HOW BIRDS MAKE LOVE.

Otago Witness, Issue 1892, 15 May 1890, Page 39

HOW BIRDS MAKE LOVE.

The familiar expression, " As loving as a pair of turtle doves," might reasonably give rise to the supposition that the birds generally are as much given to love-making as human beings ; and whilst sorry to dispel so charming an illusion, we regret that veracity compels us to state that the inordinate amount of billing and cooing gone through by amorous pairs of pigeons is decidedly the exception rather than the rule in connection with ornithological matrimony, or the courtship which precedes it.

In the case of pigeons and certain other monogamous birds, notably ravens, it has been pretty conclusively established that when once mated their union continues (unless death overtakes one or other of the loving pair) for an indefinite period, although in the oase of wild birds there is reason to suppose that after the young ones of each year's hatching have become old enough to shift for themselves, their parents go each their different ways, only coming together again in the following spring or pairing time.

In their case it may probably be safe to assume that no great amount of love-making goes on each successive year; but with other monogamous birds, as to whose matrimonial fidelity a certain amount of doubt exists, the case is different. It is worthy of notice that just about pairingtime the <na jority of (male) birds are in their best plumage, having fully recovered from their previous season's moulting; and, to adduce a well-known instance — that of the familiar robin red-breast — the most cursory examination will at once reveal the fact that it is as we have stated. The robin is nothing if not pugnacious, and his pugnacity is never more in evidence than just at the time of pairing (in his case early in Lho spring), and we have more than once been interested spectators of a desperate battle between two oE them, the object of their adoration often looking on from a convenient coign of vantage.

Books do their love-making in a less aggressive manner. The occupants of a rookeryhaving—as is their wont— assembled in the trees in which the nests of many generations are established, set up a continuous and prolonged series ,'of cawings, and from time to time it will be observed that about half the birds (presumably the males) take wing together, as if animated by a common impulse ; and, having risen to a certain height, commence to fly round and round in ever widening circles, every now and then performing all sorts of queer movements, somewhat after the manner of tumbling pigeons, and then suddenly alighting again on the branches they have but recently vacated, when the cawing is recommenced with redoubled ardour. This usually goes on for some days, and then, in place of the flocks being scattered about indiscriminately when engaged in feeding on the grassland, it will be observed that the various pairs keep pretty close to each other, and from time to time one bird will be observed feeding another— a decidedly practical style of love-making this.

Cock partridges, it has often been noted, fight assiduously prior to pairing, and when once the combat has been decided and the victor proudly claims the object of his affection, it is extremely interesting to watch them together before the all-important question of a suitable locality for the nest has been decided upon. For gallantry of an extra pronounced order, however, it is necessary to turn to the polygamus species ; and first and foremost must be placed the capercailzie and blackcock. Both set about their love-making in the same way — challenging to combat any of their species that may be within hearing distance ; but the capercailzie has the inestimable advantage over the blackcock in that he can emit peculiarly beautiful, deep, and unmistakeably amorous notes, which can be heard to a great distance, whereas the blackcock (undeniably handsome bird that he is, and never more so than when clothed in his full adult plumage early in the year) can only issue a challenge to all and sundry in the way of harsh, discordant crowing.

At sunrise and sundown each day during the pairing season the male capercailzie station themselves on the loftiest pines in their respective beats or localities, and commence their pairing notes; whereas the blackcock content themselves with crowing defiance on open spaces on the ground (playing grounds, as they are termed). In both cases the result is the same : from adjoining wood and thickets the hens emerge, and having surrounded their future lords and masters, they (the males) proceed to strut about and display their plumaged attractions to the best advantage. Anon a rival appears upon the scene, and forthwith the two become engaged in a battle royal, the hens looking on and occasionally giving vent to a subdued " Gluok 1 gluck ! " as one or other of the combatants scores a manifest advantage. In due course one of the latter becomes vanquished, leaving his opponent in undisputed possession, but only for awhile, for ere long another puts in an appearance ; and it is often not until a number of successive encounters have been undertaken that the opposition is withdrawn.

The Flight of Birds.— Marey, the wellknown French authority on the motion of animals, has constructed an ingenious model to illustrate how birds are able to take advantage of puffs of wind and often to get more out of them than from a steady breeze. He cuts an outline on a board like that of a switchback railway, that is, a series of undutions between a high and alow level, a groove is cut in the edge of the board for a billiard ball to run in. If the billiard ball is started with a slight velocity and the board isierked at the right instant, the ball can be got to climb from the low level to the high one ; the jerks of the board correspond with the puffs of wind in the flight of the bird, and the whole motion of the ball is a close imitation of that of the bird. This promises great sport for the sailers of flying machines in the future, compared to which yachting will appear clumsy and tame. The problem will then be to understand the puffs in the wind at different heights, so as to get the machine worked up to half-mile above the surface of the earth, and then swoop down 20 miles or 30 miles in 10 minutes.

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