William Storrs Fox

“ With birds is it not mainly the food-supply which confines the breeding to a certain season? Can it be supposed that our insectivorous summer visitants usually nest only once in the season because they feel that the time for migration is approaching, and a second nest is therefore useless? I understand Mr. Davies to suggest this. These birds leave us partly because the supply of insect-food is running short, and partly because a mighty impulse drives them to go. ”

“ Davies compares the reproduction of birds and mammals. He says: "Birds feel it their duty not only to produce a certain number of offspring each year, but also to bring a certain number to maturity." To illustrate this he compares the Cat and the Nightingale. The former breeds at stated periods whether you destroy her offspring or not; but the latter at once prepares to produce a second brood if the first is destroyed. The truth is that the main object of every organism is to reproduce itself. Each species has its own method of bringing this about. ”

“ Soon after I came to live in Derbyshire, to my surprise I met him in the wilder parts of our dales, and there found his nest concealed in some corner of the limestone crags. Nor is it really surprising that he loves to haunt these dales. They are not wide fertile valleys, nor are they glens with sloping sides, dividing mountain from mountain. They are rather rifts cut right through the middle of a flat-topped hill. ”

“ If the colours of eggs have any meaning, they are obviously a protection against marauders above the nest. It is not usual for eggs laid in open nests to be white, even when dense foliage overhangs them. The eggs being white and the nest so flimsy, it might be supposed that until recently these birds built in holes. But the fact that by far the majority of the members of this great family (Columbidæ) —which embraces some three hundred species—does not nest in holes is a very strong argument against such a theory. ”

“ On a bleak April day the traveller may wander over the dreary uplands, disheartened by the everlasting greyness around him—grey sky above, grey stone walls, grey grass—with no colour; not even a hedge or ploughed field to relieve the monotony with their deeper browns. ”

“ But under all circumstances, during their stay with us, they fly boldly up when alarmed, pitching on the top of a rock or wall, or sometimes a tree, from whence they can closely watch all the movements of intruders. Very rarely have I been able to approach near enough to see the sitting bird before it left the nest. I say it, because I have some reason to believe that at times the cock assists in the duties of incubation. On June 2nd, 1894, I found a Ring-Ouzel's nest in a hollow on the moors. The eggs were partly incubated, and the cock was on the nest. ”

“ If for a time more than the average numbers of a species are destroyed by enemies, the quantity of food per head will necessarily increase, and the birds of that species will become temporarily more fertile, as a result of more liberal feeding. But, should such additional destruction become a normal and permanent condition, it may be essential that the lives of the individuals of the species be prolonged, in order that the species may avoid extinction. ”

“ David Peat, who has lived all his life on the Derbyshire moors, and who now lives in the midst of the best ground for Ring-Ouzels which I know. He is a most careful and accurate observer of birds. And I am glad to find that his experience entirely supports my own. I am inclined to suppose that the birds of one locality sometimes differ slightly in habits from those of another. It is for this reason that I have headed my paper "The Ring-Ouzel in Derbyshire."
I believe that most ornithologists agree with me in considering this bird a special favourite. ”

“ When it is clear that eggs are usually protectively coloured, it is strange that we ever should come across any which lack such protection. So also with the birds themselves, it is difficult to see why the cock Song-Thrush should be protectively coloured, but the cock Blackbird conspicuous on account of his intense black plumage. I am not aware that the former assists in incubating the eggs, and that the latter does not perform any such office. It is obvious that certain birds have little or no need of protectively coloured plumage. Some are naturally protected by their size and strength, e.g. ”

“ It sometimes happens that two varieties are to be found in one nest. Even then it is needless to take more than two eggs. My notes tell me how many eggs each nest contained, and they do this more satisfactorily than can be done by the keeping of clutches, individual eggs of which may get broken. In a public museum it may be desirable to show one clutch of each species, but this can hardly be necessary in a private collection. ”

“ Peat nor I have ever witnessed anything of the sort. On the moors there are very few snails, but in the wilder parts of the dales great quantities may be found.
There is no doubt that Ring-Ouzels are fond of berries. In July and August their droppings are often stained as a result of the bilberries and cloudberries which they have eaten. And at times they take heavy toll on gardens near their haunts.
But I must recur to their supposed skulking habits. When the young birds first leave the nest they have a peculiar twittering call, not altogether unlike the song of the Wheatear. ”

“ We are at present considering what are those factors which tend to limit or increase productiveness in birds. But length of life does not affect their egg-bearing powers; though the converse of this is probably true. Roughly, it may be said that the number of eggs laid by a species corresponds to the amount of destruction to which it is subjected. ”

