(492) Saxicola caprata burmanica Stuart Baker.
THE BURMESE STONE-CHAT.
Saxicola caprata burmanica, Fauna B. I., Birds, 2nd ed. vol. ii, p. 24.
This little Stone-Chat is extremely common over practically the whole of Burma, extending West to Assam South of the Brahma¬pootra and East to Yunnan and Siam. South it extends to Tenas¬serim.
They seem to breed at all elevations in Burma from the level of the plains up to 6,000 feet and, in Assam, certainly up to 7,000 feet in the Naga Hills, at which elevations its nest and eggs were taken by Col. H. Tytler and J. P. Mills. In North Cachar it was not rare in the grass-lands in the North-East between 1,500 and 2,500 feet but the higher hills were all too heavily forested and, though casual pairs turned up at odd times in odd places, especially in Winter, none ever bred. They are birds of open country, grass-lands, bush and scrub-covered hill-sides and plains and, wherever these are available, are common. It breeds in the plains near the bills but is certainly a more common breeding bird over 1,000 feet than under.
The nest is a cup-shaped affair made of grass, generally rather coarse, and lined with finer grass often mixed with hair and, some¬times, entirely with the latter. With the grass of the body of the nest is often mixed a few roots and, perhaps, a leaf or two, but grass always seems to furnish at least nine-tenths of the material used. The lining is neat and compact but the nest itself is often most untidy and carelessly built, although its position generally ensures its being held well together. In size, excluding the odd ends which stick out in all directions, the nests may measure anything between three and a half and four and a half inches across the top, with a cavity for the eggs something under three inches in diameter by half an inch to one and a half inches deep. The situation for the nest is one always on the ground but, otherwise, may be placed in almost any position. The favourite place is undoubtedly a grassy bank, with or without other vegetation and bushes, when the nest is either tucked away in some natural hollow among the roots of the longer, coarser grass and weeds or under a bush.
An interesting note of Wickham’s (Journ. Bomb. Nat. Hist. Soc. vol. xxxiii, p. 817, 1928) shows the kind of places they sometimes select. He says of this bird that in the Upper Burma Hills it is “ubiquitous. Probably breeds more in the hills than in the plains, and it is probably the commonest of the common birds of the country. Whereas some nests are beautifully hidden under a bush, like our English Stone-Chat’s, an empty tin or the hollow of a bamboo lying on the ground out in the open may be utilized ; again, a favourite site is a hole in a bank, the nest just placed at the edge or under a clod. I have seen a nest actually down a hole in the ground and one also in a small grassy hollow in a field, absolutely open and exposed to the weather.
“Although fresh eggs may be taken in May, it begins to breed as a rule at the end of March.”
In the Chin Hills Mackenzie, Macdonald, Hopwood and others took many nests, nearly all in banks quite close to the road, and others from holes in the banks of streams where these ran through open country. Although so common in the Chin Hills and occurring also in North Cachar, I never found it breeding in the Khasia Hills, although there was exactly the same country available, great stretches of grass-land, running for miles over rolling hills between 3,000 and 4,000 feet. In this kind of country in North Cachar I found the birds nesting freely, though we found very few nests because the ground was too extensive and the nests too well hidden among the roots of the grass. By watching the male singing his little song, perched on a tall grass-stem, we could sometimes work the grass all round until we kicked up the female.
In Pegu Oates found the nest “usually placed in a hole in the ground, the deep footprint of a bullock serving the purpose very frequently ; sometimes placed on the ground under shelter of a tuft of grass.”
An extraordinary instance of this bird’s breeding is related by Judge S. M. Robinson (Journ. Bomb. Nat. Hist. Soc. vol. xxvi, p. 843, 1919):—“ A Pied Bush-Chat laid her eggs this year in a rusty old kerosine tin lying on the ground behind the line of railway carriages occupied by visitors to Kalate. The tin was frequently picked up and carried about to show off the nest. The bird was caught by a servant and tied by the leg to his mistress’s carriage, and she nursed and fondled it. When let go the bird returned to its nest. The tin was brought to show me some days later, the bird flying off the nest at the time. I took a Cuckoo’s egg out of the nest (Cuculus canorus). In spite of these frequent attentions the bird still sat. Two days after I first saw it there were two more Cuckoo’s eggs in the nest. The small bird has had her reward. She has hatched her brood and been spared the Cuckoo’s.”
The breeding season seems to be from early March to the end of May and many birds probably have two broods. In Maymyo Cook found them breeding in May but, at that time, many young birds of the year were already on the wing.
The full clutch of eggs is four but both five and three are laid occasionally, and in the Chin Hills Mackenzie took several fives, as did K. Macdonald round Pakokku and in the Upper Chindwin.
The ground-colour of the eggs is a very pale bluish-green, still paler yellowish stone colour, or pale dull buffy stone colour. The markings consist of small irregular blotches and freckles of light reddish-brown, numerous but not dense, over the whole surface of the egg. In some, however, the blotches are decidedly more numerous at the larger end and in a good many they form very definite rings, but in none that I have seen do they coalesce to make caps. In most clutches there is one egg which differs considerably from the others. Thus in one of the blue-ground type three eggs are normally marked with reddish-brown, forming fine rings round the larger end, whilst the fourth egg is immaculate except for the ring and a few specks inside it. In other clutches there is one egg much more heavily or much less heavily marked than the others, and in one clutch of three two eggs are normal and one is only faintly marked with grey.
In shape the eggs are short, broad ovals, only exceptionally pointed at the smaller end. The texture is rather fine and close but there is little or no gloss.
Sixty-two eggs average 16.8 x 13.9 mm. : maxima 18.5 x 13.8 and 17.1 x 14.6 mm. ; minima 15.6 x 13.1 mm. These figures include a considerable number measured by Mackenzie, but the extremes are all of eggs in my own collection.
I have no eggs of the typical form from Java, but of our three Indian races it is interesting to note how the difference in the size of the birds agrees with the size of the eggs :—
Saxicola c. burmanica ..... Wing 67 to 72 mm. ; eggs 16.8 x 13.9 mm.
Saxicola c. atrata ..... Wing 70 to 81 mm. ; eggs 19.5 x 15.2 mm.
Saxicola c. bicolor ..... Wing 67 to 77 mm. ; eggs 17.6 x 13.9 mm.
In Burma this Chat is frequently cuckolded by the Cuckoo (Cuculus canorus bakeri), Wickham, Cook and Harington taking numerous nests of the Chat with Cuckoos’ eggs in them. Wickham remarks:— “I suppose I have taken more Cuckoos’ eggs out of the nests of this species than the nest of any other bird.” Harington also writes :— “I found three nests containing Cuckoos’ eggs ; one nest found by P. F. Wickham when we were out together was placed at the bottom of a hole in the ground at least 12 inches from the entrance, which was so narrow that no Cuckoo could possibly have got in, so that the egg must have been rolled into the nest, which contained five eggs of P. caprata and one Cuckoo’s egg, showing that the Cuckoo had probably been unable to take out the customary one in exchange for its own.”
So far as I know the male takes no share in incubation, whilst there is nothing on record as to whether both sexes assist in the building of the nest.
492. Saxicola caprata burmanica
(492) Saxicola caprata burmanica Stuart Baker.