MARSH HAWK.
Falco cyaneus, Linn.
PLATE CCCLVI.
With ease and elegance of flight, guided by an uncommon acuteness of what I would call short-sightedness, the Marsh Hawk, like an experienced gleaner, ranges over the wide extent of the prairie. The pure white of the hind part of the female’s back, and the pale blue of the male, attract your eye so long as the pair remain within sight. The diligence and industry which they exhibit remind you of the search of a well-trained pointer.
This species visits the greater part of the United States. Dr Richardson procured some specimens in latitude 65° north, and Dr Townsend found it on the plains of the Columbia River, as well as on the extensive prairies bordering on the Missouri. I have met with it in Newfoundland and Labrador on the one hand, in Texas on the other, and in every intermediate portion of the country.
In the Fauna Boreali-Americana, Mr Swainson has published an excellent paper relating to such birds as have and have not been considered as identical with this bird and the European one bearing the same name. I perfectly agree with that gentleman when he says that “the typical structure of the wing in the present group must unquestionably be that most prevalent among the species. It must, however, be remembered, that even this character is subject to variation, according to the age and perhaps the locality of the bird, and that it must not be insisted upon with too much rigour.” I regret that this learned ornithologist did not introduce the word sex into the above well-founded remark, as in the sexes of birds, as well as in individuals of different ages, remarkable differences are often observed.
It is to Montagu that we are indebted for our first knowledge of the differences that exist between the male and the female of the European Hen Harrier, with which Wilson believed the Marsh Hawk of America to be identical. The Prince of Musignano, in his continuation of Wilson’s American Ornithology, also considered these birds as the same; although he has since altered his opinion. For my part, having carefully observed the habits, and compared specimens of both, I have come to the conclusion of their being the same species.
The flight of the Marsh Hawk, although light and elegant, cannot be said to be either swift or strong; but it is well sustained, and this may be accounted for on comparing the small size and weight of its body with the great extent of its wings and tail, which are proportionally larger than those of any other American Hawk. While searching for prey, it performs most of its rambles by rather irregular sailings; by which I mean that it frequently deviates from a straight course peeping hither and thither among the tall grasses of the marshes, prairies, or meadows, or along the briary edges of our fields. It is seldom indeed seen to chase birds on wing, although I have met with a few instances; nor is it much in the habit of carrying its quarry to any distance; for generally as it observes an object suited to its appetite, it suddenly checks its speed, and almost poising itself by a few flaps of its wings, drops with astonishing quickness on its unfortunate victim, which it usually tears to pieces and devours on the spot. If disappointed, however, it rises as quickly as it dropped, and proceeds as before. Whilst engaged in feeding, it may very easily be approached, surprised, and shot, by an experienced sportsman, for it rises in a flurried manner, and generally cuts a few curious zigzags at the outset. To obtain it, one has only to mark the spot with accuracy, keep his eye upon it, and advance with his gun in readiness, for he will probably get within a few yards before the bird rises. I have frequently seen it shot in this manner. At other times, by watching its beats over a field or meadow, one may obtain a good opportunity by concealing himself near a spot where he has seen it miss its object, as it is sure to repass there in a short time, at all events before it removes to another field. When wounded and brought to the ground, it makes off on the approach of its enemy by great leaps, and at times so swiftly that great exertion is requisite to overtake it; and when this is accomplished, it throws itself on its back, strikes furiously, and can inflict pretty severe wounds with its very sharp claws.
This species flies very high at times, and in a direct course, as if intent on proceeding to some great distance; but as I observed that this frequently occurred when the bird was satiated with food, I have thought that it preferred this method of favouring digestion, to its more usual mode of sitting on the top of a fence rail, and there remaining quiet until again roused by the feeling of hunger. I have often seen it, after sailing about in circles for a long while, half-close its wings, and come towards the ground, cutting curious zigzags, until within a few feet of it, when it would resume its usual elegant and graceful mode of proceeding.
I have observed it in our western prairies in autumn moving in flocks of twenty, thirty, or even so many as forty individuals, and appearing to be migrating, as they passed along at a height of fifty or sixty yards, without paying any attention to the objects below; but on all these occasions I could never find that they were bent on any general course more than another; as some days a flock would be proceeding southward, on the next to the northward or eastward. Many times I have seen them follow the grassy margins of our great streams, such as the Ohio and Mississippi, at the approach of winter, as if bent on going southward, but have become assured that they were merely attracted by the vast multitudes of Finches or Sparrows of various sorts which are then advancing in that direction.
