THE INDIAN SAND-MARTIN 241 



twittering note, not so harsh as that of the sparrow, 

 but sufficiently harsh to make it appear that the birds 

 are squabbHng. A certain amount of bickering does 

 take place among the sand-martins. Every now and 

 again a bird may be observed chasing its neighbour in 

 a very unneighbourly manner. Occasionally two will 

 attack one another with open beak, and fall interlocked 

 to the ground. A prettier sight is that of a couple of 

 martins resting side by side at the orifice of the nest hole 

 twittering lovingly to one another. The excavation 

 that leads to the nest is a round passage, less than three 

 inches in diameter. After proceeding inwards and 

 slightly upwards for about two feet, it ends in a 

 globular cavity of larger diameter. This is the nesting 

 chamber, and is lined with grass, fine twigs, feathers, 

 and the like. Two or three white eggs are laid. Sand- 

 martins probably bring up more than one brood in the 

 year. Their nests are likely to be found in all the 

 winter months. 



Cotile sinensis is a permanent resident in India and 

 is common in all the northern portions of the country, 

 but is not often seen so far south as Madras. It is 

 curious that this species should be abundant in North 

 India and rare in the south, where insect life is so 

 plentiful. There must be something in the climatic 

 conditions of South India that suits neither this nor 

 the other species of sand-martin. Precisely what this 

 is I cannot conjecture. Birds vary greatly in their 

 adaptability to climate. Some, such as the hoopoe, 

 appear absolutely indifferent to heat or cold, moisture 

 or dryness ; others, as most wagtails, shun heat. 



