(2030) Heliopais personata Gray.
THE MASKED FINFOOT.
Heliopais personata, Fauna B. I., Birds, 2nd ed. vol. vi, p. 36.
This very remarkable bird is found from Eastern Assam and Eastern Bengal, North and East of the Bay of Bengal, Burma and Malay States to Sumatra, while East it occurs in Siam and Cambodia. Nothing was known of the breeding of this bird until Dr. Gregerson and Mr. A. Nuttall found a nest with young birds and a single pigmy infertile egg in Digaltarang, Assam, in July 1904, These two gentlemen were engaged in surveying some of the endless swamps which stretch for many miles on end through the forests at the foot of the Himalayas in Assam. Sometimes the waterways run like narrow canals through gigantic trees which meet over¬head in a gloomy arch of tree-branches, creepers and parasites ; sometimes they widen out into great areas of swamp and lake. As the canoe these two gentlemen were in glided out of the deep forest into one of these open swamps they noticed a Masked Finfoot slide off what looked like some debris in a tangle of low tree and creeper. Following the bird up, they shot her but failed to catch any of the chicks which they thought they had seen with her ; they, however, examined the debris and, to their surprise, found a nest, very like a Crow’s, made of sticks and rubbish, lined with grass and reed-bits and containing an egg which was sent to me and was found to be clear. Later, when we had other eggs to compare it with, it was found to be a pigmy.
Nothing more was discovered about this bird’s breeding until 1920, when Messrs. Marlow and Smith obtained several nests and gave Hopwood full notes, from which he compiled a most interesting account of the breeding (Journ. Bomb, Nat. Hist. Soc. vol. xxvii. pp. 634-636, 1921), from which the following is an extract:—
“The upper reaches of the Rangoon River are known locally as the Myitmaka River, a sluggish stream flowing through the Plains of the Tharrawaddy district, and in places opening out into big lagoons, the chief of which is the large lake known as the Mindu In. When the Irrawaddy rises, the flood water covers large areas of the low- lying country and backs up the Myitmaka, the result being a huge swamp, in which the depth of water varies from 5 to 15 feet or even more. Much of the inundated area is under forest growth, consisting of trees, shrubs, and a tangled growth of creepers, and, as might be expected, the Finfoot revels in country of this nature. The birds are by no means uncommon and are well known to the villagers by the name of Ye Ballen, which means the Water-Babbler, due to the bubbling noise made by the birds, similar to that made by blowing bubbles through the water.”
Hopwood then quotes Marlow’s account of the finding of the first nest:—“On July 20th a hunter sent me word that he had found a nest of Ye Ballen at Mindu and the bird was sitting. The next day I visited the nest at about 5.30 P.M. and saw the bird sitting tight on a nest of twigs about 15 inches in diameter on a horizontal branch of a kyt-lin’ (Barringtonia) about 7 feet above the level of the water, which was here about 5 feet deep. The nest was also supported by creepers which covered the branch. I had approached to within about six feet of the bird, but except that she watched me closely she was not disturbed. At about 0.30 P.M. Mr. Smith and I approached the nest carefully and found the bird still sitting closely and with her head tucked away in the nest. She raised her head to look at us and did not fly away until Mr. Smith was only about three feet from her. We climbed the tree and beheld a glorious sight. In a large boat-shaped nest of twigs, lined with a few dead leaves, were seven spheroidal, glossy, cream-coloured eggs mottled with brown and purple. On the 30th July on the same river we found another nest with seven eggs. The eggs were in a similar nest similarly placed to the first but rather neater, and only about 3 feet above the water.
“Our next find was on the 2nd August. This nest was about nine feet above the water and on the higher branches of a thorny bush, not so much overhung as the first two nests,”
Many more nests were found that year during August containing two to five eggs, nests and positions being the same except that one was only a few inches above the water and would undoubtedly have been swamped later on as the river rose.
Hopwood adds :—“A nest sent me is a very thick mass of small sticks, heaped one upon the other to form a large pad ; I should say it must have been nearly a foot in height. Mr, Marlow gives the average dimensions of nests as 15 inches in diameter, outer measure¬ment, while the egg-cavity, a shallow cup, is about 8 inches in dia¬meter ; the nests are roughly circular.
“The nests found so far have all been close to villages, which are not numerous, as may be expected from the nature of the country.”
There is little one can add to the above. Messrs. Marlow and Smith continued to find nests and eggs during July and August in the next few years and sent me a wonderful series of the latter. These were all found between early July and late August and it seems evident that the birds do not breed until the rains have already had time to flood the vast area of forest land in which they collect to breed. Probably birds from elsewhere migrate locally to this area from other parts of Burma for the purpose and, possibly, even from Assam, for there seems in that province to be a semi¬migration South in April and May, whilst birds have been seen moving North and North-West in October and November.
The number of eggs in a full clutch seems to be five or six and sometimes seven or four only.
They are sui generis, yet very Ralline in many respects. In size they are simply huge in proportion to the bird ; in shape they are spheroidal, a few being less so than the others ; in one or two dutches also the eggs are slightly pointed at both ends, a most unusual character in eggs of this shape. The texture is fine, finer than in any Ralline eggs known to me, very hard and close and with a very high superficial gloss. In texture and gloss and, indeed, in shape they remind me much of the eggs of some of the Bustards. The ground-colour is a very faint cream, in some eggs faintly tinged with pink, in others, according to Hopwood, equally faintly tinged, with green. Of these latter I have seen none and, perhaps, this tint disappears soon after blowing. The primary markings consist of small or fairly large blotches of reddish-brown or blackish-brown, sparsely scattered over the whole surface, generally equally so but, sometimes, more numerous at the larger end. The secondary markings of lavender-grey are similarly distributed and are sometimes more, sometimes less, numerous than the primary.
Forty-four eggs average 52.0 x 43.7 mm. : maxima 56.1 x 45.8 and 50.9 x 46.0 mm. ; minima 50.0 x 43.7 and 50.7 x 41.1 mm.
Both sexes incubate hut there is no information about the nest-building or length of incubation.
2030. Heliopais personata
(2030) Heliopais personata Gray.