Though nowhere especially abundant, the American bittern is widely and generally distributed over nearly all of the North American continent and adjacent islands, wherever it can find the secluded bogs and swamps, in which it leads a rather solitary existence. It is less gregarious and more retiring in its habits than the other herons, hence less conspicuous and not so well known, even in localities where it is really common. Doctor Coues (1874) has well described its character, as follows:

No doubt he enjoys life after his own fashion, but his notions of happiness are peculiar. He prefers solitude, and leads the eccentric life of a recluse, "forgetting the world, and by the world forgot." To see him at his ordinary occupation, one might fancy him shouldering some heavy responsibility, oppressed with a secret, or laboring in the solution of a problem of vital consequence. He stands motionless, with his head drawn in upon his shoulders, and half-closed eyes, in profound meditation, or steps about in a devious way, with an absent-minded air; for greater seclusion, he will even hide in a thick brush clump for hours together. Startled in his retreat whilst his thinking cap is on, he seems dazed, like one suddenly aroused from a deep sleep; but as soon as he collects his wits, remembering unpleasantly that the outside world exists, he shows common sense enough to beat a hasty retreat from a scene of altogether too much action for him.

In spite of its peculiarities this recluse of the marshes has proved to be an interesting and an attractive object of study for many observers, perhaps on account of difficulties to be overcome in making only a slight acquaintance with it. There is a certain fascination in searching out and studying the home secrets of these shy denizens of the swamps. On a warm spring evening, when the waters are teeming with new life and the trees and shrubberies are enlivened by the migrating host of small birds, one loves to linger on its border and listen to the voices of the marsh. Many and varied are the sounds one hears at such a time. The air is full of twittering swallows, coursing back and forth in search of their evening meal; the spirited, resonant trill of the swamp sparrow is heard in the long, tufted grass of the open spaces; the loud gurgling songs of the long-billed marsh wrens come from the cat-tail flags, where an occasional glimpse may be had of the lively little birds; from way off in the marsh the clucking, clattering voice of the Virginia rail alternates with the whinnying cry of the sora, only a few feet away. But above them all in intensity and volume are the loud, guttural pumping notes of the bittern, the weird, wild love notes of the "thunder pumper" or "stake driver."

Courtship.--The nuptial display of the American bittern, a remarkable and striking performance, has been well described by Mr. William Brewster (1911); I quote from his excellent paper on the subject as follows:

At morning and evening I have heard them pumping or have seen them flying to and fro, or standing erect with heads and necks stretched up on the watch for danger, but previous to to-day (Apr. 17), I have paid little attention to them. Two, which I saw this morning, however, presented such a strange appearance and acted in so remarkable a manner that I watched them for half an hour or more with absorbing interest. When I first noticed them they were on the farther margin of a little lagoon where red-winged blackbirds breed, moving past it eastward almost as if not quite as fast as a man habitually walks, one following directly behind the other at a distance of 15 or 20 yards. Thus, they advanced, not only rapidly, but also very evenly, with a smooth, continuous, gliding motion which reminded me of that of certain gallinaceous birds and was distinctly unheronlike. Occasionally they would stop and stand erect for a moment, but when walking they invariably maintained a crouching attitude, with the back strongly arched, the belly almost touching the ground, the neck so shortened that the lowered head and bill seemed to project only a few inches beyond the breast. In general shape and carriage, as well as in gait, they resembled pheasants or grouse much more than herons. But the strangest thing of all was that both birds showed extensive patches of what seemed to be pure white on their backs, between the shoulders. This made them highly conspicuous and led me to conclude at first that they must be something quite new to me and probably because of their attitudes and swift gliding movements pheasants of some species with which I was unfamiliar. Thus far I had been forced to view them with unassisted eyesight, but when I had reached the cabin and they the edge of our boat canal directly opposite it, I got my opera glass and by its aid quickly convinced myself that despite their unusual behavior and the white on their backs they could be nothing else than bitterns.

