Contributed by Alfred Otto Gross
[Published in 1949: Smithsonian Institution United States National Museum Bulletin 196: 143-162]
The hermit thrush ranks high in the list of our favorite North American birds. The exquisite song of this modest bird of the northern woodlands has captivated the affections of a host of bird lovers. Those who have been privileged to hear its song possess delightful memories of associations with the hermit: perhaps a wooded border of some mirrored lake or some fern-carpeted woodland; or again they may have heard the fluted notes ringing across some brilliant sunset scene.
John Burroughs has beautifully expressed the inspiration, the elevating character of the emotions with which the hermit's song infuses us when he wrote the following lines in "Wake Robin": "Mounting toward the upland again, I pause reverently as the hush and stillness of twilight come upon the woods. It is the sweetest, ripest hour of the day. And as the hermit's evening hymn goes up from the deep solitude below me, I experience that serene exaltation of sentiment of which music, literature, and religion are but the faint types and symbols."
Unfortunately those who know the hermit only as a migrant are unfamiliar with this bird as the accomplished singer, for it passes on its migration without uttering more than a few uninteresting calls. Some of the earlier ornithologists were evidently unaware of its accomplishments. Wilson did not know of its song and Audubon as far as his personal acquaintance with the bird is concerned speaks only of its single plaintive note. One must meet the hermit in its nesting haunts of the northern woods to know this bird at its best.
O. Bangs and T. E. Penard (1921) found the two original names of the hermit thrush untenable. Turdus solitarius Wilson is preoccupied by Turdus solitarius Linnaeus. Wilson's description is of the hermit thrush, but the plate to which he referred represents Hylocichla ustulata swainsonii (Cabanis). Turdus brunneus Brewer is preoccupied by Turdus brunneus Boddaert =Euphagus carolinus (Muller). But from Brewer's article it is difficult to determine whether Turdus brunneus "Gmel." refers to Hylocichla guttata pallasii or Hylocichla ustulata swainsonii. Both names are thus of a composite nature, and the authors considered it best to propose an entirely independent name, Hylocichla guttata faxoni subsp. nov., for the eastern hermit thrush.
According to Ridgway (1907) the eastern hermit thrush is most like Hylocichla guttata nana of the six western subspecies, but the upper parts are of a lighter, more isabelline or cinnamomeous brown, spots on chest averaging larger, sides and flanks more buffy brown, and bill stouter. The various subspecies of the hermit thrush are of minor importance in a discussion of the habits and life history, and what is true of the eastern hermit thrush will in most instances also apply to the western forms.
Spring.--The migration of the hermit thrush through the United States is confused by the presence of wintering individuals. There are countless numbers of migration records early in March, but it is apparent that the peak of migration up the Mississippi Valley and into Canada is during April. An examination of some of the Canadian records of migration is of interest. According to J. H. Fleming (1907) the hermit is an abundant migrant at Toronto from April 13 to May 10. His earliest date of spring arrival is April 8. At Aweme, Manitoba, latitude 49o 42' N., Norman Criddle (1922) in 19 years of observation found the average date of its first arrival to be May 2. His earliest record is April 19, 1917. Lynds Jones (1910) made extensive studies of bird migration on the sand spit of Cedar Point, Ohio. The comparative isolation of the spit from the mainland makes it the first step in the flight to Point Pelee on the Canadian shore of Lake Erie. In migration the birds are concentrated in this strip, which can be likened to the neck of a funnel. According to Jones the hermits are usually so numerous during migration that they spread well over the whole of the sand spit. The median date of spring arrival is April 2, the earliest March 21, 1903. The median date of spring departure is May 5, the latest May 20, 1907. It is seen that although a few individuals arrive at the spit in March, possibly individuals that wintered a relatively short distance south, the bulk do not arrive until April and do not leave until May.
The hermit thrush is the hardiest member of its group, for it is the first to arrive in spring and the latest to leave in autumn. Indeed, some individuals remain in certain sections of the southern limits of the breeding range, wherever there is an adequate food supply, to brave the cold winter. It dislikes snow, however, and usually manages to keep south of the line where snow remains on the ground for an extended period. It normally winters south of the 40th parallel to the Gulf States and west to central Texas. The migration starts in March, and by the middle of April it arrives in central New England, New York, southern Michigan, and Minnesota. During the first week of May it has reached the northern limits of its breeding range. It makes the journey by night and rests during the day. During the height of the migration large numbers are often seen in the parks and churchyards among the tall buildings and bustling life of our larger cities. After the ordeal of the nocturnal flight the birds are hungry, often exhausted, and at such times exhibit little fear and may be seen feeding about dooryards, allowing human observers to approach near to them. It they are caught in a snowstorm this behavior becomes even more pronounced. I have had individuals, benumbed by the cold, eat out of my hands, and one bird even allowed me to pick it up to be carried to the house to be warmed.
The hermits follow no special migration route in reaching their northern home except in the far West. Here they fly on a direct northwest route that takes them as far as the Mackenzie and Yukon Valleys. In fall the hermit starts southward in September, but it is well toward the end of October before the bulk of them have left their northern summer ranges. E. A. Preble tells me that he saw one early in December in Wilmington, Mass., about 1890.
Nesting.--The nest of the hermit thrush is a compact structure but often bulky in the amount of nesting materials used. The foundation and exterior of a typical nest are composed of twigs, strips of wood, bark fibers, dried grass, and ferns and ornamented on the outside by bits of green moss. The lining is made up of pine needles, delicate plant fibers, or fine rootlets. The interior dimensions of the nesting bowl are about 2 3/4 inches across by 2 inches deep.
