(998) Acridotheres ginginianus (Lath.).
THE BANK MYNA.
Acridotheres ginginianus, Fauna B. I., Birds, 2nd ed. vol. iii, p. 55.
The Bank Myna occurs all across Northern India from Sind and Mussoorie in the Himalayas to Eastern Bengal and Assam. On the West of India it breeds as far South as Rajputana (Barnes), practically throughout Oudh, and commonly in Bengal and Behar, South to Orissa.
This is an extraordinarily common bird, building in colonies, in some cases of great size, in the banks of rivers, earthen cliffs, borrow pits beside roads and in the walls of wells. Hume’s description of one of their breeding places would do equally well for most. He writes :—“We found that a colony of Bank Mynas had taken possession of some fresh excavations on the banks of a small stream. The excavation was about 10 feet deep, and in its face, in a band of softer and sandier earth than the rest of the bank, about a foot below the surface of the ground, these Mynas had bored innumerable holes. On digging into the bank we found the holes all connected with each other, in one place or another, so that apparently every Myna could get into or out from its nest by any one of the hundred odd holes in the face of the excavation. The holes averaged about 3 inches in diameter, and twisted and turned up and down, left and right, in a wonderful manner ; each hole terminated in a well-marked bulb, or egg-chamber, situated from 4 to 7 feet from the face of the bank. The egg-chamber was floored with a loose nest of grass, a few feathers and, in many instances, scraps of snake-skins.
“I noticed the tops of all the mud pillars (which had been left standing to measure the work by), had been drilled through and through by the Mynas, obviously not for nesting purposes, but either for amusement or to afford pleasant sitting-places for the birds not engaged in incubation. Whilst we were robbing the nests, the whole colony kept screaming and flying in and out of their holes in the various pillar-tops in a very remarkable manner, and it may be that they thought to lead us away from their eggs and induce a belief that their real homes were in the pillar-tops.”
A colony very similar to the above bred in some deep borrow pits not far from my bungalow in Nadia, which I was able to frequently visit and watch. I then noticed that the holes in the pillar-tops were nearly all made by the male birds after the hens had begun to incubate, though twice I took nests from these holes, visible from the entrance on either side. The depth of the nest-holes varies according to the soil in which they are made. In very soft soil they may run to as much as 7 feet, but in the sandy banks of the Brahmapootra, where I found a mixed colony of Sand-Martins and Mynas breeding together, the nests were only 3 or 4 feet deep and easily reached by hand. The nest-chambers were about a foot long by 8 or 9 inches wide and the same high. I have found them breeding in rather hard soil in borrow pits, making tunnels, two feet or under in depth, which were never joined together, each pair of birds having their own exit, as, indeed, had the colony on the Brahmapootra.
The nest is always the usual pile of rubbish and very often contains cast snake-skins.
The breeding season may be said to be from April to July but the great majority of birds breed in May and June. Where, however, they nest in banks likely to be flooded in the first rains they lay in early April and the young are fledged and away before the rivers rise in the end of June.
In Sind Bell found them breeding in March and April.
This Myna lays three to five eggs or, in Sind, four to six, which only differ from those of the Common Myna in being smaller and, perhaps, on an average, a little darker and slightly more glossy.
Sixty eggs average 27.5 x 20.3 mm. : maxima 29.9 x 20.0 and 27.4 x 22.0 mm. ; minima 24.5 x19.8 and 29.3 x 19.6 mm.
998. Acridotheres ginginianus
(998) Acridotheres ginginianus (Lath.).