Essays in Natural History and Agriculture Part 9

I cannot see how we can explain this action of birds in relation to any other object. It certainly does not seem calculated to expel or disturb any vermin lodged there, and I remarked that it never occurred except when the bird had been applying its bill to the gland as above mentioned. However, Mr. Waterton, and anyone who doubts this oiling, may readily judge for themselves. Let them take a common duck, and shut it up for two or three days, so that it can have no access to water except for drinking, and at the end of that time let them turn it out, and allow it to go to a brook or pond; it will give itself a thorough ablution--ducking, diving, and splashing with its wings--and on coming out, will begin to dress and arrange its feathers, very frequently applying its bill to the gland on its rump. If this application is not for the purpose of procuring a supply of oil, perhaps Mr. Waterton will have the goodness to inform us what it is for, and what end this gland answers in the economy of the feathered tribes if not that which has. .h.i.therto been supposed. (June 30, 1832.)

MOCKING POWERS OF THE SEDGE-WARBLER.

In the article "Sedge Bird," in Montagu's "Dictionary of Ornithology" (Rennie's edition, p. 455), the writer says: "It has a variety of notes, which partake of those of the Skylark and the Swallow, as well as the chatter of the House-Sparrow." According to my observation, it has a much greater variety than this. I have heard it imitate in succession (intermixed with its own note, _chur, chur_), the Swallow, the House-Martin, the Greenfinch, the Chaffinch, the Lesser-Redpole, the House-Sparrow, the Redstart, the Willow-Wren, the Whinchat, the Pied-Wagtail, and the Spring- Wagtail; yet its imitations are chiefly confined to the notes of alarm (the fretting-notes as they are called here) of those birds, and so exactly does it imitate them in tone and modulation, that if it were to confine itself to one (no matter which), and not interlard the wailings of the little Redpole and the shrieks of the Martin with the _curses_ of the House-Sparrow, the _twink, twink_ of the Chaffinch, and its own _care-for-naught_ chatters, the most practiced ear would not detect the difference. After being silent for awhile, it often begins with the _chue, chue_ of the House-Sparrow, so exactly imitated in every respect that were it not for what follows, no one would suppose it to be any other bird. It is called a Mocking-Bird here, and it well deserves the name, for it is a real scoffer at the sorrows of other birds, which it laughs to scorn and turns into ridicule by parodying them so exactly. I never heard it attempt to imitate any of the Larks or Thrushes, although I have listened to it for hours.

This bird was very plentifully met with in Wharfdale ten years ago, and is also found in this neighbourhood, but I am not aware that anybody in either of these districts ever attempted to keep one in confinement, although from their powers of imitation, I think the experiment well worth trying; probably the idea that it would be difficult to supply them with proper food has prevented the experiment being made. (May 2nd, 1832.)

I am surprised that no other writer on Natural History has noticed the wonderful imitative power of this bird. So far is the above notice from overstating this bird's powers of imitation, that I have scarcely enumerated half the notes which it hits off with such wonderful exactness.

In listening to one the other day for about a quarter of an hour, I heard it give three notes of the Swallow, two of the Martin, and two of the Spring-Wagtail; and in addition, notes of the House- Sparrow, Whinchat, Starling, Chaffinch, Whitethroat, Greenfinch, Little Redpole, and Whin-Linnet, besides the notes of half-a-dozen birds which I did not know; at least, a reasoning from a.n.a.logy would induce me to think them imitations, and I have no right to suppose they were not because I did not happen to recognize them.

I am not strictly correct when I say that it only imitates the alarm-notes (called here fretting-notes) of other birds, for although this is generally the case, it is not invariably so. For instance, in addition to the alarm-note of the Swallow, _chizzic, chizzic_, it also had the _whit, whit_, which the Swallow uses when flying about, and the chatter of self-satisfaction (not the song) which one often hears in a barn when two Swallows are arranging their plan of operations in the spring. Again, in addition to the shriek of the Martin, there was the note which it utters when on the wing in pursuit of its food. There was also the chirrup of the Greenfinch, and the _whee, whee, whee_ which is the climax of the Linnet's song, by which it is so irresistible as a call-bird, and which appears to bring down the flock in spite of themselves.