The white first appears at or very near the shoulders of the folded wings and then expands, sometimes rather quickly (never abruptly, however) but oftener very slowly until, spreading simultaneously from both sides, it forms two ruffs apparently almost if not quite equal in length and breadth to the hands of a large man but in shape more nearly resembling the wings of a grouse or quail held with the tips pointing sometimes nearly straight upward, sometimes more or less backward, also. As they rise above the shoulders these ruffs spread toward each other at right angles to the long axis of the bird's body until, at their bases, they nearly meet in the center of the back. Sometimes they are held thus without apparent change of area or position for many minutes at a time, during which the bird may move about over a considerable space or perhaps merely stand or crouch in the same place. We frequently saw them fully displayed when the bitterns were "pumping" but not then more conspicuously, or in any different way, than at other times. When the bird was moving straight toward us with his body carried low and his ruffs fully expanded he looked like a big, white rooster having only the head and breast dark colored, the breast often looking nearly black. For in this aspect and at the distance at which we viewed him (perhaps 200 yards) the broad ruffs, rising above and reaching well out on both sides of the back and shoulders, completely masked everything at their rear while the head and the shortened neck, being carried so low that they were seen only against the breast, added little or nothing to the visible area of dark plumage. When he was moving away from us in the same crouching attitude the ruffs looked exactly like two white wings--nearly as broad as those of a domestic pigeon but less long--attached to either side of the back just above the shoulders. When we had a side view of him the outline of the ruffs was completely lost and there seemed to be a band of white as broad as one's hand, extending between the shoulders quite across the back. Thus whichever way he moved or faced the white was always shown, most conspicuously, however, when he turned toward us.

I was now joined by Miss E. R. Simmons, Miss Alice Eastwood (the California botanist), and my assistant, R. A. Gilbert, all of whom became at once deeply interested in the birds which had stopped and were standing erect by the canal about 20 yards apart. Suddenly both rose and flew straight at one another, meeting in the air at a height of 4 or 5 feet above the marsh. It was difficult to make out just what happened immediately after this but we all thought that the birds came together with the full momentum of rapid flight and then, clinching in some way, apparently with both feet and bills, rose 6 or 8 feet higher, mounting straight upward and whirling around and around, finally descending nearly to the ground. Just before reaching it they separated and sailed (not flapped) off to their former respective stations. After resting there a few minutes the mutual attack was renewed in precisely the same manner as at first only somewhat less vigorously. It was not repeated after this. Although a most spirited tilt (especially on the first occasion), by antagonists armed with formidable weapons (the daggerlike bills), we could not see that any harm resulted from it to either bird. When we crossed the river in a boat some 15 minutes later both bitterns were still standing near the canal. Up to this time both had shown white continuously but it disappeared as we were approaching them. One took flight when we were in the middle of the river. We got within 20 yards of the other before it moved, and then it merely walked off the marsh.

Nesting.--Strangely enough neither Wilsor nor Audubon ever saw a bittern's nest. But much has been published on it since and nesting bitterns have been favorite subjects for photographers. It has often been said that the nest is hard to find, but I have never experienced any great difficulty in finding those for which I have looked; I have even found as many as five in one day.

In Massachusetts the favorite nesting site seems to be in an extensive and rather dense cat-tail marsh, where the nest is at least partially concealed among the tall dead flags (Typha latifolia) of the previous year's growth. While incubation is progressing the new growth of green flags is going on, so that by the time the young are hatched the concealment is complete. The nest consists of a practically flat platform of dead flags, a foot or more in diameter and raised only a few inches above the surrounding water or mud. The color of the eggs matches that of the flags almost exactly. Sometimes the flags are arched together over the nest, but more often it is open above. The nests are sometimes placed in other kinds of swamps or floating bogs, where whatever nesting material is most easily available is used; sometimes the eggs are laid on what is practically bare ground. I once saw a nest at least 50 yards from a wet meadow; it was found by mowing a grassy slope; the nest was concealed in the long grass, but was on absolutely dry land, on which hay was regularly cut.

In the sloughs and meadows near Crane Lake, Sasketchewan, we found the American bittern nesting among the cat-tail flags and among the bulrushes (Scirpus lacustris). It was here that I found the five nests in one day, referred to above, all of which were in one slough less than a quarter of a mile square. This is at variance with the statement I have seen in print that only one pair of bitterns nests in a marsh. The nests were the usual platforms of dead flags or bulrushes, to match their surroundings; the measurements of the nests varied from 12 by 14 to 14 by 16 inches; they were built up 6 or 7 inches above the water, which was from 1 foot to 18 inches deep. One of these bitterns sat on her nest contentedly while my companion, Herbert K. Job, photographed her at short range. We also found a bittern's nest here on the open meadow, near the slough, where the grass was rather short and the ground nearly dry.

