37

HOUSE MARTINS AS BUILDERS.

BY HENRY J. SLACK, F.G.S., SEC. R.M.S.

THE popular notion that all nest-making birds work by instinct, neither controlled nor modified by reason, has not been accepted by many distinguished observers, and has been demolished by Mr. Alfred Wallace, who supplies abundant reasons for his opinion "that the mental faculties exhibited by birds in the construction of their nests are the same in kind as those manifested by mankind in the construction of their dwellings." If it is said that birds are accustomed to do the same things in the same way, over and over again for years and generations, it should be remembered that this is also true of many races of men, and, to some extent, of all men. Such propositions are only true in a broad and general sense, and it is probable that a great many exceptions would be found amongst building birds if they were carefully looked for. After any building creature has formed a habit of constructing its abode in a particular way, it will most likely continue it until some change of circumstances renders it impracticable or inconvenient, and then whatever powers of reason and observation it possesses will be exerted to get over the difficulty by some alteration in the material or the plan.

Some time ago, M. Pouchet, of Rouen, noticed that the swallows of the present day, inhabiting that picturesque city, had a better pattern for their nests than those of older date which had been preserved in the museum. The new construction is more roomy than the old. Here, then, is a proof of divergence from any supposed "instinctive" pattern, and it is not likely to be a solitary exception.

During the last three or four years the writer has noticed numerous divergencies and varieties in the nests made by house martins round his own dwelling. Instead of saying they all build alike, it would be much nearer the truth to say that each pair have their own notions on the matter, and vary them

• "Intellectual Observer," vol. xi. p. 420.

within certain limits from time to time. At the present moment, on the north side, near the point of a gable, is a nest built against one slope of woodwork, and the rough, cast-wall below it. This nest has an oblique, rough-edged entrance, following the line of the eaves. Another nest was built touching it with an opening in another direction, but, being much exposed to wind and weather, it tumbled down. In another gable nests are built every year, and fall sooner or later from wind and rain. The new nests in this situation have not been exact repetitions of the old ones, but somewhat broader at the base, and with an entrance differently arranged. The birds do not choose to leave this place, but they have not yet succeeded in making a nest to last long, though they may be said to be improving.

On the east side of the house, under the projecting roof, there are now two nests attached to each other, side by side. The first built had a roundish hole for an entrance on the right-hand side, just under the woodwork. The second nest has its entrance on the left side of its curve, not close to the woodwork like the former, but provided with a slightly thickened and projecting rim. Another nest may be roughly likened to a big convex oyster shell, stuck up under a horizontal part of the projecting roof, and open all along the top, with a rough edge. This has been a very common form of nest for three or four years in several situations.

At the point of a southern gable a nest was made this year attached to the right-hand slope of the woodwork as well as to the wall, showing a large sloping opening on that side.

Two nests are fixed side by side, and attached under the projecting window of an upper room, and in the top corner of the window of the room below. When the first nest was built, cats used to sit on the window-sill and look longingly at its inhabitants. This did not trouble the birds-they had apparently satisfied themselves that it would be too awkward a jump for pussy to succeed in, and up to the present they have been right. So tame are the birds when building, and so satisfied of protection, that they did not show any anxiety when workmen were close by them coating the walls with a silica preparation, some of which was washed over their unfinished nest.

The second of these attached nests was made this year. It is much larger than the first, and has a different sort of entrance. The way into the first nest is by a round hole just in the middle and at the top of its convex curve. The second one is entered by a large irregular aperture in the left-hand corner, being a space left in the construction, by not carrying the edge of the nest at that place up to the wall of the house. This

mode of entrance might be thought extremely inconvenient, but the birds constantly approach it at a right angle and make a sudden sharp turn into it, with no diminution of their customary speed. This performance will remind the old coach traveller of the way in which four horses and the vehicle were suddenly whisked round at Guildford, and got through an entrance that was barely wide enough for their admission, and at right angles to the road.

Three nests were made two or three years ago under the eaves of a lower part of the house on the north side, but well protected against the violence of wind and rain. The droppings from the young birds being inconvenient at this spot, a board was put under the nests to catch them. The birds did not approve of this alteration, and took the trouble to construct. fresh abodes in worse positions rather than put up with it. Perhaps the board was placed nearer to the nests than they approved of. It might also have offered too convenient a restingplace for enemies wishing to attack them, which once happened when one nest was used by other birds.

