Contributed by Doris Huestis Speirs
[Published in 1968: Smithsonian Institution United States National Museum Bulletin 237 (Part 1): 206-237]
The evening grosbeak was first described by William Cooper (1925) from a specimen sent to him by Henry R. Schoolcraft from Sault Ste. Marie, Mich. The first words written about it were those Schoolcraft (1851) penned in his journal for Apr. 7, 1823: "During severe winters in the north, some species of birds extend their migrations farther south than usual. This appears to have been the case during the past season. A small bird, yellowish and cinereous, of the grosbec species, appeared this day in the neighbourhood of one of the sugar-camps on the river below, and was shot with an arrow by an Indian boy, who brought it to me. The Chippewas call it Pashcundamo, in allusion to the stoutness of its bill, and consequent capacity for breaking surfaces."
William Cooper (1825), in his observation following the original description, quotes from the notes of Major Delafield who, as agent of the United States for boundaries, met the bird in August 1823 near the Savannah River, northwest of Lake Superior:
At twilight, the bird which I had before heard to cry in a singular strain, and only at this hour, made its appearance close by my tent, and a flock of about half a dozen perched in the bushes in my encampment. They approached so near, and were so fearless, that my canoe-men attempted to catch them, but in vain. I recognized this bird as similar to one in possession of Mr. Schoolcraft, at the Sault Ste. Marie.
Its mournful cry about the hour of my encamping (which was at sunset) had before attracted my attention, but I could never get sight of the bird but on this occasion. There is an extensive plain and swamp through which flows the Savannah river, covered with a thick growth of sapin trees. My inference was then, and is now, that this bird dwells in such dark retreats, and leaves them at the approach of night.
Major Delafield's inference is the source of the species' vernacular name--manifestly a misnomer. I do not doubt that the good major's birds cried out at sunset "in a singular strain" because he and his party disturbed them as they made camp. Ordinarily the species is not crepuscular, and in fact it might better be called "morning grosbeak," for it is most active early in the day. *** And it inspired Elliott Coues (1879) to write: "A bird of the most distinguished appearance, indeed, is the Evening Grosbeak ***. Clothed in the most striking color-contrasts of black, white, and gold, he seems to represent the allegory of diurnal transmutations; for his sable pinions close around the brightness of his vesture, just as the night encompasses the golden hues of the sunset; while the clear white space enfolded in these tints foretells the dawn of the morrow."
Before 1854, in addition to the localities mentioned in Cooper's account, this grosbeak had been reported from Lake Athabaska (Bonaparte, 1828), from Carlton House and the Saskatchewan plains, where it was known as the "sugar-bird" (W. Swainson and J. Richardson, 1831). Forbush (1929) tells of the eastward extension of range:
The first recorded extension of its range east of the Great Lakes was at Toronto in 1854. About the beginning of the last quarter of the nineteenth century there seems to have been some increase of the species in winter in the northern tier of mid-western states. The first verified occurrence of the species in Indiana, according to Dr. A. W. Butler, was in November, 1878, although it was reported there in 1876. In the winter of 1886-87 its numbers increased in Indiana, and it was noted in Ontario and also in some numbers in western Kentucky in the spring of 1887, and a few reached New York state. Up to the winter of 1889-90, however, it was almost unknown in the East, and even as far west as Ohio. In that winter a great eastward migration occurred, which in January, 1890, penetrated almost to the Atlantic coast of Massachusetts.
By February 1890 the birds had reached Revere Beach, on the Atlantic Coast of Massachusetts, and finally the migration reached as far east as the city of Quebec, and east in Maine as far as Orono.
Mr. Bent writes of his first youthful encounter with "this fine, large, and handsome grosbeak" as follows: "It was on March 8, 1890, that I saw my first evening grosbeak. I was leaving my father's house to go to work in a cotton mill in Fall River, when I saw three plump, handsome birds feeding on the buds of a sugar maple in the front yard. I promptly forgot about the mill job, and soon had two fine males and a female laid out on my skinning table. This was, I believe, the first record for the species in southeastern Massachusetts. Since then, at frequent intervals, we have had them here at feeding stations, sometimes in large numbers."