Dr. P. L. Hatch (1892) says that in Minnesota the nests "consist of small sticks, coarse grass, with more or less leaves of sedge brush and are placed directly on the ground in the most inaccessible bog marshes and slough. Preferably a tuft of willowy sedge is chosen that gives the nest a slight elevation, yet not uniformly so, for I find them not infrequently placed between the bogs in the marshes that are devoid of all kinds of brush. A rank bunch of grass that springs up in these places will most naturally be the place to look for them first, however."

R. C. Harlow writes to me that he has found the American bittern "nesting regularly on the salt marshes of the coast from Cape May to Ocean County," New Jersey. William B. Crispin of Salem, New Jersey, wrote me: "The only set I have taken contained three eggs built in a dry meadow amongst tall, blue, bent grass, with little or no nest material except a few dry grass stalks."

Several observers have noted that the bitterns usually make paths leading to and from their nests, using one as an entrance and one as an exit; and they say that the bird never flies directly from or to its nest, but runs out and flies from the end of one path in leaving and alights at the end of the other path and walks to the nest in returning. Ira N. Gabrielson (1914) had an opportunity to watch a bittern making one of these paths which he describes as follows:

The paths were marked by a broken and trampled line of vegetation and ended in a small platform. Our boat was placed directly across the path for leaving, and we had an opportunity to watch the building of a new one. On the first visit she walked off through the wild rice to the east of the nest, grasping the upright stalks with her feet and climbing from one to another. Her weight broke numbers of them and made the beginning of the trail. After going about 25 feet, she commenced to break other stalks down and lay them in a pile. Some were already in the water and she soon had a platform capable of sustaining her weight. The reeds were seized in the beak and broken with a quick sidewise jerk of the head. When the platform was finished, she stepped upon it and stood there for a time before she flew away.

Eggs.--The American bittern lays from three to seven eggs; the set usually consists of four or five, but six eggs are often laid. The eggs are quite distinctive and are easily recognized. The shape varies from oval to elliptical ovate. The shell is smooth with a slight gloss. The color varies from "Isabella color" or "buffy brown" to "ecru olive" or "deep olive buff."

The measurements of 43 eggs average 48.6 by 36.6 millimeters; the eggs showing the four extremes measure 54.2 by 38.6, 45.5 by 36, 48 by 33.5 millimeters.

Young.--The period of incubation is about 28 days and the young birds remain in the nest for about two weeks. Mr. Gabrielson (1914) has made some very interesting observations on the behavior of young bitterns and their feeding habits, from which I quote as follows:

During the absence of the parents, however prolonged, no outcry was ever made by the young bitterns unless one of us went out of the blind and tried to touch one of them. When we did this they backed away from us, uttering a curious hissing sound and pecking viciously at our fingers. It was interesting to note the change in their actions after the parent left the nest. For perhaps 10 minutes they remained in the position assumed after feeding, as described above. At the end of that time they commenced to raise their heads and look around. For the next hour they sat contentedly on the shady side of the nest, occasionally dipping the tip of the beak into the water but never drinking anything. In the next half hour they began to grow uneasy and to keep watch for the parent. Every blackbird that flew above the nest caused each head to rise to its full height and silently watch his flight across their horizon. At times they seized each others' beaks in the same manner as the parent's was held. At other times they seized the reed stems crosswise and pulled vigorously on them, sometimes working the mandibles as if chewing. This continued until the return of the parent, when all would assemble on one side of the nest and watch her approach through the reeds. No sanitary measures were noted, and the nest became a rather unpleasant smelling place before our work was finished. At 9:55 a.m. I heard the flapping of heavy wings and the female settled down into the rushes about 20 feet from the nest. She consumed 10 minutes in covering that distance advancing a few steps and then remaining motionless for a time. When only 4 or 5 feet away, she stopped for five minutes, remaining, as far as I could see, absolutely motionless, and then, apparently satisfied, stepped up to the nest. She progressed by grasping the upright stems of the aquatic plants and when she stopped to listen looked as though she were on stilts. As soon as she reached the nest, the young commenced jumping at her beak, continuing this until one succeeded in seizing it in his beak at right angles to the base. A series of indescribable contortions followed, the head of the female being thrown jerkily in all directions and the muscles of the neck working convulsively. Finally her head and neck were placed flat on the nest for several seconds and then slowly raised again. As it came up the food came slowly up the throat into the mouth. As the food passed along the beak, the open beak of the young bird followed its course along until it slid into its mouth and was quickly swallowed. The young one then released his hold and the parent stood with the muscles of the neck twitching and jerking. The remaining young kept jumping at the beak until one secured a hold on it, when the process was repeated. By 10:30 all five of the brood had been fed. Each one after receiving the food staggered across the nest and lay down with the head and neck flat on the weeds and remained in this position for some time before showing any signs of life again.