In winter, the notes which the Marsh Hawk emits while on wing, are sharp, and sound like the syllables pee, pee, pee, the first slightly pronounced, the last louder, much prolonged, and ending plaintively. During the love-season, its cry more resembles that of our Pigeon Hawk; especially when the males meet, they being apparently tenacious of their assumed right to a certain locality, as well as to the female of their choice.
The Marsh Hawk breeds in many parts of the United States, as well as beyond our limits to the north and south in which it finds a place suited to its habits; as is the case with the Blue-winged Teal, and several other species, which have until now been supposed to retreat to high latitudes for the purpose. That many make choice of the more northern regions, and return southward in autumn, is quite certain; but in all probability an equal number remain within the confines of the United States to breed.
It is by no means restricted to the low lands of the sea-shores during the breeding season, for I have found its nest in the Barrens of Kentucky, and even on the cleared table-lands of the Alleghany Mountains and their spurs. In one instance, I found it in the high-covered pine-barrens of the Floridas, although I have never seen one on a tree; and the few cases of its nest having been placed on low trees or bushes, may have been caused by the presence of dangerous quadrupeds, or their having been more than once disturbed or robbed of their eggs or young, when their former nests had been placed on the ground.
Many birds of this species breed before they have obtained their full plumage. I have several times found a male bird in brown plumage paired with a female which had eggs; but such a circumstance is not singular, for the like occurs in many species of different families. I have never met with a nest in situations like those described by some European writers as those in which the Hen-harrier breeds; but usually on level parts of the country, or flat pieces of land that are sometimes met with in hilly districts. As I am well aware, however, that birds adapt the place and even the form and materials of their nests to circumstances, I cannot admit that such a difference is by any means sufficient to prove that birds similar in all other respects, are really different from each other. If it be correct, as has been stated, that the male of the European bird deserts the female, as soon as incubation commences, this indeed would form a decided difference; but as such a habit has not been observed in any other Hawk, it requires to be confirmed. Our Marsh Hawks, after being paired, invariably keep together, and labour conjointly for the support of their family, until the young are left to shift for themselves. This is equally the case with every Hawk with which I am acquainted.
Having considerable doubts as to whether any American writer who has spoken of the Marsh Hawk ever saw one of its nests, I will here describe one found on Galveston Island by my son John Woodhouse, and carefully examined by him as well as by my friend Edward Harris and myself. As is usually the case when in a low and flat district, this was placed about a hundred yards from a pond, on the ground, upon a broom-sedge ridge, about two feet above the level of the surrounding salt marsh. It was made of dry grass, and measured between seven and eight inches in its internal diameter, with a depth of two inches and a half, while its external diameter was twelve inches. The grass was pretty regularly and compactly disposed, especially in the interior, on which much care seemed to have been bestowed. No feathers or other materials had been used in its construction, not even a twig. The eggs were four, smooth, considerably rounded, or broadly elliptical, bluish-white, an inch and three-quarters in length, an inch and a quarter in breadth. The two birds were procured, and their measurements carefully entered in my journal, as well as those of others obtained in various parts of the United States and of the British Provinces. A nest found on the Alleghanies was placed under a low bush, in an open spot of scarcely half an acre. It was constructed in the same manner, as the one described above, but was more bulky, the bed being about four inches from the earth. The eggs, although of the same form and colour, were slightly sprinkled with small marks of pale reddish-brown. In general, the Marsh Hawks scoop the ground, for the purpose of fixing their nest to the spot. On returning to London, in the summer of 1837, I shewed several of the eggs of the American bird to William Yarbell, Esq. who at once pronounced them to belong to the Hen Harrier; and on comparing their measurements with those of the eggs described by my friend William Macgillivray, I find that they agree perfectly.
The young are at first covered with soft yellowish-white down, but in a few weeks shew the brownish and ferruginous tints of their female parent, the young males being distinguishable from the females by their smaller size.
