Terns are so beautiful that, where they occur, they are apt to attract unto themselves all attention. This is, I think, the reason why so little is on record regarding the swallow-plovers, which haunt all the larger rivers of India to such an extent that it is scarcely possible to spend an hour on the Ganges, the Jumna, the Gogra, the Indus, the Brahmaputra, the Nerbudda, the Mahanuddy, or even the distant Irawaddy without meeting with a flock of those curious little birds.

Swallow-plovers, or pratincoles, as they are often called, are easily described. They are plovers that subsist largely upon flying insects which they catch when on the wing. As a result of this habit swallow-plovers (Glareola lactea) have taken on some of the attributes of the swallow, notably the long wings and the broad gape.

The total length of a swallow-plover, including the tail, is 6½ inches, while the wing alone is nearly six inches long. It is these long wings that give the bird a swallow-like appearance.

The general hue of Glareola lactea is that curious sandy-grey shade of brown which, for some occult reason, is known as isabelline. The short tail is white with a black tip. There is a black streak through the eye and a white one near the margin of the wing. The abdomen is white. The legs are short for those of a plover; nevertheless, the species is very nimble on its feet, and runs in the manner peculiar to the peewit family.

Swallow-plovers are to be found at a distance from water, but they are essentially river birds.

At sunset, when insects in their myriads disport themselves over the surface of rivers, the swallow-plovers issue forth and hawk these flying hexapods just as swallows do, and, as they fly low over the face of the waters, they are doubtless often mistaken for swallows.

Jerdon states that swallow-plovers live exclusively on insects which they catch on the wing. I doubt whether this assertion is correct. These birds certainly feed largely on flying insects, but as they spend the major part of their time on the sand, over which they run swiftly, I think that creeping things constitute a not inconsiderable portion of their diet.

Their nesting habits are similar to those of terns and plovers; that is to say, the eggs are placed on the sand or bare ground without any semblance of a nest.

I make a point every year, if possible, of spending a morning on a river at the beginning of the hot weather looking for the nests of terns and other birds which lay on churs and sandbanks. Almost every Indian river is plentifully studded with islets which render its navigation difficult, but afford most convenient nesting sites for many species of birds. The sandy islets whereon eggs are laid are nearly always those of which some portion is sufficiently high to escape being flooded when the river rises in consequence of the melting of the snow on the higher peaks of the Himalayas. The selected islands are almost invariably sufficiently far from the river bank to prevent jackals and other predaceous creatures wading across to them. If terns or plovers fail to take such precautions, the chances are that their eggs will come to grief.

This year (1912), on the 15th April, I went out on the Gogra at Fyzabad, and found over thirty nests of swallow-plovers on one islet, on which I also saw two eggs of the black-bellied tern (Sterna melanogaster).

Immediately I set foot on the island the terns and small pratincoles commenced making an uproar, which, of course, amounted to an assurance that they had eggs on the island. One portion of it was well sprinkled with stunted vegetation, and thither I at once repaired, to the great disgust of the swallow-plovers, who flew about excitedly, uttering their lapwing-like cry—titeri, titeri. A search of less than a minute served to reveal a couple of eggs placed on the bare ground between two small plants that were growing out of the sand. As I stooped down to examine these eggs I looked round and saw a very curious and pretty sight. Swallow-plovers were surrounding me. They were nearly all on the ground and striking strange attitudes. Some were lying on the sand as though they had been wounded and fallen to the ground; others were floundering on the ground as if in pain; some were fluttering along with one wing stretched out limply, looking as though it were broken; while others appeared to have both wings injured. I did not count the birds, but at least twenty of them were seemingly injured. I had often seen one bird or a pair behave thus, but never a whole flock.

All the plover family have this injury-feigning instinct, but in none is it so well developed as in the pratincoles.

