Four species of swift are to be seen on the Nilgiris; two of them are the fleetest birds in existence; these are the alpine swift (Cypselus melba) and the brown-necked spine-tail (Chætura indica). The former progresses with ease at the rate of 100 miles an hour: the latter can cover 125 miles, while the former is flying 100. If we poor human beings were possessed of the motive power of swifts we should think nothing of flying to England on ten days' casual leave. This may be possible a few years hence, thanks to the aeroplane; but even then the swifts will have the advantage as regards cheapness of transit. The lower parts of the alpine swift are white, while those of the spine-tail are rich brown. Hence the two species may be differentiated at a glance.
The edible-nest swiftlet (Collocalia fuciphaga) is the commonest swift on the Nilgiris. It is only about half the size of the species mentioned above, being less than 5 inches in length. In my opinion, this bird is misnamed the edible-nest swiftlet, because a considerable quantity of grass and feathers is worked into the nest, and I, for my part, find neither grass nor feathers edible. But chacun à son gout.
There is, however, an allied species--the little grey-rumped swiftlet (C. francicia)--found in the Andaman Islands--of which the nests are really good to eat. This species constructs its tiny saucer-shaped nursery entirely of its own saliva.
April and May are the months in which to seek for the nests of the Nilgiri swiftlet, and the insides of caves the places where a search should be made.
The fourth swift of the Nilgiris, the crested swift (Macropteryx coronata), is not sufficiently abundant to merit description in this essay.