the sea-shore, where the dunlin (Tringa variabilis, MEYER), a bird, similar in its feeding to the sandpiper, congregates in considerable bands. These birds pick up an abundant supply of small marine insects within the tide mark, and, at the same time, keep so close to their companions, that we may say we never saw one a yard from the flock. Whether they appoint a watch or not we have not been able to determine; but they are so wary that several keen sportsmen, at a watering-place, failed in procuring us a single specimen, though they tried for two or three months to get within shot of several flocks that frequented the coast*.

CHAPTER III.

BIRDS, SOLITARY OR GREGARIOUS, ON ACCOUNT OF SHELTER OR ASSISTANCE.

UPON glancing back over the details which we have already given of the solitary and social habits of birds, it will be obvious, that their sociality produces no apparent result, except it may be the appointment of a sentinel to give intimation of danger, if such appointment (as may well be doubted) actually takes place. Except in the instance of the sociable grosbeak (Loxia socia) of Africa, we do not recollect any authentic instance of birds uniting their efforts to assist in performing a common work. Even in this instance, the accurate observations of M. Vaillant have proved, that so far from building streets, as Paterson and others represent these birds to do, they merely build their nests in actual contact*, as rooks may sometimes be observed to do in this country. The notion of their building streets is of the same character with Pliny's account of the swallows in Egypt raising an embankment to oppose the inundation of the Nile, adopted by him from some hasty observer who had seen the bank-swallows (Hirundo riparia), not building (as he supposed), but mining into an escarpment of the rivert. In the same way we find it related by authors of celebrity, that when a pair of sparrows take felonious possession of the nest of a swallow, the swallow summons its companions to its * See Voyage, p. 3.

+ See Architecture of Birds, p. 96.

seems to indicate a dislike to the labour of digging, that it frequents the same hole for a series of years, and will not abandon it, though the nest be repeatedly plundered. The accumulation of cast bones in one of these old holes has perhaps given origin to the notion of the nest being formed of them.

Our own opportunities of carefully studying the habits of this bird, lead us to remark, that it is not so very shy and solitary as it has been represented, for it has more than once allowed us to approach within a few yards of the bough on which it was perched. Mr. Jennings says that it is " rarely if ever found near the habitations of man*." On the contrary, we are in the habit of seeing kingfishers very often on the banks of a brook which runs past our garden, not a hundred yards from the house. A kingfisher's nest was found with young last summer on the bank of the same brook, and within gun-shot of a whole row of houses †. This fact was stated in the Magazine of Natural History. Another correspondent of Mr. Loudon's says, "that for the last nine years, and perhaps more, I have observed that a pair of kingfishers have uniformly constructed their nests in a hole of a bank which projects over a piece of water, on my premises, not one hundred yards from the house ‡." In the summer of 1828, a single kingfisher took up his abode at Stamford Hill, in the immediate neighbourhood of London, in a narrow garden, much frequented, and close to several houses, on occasion of a small pond being stocked with gold-fish. The bird was frequently seen perched upon an ornament in the middle of the pond watching the fish, and was at last shot by the gardener from an apprehension that he would destroy the young fry. The necessity for obtaining its food from streams and shallow *Ornithologia, p. 172. † J. R. Loudon's Mag. of Nat. Hist., iv. 82.

Now we doubt not that these swallows crowded to their companion, as M. Dupont has recorded, for all small birds are apt to come when called by their fellows, as is well known to bird-catchers, who employ call-birds to bring the wild ones to their nets; but we much doubt whether they united their efforts with the design of cutting the string, and think the observer must have been deceived as to this parti cular. In a similar instance of a pair of sparrows becoming entangled, which fell under our observation, their neighbours crowded to the place, but, apparently, only for the purpose of scolding, not of assisting, the entangled birds*.

It is rare indeed among quadrupeds, and rarer still, if it occur at all, among birds, to meet with instances of mutual assistance, such as we find so strikingly exemplified among social insects †. Beavers unite in forming dams across a stream and in burrowing out chambers in the banks; but stories are told of the mutual assistance of some other quadrupeds, evidently as much overcoloured as that of M. Dupont's swallows. Thus the preparation of a winter abode by the marmot (Arctomys marmota, A. Bobac, &c.,) which has always excited admiration, has been, as is usual in such cases, greatly exaggerated by the fancies of inaccurate observers. "Their wit and understand→ ing," says Gesner, "is to be admired; for, like beavers, one of them falleth on the back, and the residue load his belly with the carriage, and when they have laid upon him sufficient, he girteth it fast by taking his tail in his mouth, and so the residue draw him into the cave; but I cannot," he well adds, "affirm certainly whether this be truth or falsehood; for there is no reason that leadeth thereunto, but that some of them have been found bald on the back." This evident fable is still gravely stated by some writers See Architecture of Birds, p. 319.

+ Insect Miscel. § iii. Hist. of Anim, by Toplis, p.407.

as an ascertained fact; and M. Beauplan goes so far as to imagine that he has seen a party trailing one of their companions by the tail, taking care not to overset him*. This feat, however, seems to be outdone by the one recently given on anonymous authority as authentic, of the marmot's skill in haymaking. "They bite off the grass," it is also said, "turn it and dry it in the sun †."

The only obvious and decided instance of mutual assistance which we recollect as occurring among birds, is that of parents feeding their young, keeping them clean and warm, and defending them against enemies, of all which habits we shall give ample details in the sequel of this volume. But in order to secure warmth, many species certainly take advantage of the animal heat of their kindred, and we may with some plausibility say, that in most cases this is done by mutual sufferance, if not by distinct permission.

It is one of the most extraordinary as well as one of the best ascertained facts in the animal economy, though by no means as yet satisfactorily explained, that the interior heat of warm-blooded animals varies extremely little in the coldest and in the hottest climates. To the uninstructed it appears no less erroneous to say that the body is equally warm on a cold winter's morning and on the most sultry of the dog-days, as to affirm that the sun is stationary contrary to the apparent evidence of the senses; yet the one truth is as well ascertained as the other. For example, Captain Parry found that when the air was from 3° to 32° at Winter Isle, lat. 66° 11' N., the interior temperature of the foxes when killed was from 1063° to 98°; and at Ceylon, Dr. Davy found that the temperature of the native * Descript. Ukraine.

Mag. Nat. Hist. i. 377.

Second Voyage, p. 157.