In his comprehensive study of the summer distribution of the eastern evening grosbeak, James L. Baillie (1940) maps 82 summer records. These form an almost continuous belt on both sides of the international boundary, from southeastern Manitoba to eastern Ontario, and concentrated mainly in the vicinity of the Great Lakes. He also gives 6 summer records for Alberta, 1 for Saskatchewan, 4 for Manitoba and 6 for New England. Many of these birds seen or collected in June, July, or August at least suggest the possibility of breeding. In several cases parents were seen with recently fledged young apparently hatched in the vicinity. Baillie's table gives full references for all the records, which he summarizes as follows:
The more recent and regular occurrences of the species in eastern North America in winter seem to be correlated with an increase of the species in summer and it seems evident that its summer range has been extended eastward by gradual stages during comparatively recent years. . . . Facilitating their eastward extension has been the widespread planting in the east during the past few decades of the box elder (Acer negundo) as a shade tree (Allen, 1919). The seeds of the box elder, which hang on the trees all winter, are preferred by the evening grosbeak to anything else, when available, and Taverner (1921) calls the situation a "baited highway" along which the grosbeaks have been able to pass.
In the 25 years since publication of Baillie's paper, the grosbeaks have continued to extend their range eastward. They have now been reported from Newfoundland in winter and from eastern Quebec, New Brunswick, and Nova Scotia in summer. It is probably only a question of time before their breeding in the easternmost Maritime Provinces and Newfoundland is reported.
Spring.---"When the snow is heavy the birds congregate at feeding stations," writes Christopher M. Packard. "When it thaws, and the ground and seeds begin to appear again, their attendance at feeders drops noticeably, doubtless because the birds can now find enough natural food. They can once again revert to the maple stands and rummage about through the soggy leaves in search of seeds fallen the autumn before. With the advent of warmer weather, two new sources of food becomes available, the new tender buds and the maple sap, of which they are particularly fond."
At North Bay, Ontario, the grosbeaks arrived early one winter at the western edge of the town. Day by day they visited various box elder or Manitoba maple trees (Acer negundo) and in a kind of micro-migration moved eastward across the town until, by the time the snows melted, they had reached its eastern limits. On a March day in 1945 we watched a small flock feeding in a Manitoba maple. The birds kept flying from the tree to a snow-covered house roof nearby to eat snow. Individual birds went to a dark patch on the roof where the snow was melting, filled their bills with the water, threw back their heads and drank. My notes written at the time read: "The wind was blowing and waving the innumerable samaras to a tinkling music. The sound of the blowing seeds, of the birds' musical chatter, was like an elfland symphony to our ears." Wings and seeds lay scattered in the snow beneath every Manitoba maple the grosbeaks had visited. We examined many of the now seedless wings, bitten off with neatness and precision.
Later that spring in the Haliburton District of Ontario we found the grosbeaks feeding beneath the mountain maples (Acer spicatum). A flock was actively searching for the fallen seeds amongst the forest litter. They were quiet when feeding, but punctuated their activity with loud call notes as various members of the flock flew up into yellow birch or spruce and down to a little stream under alders to drink. They drank the cold pure water of this northern stream with as much apparent relish as the North Bay grosbeaks drank the melted snow from the city rooftops.
In Ontario, New York, and New England, small flocks move from feeding station to feeding station on the way to the breeding grounds. As evening grosbeaks are not early nesters, a few birds often remain in the vicinity of feeding stations until May. In recent years May reports have come from states south of New York and New England. But gradually the flocks diminish in size until the last bird has left.