The nest is generally built on the ground and in a natural depression of a knoll or hummock, often under a small fir or hemlock whose branches touch the ground, forming a kind of protective canopy over the nest. One nest found in northern Michigan was in a rather open space of woodland and was completely surrounded by blossoming bunchberries, and another nest was completely hidden from view by a luxuriant growth of ferns. I have found them along the edges of old wood roads and on the borders of pasturelands skirted by shrubbery and trees. In northern Maine the nests may be found in tussocks of the wet sphagnum bogs that are surrounded by growths of larches, spruce, and other coniferous trees. On Long Island the hermit frequents the hottest and driest barrens where the ground is carpeted with little else but bearberry and pine-barren sandwort. Near the site of the University of Michigan Biological Station, Douglas Lake, northern Michigan, the hermit is one of the commonest of the nesting birds. During July 1928 we found six nests in dry upland covered with a second growth that had sprung up after a severe fire that had raged through the section a few years before.
The hermit sometimes departs from its usual habit of nesting on the ground. Henry R. Carey (1925) reports finding a nest 5 feet up in a small hemlock, and Horace W. Wright (1920) found a hermit's nest resting firmly on several bean poles at a point 4 feet above the ground. A pair observed by John May was nesting in what appeared to be a typical robin's nest 2 feet up in a young hemlock. This nest had a foundation of coarse grasses and weeds, a middle layer of mud, and a lining of fine grasses. I found a hermit's nest on a barren shelf of rock of a perpendicular ledge adjoining a deserted feldspar quarry in Topsham, Maine. The shelf on which the nest was built was 15 inches wide and 3 feet long and about 7 feet above the ground. The nesting site though in an exposed situation was well shaded during most hours of the day by the dense foliage of several large hemlock trees. The nest was made of the usual nesting materials, but the twigs and leaves of the foundation were spread over an area of 12 to 15 inches. The nesting bowl of the deep cupped nest was well formed and firmly constructed.
Though we associate the hermits with lonely situations remote from the habitations of man, they have been known to nest about buildings. Miss Annie L. Warner, of Salem, Mass., wrote to Mr. Forbush (1929) that she found a hermit's nest with two well-grown fledglings about 7 feet from the ground, on a shelf under the eaves of a piazza of an occupied camp on Lake Winnipesaukee. Another hermit was reported nesting in a tin gutter under the eaves of the second story of a home at Holderness, N. H. (E. DeMeritte, 1920). Verna R. Johnston (1943) found a hermit thrush nesting on a rafter under a roof of a building at the University of Colorado Biological Station, at Boulder, Col. The station is located at an elevation of 9,500 feet.
Eggs.--The eggs of the hermit thrush are ovate or elongate-ovate and a plain greenish blue in color. They are similar in appearance to the eggs of the Wilson's thrush but are of a much more delicate and lighter shade of blue. Occasionally the eggs are spotted. In correspondence received from Francis H. Allen he writes that one egg of a set of three found at Bridgewater, N. H., on August 1, 1883, has thinly scattered small brown spots. Another found near the same place on August 9 of the same year contained three eggs, one of which was spotted. Harry O. Parker (1887) writes that in two eggs in a set of three there were minute spots of black. An application of an acid wash failed to remove the spots. Others have reported similar markings on the eggs of the hermit thrush, but spotted eggs are by no means of common occurrence.
The number of eggs per complete set varies from three to six, but the vast majority of nests contain three or four eggs.
The measurements and weights in millimeters and grams of two typical sets of eggs are as follows:
NEST FOUND AT BRUNSWICK, MAINE, JULY 16, 1928
|Long diameter||Short diameter||Weight|
NEST FOUND AT BRUNSWICK, MAINE, AUGUST 1, 1930
The measurements of 40 eggs in the United States National Museum average 22.1 by 16.8 millimeters; the eggs showing the four extremes measure 23.6 by 17.3, 22.6 by 18.0, 20.1 by 17.5, and 20.8 by 15.8 millimeters.
Incubation.--The determination of the incubation period of 12 days is based on the study of two nests that were under continuous daily observation at Brunswick, Maine. On May 26, 1928, a nest of the hermit thrush located at the base of a small fir tree contained two eggs. On May 27 there were three, and on May 28 the set of four eggs was completed. Incubation, however, did not start until the following day, May 29. At 8 o'clock on the morning of June 10 there were three freshly hatched young, and the fourth hatched during the afternoon. A second nest was nearly completed but contained no eggs when it was found on June 10, 1940. This nest was in a natural depression located in a thick growth of blueberry vines. The first egg was laid during the morning of June 12. On June 16 there were four eggs and incubation started. The first egg laid hatched at 5 p.m. on June 28; the other three were hatched by dawn the next morning. The incubation period of the hermit. thrush as reported by various observers varies from 10 to 13 days, but this wide range does not represent a real variation but probably is due to the failure to ascertain the exact time of the beginning of incubation as well as that of hatching.
In the nests I have had under observation only one of the pair, presumably the female, took part in the incubation of the eggs. The incubating bird was seen to leave the nest in search of food, but much of the food was delivered to her by her mate while she was attending her duties on the nest. During the 12 days of incubation the male spent much of his time singing and serving as guard against the intrusion by other birds or enemies that appeared in his territory. He often chose as a sentinel post the lower branch of a large pine tree that stood about 40 feet from the nesting site. At other times he perched at the tip of a small dead tree stub in an open situation where he was readily observed from the blind. Whenever there was an accidental noise or disturbance inside the blind to arouse his suspicions he would utter a chuck, chuck call accompanied by a characteristic sudden up-tilting and slow lowering of his tail.