I have found a greater number of barren females in this species than in any other; and to this I in part attribute their predominance over the males. The food of the Marsh Hawk consists of insects of various kinds, especially crickets, of small lizards, frogs, snakes, birds, principally the smaller sorts, although it will attack Partridges, Plovers, and even Green-winged Teals, when urged by excessive hunger. The only instance in which I have seen this bird carry any prey in its talons on wing, happened on the 2d of April 1837, at the south-west Pass of the Mississippi, when I was in company with Edward Harris, Esq. and my son John Woodhouse. A Marsh Hawk was seen to seize a bird on its nest, perhaps a Marsh Wren, Troglodytes palustris, and carry it off in its talons with the nest! A pair were hovering over the marsh during the whole of our stay, and probably had a nest thereabout. It is rather a cowardly bird, however, for on several occasions, when I was in the Floridas, where it is abundant, I saw it chase a Salt-water Marsh Hen, Rallus crepitans, which courageously sprung up, and striking at its enemy, forced it off. My friend John Bachman has frequently observed similar occurrence in the neighbourhood of Charleston. Whenever it seizes a bird on wing, it almost at once drops to the ground with it, and if in an exposed place, hops off with its prey to the nearest concealment.
In autumn, after the young have left their parents, they hunt in packs. This I observed on several occasions when on my way back from Labrador. In Nova Scotia, on the 27th of August, we procured nearly a whole pack, by concealing ourselves, but did not see an adult male. These birds are fond of searching for prey over the same fields, removing from one plantation to another, and returning with a remarkable degree of regularity, and this apparently for a whole season, if not a longer period. My friend John Bachman observed a beautiful old male which had one of its primaries cut short by a shot, regularly return to the same rice-field during the whole of the autumn and winter, and believes that the same individual revisits the same spot annually. When satiated with food, the Marsh Hawk may be seen perched on a fence-stake for more than an hour, standing motionless. On horseback I have approached them on such occasions near enough to see the colour of their eyes, before they would reluctantly open their wings, and remove to another stake not far distant, where they would probably remain until digestion was accomplished.
I have never seen this species searching for food in the dusk. Indeed, in our latitudes, when the orb of day has withdrawn from our sight, the twilight is so short, and the necessity of providing a place of safety for the night so imperious in birds that are not altogether nocturnal, that I doubt whether the Marsh Hawk, which has perhaps been on wing the greater part of the day, and has had many opportunities of procuring food, would continue its flight for the sake of the scanty fare which it might perchance procure at a time when few birds are abroad, and when quadrupeds only are awakening from their daily slumber.
Wilson must have been misinformed by some one unacquainted with the arrival and departure of this species, as well as of the Rice Bird, in South Carolina, when he was induced to say that the Marsh Hawk “is particularly serviceable to the rice-fields of the Southern States, by the havoc it makes among the clouds of Rice Buntings that spread such devastation among the grain, in its early stages. As it sails low, and swiftly, over the surface of the field, it keeps the flocks in perpetual fluctuation, and greatly interrupts their depredations. The planters consider one Marsh Hawk to be equal to several Negroes for alarming the Rice Birds.” Now, good Reader, my friend John Bachman, who has resided more than twenty years in South Carolina, and who is a constant student of nature, and perhaps more especially attentive to the habits of birds, informs me that the Marsh Hawk is proportionally rare in that State, and that it only makes its appearance there after the Rice Birds have left the country for the south, and retires at the approach of spring, before they have arrived.
European writers have generally considered our Marsh Hawk as larger than their Circus cyaneus; but this opinion must have originated from a want of specimens for comparison, and perhaps also a want of books on which one might depend. Were all ornithological works characterized by the accuracy and detail to be found in those of my friend William Macgillivray, the case might be different. The measurements which he has taken from recent specimens correspond with those which I also have taken from individuals newly killed, as nearly as is usual in birds of other species. Indeed, should you measure as accurately as possible a hundred specimens of any bird as large as our Marsh Hawk, I am persuaded you would not find many of them to agree in all their proportions. Instead of the American exceeding the European bird in size, I think it will generally be found to be as nearly equal as possible.
Falco cyaneus and F. pygargus, Linn. Syst. Nat. vol. i. p. 126.
Falco cyaneus, Lath. Ind. Ornith. vol. i. p. 39.—Ch. Bonaparte, Synopsis of Birds of United States, p. 33.
Marsh Hawk, Falco uliginosus, Wils. Amer. Ornith. vol. vi. p. 67, pl. 1, fig. 1., young female.
Falco cyaneus, Ch. Bonaparte; Amer. Ornith. vol. ii. p. 30, pl. xi. fig. 1., male.