Courtship.--After watching a pair of evening grosbeaks on their breeding ground in northern Michigan, Bayard H. Christy (1930) gave the first published account of the colorful courtship display. He writes: "As the female. . .perched near, the male made a beautiful display. He crouched low, puffed out his plumage, extended his wings horizontally and set them quivering. The gorgeous contrast of the glossy black wings with the golden body suggested the appearance of a bird of paradise. There was no song; it was about half past five in the afternoon, and the sun was still high."
On Apr. 4, 1937, at Hanover, N.H., I watched a pair of evening grosbeaks bowing to each other with great formality. They were not more than a foot away from each other when the formalities began. First the male bowed very low, then the female bowed. The male bowed again, and the female again. The rhythm accelerated until they were bowing so low that I almost expected to see them lose their balance and fall off the branch. The female punctuated her jerky movements with loud call notes. As she bowed she called peter! and flicked her tail. From the male came no sound. The female seemed the more enthusiastic, and continued to bow after the male apparently had lost interest. On April 21 I saw a female jerking up and down in somewhat the same way a flicker does during courtship. She seemed to be pursuing the male, or at least she moved toward him, but he disregarded her, dropped to a lower branch, and turned his back to her.
While observing two pairs at a salt lick by Clear Lake, Haliburton County, Ontario, on June 1, 1945, I noted that the females were as combative as the males, spreading their wings, jerking from side to side, and clinching bills. During one duel the two females rose into the air as fighting male robins sometimes do.
On May 2, 1949, in Iron County, Mich., among a loosely scattered flock in the crown foliage of tall sugar maples at noon I watched (Speirs, 1949) a male in courtship display: "The pair were about 40 feet up in a maple, the male about a foot above the female on another branch. Suddenly he threw back his head, lowered the yellow rump, raised and fanned his black tail and commenced vibrating his black and white wings so fast that they looked transparent as a hummingbird's. He then glided along the branch above her as swiftly as a geisha, but with his back in the form of a U. The female did not look at all impressed, flew to a tree eastward, followed by her swain."
Elizabeth Holt Downs (1958) has given a full account of the courtship as she observed it on Glebe Mountain, South Londonderry, Vt., in the spring of 1956. She writes:
During the first part of April the grosbeaks began "chasing" each other and on April 18th I witnessed the first courtship feeding. . .the female initiated this first feeding by "flirting" her tail (a quick spreading and closing of the tail), bobbing her head and swinging her body slightly in front of the male. Some males do not respond at first to this invitation but in this instance the male fed the female sugar maple buds. Within a few days courtship feeding was a daily occurrence. On one occasion I watched a male grosbeak go through all the motions of feeding a female but without any food to give her. . . .
Beginning with 1953 I have been able to observe much of the courtship behavior of the Evening Grosbeaks every year. Their courtship seems to follow a certain pattern with possibly some slight variations. It is initiated by the female asking to be fed. The first food she receives from the male is tree buds; later she is fed salt-impregnated earth and still later (after pair formation has taken place) the female is fed sunflower and tree seeds. After pair formation has occurred, more often than not it is the male who takes the initiative and offers the seeds to the female. At this time when the female accepts the food (or asks for it) she assumes a posture similar to that of the young begging to be fed (crest raised, body crouched slightly and wings fluttering). Some females swing their bodies from side to side and occasionally a female will "cry." But sometimes the feeding is accompanied by very little display by the female.
"Dancing" by the males usually begins shortly after the initial courtship feeding and before pair formation has taken place. When dancing, the male grosbeak faces the female. With crest raised, bill and tail pointed upwards, breast almost touching the ground and wings drooped but spread wide and vibrating, he slowly pivots back and forth. He does not sing while dancing. If he utters any sound at all, it is too low for me to hear.
On June 1 she witnessed two matings. The second "was a very elaborate ceremony. . . . The pair, on the road in front of our house, faced each other. The male danced (but all his movements were more subdued than in the usual dance). The female quivered her wings (short, rapid movements with wings held close to her body) and held her tail high. Then still in this posture but with her breast thrust forward she hopped a few inches to the dancing male. I could not be certain that their breasts touched. She continued to dance. It looked as if they touched bills twice. He then mounted her."