The hermit is a wary bird, and during the first few days I spent in the blind the least provocation caused the bird to leave the nest with a whir of wings. But in the course of a few minutes after each such disturbance she flew back to a place within a few yards of the nest and from that point approached with caution, frequently stopping at some elevated knoll carefully to scrutinize the surroundings. She then crept close to the ground under cover of the vegetation, her progress being made known by the rustling of the leaves. She often took a circuitous route and when near sometimes circled about the nest on wing suspended in hummingbird fashion. Again after alighting she went along stealthily in a series of hops and when finally assured all was well went confidently to the nest. She adjusted the eggs with her bill and then settled on them, moving her body back and forth until the feathers of the breast were separated, permitting the eggs to come in direct contact with her warm body. This adjustment is repeated several times and not until it meets with her complete satisfaction does she settle down to the arduous task of incubation. The raised feathers of the neck and back then fall back to their normal position, the tips of the primaries are crossed over the rump, and the bill assumes an upward tilt. She is then motionless and her soft brown colors blend so into the lights and shadows of the surroundings that she is practically hidden from view. The eggs are turned at frequent intervals during the course of the day. From time to time the male, who seemed even more cautious than his mate, would timidly approach the nest, announcing his coming with a wee call. With a look of apparent admiration and devotion he delivered some choice insect or larvae in commendation of a task well done. Sometimes instead of bringing food he carried nesting material. This was graciously received by the female who merely cast it to one side of the nest. This behavior is of frequent occurrence among certain groups of birds such as the herons, gallinules, and hawks, but I have never before noted this behavior, a response to an emotional urge, exhibited in the Turdidae.
Once a red-eyed vireo unwittingly alighted in the small tree under which the nest was located. The male immediately uttered his war cry and dashed at the unwelcome intruder. He was joined by his mate and both birds chased the vireo into the dense woodland beyond. At another time a red squirrel making his way through the grass and vines passed within 2 feet of the nest, but strangely enough his appearance did not seem to excite the birds in the least. However, the female on the nest after having caught sight of the squirrel followed every move until he had passed and was well out of sight. On another day a hummingbird hovered for 30 seconds between the nest and the blind not more than 3 feet above the nest, but neither bird paid any attention to this unusual visitor. O. S. Pettingill, Jr. (1930), writes of a garter snake that appeared among the leaves near a nest he was observing from a blind. The parent bird was much perturbed. She flew from the nest screaming alarm calls and hovering over the unwelcome guest in a defiant defensive attitude. It is apparent that through some previous experience or hereditary tendency the birds recognized the snake as an enemy to be challenged on sight.
Unless disturbed the female remained on the nest during the day, especially if it were cold and raining or when it was excessively hot. During the latter condition she would perch on the edge of the nest with her wings somewhat extended to keep the burning sun rays off the eggs or young. At one time when the temperature arose above 90o she kept her beak wide open and panted incessantly in order to retain her normal body temperature. Only in the early morning or late in the evening just before sunset did I see her leave the nest voluntarily. These trips were doubtless taken to supplement the food delivered to her by the male.
Young.--After the eggs are pipped hatching proceeds rapidly. The struggling embryo breaks the shell in two parts, the crack taking place near the greatest diameter. In the course of a few minutes the embryo is entirely free. Each time I saw this critical event happen the adult was away from the nest. On her return, after carefully inspecting the young, she picked up an empty half shell and carried it away returning immediately to remove the other part. The appearance of the young is an important event in the household and seems to excite the parents to greater activity. Both parents flit about nervously and seem most anxious to serve their offspring. They now exhibit less caution and more daring in approaching the nest. A small green larva was delivered and fed to the young in less than five minutes after it had come into the world.
At the time of hatching the young are nearly naked, being clothed by only a few scant tufts of dark grayish down on the crown and dorsal tracts of the body. Though the eyes are closed during the first two or three days, the young birds are most responsive to the approach of the adults at the very start. In fact, a mere touch of the rim of the nest is sufficient to initiate the feeding response--uplifting their heads, extending their gape, and displaying the bright colors lining the mouth. Both parents take an active part in the feeding of the young and at all times take meticulous care of the sanitation of the nest. The excrement is received in their beaks as soon as it is emitted. The young are carefully examined and even stimulated by a stroke of their bills after each feeding until the fecal sac appears. During the first few days it is eaten, but thereafter it may be carried away and dropped at some distance from the nest.
The food at first consists of small green larvae, but as the young become older, mature insects, small grasshoppers, moths, beetles, and spiders are added to the diet. While the nestlings are very small they are frequently unable to swallow the food brought to them. After a morsel is thrust into an open mouth or into different mouths without being swallowed, the adult will mince it in her bill, or if the larva is large and both parents are present each will grasp an end and pull it apart. Sometimes after repeated failures of the young to swallow the food it is eaten by the adults. At one nest there seemed to be a great deal of difference in the choice of the food delivered. One of the birds would invariably bring food of the proper size and tenderness, while the other would bring enormous larvae or winged insects such as large sphinx moths totally unsuited as food for the age of the young being fed. The latter may have been a young inexperienced parent with its first offspring. Perhaps it was the male! At least human fathers are not supposed to know much about proper infant feeding.
On the third day the eyelids of the young are parted, and from then on their reactions are more and more responses to sight rather than sound. On the fourth day the papillae of the remiges have pierced the skin, and by the fifth day the chief feather tracts are well defined. On the seventh day the tips of the primaries and secondaries are unsheathed, and those of the other tracts have tips which display the olive-brown and buffy colors. By the ninth day the young frequently preen their feathers, thus facilitating the unsheathing process, so that on the following day or two the full colors of the juvenal plumage are acquired. The young now exhibit evidence of fear when one approaches or when there is a disturbance near the nest. The tail feathers are well developed at this time but do not attain their full length until later when they are about six weeks old. When the young are 12 days old they are ready to leave the nest. If they are not frightened and not forced to leave the nest prematurely they are encouraged by the adults, who stay away from the nest and perch at some distance with an appetizing morsel in their beaks. The parents hop from perch to perch calling constantly until the hungry youngster responds. At such times I have seen one or more of the nestlings standing on the rim of the nest preening their feathers, flapping their wings, and going through all the gymnastics of a young osprey whose first venture away is by flight. Finally when the decision of the young hermit does come it leaps from the rim of the nest, flutters its wings, and then makes its way along the ground and through the vegetation in the direction of the coaxing adult. After a few yards of travel the youngster is rewarded with food. This performance of the adults is continued until all have left the nest in a similar fashion. If you attempt to follow the young they take a short flight at the same time, uttering a series of distress calls, which are a signal for the adults to come to their rescue. At such times the adults exhibit unusual bravery and may even dash at the human intruder in rage.