Buteo (Circus) cyaneus ? var ? Americanus, American Hen-Harrier, Richards. and Swains. Fauna Bor.-Amer. vol. ii. p. 55.
Hen-harrier, or Marsh Hawk, Nuttall, Manual, vol. ii. p. 109.
Adult Male. Plate CCCLVI. Fig. 1.
Bill short, compressed. Upper mandible with its dorsal line a little tumid at the base, sloping to beyond the cere, then decurved in the fourth of a circle, the sides sloping, towards the end a little convex, the edge with a festoon a little anterior to the nostril, the tip acute, concave beneath. Lower mandible with the angle broad, the dorsal line ascending and convex, the edges a little inflected, the tip rounded, with the edges decurved. Nostrils large, ovato-oblong, in the middle and fore part of the cere, and having an oblique ridge from the upper edge.
Head of moderate size, oblong; neck short; body slender, much compressed behind. Legs long and slender; tibia long but muscular; tarsi long, compressed, with seventeen or eighteen large oblique scutella on the fore and outer side, oval or subhexagonal scales on the sides, and scutella behind, excepting at the upper and lower parts; toes small, slender, the outer with a short web at the base, connecting it with the third; first considerably shorter than second, fourth a little longer than the latter, third much longer; all covered above with scutella, unless at the base, where there are small scales, beneath tuberculate and papillate, there being a long fleshy tubercle on the last joint of each toe, and one on the next joint of the two outer. Claws long, compressed, rounded above, flat beneath, curved into the fourth of a circle, those of the first and second toes largest, that of the third with a slight internal edge, of the fourth much smaller and less curved.
Plumage very soft, generally blended. Cere covered on the sides with rather long bristle-tipped feathers, which curve upwards and partially conceal the nostrils; space between the bill and eye with radiating feathers of the same nature. A distinct ruff of narrow feathers, which are decurved, but with the tips recurved, extends from behind the eye on each side to the chin. Wings long, much rounded; the fourth quill longest, the third two-twelfths of an inch shorter, the second a quarter of an inch shorter than the fifth, the first and seventh about equal. The outer webs of the first five are attenuated towards the end; and the outer four have their inner webs sinuate; the secondaries are broad and rounded. Tail straight, long, of moderate breadth, and slightly rounded, the middle feathers longest (in perfect specimens, but often worn). The quills and tail-feathers are extremely soft, being covered with a velvety down.
Bill bluish-black, cere yellow; inside of mouth dark bluish-grey. Iris yellow. Tarsi and toes yellow, tinged with orange; claws black. The general colour of the plumage above is light greyish-blue, the head and scapulars of a deeper tint, the hind part of the back paler; the bases of the occipital and ruff feathers white; the bristles of the cere and lores black, their downy bases white. The fore neck and anterior part of the breast are also greyish-blue; the middle of the breast and the sides white, tinged with blue, the feathers having their shafts dusky, and some very faint indications of bars; those of the legs, the lower wing-coverts, and lower and upper tail-coverts, pure white. The seven outer primaries are black, tipped with pale brown at the base white, and on the outer edge tinged with grey; the rest and the secondaries of the general colour, but with more or less brown towards the end, their inner webs white, and obscurely barred with dark grey. The two middle tail-feathers are of a lighter tint than the back, and the colour on the outer webs of the rest gradually fades into white; the inner webs of all but the two middle more or less white, with eight irregular narrow bars of darkish grey.
Length to end of tail 19 3/4 inches, to end of wings 16 1/2, to end of claws 16 1/2; extent of wings 44; wing from flexure 14 4/12; tail 8 9/12; bill along the ridge 1 2/12, along the edge of lower mandible 1 2/12; tarsus 2 8/12; hind toe 7 1/2/12, its claw 10/12; middle toe 1 2 1/2/12, its claw 8 1/2/12. Weight 16 oz.
Adult Female. Plate CCCLVI. Fig. 2.