Although the Sedge-Bird imitated all I have mentioned, it made much more frequent use of the notes of some than of others--the Sparrow, the Whinchat, the Swallow, and the Starling appeared to be its chief favourites, whilst it only touched once or twice on the notes of the Greenfinch and the Linnet. It had been very sparing also in its use of the Chaffinch's note, until one in the neighbourhood had begun to _twink, twink, twink_; then the Mocking-Bird took it up, and _twinked_ away for fifty times together. Next morning the Linnet's note was much more frequent in request, and it also made more use of notes with which I was not acquainted. On neither day did it touch upon the notes of the Redstart, or Pied-Wagtail, both of which I had heard frequently used by the Mocking-Bird before. On the other hand, I had not previously observed the notes of the Starling and Whin-Linnet, and therefore, although I have said that I have never heard it make use of the notes of any of the Larks or the Thrushes, I would not be understood to say that this never happens. It is, perhaps, difficult to say whether it has a note which is not an imitation of some other bird, but there is one which it always makes use of when any person approaches its nest (intermixed, however, with the notes of the Swallow, Whinchat, and Whitethroat). This is something like _chur-r-r, chur-r-r_, prolonging the sound of the _r_ very considerably, and in a style which would be quite an acquisition to the Northumbrians if they could attain it. (May 29th, 1834.)

THE WATER OUZEL.

The Water Ouzel sings very frequently, and as much in winter as at any time. Perched on a stone or a piece of ice, it chirps away at a famous rate, but its song consists almost entirely of its note _zeet, zeet_, which it hashes up in all sorts of ways, lengthening and shortening--now a crotchet, then a semiquaver, rising an octave or so, and then descending again. It makes as much of it as can be made, but with all its efforts its song is a very _so-so_ affair, all its syllables beginning with _z_, and almost ending with it too. Yet, although it is not much of a songster, it is almost a sacred bird with me, in consequence of the a.s.sociations connected with it. A pair had built for forty years, according to tradition, in a wheel-race near to where I was born, and had never been molested by anybody until a gentleman in the neighbourhood, who was a great ornithologist, employed his gamekeeper to shoot this pair. I think the natives of Calcutta were not more indignant when an unlucky Englishman got one of their sacred bulls into his compound and baited him, than was our little community at what we considered so great an outrage. The gamekeeper narrowly escaped being stoned by myself and some more lads, any one of whom would have shot fifty Blackbirds or Fieldfares without any misgivings.

This bird very much resembles the Wren in its habits and motions, its nods and curtsies, and c.o.c.ks its tail in exactly the same manner. Its nest is also similar in form to that of the Wren.

Some persons seem to think that it is impossible for the Water Ouzel to walk at the bottom of the water, owing to its body being of less specific gravity. I will not argue the point with them, but disbelieving my own eyes, I will endeavour to submit with a good grace; otherwise I should have said that I have repeatedly seen it doing so, from a situation where I had an excellent opportunity of observing it, the window of a building directly over the place where it was feeding. It walked into the water and began to turn over the pebbles with its bill, rooting almost like a pig, and it seemed to have no difficulty whatever in keeping at the bottom at all depths where I could see it; and I have frequently observed it when the water just covered it, and its head appeared above the water every time it lifted it up, which it did incessantly, turning over a pebble or two, then lifting its head, and again dipping it below to seize the creepers (_aquatic larvae_) it had disturbed from their hiding-places. Besides, its speed was too slow for diving. Every aquatic bird with which I am acquainted moves much faster when diving than when it is swimming or walking, and its course is generally in a straight line, or nearly so; but the Water Ouzel, when feeding, turns to the right or left, or back again to where it started, stops and goes on again, just as it does when out of the water. Yet when it wished, it seemed to have the power of altering its own gravity, as after wading about two, or perhaps five minutes, where it could just get its head out, it would suddenly rise to the surface and begin to swim, which it does quite as well as the Water-hen. The awkward, tumbling, shuffling wriggle which it appears to have, is occasioned by the incessant motion of its head as it turns over the gravel in search of creepers, which appear to me to form the bulk of its food.

Sir George Mackenzie seems to think that these birds destroy salmon sp.a.w.n, and this opinion is prevalent in Scotland. If it is correct, it would go far towards putting an end to my partiality for them; but I rather think that they are unjustly accused, and believe they are catching creepers when they are supposed to be eating sp.a.w.n. If this is the fact (and it is well worth ascertaining) they are rendering an essential service to the fisheries instead of injuring them, because these creepers (the larvae of the stone-fly, bank-fly, and all the drakes) are exceedingly destructive to sp.a.w.ning-beds, and as the Water Ouzel feeds on them at all other times, and as they are more abundant in the winter than at any other season, I think this is the more probable supposition. Of course, if Sir George Mackenzie has shot the bird, and speaks from his own knowledge, after dissecting it, there can be no doubt of the fact that it destroys sp.a.w.n; but if he merely supposes so because the Water Ouzel feeds in the same streams where the salmon are sp.a.w.ning, it is very probable he is mistaken, for the reasons before mentioned. (May 29th, 1834).