As is true with other ground-nesting birds a comparatively small percentage of young reach maturity. Miss Cordelia J. Stanwood (1910) states that out of 14 nests containing a total of 47 eggs only 19 fledglings left the nest. Others are lost after leaving the nest before they are able to fly well enough to perch well above the ground out of reach of terrestrial enemies.
The relative growth of the young during the 12 days spent in the nest can be shown by their daily weighings. The average daily weights of three young of an apparently typical family brood were 4.12, 4.93, 7.21, 10.12, 14.76, 16.98, 19.21, 22.35, 24.60, 25.13, 25.61, and 24.81 grams, respectively, for the 12 days. It will be seen that the weighings increase rapidly during the first week of nest life, but the proportionate increase diminishes as they grow older and was actually less on the twelfth than on the preceding day. The weight at the end exceeded six times the weight at the beginning of nest life.
The nesting season of the hermit thrush extends over a relatively long period from May to August, or about three months. O. W. Knight (1908) reports that he has found nests of the hermit thrush with full complements of eggs as early as May 1. Others have found nests with eggs during the first week of May. Miss C. J. Stanwood (1910) found a nest of the hermit thrush, containing three eggs, at Ellsworth, Maine, on August 22, 1909. The young left on September 8. Dr. C. Hart Merriam (1882) found a nest containing fresh eggs at Locust Grove, Lewis County, N. Y., on August 24, 1870. August nesting dates are by no means rare. This wide range in time of nesting dates, more than three months, is very suggestive that two or even three broods may be reared by a single pair of birds during one season. The incubation period is 12 days, and the time spent by the young in the nest is also only 12 days; hence a nest can be built and the young matured in the course of a month. The two distinct summer singing periods of the hermit are also suggestive of two nestings. It is well known that if the first nest proves a failure a second attempt will be made during the same season.
Juvenal plumage acquired by a complete postnatal moult. Above, including sides of head, sepia or olive-brown, the rump russet, and everywhere spotted with large buffy white guttate spots bordered with black. The wings rather darker, the coverts and tertiaries with small terminal buffy spots. Tail burnt umber-brown. Below, white faintly tinged with buff, spotted with deep black, on the sides of neck, across the breast and on the flanks and crissum, the throat and breast, the fore part of the abdomen and flanks faintly barred. Bill and feet dull pinkish buff remaining pale when older. . . .
First winter plumage acquired by a partial postjuvenal moult, beginning late in August, which involves the body plumage, most of the lesser and median coverts, but not the rest of the wings nor the tail. Similar to previous plumage but without spotting above and the black spots below fewer. Above, including sides of head olive tinged mummy-brown, burnt-umber on rump and upper tail coverts. Below, white tinged faintly with buff on throat and breast, with olive gray on the sides and spotted heavily on the throat and faintly on the breast with large deltoid black spots. Lores and submalar lines black; orbital ring pale buff. The buff spotted coverts retained distinguish young from adults. . . .
First nuptial plumage acquired by wear, the upper surface becoming rather grayer and the buff below mostly lost.
Adult winter plumage acquired by a complete post-nuptial moult in August and September. Averages darker and lacks the tell-tale coverts and tertials of the first winter dress. Young and old become indistinguishable.
Adult nuptial plumage acquired by wear as in the young bird, from which it is usually distinguishable by the wing coverts.
The plumages and molts are alike in the two sexes.
Dr. Alexander Wetmore (1936) has determined the number of
contour feathers in a number of passeriform and related birds. His
counts of the contour feathers of three hermit thrushes is as
|Date||Sex||Number of feathers||Weight of bird||Weight of feathers|
October 21, 1933
Apparently albinism is not of frequent occurrence in the hermit thrush as only two cases have come to my attention. John H. Sage (1886) reports a partial albino hermit thrush taken at Portland, Conn., on October 27, 1885, which had the top of the head and the back light gray. Below it was white, the spots on the breast fairly distinct. The primaries and secondaries were a fawn color. A pure albino hermit thrush was shot at Stamford, Conn., by W. H. Sanford.
Food.--F. E. L. Beal (1915b) examined the stomach contents of 551 hermit thrushes, which were collected in 29 states, the District of Columbia, and Canada. These specimens represent every month of the year, though all the birds taken in winter were collected from the southern states, the District of Columbia, and California.
Animal matter, consisting chiefly of insects and a few spiders, comprises 64.51 percent of the total amount of the food eaten by the hermit thrush. The insects consisted of beetles 15.3 percent, ants 12.46 percent, bees and wasps 5.41 percent, caterpillars 9.54 percent, Hemiptera (bugs) 3.63 percent, Diptera (flies) 3.02 percent, grasshoppers and crickets 6.32 percent, miscellaneous insects 0.27 percent, and spiders and myriapods 7.47 percent. Miscellaneous animals such as sowbugs, snails, and angleworms make up the balance of the animal food of 1.26 percent. Of the insects listed above less than 3 percent can be considered useful; the remainder according to Professor Beal are chiefly harmful to man's interest.
The vegetable diet of the hermit thrush (35.49 percent) consists largely of fruit, but little of this can be classed as cultivated. Beal found that 5.45 percent of the food eaten during September did consist of cultivated fruits but in most months the quantity was small, and in March, April, and May was completely wanting. The total amount of cultivated fruit eaten during the entire year was only 1.20 percent. Of the wild fruits (26.19 percent) 46 species were identified. A few seeds, ground-up vegetable matter not identified, and rubbish made up the remainder of the vegetable food, or 9.10 percent of the total.