“The strange antics,” writes Hume, “played by these little birds, at least those of them that had young or hard-set eggs, whenever we approached their treasures were very remarkable; flying past one, they would come fluttering down on to the sand a few paces in front of one, and there gasp and flutter as if mortally wounded, hobbling on with draggled wings and limping legs as one approached them, and altogether simulating entirely helpless and completely crippled birds. No one unacquainted with the habits of this class of birds could have believed, to see them flapping along on the sands on their stomachs, every now and then falling head over heels and lying quite still for an instant, as if altogether exhausted, that this was all a piece of consummate acting intended to divert our attention from their nests.”

Hume here voices the popular opinion that birds, when they behave as though they are injured, are deliberately pretending to be wounded with the object of diverting the attention of an intruder from their eggs or young. I hold this view to be utterly and entirely wrong. Consider the long chain of reasoning that a bird has to make before behaving as swallow-plovers are supposed to do. In the first place the birds must know or believe that the intruder has come with the object of taking their eggs or young ones. They must know or believe that the said intruder would like to capture them in preference to their eggs or young. They must further have discovered that a bird with a leg or a wing broken is easier to capture than one that is sound in limb. They must also know how a bird with a broken wing or leg behaves when endeavouring to escape from a foe. Knowing and believing all these things, the swallow-plover must reason thus within itself: “If I pretend that I am injured the intruder will try to catch me and thus be drawn away from my eggs or young. I will, therefore, proceed to act the wounded bird to the best of my ability.”

I do not for a moment believe that the average swallow-plover has half this knowledge and power of reasoning. Its behaviour can be accounted for in a far more probable manner. We all know that instinct teaches birds to fly away from all birds or beasts of prey or large strange moving objects; but instinct teaches them to guard their eggs. Now, when a human being approaches the eggs of a pratincole, these two instincts come into violent opposition, and the bird’s mental equilibrium is much disturbed; the result is that the bird undergoes all manner of strange contortions. We look at these and say, “What a clever little bird! How well it is acting!” The contortions of the swallow-plover undoubtedly do tend to attract the attention of predaceous creatures, and are probably useful to the species when there are young, for these are able to slip away while the attention of the attacker is momentarily diverted by the parent birds. Hence such behaviour must tend to be perpetuated by natural selection. That it is in no sense an intelligent act is obvious from the fact that such behaviour occurs when there are eggs, and so can do no good; moreover, the parents will go on behaving in this manner even after the intruder has taken the eggs and put them in his pocket!

Textbooks tell us that Glareola lactea lays from two to four eggs. I have never found more than two in a clutch, and think that Hume made a mistake when he said “from two to four,” and as plagiarism is very rife among writers on ornithology, other ornithologists have copied his statements without acknowledgment, and, of course, reproduced his mistake!

The eggs of this species are interesting on account of the extraordinary variations they exhibit. As Hume well says, it is scarcely possible to find two eggs (outside the same clutch) that closely resemble each other. It not infrequently happens that the two eggs in the same clutch differ so greatly that it is difficult to believe that they are the produce of one hen. The ground colour may vary from pale green, almost white, to fawn colour. The markings sometimes take the form of blotches, so that the eggs look like those of a small tern. More usually the markings appear as tiny spots, freckles, pencillings, or cloudy smudges. On a sandbank containing twenty nests it is possible to pick out ten eggs, each of which differs so greatly from the others that the casual observer would certainly say they all belonged to different species. The size is, of course, fairly uniform, but the shape varies greatly; some are elongated, while others are nearly as broad as they are long. Occasionally a pear-shaped egg is found, but as a rule the narrow end of the egg is comparatively blunt. That eggs which are laid on the sand in the open should display these extraordinary variations is an awkward fact for those who consider that the colouring of birds’ eggs is the direct result of natural selection. If this were so we should expect to find a wonderful sameness about the eggs of this species, which are laid in such exposed situations. The fact is, of course, that on a sandbank eggs of any colour that is not too pronounced are difficult to see; hence, for purposes of protection, the actual colours of the background and the markings of the egg are matters of little importance.