He says further:

An observation made in 1910 may be of some interest in this connection. While a piece of wild hay was being cut a nest of this species was uncovered and four of the five young were killed before the team could be stopped. A small patch of hay was left standing about the nest and the young one placed in it. At this time he was fully feathered out but was unable to fly. The next day the parent was noted flying into the patch of hay without anything in her beak. After she left I walked over and approached the young one, who immediately started to run. Seeing that he could not escape, he stopped and disgorged the contents of his stomach. An examination showed one garter snake about sixteen inches long, a meadow mouse and three crayfish, all partially digested. The observation seemed to prove that at this age the young were still being fed by regurgitation.

The following observation by Dr. Charles W. Townsend (1905) is of interest:

On June 26, 1904, while looking for sharp-tailed sparrows in a salt marsh reached only by the high spring and fall tides, I started a bittern that flew off with a complaining and frequently repeated quacking croak. Soon after I became conscious that a series of four stakes, projecting above the grass, was in reality the motionless necks and bills of four young bitterns. My companion noticed them too, but thought they were the remains of a shooting blind. The early age at which this protective habit was assumed is interesting, for the birds were entirely unable to fly, being only about two-thirds grown, and their scanty juvenal feathers were tipped with the fluffy natal down. When closely approached they abandoned this method of deception, snapped their bills loudly in anger, erected the feathers of their necks, spread their feeble pin-feather wings, and sprang defiantly at us, emitting a faint hissing snarl. One that I handled to examine closely, spat up great mouthfuls of small fish. The manner in which they attempted to escape was interesting. Crouching low, with necks drawn in  and level with the back, they walked rapidly through the short grass, and we found one drawn up in a small bunch at the foot of the camera stand. Both the motionless and the crouching postures are the familiar protective methods used by the adults.

Plumages.--The young bittern, when first hatched, is covered on the head, back and rump with long fluffy, light buff down, "tawny olive" or "clay color"; the down on the under parts is more scanty and grayer or more whitish in color; the eyes are yellow, the bill flesh color and the feet and legs flesh color tinged with greenish.

The juvenal plumage appears at an early age, a week or 10 days, showing first on the back, scapulars and neck. By the time that the young bird is half grown it is practically fully fledged, except that the under parts are largely downy and a few shreds of down remain on the head. The juvenal plumage is much like that of the fall adult, but the crown is darker, the whole plumage is brighter colored and the back neck-ruffs are entirely lacking. The crown is dark "chestnut brown," variegated with dark "seal brown"; the back is "ochraceous tawny," tinged with "russet," sprinkled and barred with dusty markings; the buff in the wing-coverts is "yellow ochre" or "buckthorn brown." These bright colors soon fade and before the end of October the black neck-ruffs have appeared so that the young bird assumes, during the first winter, a plumage which is practically adult.

At the first postnuptial molt, the following summer and fall, the young bird becomes fully adult. This and all subsequent postnuptial molts are complete. There is little seasonal change in adult plumages; the spring plumage is grayer above and paler below, less buffy than the fall plumage; this change is probably due to wear and fading.

Food.--The American bittern enjoys a varied diet and a large appetite, but it is no vegetarian; it will feed freely, even gluttonously, on almost any kind of animal that it can find in the marshes and meadows that it frequents or about the edges of shallow, muddy ponds. Its favorite food seems to be frogs or small fish, which it catches by skillfully spearing them with its sharp beak, as it stands in wait for them or stealthily stalks them with its slow and cautious tread. It also eats meadow mice, lizards, small snakes and eels, crayfish, various mollusks, dragon flies, grasshoppers, and other insects. Fish and other small creatures are gulped down whole, but the larger vertebrates and crustaceans are more or less crushed and broken before they are swallowed. Mr. Gabrielson (1914) describes its feeding habits as follows:

The bittern soon came flying from the direction of the nest and dropped into the grass a short distance from me and immediately became stationary. The frogs, which were as thick here as on the other shore, soon forgot her presence and began to swim about or climb over the bogs. When one came within reach, out shot the long neck and beak and seized him. He was hammered against a bog a few times and swallowed. After securing a number in this fashion she stepped up onto a bog and went to sleep. After a short rest she flew a little way down the shore and went to hunting again. After her hunt and rest this time she flew heavily across the swamp toward the nest.