S. A. Forbes (1880) in the examination of 150 thrushes obtained in Illinois found them destructive to useful predaceous beetles. The worst of the group in this respect was the hermit thrush, which maintained a high ratio of these beetles throughout the fruit season when the total insect food fell away rapidly. It is important in considering the insect food of any species to take into account the beneficial as well as harmful insects.
While in its winter haunts of the southern states the hermit thrush feeds largely on wild fruits and berries such as dogwood, pokeberries, serviceberries, holly berries, blueberries, mistletoe, frost grapes, elderberries, spiceberries, mulberries, blackberries, and seeds of the greenbrier, Virginia-creeper, and sumac including the poison ivy and poison oak.
The hermit keeps close to wooded retreats, and hence the products of the farmer are seldom molested. The majority of the insects on which it feeds are injurious to trees and hence it can be considered a valuable tenant of the forest.
Lewis O. Shelley (1930) reports that in southern New Hampshire after a snowstorm on April 12, 1929, many species of birds including the hermit thrush made efforts to find earthworms and insects near his home. The thrushes became so tame that they readily took earthworms from his fingers. In notes received from F. H. Kennard he states that a hermit thrush was found in the middle of a meadow, warm but dead. There was a large earthworm protruding from its mouth which had choked it to death.
Coit M. Coker (1931) reports an interesting experience with a nesting pair of hermit thrushes in the Allegheny foothills of western New York. He states that in fully one-quarter of the trips made to the nest with food both adults brought small salamanders of two species, the Allegany and red-backed salamanders. During the hotter parts of the day fewer salamanders were brought, and this Mr. Coker attributed to the fact that the heat had driven the salamanders deeper under cover. Others have reported salamanders comprising a part of the food delivered to the young. While observing a nest of hermit thrushes at Brunswick, Maine, I observed one of the adults deliver a salamander about 2 inches in length to the bird at the nest. In this case the salamander was not fed to the young, then five days old, but she ate it herself. A similar case was observed at a nest at Douglas Lake in northern Michigan, indicating that salamanders are by no means a local menu.
During the summer of 1941 I had an opportunity to observe the food brought to the young throughout their life in the nest at Brunswick, Maine. The food was invariably held in the beaks of the adults so that it could be easily seen and often identified from the blind placed within 5 feet of the nest. The food the first three days consisted of small green larvae. During the first day the larvae were minced in the beak of the adult before they were delivered, and at other times the larvae if large would be divided in two by each of the pair of birds grasping an end of the worm and pulling until it parted. On several occasions larvae too large for the young to negotiate after they were thrust into the extended mouths were swallowed by the parent. After the third day winged insects, spiders, and ants were added to the diet. On the seventh and eighth days large moths, grasshoppers, and beetles were fed to the young without any mincing or tearing apart. During the many hours spent in the blind I did not see fruit, berries, or vegetable matter delivered to the young, but Henry R. Carey (1925) reports that fruit including blueberries and wild cherries was delivered to the young of a nest observed in the Pocono Mountains of Pennsylvania.
Daniel E. Owen (1897) kept a young hermit thrush in captivity from the time it left the nest on June 26 until July 31. During this period of about five weeks he made interesting observations on its behavior and especially of its food habits. Mr. Owen substituted its usual food with raw beef cut into bits about one centimeter long by half a centimeter wide. To facilitate swallowing the pieces of meat were dipped in water. On June 28 between 8 a.m. and 7 p.m. it was fed eight times and swallowed 27 bits of meat. After July 4 be weighed the bird's food as well as the bird itself. The bird's average weight during five days was 27.7 grams and the average weight of the meat eaten daily was 13.56 grams, indicating that it ate about 50 percent of its weight in meat. He experimented with earthworms and found that the thrush ate 19 worms between 8:30 a.m. and 1 p.m. He noted that worms from a dung heap were frequently rejected, whereas worms taken from cool black garden mold were eaten with a relish. The thrush ate 9 grams of worms an hour, so at this rate it would not take more than a few hours for it to eat its own weight in worms. Experiments were made to determine the time required for the food to pass through the alimentary tract by the use of blueberries, which dyed the bird's excretions. Only half an hour was required, which explains the enormous capacity the birds have for food.
Behavior.--H. R. Ivor (1941 and 1943) has observed the peculiar behavior of "anting" in many species of birds, including the hermit thrush. In "anting" the birds seize the ants and place them in their feathers, usually under the primaries of the wings. They may also crush the ants with their bills and rub the juices on the feathers, or the birds may dust themselves in anthills. Various theories have been advanced to explain this behavior: The ants are placed among the feathers to drive out ectoparasites; the bird anoints its feathers with the formic-acid secretions of the ant to repel ectoparasites; the bird eats the ants for the formic acid, which may be beneficial as a medication to increase muscular energy or to expel endoparasites; the bird places the ants in the feathers to have a reserve food supply during migration. These and other suggestions have been made. Further observations and study of this behavior will be required to enable us to interpret the true biological significance of "anting."
Voice.--As a boy living in central Illinois I knew the hermit merely as the thrush with the reddish-brown tail, and in those days I never heard its exquisite song as it passed through that part of the state on its way to and from the nesting grounds. It uttered nothing more than a protesting quoit or chuck when we intruded upon its transitory haunts in the few scattered wooded areas of that prairie section. It was not until I came to Maine to live in the midst of its breeding area that I fully appreciated this aristocrat of the bird world. In Maine this gifted songster is at its best soon after its arrival during the last week of April. At this season any visit during the early morning or evening hours to a particular evergreen forest traversed by a cool meandering trout stream is certain to be rewarded by the superb performances of this prima-donna songster. Indeed, the hermit has been given the tribute of being the most gifted songster in North America, and its song has often served as the inspiration for poetic writers.
