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Birds.
359
again which has once had a fair taste of the pseudo-food offered him: at least, not at the same time and with the same fly. Moreover, in a trout-stream which is much fished, the trout, after a while, refuse to rise at even the most tempting artificial fly which can he shown them: they have learned its delusive nature. Again, the birds which pecked at the Greek painter's grapes, did not prosecute the attempt to gratify their appetite beyond the first or second trial; if they had, we should never have heard the anecdote mentioned in proof of the excellence of the painting. Now if these birds learned by experience that a bit of painted—canvas I was going to say, but the ancients did not use canvas, I think—panel was not good for food, and desisted from their attempts to eat it;—if the trout quickly learns that an object which looks vastly like a drowning fly, is nevertheless not one, nor yet anything else fit to eat (and other analogous cases might be adduced);—it is, as I have said, surely questionable whether the wagtail, described as flying repeatedly against a window, did so in pursuit of an imaginary insect (Zool. 137), and that in spite of repeated discomfiture. Nor does the other hypothesis, namely, that the bird saw his own image, which "he took for a lost mate " (Id. 232), appear to carry more of probability with it. In early spring the wagtails[1] are seen in small flocks of ten or twelve, or sometimes more. In the course of a week or two they pair. In the summer they may be seen in family groups; but as the autumn wears on, the tie which once connected them seems to have been dissevered, and you see them more frequently alone than in company: nor do any facts relative to their natural history give room for supposing that the matrimonial compact remains in force after the last brood of nestlings has been sent to shift for themselves. Besides, supposing for the sake of argument, that the bird whose conduct is under consideration had lost his mate, and that at first he was deceived by the reflected image of his own form so far as to think it was his mate; yet, having detected the illusion by flying against the glass, he would scarcely have persevered in his futile efforts for days and weeks! It is observable, too, that in the earlier communication, the wagtail is spoken of as commencing its attentions to the window so early as the beginning of April. After continuing them six weeks, it absented itself for "a couple of months or more;" and was again seen "at its old station early in September," (Zool. 136). It is to be presumed that the eight or nine weeks of its absence were spent in nidification &c.: it must, therefore, have met with a mate somewhere. But if we accept the second hypothesis, this mate must have been the second that year; since by the beginning of April it was already looking out for one it had lost. Six weeks also were spent in the search. Other birds, we know from numerous facts, experience no difficulty in obtaining a new mate, should they have the misfortune to lose their old one. To mention but one instance, which occurred within my own experience. A pair of starlings had occupied part of a water-trough or eaves-drain to nest in. This might have occasioned inconvenience, and consequently one was shot: the survivor, within a few hours, formed a union with another. One of the second pair was shot, and with the like result. And if my memory does not fail me, no less than five new mates had been found by the surviving bird in the space of eight or nine days. How is it, then, that the grey wagtail alone should, on losing his mate, be compelled to live
- ↑ By the river Wye, in Herefordshire, I used to see the yellow wagtail in such flocks in March; here, by the Whitadder and Tweed, I see the grey wagtail, and my remarks apply to both.