SCOLOPAX, SABINES, SABINE'S-SNIPE.

Some years ago I killed what I am now persuaded was a Sabine's- Snipe, but unfortunately it was not preserved, for hanging it up in the larder with the other birds I had killed, I found to my great mortification that the cook had stripped it of every feather before I was aware, and before I had noted down the markings of the plumage.

The dry weather of August, 1820, had driven a flock of the Golden Plover from the moors to the banks of the river Wharfe, and on the 14th of that month I had been out with my gun, endeavouring to shoot some of them. On my return I sprung this Snipe from a pond near home, and killed it. When I picked it up, I was astonished to find a Snipe with the plumage of a Woodc.o.c.k, and showed it to a friend of mine, who is a good practical ornithologist, but he was as much puzzled as myself to give it a name; so not being able to find a description of it in any books to which we had access, we jumped to the conclusion that it was a hybrid between the Snipe and the Woodc.o.c.k, and called it a b.a.s.t.a.r.d Woodc.o.c.k.

According to the recollection I have of it, it was as large as the solitary Snipe, and the bill was a little longer; the general appearance of the plumage on the wings and back resembled a dark- coloured Woodc.o.c.k; but under the wings the fine blue inner coverts exactly resembled those of the Snipe. In those days I had no idea of the value attached to rare birds, nor did I know anything of the art of preserving birds, or of bird-preservers, and no doubt some of these gentlemen will p.r.o.nounce me a great Goth when I tell them that what I regretted most, when I found that the bird was plucked, was the loss of the wings, the feathers of which I wanted to dress artificial flies with. Three days after I had killed this, I saw another in a ditch adjoining Sir Henry Ibbetson's park, at Denton, but being in his preserve I had no opportunity of procuring it. I had never seen one since, and until I had seen the sixth edition of Bewick's "Birds," I was unable to make out its name, about which I may still be mistaken. (May 29th, 1834.)

FISH AND OTHER RIVER PHENOMENA.

A writer in the "British Naturalist" says, that "fish don't feed, and therefore we may conclude they don't discern in sunny weather." If the author had ever been a May-fly-fisher he would have known that bright weather and clear water were essentially necessary to his success.

This fly is one of the best baits I know for large Trout, and is much used by the anglers in some of the rivers in Yorkshire (perhaps in other counties also), where two methods of fishing it are practised. The one is bobbing, which with one sort of bait or another is universal, and therefore needs no description. However, it is always practised in bright weather. In the other method (which I believe is peculiar to the North of England) the May-fly (stone-fly) is fished with a long line in rapid streams, in the same way as the artificial fly, except that it is fished up the stream; that is, the angler throws his line into the stream above where he stands, and allows it to float down opposite to him, when he makes another throw; by this means he always keeps his line slack, and the May-fly floats on the surface, which is essential to his success. I mention these two methods of angling because both are practised in bright weather, and therefore prove that fish both discern and feed in such days. I believe the fact is, that at such times they frequently see too well for the angler, and are consequently aware that his artificial flies are not what they seem to be. Fishes, particularly Par and Grayling, may be seen rising by dozens at the small flies (midges) which abound in sunny weather, yet the angler is unable to hook a single fish.

First-rate anglers are well aware of this, and abandon their larger flies as the summer advances, use smaller hooks, dress their flies much finer, and subst.i.tute horsehair for the fishing- gut, when they can procure it of good quality.

LAMPREYS.

Lampreys abound in the Ribble. Some of them, of the large species (_Petromyzon marinus_), weigh three and four pounds each, [12] but owing to a prejudice against them (I suppose on account of their ugliness) they are seldom eaten. I will ill.u.s.trate this prejudice by giving the remark of a keen fisherman to myself, on my saying that I should eat a large one I had just caught. "Well," said he, "if you can manage to eat such a thing as that, you would not stick at devouring a child in the small-pox." This, if not an elegant, was at least a forcible expression of his opinion on the subject, and this dislike of them is almost universal in this neighbourhood. (Jan. 17th 1832.)