The female is larger than the male, and differs extremely in the colours of the plumage, although those of the bare parts are the same. The general colour of the upper parts is umber-brown, of the lower light yellowish-red. The upper part of the head is deep brown, the feathers edged with light yellowish-red; the anterior part of the forehead, a band over the eye, and the loral space, pale greyish-yellow, the bristle-tips of the latter black. The cheek feathers are dull brown, slightly edged with yellowish-red; the ruff feathers light yellowish-red, with a narrow brown central band. The upper hind part, sides, and fore part of the neck, the breast and sides, are light reddish-yellow, each feather with an oblong-lanceolate umber-brown mark. Some of the hypochondrial feathers have four light spots; the central part of the outer tibial feathers is light brownish-red; the feathers of the middle of the breast, the abdomen, and the lower tail-coverts, are of a uniform light yellowish-red. On some of the scapulars, as well as many of the wing-coverts, are one or two round light red or whitish spots; and the bases of the occipital feathers are white. The primary and secondary quills are of the same colour as the back, slightly edged with paler, the greater part of the inner webs whitish, the primaries with broad bands of deeper brown. Upper tail-coverts white. Tail light greyish-brown, white at the base, with six broad bands of deep brown on the middle feathers, four on the lateral, the last band much larger, the tips brownish or reddish white, the inner webs, excepting the two middle feathers, reddish-grey or whitish, the shafts light brown. Lower wing-coverts reddish-white, with central lanceolate brown markings: lower surface of primary quills greyish-white, with very conspicuous broad blackish-brown bands; tail reddish-grey beneath, with the dark bands more distinct.
Length to end of tail 20 1/2 inches, to end of wings 18 3/4, to end of claws 15 3/4: extent of wings 46 3/8: wing from flexure 15 1/4: tail 9 10/12; bill along the ridge 1 3/12, along the edge of lower mandible 1 2/12; tarsus 3 2/12; hind toe 10/12, its claw 1 2/12; middle toe 1 1/2, its claw 10/12.
Young fully fledged. Plate CCCLVI. Fig. 3.
The young of both sexes when fully fledged, resemble the adult female, but have the colours of a richer or deeper tint; all the lower parts with an elongated brown streak on each feather; the upper tail-coverts white, with a lanceolate reddish-brown spot.
After the first moult, the male still resembles the adult female. At least, such is the case with a specimen presented to me by Dr Richardson, and marked “Buteo (Circus) cyaneus. Spec. N. 6. Male. May 31. 1826. Fort Franklin,” being the one elaborately described at p. 63 of the second volume of the Fauna Boreali-Americana. In this specimen the colours are much faded, and the feathers worn, the upper tail-coverts in particular being reduced almost to the shafts. It is valuable as indicating by two feathers on the leg, which are new, the next state of plumage of the male, which is as follows:—
The upper part of the head and the hind neck are light brownish-red, with dusky streaks, the white of the nuchal feathers conspicuous. The upper parts are brown, with a tinge of grey, more apparent on the wings, the scapulars and some of the smaller wing-coverts still marked as in the young and females; the upper tail-coverts pure white; the tail-feathers grey, with a tinge of brown, the lateral reddish-grey; the dark bars much diminished in breadth, and the inner webs still tinged with yellowish-red. The ruff is brownish-grey, margined with reddish-white; the fore part of the neck and breast pale brownish-red, tinged with grey, each feather marginally spotted or edged with dull white. The rest of the lower parts are white, the feathers generally with several spots of light red along the centre; these spots assuming the appearance of transverse bars on the sides and legs; the smaller wing coverts are similarly spotted, but those near the edge have only a dusky streak, and the secondary coverts are barred with dusky. The inner webs of the quills toward the base are white, with narrow bars of brownish-black, and the extremities of the primaries are as in the adult.
After a very careful comparison of seven skins of American birds with an equal number of European, no essential differences can be observed. I am therefore compelled to conclude, that the Marsh Hawk of America is the Hen-Harrier of Europe. The following measurements are obtained from a comparison of eight individuals.