M. Chamberlain (1882) described his impressions of the song of the hermit thrush as he heard it near St. John, New Brunswick, Canada, as follows:
The music of the Hermit never startles you; it is in such perfect harmony with the surroundings it is often passed by unnoticed, but it steals upon the sense of an appreciative listener like the quiet beauty of a sunset. Very few persons have heard him at his best. To accomplish this you must steal up close to his forest sanctuary when the day is done, and listen to the vesper hymn that flows so gently out upon the hushed air of the gathering twilight. You must be very close to the singer or you will lose the sweetest and most tender pathetic passages, so low are they rendered--in the merest whispers. I cannot, however, agree with Mr. Burroughs that he is more of an evening than a morning songster, for I have often observed that the birds in any given locality will sing more frequently and for a longer period in the morning than in the evening. I prefer to hear him in the evening, for there is a difference; the song in the morning is more sprightly--a musician would say "has greater brilliancy of expression"--and lacks the extreme tenderness of the evening song, yet both have the same notes and the same "hymn-like serenity." The birds frequently render their matinal hymns in concert and the dwellers in a grove will burst out together in one full chorus, forming a grander "Te Deum"--more thrilling--than is voiced by surpliced choir within cathedral walls. On one occasion an Indian hunter after listening to one of these choruses for a time said to me, "That makes me feel queer." It was no slight influence moved this red-skinned stoic of the forest to such a speech.
Aretas A. Saunders, who has made intensive studies of many bird songs, has written his interpretations and analysis of the hermit's song, in personal correspondence as follows: "The song of the hermit thrush is a long-continued one, made up of rather long phrases of 5 to 12 notes each, with rather long pauses. All the notes are sweet, clear, and musical, like the tone of a bell, purer than the notes of the wood thrush, but perhaps less rich in quality. The notes in each phrase are not all connected. The first note is longest and lowest in pitch, and the final notes are likely to be grouped in twos or threes, the pitch of each group usually descending. Each phrase is similar to the others in form but on a different pitch, as if the bird sang the same theme over and over, each time in a different key. If one listens carefully for each note, however, two different phrases are rarely exact duplicates in form, but slightly varied, a likeness to certain symphonies of some of the great composers.
"In records of 38 different individual birds the pitch ranges from F'' to D#'''', one tone less than two octaves. The average individual has a range of about an octave. In looking over my records it is quite apparent that birds in the Adirondacks have a greater range of pitch than those in Allegany State Park in southwestern New York. Most of my records come from those two localities. The Adirondack birds average two tones over an octave, and the Allegany Park ones nearly three tones less than an octave. The average bird, from my records, has six different phrases, but some have as few as three, several have nine, while one bird in Allegany Park had 14.
"Nearly every individual has one or two phrases pitched considerably higher than the rest, and these very high phrases sound weak and of poorer quality than the others. This may be due, however, not to actual poorer quality but to man's inability to perceive the overtones of the very high notes. It is the overtones that cause the poor or rich quality or timbre of a sound."
Albert R. Brand (1938) writes that in his study of bird recordings on film it is revealed that certain high notes are inaudible to the human ear, and his field observations of certain birds including the hermit thrush seem to confirm the suspicion. He states that he has observed birds singing nearby through field glasses, he has seen their bills open as if emitting notes, yet he heard no sound. Mr. Brand (1938) reports the lowest note recorded for the hermit thrush was 1,475 vibrations per second, the highest 4,375 vibrations, with an approximate mean of 3,000 vibrations per second.
Henry Oldys (1913), after describing the usual song of the hermit thrush and comparing it with the human voice, analyzes an unusual song in developing a theory of the independent evolution of bird song. Mr. Oldys heard the unusual hermit thrush song at Pompanoosuc, Vt., in which he noted a very perceptible normal order in the basal notes and their independent phrases, and that order made a harmonic progression such as completely satisfies the requirements of human music. He concludes "that the evolution of bird music independently parallels the evolution of human music and that, therefore, such evolution in each case is not fortuitous, but tends inevitably toward a fixed ideal."
At Lost River, N. H., located in the midst of the White Mountains, both the hermit and olive-backed thrushes nest, and there I had an unusual opportunity to compare the songs and notes of these two songsters. The musical ability of the hermit is more varied than that of the oliveback. Its usual song dies out without the rising inflection of the latter and there is a pause after the first syllable, while in the oliveback's song there is no pause and the second syllable is strongly accented, the whole song being quickly delivered.
The alarm notes of the two thrushes are also quite different. The oliveback thrush when disturbed utters a metallic note, short and sharp, often ending in a querulous call. The alarm note of the hermit has a catbird quality about it, lower pitched and less metallic than that of the oliveback. The hermit has a nasal note of complaint uttered in two syllables, a chuck like that of the blackbird, and a lisp not unlike that of a cedar waxwing. The oliveback utters a similar nasal note, but it is more liquid in quality and the cluck of the hermit may be compared to the puk or pink of the oliveback. The lisp is peculiar to the hermit, while there is a queer multiple note of soliloquy peculiar to the oliveback.
Norman McClintock (1910) has recorded the various notes uttered by the hermit thrushes about a nest which he observed at close range from a blind. He frequently heard a note resembling quirk or quoit, which was uttered when the birds were slightly suspicious or when they mildly protested against the presence of an intruder. A second note was a high-pitched, thin, and wiry call resembling a cedar waxwing's note but pitched several tones higher. This note was used in warning the young of approaching danger. "To the little birds this call meant 'freeze'." McClintock continues:
A third note, which this pair of Hermits used signified extreme distress. This note sounded to me much like the note of a hoarse Canary. I can best describe it by the word "boyb," spoken slowly and with a rising inflection. The note also reminded me of a mew of a kitten. "Boyb" was uttered by the thrushes with the mandibles well open, whereas the Cedar-bird call was made with the mandibles almost closed.
