1344. Picus canus gyldenstolpei

(1344) Picus canus gyldenstolpei Stuart Baker.
THE ASSAM BLACK-NAPED GREEN WOODPECKER.
Picus canus gyldenstolpei, Fauna B. I., Birds, 2nd ed. vol. iv, p. 15.
The Assam race of this Woodpecker extends West to Eastern. Nepal and East to Manipur, the Lushai Hills and the districts of Bengal East of the Bay of Bengal.
This is an exceptionally common bird in Assam at all elevations from the plains up to about 5,000 feet, occasionally somewhat higher as a breeding bird and, exceptionally, up to 7,000 feet, I have found them equally common in the densest evergreen-forest and in the open park-like lands in the North Cachar Hills, as also in gardens, tea estates and similar country. They make their nest holes in any kind of tree, but nearly always bore them in the trunks or one of the main limbs, and this at no great height from the ground. They prefer trees which are rotten at the centre, so that once the tunnel-entrance into the soft core is completed the work of making the egg-chamber is very quick and easy. I have found the chambers some times cut out of sound timber, and in these instances they measure about 0 inches deep by about 4 to 6 wide ; when made in rotten timber they are much larger. This is the only Woodpecker with which I am well acquainted which sometimes makes use of a natural entrance to a natural hollow, though such of these that I have seen have all been small and have had to be enlarged by the birds.
Most nest-holes are very low down, few being out of reach of one’s hands, while occasionally they are placed actually among the roots of a tree, and many are only 2 dr 3 feet above them.
The breeding season is April and May, though many birds commence laying in March, and I once found young birds hatched on the 23rd of that month.
The normal full clutch is four or five only, and I do not remember ever seeing six eggs or young.
Forty eggs average 28.9 x 22.0 mm. : maxima 32.0 x 22.0 and 29.0 x 23.5 mm, ; minima 26.0 x 21.0 and 28.0 x 20.4 mm.
The male bird does far more incubation work than the female, and when we trapped birds on their eggs, in three cases out of four it was the male which was caught. So too I think he does more of the work of cutting out the nest-hole and tunnel than does the female, though the two birds may be seen each working for a few minutes at a time and then being relieved by the other. They work mornings and evenings and very often at odd hours during the day and the reverberations of the tapping for excavation work are faster, duller and more continuous than those made in feeding, and I found several nests by following up the noise so made.
The time of incubation is fifteen or sixteen days and the young birds leave the nest in about twenty-one days after hatching.
A curious habit of this and many other Woodpeckers is that of boring a new entrance even if the same nesting-bole is used again the following year. I have more than once seen three entrances all leading to the same hollow.