the mazes of a temple of twilight, in which all the life, light, and beauty exist, not below and within, but upon the roof. On the side remote from earth life goes on gaily, and with such completeness, that not only do the birds, insects, and monkeys enjoy a world of their own, but in the cups and reservoirs of the gigantic flowers and creepers water-insects and molluscs live and reproduce themselves without ever coming in contact with the ground.
In the island of Samar this impracticable forest is found in its most impracticable form. Life there is more "aloof " from the ground level than in any other forest region. Mr. Ogilvie Grant dwells with due emphasis on this often forgotten "aspect of Nature" in these regions. He points out that the greater part of the island is covered with dense and lofty forests, many of the trees being over 240 ft. high, while there are no hills or rocks from which the forest can be surveyed. The forest animals, monkeys, lorises, and the like, live at a height of 200 ft. from the ground, that being the "sunlight level," below which direct light and heat do not penetrate. Invisible, on the top of this region, live the birds of the tropical forest ; and on a still higher aerial plane, also invisible, float the raptorial birds which prey upon them. This" tree-top" plane of the great forest being still terra incognita, has always been regarded as a possible region in which some great bird or ape may be discovered ; and in spite of accumulated difficulties, Mr. Whitehead did make such a discovery. He has found, and brought home from the island, the largest raptorial bird yet discovered, the great forest eagle of Samar.
The discovery of this mighty bird of prey is the more creditable to the explorer, because only one pair of the giant eagles was seen. Their haunt was watched daily, and at last the male bird was shot, and though it remained in the top of one of the lofty trees, clinging firmly with its huge claws to the branches, a native climbed to the summit and brought it down. Its weight was judged by Mr. Whitehead at between 16 lb.
and 20 lb., and being then weakened by fever he could scarcely hold it out at arm's length. Taking the mean of the two weights mentioned as probably correct, the great forest eagle weighs exactly half as much again as the golden eagle, the female of which weighs 12 lb.
The skin of this bird is now preserved at the Museum of Natural History at South Kensington. As it is the only adult specimen in the world available for inspection by naturalists, it is not exhibited in the public part of the col- lection, and though the coloured plate by Keulemans which illustrates Mr. Ogilvie Grant's paper is a model of accurate drawing, it does not leave the impression of size given by the skin when actually seen and handled. The length of the eagle and the huge size of its beak and claws are the features most striking in the specimen at South Kensington. Like most raptorial birds which seek their prey in woods or forests, from the sparrow-hawk upwards, it has rather short wings in propor- tion to its great bulk. The tail, on the other hand, is very long. In its equipment for flight and steering it is much like an enormous goshawk. There are two or three such hawks, as large as many of the eagles, half goshawk, half buzzard, which have been found in parts of the tropical forest, though for the reasons mentioned above they are very rarely seen, and still more rarely captured for collections. But in its combined armament of beak and claws the forest eagle exceeds not only all these great hawks, but each and every one of the other eagles. The beak is not larger than that of Pallas's sea eagle, and the power of the wrist and claws is not so great as that of the harpy eagle. But the combination of the two weapons of offence possessed by the Samar eagle is greater than that of either of the formidable species named.
The beak is so hooked that the outline in profile is the perfect segment of a circle, the exact centre of which is the point at which the skin, called the cere, joins the cutting edge of the upper mandible. Mr. Grant notes that the depth of the bill is greater than that of any known bird of prey, except Pallas's sea eagle, and it is so compressed that the edges must cut
like a doable-bladed knife. The skull is very large, much larger than that of the harpy eagle, and the claws and feet are specially adapted for holding large animals with close, thick , fur. the length of wrist and close covering of scales giving fulls play to the talons. The nature of the prey against which thibf exceptional armament is directed is still matter of conjectar'? The natives say that the eagle lives mainly by killing monkeys.
This is a very probable statement ; there is some evidence from the state of the eagle's skin brought to Europe that it takes its prey on the trees. The quills of several of the wing and tail feathers were broken, "bearing testimony to many a savage struggle among the branches." The green macaque is the monkey believed by the people of Samar to be the chief prey of their great eagle. But among the monkeys of these islands are several species of singular size and strength. Even if the great apes of Borneo are not found in Samar, there are probably other species of the monkey tribe, like those found in Java and in the neighbouring islands, which would be most dangerous animals for any bird to attack. No creatures are, for their size, so full of unexpected resources when attacked as the medium-sized and large monkeys. Their arms and hands are surprisingly strong. They can leap instantaneously for a considerable distance without gathering their bodies together for a spring, and their power of biting is that of a bulldog.
Against birds they have the power, which they well know how to use, of grasping and breaking a limb, or tearing out the wing or tail feathers. Their habit of combining to rescue one of their fellows makes them still more formidable to animals of prey ; and, with the exception of the leopard and the python, moat of these agree to let the " bandur-log " alone. A battle between the great forest eagles and the great forest apes must be one of the heroic episodes of " high life above stairs " in the jungle, and it may be hoped that when the pacification of the Philippines renders it possible for Mr. Whitehead to revisit the islands, he may bring back some " field-notes " on the daily life of the new eagle. It is characteristic of the difficulty of making such observations, that though he never saw the bird on the neighbouring island of Leite, he often heard its cry above tie tree-tops, and identified it by his experience in Samar. It .s also said to be found on the island of Luzon.
Mr. Ogilvie Grant conjectures that the crowned harpy eagle of tropical America is the nearest known ally of the great forest eagle of the Philippines. In this connection it is interesting to note how very little is still known of this other forest eagle. Mr. Salvin, during several years spent in the forests of Central America, only once saw a harpy eagle. Oswald in his " Birds of America" gives perhaps the fullest account of its habits. The list of its prey shows how formidable a creature it is, and enables us to form some idea of the prowess of the great raptor of Samar. In Mexico the harpy eagle " kills fawns, sloths, full-grown foxes and badgers, middle-sized pigs, and the black Sapa.jou monkey, whose weight exceeds its own by more than three times." This last feat may be compared with the natives' statement that the Samar eagle also lives on monkeys. But the most interesting reference to the harpy eagle is one quoted from the pages of De Vega, the Spanish historian. He states that the Mexican and Aztec nobles were in the habit of keeping trained harpy eagles for purposes of sport. A Mexican satrap presented one of these eagles to Cortez, valued at the price of ten slaves. The only bodily injury received by Cortez during his adven- tures in Mexico was inflicted, says the historian, by this eagle, called El Hidalgo del Aire, when dying from a wound in- flicted by Cortez in a moment of passion. " Before it resigned itself to death it raised its head once more, and caught the first finger of the right hand of its cruel master, and bit it through, crushing it completely, so as not to leave the world nnavenged."
Considering the interest attaching to the habits of all raptorial birds, and especially to those of the eagles, it is matter for regret that so little authentic observation has been recorded about their habits. It is only recently that observers like the late Mr. Booth took the trouble to watch and record the daily life and adventures of the golden eagle. Of the ways and habits of many of the foreign eagles there is almost no account available. Mr. J. G. Millais in his " Breath from the Veldt " gave an admirable description of the method of hunting used by the Batelenr eagle. But few or none of the numerous other eagles of Africa have found a vates sacer to record their feats. Mr. Ogilvie Grant has recently written an excellent " Handbook of the Game Birds,"* dealing with the various species included in this category in all parts of the world. He might well follow up this work with a monograph on the eagles, containing authoritative accounts of the ways fun/ habits of the very numerous and beautiful species found m all countries from the Poles to the Equator.
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