It is well known that the house martin will often make experiments, before determining the site of a nest, by sticking little bits of mud to a wall; but works of this kind have been noticed for several years when no more nests seemed to be wanted for that season. Were these elementary building lessons for the benefit of the rising generation, or preparations for a subsequent season? The latter may be probable, though why should they put some dozen or more patches all of a row when only a few would be used? Anyhow, those who had not been builders in a previous year would have an opportunity of seeing how the process was commenced.

In "The Birds of Sherwood Forest," an interesting book by Mr. Sterland, the writer, speaks of the eaves of buildings, or corners of windows as the most favourite spots for martins building, "but," he adds, "I have never met with a nest in such places open at the top, as I have frequently seen it represented in works of natural history. In one recent book, the illustrations of which are generally very faithful, the nest is figured as a shallow dish fixed to a wall and entirely open at the top. Surely this must be a mistake, or if drawn from nature it cannot be taken as the type of the nest of this species. All that I have ever seen have had their walls carried up until they met the projection under which they were built, leaving a rounded hole immediately under the angle of the tile, or

cornice."

In none of the nests which it is the purpose of this paper to describe could the form be likened to "shallow dishes," but the open tops have been common. Mr. Sterland is not likely to be

mistaken in his observations, and if open-topped nests have been unknown in the regions of his observation, it is strange that they should be found elsewhere. The inference seems to be that variations from a normal pattern may be local; and perhaps a careful comparison of the building proceedings of the martins in different counties might throw light upon their ways, and lead to a higher view of their intelligence.

I may be fortunate in having my house frequented by a more experimental race of martins than are common, and there may be an advanced thinker among them, analogous to the reformers who sometimes spring up amongst stagnant tribes of men. I cannot, however, venture to flatter myself that this is the true explanation until I hear the result of careful inquiries in other quarters. All I can say is, that the martins' nests round my roofs exhibit nearly as much variety in form as the houses of the human folks in the village below, and a reason can usually be seen for the variations they display. Open-topped nests have been found in the most sheltered places. When the birds' abodes have been built in couples, like the semi-detached villas in the outskirts of towns, the entrances have been arranged so as not to come too close together. The distances are sufficient to render collisions of out-going and in-going birds improbable, and I notice other adaptations of means to ends.

In summer the martin families seem scarcely to sleep at all. At midnight and at early morn the young ones twitter. Late in the evening the parents keep up their elegant flight, and they are at it again as twilight passes into dawn.

41

A PHOTOGRAPH IN NATURAL COLOURS.

BY J. TRAILL TAYLOR.

JOHN

[OHN RUSKIN somewhere says that he would rather have a good engraving than the best of coloured prints. He speaks of course of those copies of masters' works which are produced with more or less approximation to fac-simile by the mechanical printing-press. And so far as many of these are concerned he may not improbably be in the right; but there remains the fact that colour, to almost all eyes, is the life of a picture. The black shades that give the form at best put before us a thing that is cold and dead, and it is only when the glow of colour is brought out on face or landscape that its full charm can enter and possess the mind. Except in the case of those who are to some extent unsusceptible to the effects of hue, either through partial colour-blindness or from want of taste or education, this is so true that we are disposed to think that a very indifferently executed picture as to its tints may really carry higher meanings to its beholders than a mere image in black and white. Without colour it is not possible to have true harmony-such harmony as a summer landscape presents, for instance. Abstract from that landscape all its wealth of green, and what would then remain that would tell of the season or express its poetry? It might be either autumn or spring for aught its black and white might say.

Colour, too, is one of the highest elements of expression in the human face, the pale lips speaking of fear or fixed resolve; the flushed brow telling of anger, rude health, or the glow of hope. True, the engraver may manage with little subtleties to hint at some of these things, and the etcher sometimes shows a wonderful faculty for simulating colour, but the fact remains that colour is the life, and that without it we but half know what a face or a landscape has to say.

With regard to photography, the immediate subject of our remarks, it is certain that the want of this element of pictorial beauty was very early felt. The chemicals had done so much; could they not be made to do a little more, and catch the shifting hues of life in all their flush and glow? A dream of