"An Old Angler," in the "Magazine of Natural History," having questioned the a.s.sertion of Sir Everard Home that the Lamprey was hermaphrodite--in fact, that all were sp.a.w.ners and emitted eggs-- the following was addressed to the "Magazine of Natural History":--

When I had the pleasure of writing to you before, I had either overlooked or forgotten the queries of "An Old Angler" respecting the Lamprey. However, your remarks have induced me to pay a little more attention to the subject. I can now confirm in the strongest and most conclusive manner the supposition of "An Old Angler" that the s.e.xes are as distinct in the Lamprey as they are in the Cod or Herring. How so distinguished an anatomist as Sir Everard Home fell into such a mistake, it is not for me to say; but I am as certain that the s.e.xes are distinct in the Lamprey as that they are so in any other animal, and I will now give my reasons for making this positive a.s.sertion.

On the 8th of May, chancing to cross a small stream, I saw a number of Lampreys in the act of sp.a.w.ning, and remembering the queries of your correspondent, I stood to watch their motions.

After observing them for some time, I observed one twist its tail round another in such a manner, and they both stirred up the sand and small gravel from the bottom in such a way, as convinced me it was a conjunction of the s.e.xes. However, there were so many of them together, and they kept so continually moving about, that I could not single out the two individuals, and thus ascertain whether they were male and female; but I felt so desirous of being able to set this question at rest, that I went again next morning, and was fortunate enough to find only two, a male and a female. I then witnessed several s.e.xual conjunctions, during which the sand and small gravel was stirred up by them, and each of which was followed by the ejection of a jet of eggs from the female. I then caught them both, and dissected them. The s.e.xual organ in the male was projected above a quarter of an inch, and the body filled with milt; the female, although she seemed to have shed a considerable quant.i.ty of her sp.a.w.n, had still a tolerable stock remaining.

I frequently afterwards witnessed the same thing, and always found the same difference of s.e.xes; in fact, there was generally no difficulty in distinguishing the male from the female, without taking them out of the water: the latter might be readily known by the enlargement of her body, and the former by a still more incontestable token. I have been induced to describe this more minutely than I otherwise should have done, in consequence of the mystery in which the propagation of fish has been wrapped hitherto; and I am not aware that what I have described has been witnessed by anyone before--at least I don't know that it has been recorded.

I caught half-a-dozen Lampreys, four males and two females, and preserved them in spirits, and these I now forward to you.

I am unable to give the same information concerning the large Lamprey, having never seen it in the act of sp.a.w.ning; but I have repeatedly caught both milters and sp.a.w.ners of species with the milt and roe as distinctly visible in them as it is in the Salmon or any other fish.

I am of opinion that the _P. marinus_ and the _P. fluviatilis_ are distinct species, for the following reasons:--1st. Because the latter stays with us the whole year, while the former only ascends the rivers to sp.a.w.n, and then returns to the sea immediately. 2nd.

Because fish that are in the habit of descending to the sea, never (unless the small Lamprey be an exception to the general rule) arrive at maturity [13] until they have visited it; and, 3rdly, because there are no intermediate sizes (at least in the Ribble) between the one which, although only six or seven inches long, and an ounce in weight, is yet capable of propagation, and the one of a pound. Not having one of the larger kind to refer to, I am unable to point out any specific difference of form. (May 2nd, 1832.)

ON THE Sp.a.w.nING OF THE MINNOW.

As I had been so fortunate in observing the Lampreys, I felt desirous of ascertaining whether the same thing could be seen in other fish (as in Natural History it is not always safe to reason from a.n.a.logy), and as there was a large shoal of Minnows sp.a.w.ning near the place where I had seen the Lampreys, I determined to watch their motions. They happened to have chosen a very convenient place for being observed, being between two large stones in the river, which lay about three feet from each other; so that by cautiously approaching them from behind one of the stones, I got close to without disturbing them, but after watching them carefully and repeatedly within the distance of two feet, I can only speak doubtfully of their operations, for they were so numerous, and their motions were so incessant; and when a female was about to shed her sp.a.w.n, the males (which were ten times more numerous than the females) crowded round her in such a manner as to render it very difficult, if not impossible, to speak with certainty on the subject. I will state what steps I took to satisfy myself, and perhaps the history of my failure may be of use to future observers.

