While he was thus employed a pied kingfisher (Ceryle rudis) appeared on the scene and took up a position on one of three neem trees that grew beside the tank. After sitting thus for a few seconds, he too began to seek for food. Save that both he and the tern drop from a height of about twenty feet into the water after their quarry, there is but little similarity between their movements. The tern sails gracefully along on pinions which move but slowly, while the kingfisher flies a little way, then remains stationary in the air for a few seconds on rapidly vibrating wings, with both tail and bill pointing downwards, so that the shape of the bird is an inverted V with the apex at the neck. It then either dives or passes on to another spot where it again hovers. Frequently it makes as if it were going to dive, then seems to change its mind, for it checks itself during its drop and passes on.
When the kingfisher was hovering in the air, the tern approached and looked as though he were going to attack him. However, he contented himself by skimming past very close to the “pied fish tiger.” This appeared to disconcert the latter, who went back to the neem tree and rested there for a few minutes. Meanwhile, the tern flew away. The moment he had departed the kingfisher renewed his piscatorial efforts and took up a position about twenty feet above the water almost directly over the spot where the ducks were floating. I thought this rather foolish on the part of the kingfisher, because the ducks must necessarily scare away all the fish from that part of the water. However, the little fisherman possessed more sense than I gave him credit for. He had not been hovering for thirty seconds when he plunged into the water and emerged with a large object in his bill. With this he flew to the muddy border of the pond. Then, by means of my field glasses, I saw that his quarry consisted of a frog about two and a half inches long including the legs. The kingfisher experienced some little difficulty in swallowing the frog. He had it crosswise in his beak and the problem that confronted him was to get the frog lengthwise head foremost in his bill without releasing the nimble little amphibian and thus giving it a chance of escape. After a little manœuvring the kingfisher got the frog in the desired position, and, having held it thus for a few seconds, swallowed it.
Then the kingfisher remained squatting on the bank for a couple of minutes looking pensive. This was scarcely to be wondered at, seeing that as regards size the frog bore to him the same relation as a large mackerel does to a man. I was interested to see whether the kingfisher would consider this a sufficient meal, or whether he would immediately resume his fishing operations. I expected him to adopt the latter course, for birds have most voracious appetites. If horses were to eat in the same ratio they would require at least a maund of oats per diem to keep them in health! My surmise was correct. In a few seconds the kingfisher flew to a large stake projecting from the water and squatted there, cocking up his tail at frequent intervals. This motion of the tail is possibly an aid to digestion! When he was thus seated, the tern reappeared on the scene and at once recommenced fishing in the manner already described. After the tern had been fishing for a couple of minutes the kingfisher resumed operations and again sought the neighbourhood of the ducks. He soon captured a second frog; but this time, instead of being able to bear it to the bank and devour it in peace, he had to reckon with the tern. He had not risen a yard above the water when the tern noticed that he had quarry. Forthwith the tern committed a breach of the tenth commandment and then proceeded to try to violate the eighth. He made a swoop at the kingfisher, which the latter adroitly dodged, squeaking loudly but without dropping the frog. Then ensued a chase which was a sight for the gods. As regards pace on the wing the kingfisher is no match for the tern. In an aerial contest the slower flier has the advantage of being able to twist and turn more quickly than the rapid flier. Of this advantage the kingfisher availed itself to the full, so that the contest waxed fast and furious, the combatants moving in a series of curves, zigzags, circles, and other geometrical figures.
The kingfisher, notwithstanding that he had just swallowed a frog, evidently had not the least intention of delivering up his catch. The tern appeared equally determined to capture it. Seeing that he would never be able to enjoy the fruits of his prowess while he remained at the tank, the kingfisher changed his tactics and flew right away, disappearing behind some trees, with the tern in pursuit. The latter, however, did not follow far. He seemed suddenly to come to the conclusion that honesty is the best policy, and returned to the pond to endeavour to secure food in a more legitimate manner. I waited on for about half an hour, expecting to see the kingfisher reappear, but was disappointed. Then the tern went to seek pastures new, and left the ducks and a solitary wagtail in possession of the tank.
XXVIII
THE RED TURTLE DOVE
Insects and birds, on account of the vast number of species they present, furnish the best available material for the study of evolution. It is owing to the fact that most Professors of Zoology are neither entomologists nor ornithologists that biological science is in its present deplorably backward condition. There exists scarcely a zoological theory, be it neo-Lamarckian or neo-Darwinian, that the competent ornithologist is not able to refute. For example, writing of sexual dimorphism in animals, Cunningham states that in the case of birds which exhibit such dimorphism the cocks differ essentially in habits from the hens, and in this way he, as a Lamarckian, would account for their external differences. “The cocks of common fowls and of the Phasianidæ generally,” he writes, “are polygamous, fight with each other for the possession of females, and take no part in incubation or care of the young, and they differ from the hens in their enlarged brilliant plumage, spurs on the legs, and combs, wattles, or other excrescences on the head. In the Columbidæ, per contra, the males are not polygamous, but pair for life, the males do not fight, and share equally with the females in parental duties. Corresponding with the contrast of sexual habits is the contrast of sexual dimorphism, which is virtually absent in the Columbidæ.”
Mr. Cunningham evidently is not acquainted with the red turtle dove (Œnopopelia tranqebarica) so common in India, or he would not have asserted that sexual dimorphism is virtually absent in the Columbidæ. The sexes in this species are very different in appearance, and I know of nothing peculiar in its habits to explain this dissimilarity. The sexual dimorphism displayed by the red turtle dove is a fact equally awkward for the Wallaceians, because the habits of this species appear to be in no way different from those of the other doves. I have seen red turtle doves feeding in company with the three other common species of Indian dove; they eat the same kind of food, build the same ramshackle nests, and lay the usual white eggs. But I will not spend time in whipping a dying horse. The poor overburdened beast which we call Natural Selection has done yeoman service; for years he has pulled the great car of Zoology along the rugged road of knowledge, and now that he is past work, now that he stands tugging impotently at the traces, it is time to pension him and replace him by a new steed. Unfortunately, the drivers of the coach happen to be old gentlemen, so old that they fail to perceive that the coach is at a standstill. They believe that they are still travelling along as merrily as they were in Darwin’s time. Ere long their seats will be occupied by new drivers, who will give the good steed Natural Selection a well-earned rest, and replace him by a fresh animal called Mutation. Then once again the coach will resume its journey.
The red turtle dove is a little bird, and the hen looks like an exceptionally small specimen of the ring dove. So great is the resemblance that a hen red turtle dove was shown at the United Provinces Exhibition at Allahabad as a ring dove. The cock red turtle dove has a pretty grey head, a black half-collar running round the back of his neck, which, as Jerdon remarks, is “well set off by whitish above,” while the remainder of his upper plumage is dull brick red. The hen is clothed in greyish brown, in the hue known as dove colour, and her one ornament is a black half-collar similar to that of the cock.
The best friends of turtle doves can scarcely maintain that they have melodious voices. Phil Robinson, writing of the species which visits England, contrasts its note with the “mellow voluptuous cooing of the ring-dove.” “The call of the turtle dove,” he says, “is unamiable, usually grumbling, and often absolutely disagreeable. To the imagination it is a sulky and discontented bird, perpetually finding fault with its English surroundings of foliage, weather, and food. ‘Do, for goodness’ sake get those eggs hatched, my dear, and let us get back to Italy.’ That is the burden of his grumble, morning, noon, and night.”
Phil Robinson’s opinion of the call of the red turtle dove is not on record; this is unfortunate, for, assuredly, it would be a document worthy to be placed side by side with Mr. Lloyd George’s invective against the House of Lords!