| Amer. | Europ. | Amer. | Europ. | |||||||||||||
| M. | M. | M. | M. | F. | F. | F. | F. | |||||||||
| Length to end of tail, | 19 | 3/4 | 16 | 1/2 | 18 | 18 | 1/4 | 20 | 1/2 | 20 | 1/4 | 21 | 21 | |||
| ................................wings, | 16 | 1/2 | 14 | 1/2 | 15 | 3/4 | — | 18 | 3/4 | 18 | 1/2 | 18 | 1/2 | 19 | ||
| Extent of wings, | 44 | 40 | 1/2 | 40 | 39 | 1/2 | 46 | 3/8 | 45 | 1/2 | 46 | 46 | ||||
| Wing from flexure, | 14 | 4/12 | 13 | 13 | 1/2 | 13 | 15 | 1/4 | 14 | 9/12 | 14 | 1/4 | 15 | 1/4 | ||
| Tail, | 8 | 9/12 | 8 | 7/12 | 9 | 8 | 1/2 | 9 | 10/12 | 9 | 9/12 | 9 | 9/12 | 10 | ||
| Bill along the ridge, | 1 | 2/12 | 1 | 1 1/2/12 | 1 | 1/12 | 1 | 1/12 | 1 | 3/12 | 1 | 3/12 | 1 | 2/12 | 1 | 3/12 |
| Tarsus, | 2 | 8/12 | 2 | 9/12 | 2 | 1/2 | 2 | 8/12 | 3 | 2/12 | 3 | 2/12 | 2 | 9/12 | 2 | 9/12 |
| Hind toe, | 7 1/2/12 | 7 1/2/12 | 8/12 | 7/12 | 10/12 | 7 1/2/12 | 7 1/2/12 | 9/12 | ||||||||
| Its claw, | 10/12 | 10 1/2/12 | 9/12 | 9 1/2/12 | 1 | 2/12 | 1 | 1 | 1/12 | 11/12 | ||||||
| Middle toe, | 1 | 2 1/2/12 | 1 | 2 1/2/12 | 1 | 1/2 | 1 | 2/12 | 1 | 1/2 | 1 | 4/12 | 1 | 4/12 | 1 | 5/12 |
| Its claw, | 8 1/2/12 | 8 1/2/12 | 8/12 | 8 1/2/12 | 10/12 | 9 1/2/12 | 10/12 | 11/12 | ||||||||
| Anterior tarsal scutella, | 17 | 18 | 18 | 15 | 19 | 17 | 18 | — | ||||||||
| Scutella on first toe, | 7 | 6 | 6 | 6 | 7 | 5 | 6 | — | ||||||||
| second, | 5 | 5 | 5 | 5 | 5 | 5 | 5 | — | ||||||||
| third, | 16 | 17 | 18 | 15 | 16 | 16 | 17 | — | ||||||||
| fourth, | 7 | 8 | 7 | 7 | 8 | 7 | 8 | — | ||||||||
If measurements of this kind are calculated to throw light on the subject, the collectors of skins are welcome to the above, which have been made with as much accuracy as possible.
An adult male examined. On the roof of the mouth are two lateral and a median prominent ridge, the intervening space covered with small papillæ. The posterior aperture of the nares is oblong, 4 twelfths of an inch in length, but with an anterior slit 7 1/2 twelfths long. The tongue, a, is 8 1/2 twelfths long, fleshy, emarginate and papillate at the base, concave above, rounded and slightly emarginate at the tip. The mouth is 1 inch in breadth. The œsophagus, a b c d e, which is 6 inches long, is very wide, with very thin parietes, and on the lower part of the neck is dilated into a sac or crop, b c, which on being distended has a diameter of 2 inches at the widest part. It then contracts to 10 twelfths as it enters the thorax; its proventricular portion, d e, has a diameter of 1 inch. The stomach, e f g is roundish, 1 1/2 inch in diameter, somewhat compressed; its muscular coat extremely thin, being reduced to small parallel fasciculi converging toward two tendinous spaces of an elliptical form, and about half an inch long. The intestine, g h, is 3 feet 2 inches long; its diameter at the upper part 3 twelfths, towards the cœca 2 twelfths. The rectum, i j, is 2 inches long, not including the cloaca, j, which is globular and 1 inch in diameter. The cœca are extremely small, being 2 1/4 twelfths long, and 1 twelfth in diameter. The pylorus has no valve properly so called, but two ridges run from it into the intestine to the length of about 3 twelfths of an inch. The gall-bladder is 7 twelfths long and 4 twelfths in breadth.
In a very small male, the œsophagus is 4 3/4 inches long; the intestine 3 feet 4 inches. In a female, the intestine is 3 feet 9 inches long.
The trachea is 4 8/12 inches long, flattened. 4 1/4 twelfths broad at the upper part, gradually contracting to 2 3/4 twelfths; its rings 95, extremely thin and unossified. The bronchi are of moderate length, with about 20 half-rings. The lateral muscles are thin, the sterno-tracheal slender.