It occurred to me from what I observed, that it was probable the males had the power of absorbing the eggs after their exclusion by the female, and impregnating them within their own bodies; and I caught a dozen males at different times, when they were attending on females, and opened them, but I could discover nothing like an egg. I then caught a female, and scattered the sp.a.w.n (which was expelled by the slightest pressure) in a place frequented by a number of males, but they took no notice of it whatever. I after this caught a female when she was surrounded by a number of males, and apparently in the act of shedding her sp.a.w.n, and examined whether the sp.a.w.n which I pressed from her body was impregnated; but it appeared perfectly h.o.m.ogeneous, and so delicate in its texture that it burst with the slightest touch, whilst in that which I picked up from among the gravel where it was scattered abundantly, the impregnation was visible with the a.s.sistance of a microscope, and it was so much tougher in its covering as to bear rolling about in my hand without injury. I then tried to impregnate the eggs _mechanically_, and applied a drop of the spermatic fluid to the egg at the moment of exclusion, and it certainly seemed, in one instance, both to increase the size and to alter the colour of the ova it was applied to; but I was not able to produce the same effect so decidedly in any of my subsequent attempts.

My observations, which were often repeated, induce me to believe that the egg is impregnated at the moment of exclusion, and that two males have (almost invariably) access to the female at the same time; for I frequently remarked, that when a female came among a number of males, they immediately pursued her: if she was not ready for shedding her sp.a.w.n, she made a precipitate retreat; but if she was, she came boldly in among them, and was immediately pressed closely by a male on each side, who when they had been in that situation a short time, were superseded by other two, who wedged themselves in between them and the female, who appeared to treat all her lovers with the same kindness.

One difficulty is, that the spermatic fluid mixes very readily with water; and I cannot imagine how its virtue is preserved, [14]

if (as I suppose must be the case) the egg is impregnated after exclusion; but I also think it probable that the ventral fins of the female serve to conduct this fluid to the place where it is needed, and the chemical affinity between it and the egg may be sufficient for impregnation.

P.S. July 27th. I tried to hatch some of the eggs I had endeavoured to fecundate. The attempt was unsuccessful. I placed the eggs, which I had put into some clean-washed gravel, in a shallow vessel (open at the top, and with holes drilled through the sides) in a small stream of water, but I found to my great mortification on looking for them a day or two after that there was not one left, but that in their stead were many aquatic insects, which had no doubt feasted on them as long as they lasted, and after this I was not able to meet with another shoal of Minnows in the act of sp.a.w.ning.

The head of the Minnow in the sp.a.w.ning season is spotted over with small white k.n.o.bs, apparently osseous in their structure, which make their appearance immediately before the fish begins to sp.a.w.n, and which disappear again as shortly after, and I think they are intended as a protection to the head of the fish during the sp.a.w.ning; as I remarked that they generally thrust their heads in between two pebbles, and had their tails sticking up almost perpendicularly. Yet this was not always the case, as they sometimes ran nearly out of the water, and it was in this situation that I observed what I have before mentioned, as I found it impossible to discover anything that was done by those in deeper water; for when a female went into such a situation, there was such a crowd of males rushed to the place that I lost sight of her in a moment.

I was astonished to find how quickly the eggs were hatched. I discovered a large shoal sp.a.w.ning on the 11th of May; on the 12th they were diminished to one-tenth of the number, and on the 14th (the 13th being Sunday) there was not one left. As I had by no means satisfied myself on the subject, I felt disappointed that they had so soon finished their operations, and I took up a handful of the gravel where they had been sp.a.w.ning, and examined it with the microscope, to see whether I could discover any ova, and how they were going on, when to my great surprise I found them already hatching and some of them already excluded from the egg.

One of them, which I took on the point of a knife, swam briskly away, and another was the means of pointing out an enemy to me which I had not previously suspected, and that I had always. .h.i.therto believed to be the prey of and not the preyer upon fish.

The poor Minnow had somehow got fast to the point of the knife, and in its struggles to free itself it attracted the attention of a creeper--the larva of one of the aquatic flies called drakes (_Ephemerae_)--which pounced upon it as fiercely as the water staphylinus does on the luckless tadpole, but, fortunately for the Minnow, either the glittering of the knife-blade or the motion of my hand, scared it away again without its prey.

The young Minnows in this state were quite transparent, except the eyes, which were disproportionately large; and they seemed to be perfectly aware that they owed their safety to concealment, as those that I saw immediately buried themselves in the gravel when they were set at liberty. (July 27th, 1832.)

EELS.

To the Editor of the "Gardener's Chronicle."