Behavior.--When disturbed at its reveries under the cover of its swampy retreat, the bittern surprises the intruder by a sudden but awkward spring into the air; with wings flopping loosely and feet dangling, it utters a croak of disgust, discharges a splash of excrement, and then gathers itself for a steady flight to a place of safety. When well under way its flight is firm and even, somewhat like that of the other herons, but stronger and with quicker beats of its smaller wings. Its flight is so slow that it is easily hit and easily killed even with small shot; when wounded it assumes a threatening attitude of defense and is able to inflict considerable damage with its sharp beak, which it drives with unerring aim and with considerable force.

The bittern is not an active bird. It spends most of its time standing under cover of vegetation, watching and waiting for its prey, or walking slowly about in its marsh retreat, raising each foot slowly and replacing it carefully; its movements are stealthy and noiseless, sometimes imperceptibly slow, so as not to alarm the timid creatures which it hunts. When standing in the open or when it thinks it is observed, it stands in its favorite pose, with its bill pointed upward and with its body so contracted that its resemblance to an old stake is very striking; the stripes on its neck, throat, and breast blend so well with the vertical lights and shadows of the reeds and flags, that it is almost invisible. Professor Walter B. Barrows (1913) has noted an interesting refinement of this concealing action, which he has described as follows:

The bird, an adult bittern, was in the characteristic erect and rigid attitude already described and so near us that its yellow iris was distinctly visible. Then, as we stood admiring the bird and his sublime confidence in his invisibility, a light breeze ruffled the surface of the previously calm water and set the cat-tail flags rustling nodding as it passed. Instantly the bittern began to sway gently from side to side with an undulating motion which was most pronounced in the neck but was participated in by the body and even the legs. So obvious was the motion that it was impossible to overlook it, yet when the breeze subsided and the flags became motionless the bird stood as rigid as before and left us wondering whether after all our eyes might not have deceived us. It occurred to me that the flickering shadows from the swaying flags might have created the illusion and that the rippling water with its broken reflections possibly made it more complete; but another gentle breeze gave us an opportunity to repeat the observation with both these contingencies in mind and there was no escape from the conclusion that the motion of the bittern was actual, not due to shadows or reflections, or even to the disturbance of the plumage by the wind itself. The bird stood with its back to the wind and its face toward us. We were within a dozen yards of it now and could see distinctly every mark of its rich, brown, black, and buff plumage, and yet if our eyes were turned away for an instant it was with difficulty that we could pick up the image again, so perfectly did it blend with the surrounding flags and so accurate was the imitation of their waving motion. This was repeated again and again, and when after 10 or 15 minutes we went back to our work the bird was still standing near the same spot and in the same rigid position. although by almost imperceptible steps it had moved a yard or more from its original station.

The most characteristic performance of the bittern, for which it is best known and from which some of its names have been derived, is one in which it is more often heard than seen, its remarkable "thunder-pumping" performance. It is more frequently and more constantly heard in the spring, as part of the nuptial performance, but it may be heard at any time during the summer and rarely in the fall. It is only within comparatively recent years that the mystery of this disembodied voice of the marshes has been thoroughly cleared up by actual observations; many erroneous theories had previously been advanced, as to how the sound was produced. Anyone who has ever skinned a male bittern in the spring, might have noticed that the skin of the neck and chest becomes much thickened and reinforced with muscular and gelatinous tissues, so that it can form a bellows for producing the loud, booming sounds. These notes have been likened to the sound made by an old wooden pump action and to the sound made by driving a stake into soft ground; the fancied similarity of the bittern's notes of two such different sounds is not so much due to different interpretations by observers, as to the fact that there are two quite distinct renderings of the notes, by different birds or by the same bird under different circumstances. Mr. Bradford Torrey (1889) has published some valuable notes on this subject, from which I quote, as follows:

First the bird opens his bill quickly and shuts it with a click; then he does the same thing again, with a louder click; and after from three to five such snappings of the beak, he gives forth the familiar trisyllabic pumping notes, repeated from three to eight times. With the preliminary motions of the bill the breast is seen to be distending; the dilation increases until the pumping is well under way, and as far as we could make out, does not subside in the least until the pumping is quite over. It seemed to both of us that the bird was swallowing air--gulping it down--and with it distending his crop; and he appeared not to be able to produce the resonant pumping notes until this was accomplished. It should be remarked, however, that the gulps themselves, after the first one or two at least, gave rise to fainter sounds of much the same sort. The entire performance, but especially the pumping itself, is attended with violent convulsive movements, the head and neck being thrown upward and then forward, like the night heron's when it emits its 'quow,' only with much greater violence. The snap of the bill, in particular, is emphasized by a vigorous jerk of the head. The vocal result, as I say, is in three syllables; of these the first is the longest, and, as it were, a little divided from the others, while the third is almost like an echo of the second. The middle syllable is very strongly accented. The second musician, as good luck would have it, was a stakedriver. The imitation was as remarkable in this case as in the other, and the difference between the two performances was manifest instantly to both Mr. Faxon and myself. The middle syllable of the second bird was a veritable whack upon the head of the stake. I have no difficulty whatever crediting Mr. Samuel's statement that, on hearing it for the first time, he supposed a woodsman to be in the neighborhood, and discovered his error only after tolling through swamp and morass for half a mile. On this one point at least, it is easy to see why authors have disagreed. The fault has not been with the ears of the auditors, but with the notes of the different birds. During the hour or more we sat upon the railway we had abundant opportunity to compare impressions; and, among other things, we debated how the notes to which we were listening could be best represented in writing. Neither of us hit upon anything satisfactory. Since then, however, Mr. Faxon has learned that the people of Wayland have a name for the bird (whether it is in use elsewhere I cannot say) which is most felicitously onomato-poetic; namely, "plum-pudd'n'." I can imagine nothing better. Give both vowels the sound of "u" in "full"; dwell a little upon the "plum"; put a strong accent upon the first syllable of "pudd'n"; especially keep the lips nearly closed throughout; and you have as good a representation of the bittern's notes, I think, as can well be put into letters.

William Brewster (1902) writes:

Standing in an open part of the meadow, usually half concealed by the surrounding grasses, he first makes a succession of low clicking or gulping sounds accompanied by quick opening and shutting of the bill and then, with abrupt contortions of the head and neck unpleasantly suggestive of those of a person afflicted by nausea, belches forth in deep guttural tones, and with tremendous emphasis, a "pump-er-lunk" repeated from two or three to six or seven times in quick succession and suggesting the sound of an old-fashioned wooden pump. All three syllables may be usually heard up to a distance of about 400 yards, beyond which the middle one is lost and the remaining two sound like the words "pump-up" or "plum-pudd'n" while at distances greater than a half mile the terminal syllable alone is audible, and closely resembles the sound produced by an ax stroke on the head of a wooden stake, giving the bird its familiar appellation of "stake driver." At the height of the breeding season the bittern indulges in this extraordinary performance at all hours of the day, especially when the weather is cloudy, and he may also be heard occasionally in the middle of the darkest nights, but his favorite time for exercising his ponderous voice is just before sunrise and immediately after sunset. Besides the snapping or gulping and the pumping notes the bittern also utters, usually while flying, a nasal 'haink' and a croaking 'ok-ok-ok-ok.'

Winter.--The bittern migrates, as it lives, in seclusion, nor is it much more in evidence in its winter home in the southern States and the West Indies, where its habits are similar to those of the summer and fall. It is said to be only of casual occurrence in Bermuda, but Capt. Saville G. Reid (1884) says:

A regular visitor in the autumn, and occasionally in March, frequenting the sedgy patches on the edge of the mangrove swamps. To show how plentifully they arrive in certain years, I may mention (though a cold shudder passes through me as I do so) that no less than 13 were shot by one officer, who shall be nameless, in the autumn of 1875.

Dr. Charles W. Townsend (1920) has found the bittern in Massachusetts in winter; he writes:

In the severe winter of 1917-18, on December 16, I flushed a bittern from the salt marsh near my house at Ipswich. It flew several hundred yards and alighted in a clump of tall grasses where I found it and again flushed it. There was snow on the ground and the temperature that morning was 2 ^o Fahrenheit.