Besides the three notes described, there was a much used conversational note that evidently contained no implication of suspicion or trouble and was a strong contrast with the several notes already described. It was an exceedingly soft and sweet little note that could be heard but a few feet, and which I can best describe by "wee." "Wee" was used by the parents to each other and to the young. It seemed, however, to be mostly employed to herald to the young the parents' approach with food. At a distance of six or eight feet from the nest a single "wee" from a parent would announce to the young the former's proximity. As the parent hopped closer, the "wees" were rapidly repeated, "wee-wee-wee-wee," and the nearer the parent came to the nest, the softer the "wees" were uttered, until they were faint whispers. To these "wees" the young responded, during their first days, by erecting their heads and opening wide their mouths; but later, when they became more mature, they would rise to their feet upon hearing the first "wee" and energetically beg for food. . . .
The fifth, and only remaining note, was one I heard but twice and both times it came from the male. It was an indescribable explosive twitter of ecstasy made with fluttering wings. I first heard it on August 3, immediately after the male had been singing for four minutes. On another day, it was uttered in the presence of the female, who was close by and towards whom it was directed.
According to Miss Cordelia Stanwood (1910) the fledglings give a clear sweet whistle, p-e-e-p, a soft, husky, breathing sound, phee-phee, and occasionally pit-pit-pit!, an almost inaudible ventriloquial call.
The adults are also capable of a certain amount of ventriloquial power. Quite often when closely observing a hermit thrush sing while I was concealed in the blind only a few feet distant, the voice seemed to come from an individual located far away from the scene. The song probably could not be heard by an observer stationed 50 yards away. At such times the throat of the bird vibrates or pulsates but the mandibles are tightly closed, thus subduing the loudness and carrying power of the varied notes.
Horace W. Wright (1912) has made a study of the times of the awakening and the evening song of the hermit thrush. Out of a list of 57 species recorded the hermit took sixteenth place in order of the first voices heard early in the morning. Of 18 records of the hermit thrush the first song was 63 minutes and the latest initial song 45 minutes before sunrise. Of 55 species of birds studied for the latest evening song the hermit stands in fifty-first place. Out of 20 records the average number of minutes after sunset was 33, the latest final song 40 minutes after sunset, and the earliest final song 25 minutes after sunset.
The song season of the hermit thrush, unlike that of many of our song birds, is not limited to the time of the breeding season, but it is also in full song in its winter haunts in the south. Aretas A. Saunders (1929b) writes that he has heard the hermit commonly and in full voice in the pine forests of central Alabama. Otto Widmann (1907) in writing of the winter resident hermit thrushes of the peninsula of Missouri states: "He greets it with his most tender strains on his return in the fall, and sings aloud before he leaves it for the north." Many other observers have had similar experiences, of hearing the full song of the hermit in their winter haunts although this bird does not sing during its migration journey.
W. DeW. Miller (1911) observed 12 hermit thrushes which wintered in a grove of red cedars, in a sheltered valley near Plainfield, N. J., where there was an abundance of food in the berries of the flowering dogwood. He writes:
I. . .heard three distinct call-notes from these birds, one, of course, the familiar low blackbird-like "chuck." The two other notes do not seem to be commonly known, at least to those familiar with the bird only as a migrant. The first is a simple, high-pitched whistle, rarely loud; the second, a curious, somewhat nasal cry recalling the unmusical note of the veery.
The Hermit Thrush seldom sings while with us in the spring, and the song is so low as to be inaudible if one is more than a few yards from the singer. On March 19, I was agreeably surprised to hear four or five of these thrushes singing through most of the afternoon, though it was raining at the time. The song of only one bird, however, was of sufficient volume to be heard at any distance.
Enemies.--The hermit thrush is subject to the usual enemies such as snakes, foxes, weasels, and skunks that molest ground-nesting birds. The domestic cat, which is so destructive to birds that nest about or near human dwellings, is less of a factor in the life of a bird that usually nests in remote situations seldom visited by cats. The stomach examinations of hawks and owls reveal that the hermit sometimes falls a victim to these predators.
Few birds are more valiant in resisting attacks on their brood and capable of creating a greater hubbub over the presence of marauders. Such an occasion invariably attracts other birds of the vicinity, adding a veritable chorus of protests. The parent birds, very tense, with crests erect, swoop and dash fearlessly, sometimes venturing so close that their wings strike the intruder. More often than not they are successful in driving the enemy to cover.
As is true with many birds, the hermit thrush is subject to infestation by a number of external parasites. Under ordinary conditions none of them prove fatal to the bird, but some of them may be very annoying to the host when they become abundant. Harold S. Peters (1936) has reported three species of lice, Degeeriella eustigma (Kellogg), Myrsidea incerta (Kellogg), and Philopterus subflavescens (Geoffroy); two species of bird flies, Ornithoica confluenta Say and Ornithomyiaanchineuria Speiser; two ticks, Amblyomma tuberculatum Marx and Haemaphysalisleporis-palustris Packard; and the mite Trombicula whartoni Ewing. In addition to the above Peters (1933) also reported the tick Ixodes brunneus Koch as a parasite of the hermit thrush.