“ This can hardly be a common habit. Many brooding birds fly low and feebly when first leaving the nest, as if stiff with long sitting; but I have never noticed even this in the Ring-Ouzel.
Song.—Perhaps its song is inspiring rather on account of what it suggests than because of its intrinsic beauty. It is not very varied, but its few rich notes ring out on the silent moor, or echo from rock to rock in the deserted dales. It is perfectly easy to distinguish it from the song of any other bird. ”

“ Davies allows that the food-supply may affect the parents, for he says that the number of eggs is often less when insect food is not abundant. And, again, he gives as a reason for the two broods of Finches, &c, that "it is necessary for them to produce eight or ten of their kind in a season to aid in killing off from the cultivated lands the vast swarms of insects to which the summer has given birth;" which means that where the supply of insects is great there will be plenty of birds to prey upon them. ”

“ To his surprise he one day found a Grouse's egg in the nest, and thought that someone had put it in for amusement; but the Grouse continued to lay in it, so he removed the Ring-Ouzel's eggs. To-day there were six Grouse's eggs in the somewhat flattened-out Ouzel's nest."
Situation of Nest.—On the moors the usual place for the nest is on a sloping heathery bank, the nest being well concealed among the heather. It is often found near a brook, not because the birds prefer to be near water, but the brook has cut deep down into the peat, and thus has furnished a convenient slope. ”

“ Birds, except very small ones, which nest in holes can dispense with protective colours. It may fairly be said that the position and structure of the nests regulate the colouring of the birds themselves as well as their eggs, and that wherever there is no special need for sombre shades of plumage, conspicuous or bright hues prevail. ”

“ When disturbed feeding in some lonely moorland field, on their first arrival here, or far from their nests, or, again, when family duties are at an end, up they fly, perch on a wall, and presently, if the unwelcome visitor does not withdraw, they betake themselves to some distant feeding ground. ”

“ They go through a form of battle for the Reeves. Such characteristics are contrary to the rule of the family (Scolopacidæ) to which they belong. By way of explanation, Darwin [4] states that the males of this species are probably polygamous.
(e) The plumage of the hen Oriole (Oriolus galbula) and the Jay (Garrulus glandarius) is quite bright enough to be conspicuous. But they nest among the thickest foliage.
Just as the coloration of birds' plumage falls naturally into divisions depending upon the nesting habits of the species concerned, so also may their eggs be grouped on similar lines. ”

“ If Guillemots' eggs were shaped like those of most birds, very few would be hatched. But the one egg is laid in a place of comparative safety, and the bird itself is quick on the wing and an apt diver, and for part of the year lives far from land, and so is probably less subject than most birds to attacks of foes. ”

“ Wood-Pigeons' nests are not always of the wicker type; and, if it is an advantage for the eggs to be unnoticeable from below, the natural course for the birds to take would be to build solid-bottomed nests always. Nor has it yet been proved that a white egg is less conspicuous from below than a coloured one. ”

“ But, if this is necessary in the case of Guillemots' eggs, how do Terns and Gulls, which nest together in such dense numbers, dispense with a similar provision? Most of the eggs of any one species are very much alike, and are so difficult to see that the greatest care must be taken by anyone visiting their nesting stations in order to avoid treading on them.
The Razorbill also lays its eggs on precipitous rocks, but they are placed under cover. Though the markings vary to some extent, the ground colour is generally white, sometimes brown. ”

“ That the hen should be sombre but the cock conspicuous is not surprising in large birds, such as Ducks and the larger Game-birds. But in a less degree it holds good also in the case of many small birds, such as the Blackbird, Blackcap, Wagtails, some of the Finches, and Buntings ”

“ It will be readily seen that small birds, and birds frequenting very exposed places, specially need protection. It is such birds which have both sexes protectively coloured, e.g. Song-Thrush, Hedge-Sparrow, Lark, smaller Game-birds, Rails, Plovers, Sandpipers. Certain species of the last-named group have the sexes different. ”

“ But when we are considering eggs laid in open nests, it is necessary to remember that such nests are nearly always partially covered by overhanging leaves and branches, by a projection of rock or stone, by thick herbage, or by sedges and long grasses. ”

“ In the case of the Wheatears and Redstarts, the hens are sombre in colour, and the cocks much more striking looking. According to my own experience of Saxicola œnanthe and Ruticilla phœnicurus, they place their nests quite out of sight. ”

“ And Seebohm also ('British Birds,' vol. i. p. 246) gives the impression that it skulks, saying that it "either drops down into the heath, or flies away to a more secluded resting-place"; though in the earlier part of his account of this species he gives quite a contrary impression. ”

“ Now, as to the number of eggs laid by Finches and Warblers. Mr. Davies gives five as the average clutch; and then proceeds to show why this is the only suitable number. I cannot agree with him that a hen of small size could not well lay more than five. As he himself states, Tits may lay very many more. ”