According to Herbert Friedmann (1929) the hermit thrush is a very uncommon victim of the cowbird, and at the time of writing he knew of only six definite records. Contrary to Friedmann's statement, I have found it to be a frequent victim. I have seen fewer than 15 nests of the hermit thrush, yet four of these were parasitized by the cowbird. On May 31, 1920, I found a nest near Brunswick, Maine, that contained three eggs of the hermit thrush and two eggs of the cowbird. This nest was destroyed by some predator a few days later. On July 8,1928, a nest containing three eggs of the hermit thrush and one egg of the cowbird was found at Douglas Lake, northern Michigan. In this nest the cowbird hatched first and continued to thrive until it left the nest. Two of the eggs of the hermit thrush hatched, the third was sterile. Both of the two hermits were also successfully reared. On July 6,1928, also at Douglas Lake, Mich., I found a nest containing two eggs of the hermit thrush and one egg of the cowbird. On July 12 the cowbird egg hatched, followed a day later by the hatching of one of the thrush eggs; the other thrush egg was sterile. The thrush and cowbird competed for food, but the cowbird proved more aggressive and maintained its lead in size throughout the nesting period. On July 19, when the cowbird was seven days old and the hermit six days old, there was a marked difference in weight and size and relative development of the feathers. By July 25 both the cowbird and thrush had left the nest. The adult hermit was seen feeding the cowbird nearby, but the young hermit was not seen, although I have no reason to believe that it perished.
A fourth nest of the hermit thrush parasitized by the cowbird was found at Topsham, Maine, on June 6,1941. This nest contained two eggs of the hermit thrush and two eggs of the cowbird. No opportunity was presented to visit this nest a second time.
In addition to enemies and parasites the hermit thrush is subject to many hazards especially during the migration season. Along the coast of Maine the lighthouses exact their toll of these birds especially during the heavy fogs and storms which often prevail during that season of the year. Mention has already been made elsewhere of the destruction to the earlier migrants, which succumb to sudden excessive cold waves and late snowstorms, especially when the available food is covered by a deep fall of snow.
W. E. Saunders (1907) records a fall migration disaster in western Ontario as follows:
The early days of October, 1906, were warm and damp, but on the 6th came a north wind which carried the night temperature down to nearly freezing. Near there it stayed with little variation until the 10th. . .the north wind brought snow through the western part of Ontario. At London there was only 2 or 3 inches, which vanished early next day; and the thermometer fell to only 32 degrees on the night of the 10th, and to 28 on the 11th, but ten miles west, there was 5 inches of snow at 5 p.m. Oct. 10, and towards Lake Huron, at the southeast corner, between Goderich and Sarnia, the snow attained a depth of nearly a foot and a half, and the temperature dropped considerably lower than at London. On that night, apparently, there must have been a heavy migration of birds across Lake Huron, and the cold and snow combined overcame many of them, so that they fell in the lake and were drowned.
Along the shore of the lake near Port Franks there were an estimated 5,000 dead birds to the mile along the beach. On the beach south of Grand Bend, Mr. Saunders counted 1,845 dead birds, including 20 hermit thrushes, in a relatively short time. On the beach at Sable River he found the dead birds even more numerous than at Grand Bend, the site of the above census. Mr. Saunders states that the bulk of the hermit thrushes had already passed by on October 6, yet they were well represented among the dead birds found.
Winter.--More than in the case of the other thrushes a considerable number of individual hermits spend the winter months in regions well north of the well-established winter range of the species. In correspordence from E. M. S. Dale he states that it is not unusual for the hermit thrush to winter in Ontario. He mentions one individual in particular that lived through the winter of 1941 - 42 at London, Ontario. It fed on currants supplemented by gleanings of suet and other food from the food shelf of the chickadees and downy woodpeckers. Its favorite spot was a corner of the front veranda, sheltered by a discarded Christmas tree, in the lee of which the currants were placed. It disappeared when the spring brought others of its kind on their journey north.
There are numerous winter records of the hermit thrush in southern New England, where it has been reported in favorable situations throughout Massachusetts and Connecticut even at times when it was very cold and the ground covered with snow. It has also been reported from various sections of New York and New Jersey during the winter months. South of this area it is a regular winter resident.
In South Carolina, according to A. T. Wayne (1910), the hermit arrives by October 23 and remains until the second week of April. The birds are not abundant until the middle of November, when they are apparently settled for the winter. Contrary to reports of the wintering hermits in New England, Mr. Wayne states that the species cannot endure a sudden change of weather, especially if very low temperatures prevail for even a few days, as great numbers perished on February 13 and 14, 1899. During January and February 1895, hundreds succumbed to cold weather, although the food supply was plentiful. Mr. Wayne states that the hermit is the least shy of the thrushes and can be readily approached within a few feet, especially during cold weather. According to W. P. Wharton (1941) the hermit has a strong tendency to return to the same winter quarters. Of 81 of the birds he banded at Summerville, S. C., he had 10 returns, or 12.34 percent.
In Florida, according to A. H. Howell (1932), the hermit is a common winter resident in the northern and central parts of the state but rare in the southern part. He states further: "During the winter season, these Thrushes inhabit thick hummocks and the borders of wooded swamps. [In many parts of the south because of this characteristic habitat the hermit is known as the 'swamp sparrow' or 'swamp robin.'] While not particularly shy, the birds are so quiet and retiring in disposition that they attract little attention as they feed on or near the ground."
In the Middle West there are winter records of the hermit
thrush for Ohio, Indiana, Illinois, and Missouri, the majority
from the southern sections of these states. In the winter of 1906
- 07 I found the hermit to be a very abundant bird in the wooded
river bottoms of the Mississippi and Ohio Rivers in southern
Illinois. Otto Widmann (1907), in writing of the wintering birds
of the Peninsula of Missouri, states: "It is seldom heard to
sing in transit, but may be heard in its winter home, where it
frequents the same swampy ground as the winter wren adjoining the
drier haunts of the fox, white-throated and other sparrows."
The hermit is very abundant in the Mississippi River Valley south
of Missouri, but the majority pass southward in October and
northward in April.
Hermit Thrush* Catharus guttatus [Eastern Hermit Thrush]
*Original Source: Bent, Arthur Cleveland. 1949. Smithsonian Institution United States National Museum Bulletin 196: 143-162. United States Government Printing Office