Nesting.--For 75 years after the discovery of the eastern evening grosbeak, its breeding range remained virtually unknown. Of its nesting habits nothing was reported until L. Osborne Scott sent some notes to W. T. Macoun (1899) in which he announced: "I have seen the Evening Grosbeaks in flocks of ten to eighty on the Peace River. The Indians say they always build in Saskatoon willows (Amelanchier), though I think there are exceptions."
Macoun also published Scott's account of nests he found near Winnipeg that year. "On the 18th of June I saw four nests of the Evening Grosbeak about one mile north of Winnipeg, near the Red River, in fact right on its bank. The nests were about twelve or fifteen feet from the ground in some grey willows; they were rather flat and slight, made of sticks and roots and lined with smaller roots. There were only two eggs in two nests and one each in the other two. The eggs were more blotched than those of the Red-breasted and not so spotted, and I fancy they are a little smaller."
Ten years later came a report from Sidney S. S. Stansell (1909) that he had located a nest 30 miles northwest of Edmonton, Alberta in June 1908 "which contained a dead full-fledged young male. The nest was 40 feet up in a white birch tree."
Dr. S. C. Kendeigh, who found a pair building in a white birch in the Thunder Bay District of Ontario in 1945, writes: "I found the evening grosbeak quite common in Algonquin Park and only a little less so north of Port Arthur. On June 22 I found a pair nest-building on one of my plots. Only the base of the nest was in position in a vertical crotch 55 feet up in a white birch that was 60 feet tall. I watched them only five minutes to avoid disturbing them, but in this time the female made 5 visits to the nest with dead twigs. These twigs she broke off a smaller white spruce about two-thirds of the way up. She broke them off with her bill, once dropping two before taking the third to the nest. At the nest she jumped into the center and adjusted the stick into the structure on the outside. It was a hot day, in the high 80s, and the female was panting with mouth wide open and wings partly spread. The male accompanied the female on each trip to and from the nest but did not help in the building. He would watch her intently at the nest while perched on a branch a few feet below."
J. Stokley Ligon (1923) found five nests of the eastern evening grosbeak on July 28, 1923, on Whitefish Point, Lake Superior, in Michigan, about 20 miles from the Canadian shore. One young bird was found on the ground, and the nest from which "it had fallen was about 25 feet up on a horizontal limb of a white pine, well concealed by small branches and needles." He climbed to this nest and examined it, which "was practically indistinguishable from nests of the Black-headed Grosbeak of the West, being almost, if not quite, as frail of construction. . . . The body of the nest was composed of hard, clean sticks and lined with black and brown hair-like rootlets, with a sprinkling of moss between the outer body and lining."
Thomas S. Roberts (1932) quotes an account published by A. G. Lawrence in the Winnipeg Free Press, June 20, 1930, of two nests near Winnipeg found by L. E. McCall, of Selkirk, Manitoba. One nest was "placed in a crotch 28 feet up in a Manitoba maple situated in a garden bordering the public sidewalk, and. . .well concealed except on one side." The other nest was 19 feet up in an elm overhanging the road, "on a fork of a long overhanging branch." Both nests contained eggs and the two birds sat closely. During the first three decades of the present century, while the eastern evening grosbeak was extending its summer range eastward, many records of probable nesting were based on females showing brood patches and on adults seen feeding juveniles. At Woodstock, Vt., Richard M. Marble (1926) saw four young come to a feeding station with their parents. "The little ones were not quite as large as the adults, their tails were very short and many downy feathers still showed on their heads."
H. R. Ivor sent Mr. Bent an interesting account of some evening grosbeaks he had in his aviary for several years. He told especially of one pair that mated, built a nest, laid four eggs, and succeeded in raising one young. J. H. Fleming (1903) also records the breeding of this species in captivity.
Louise de Kiriline Lawrence, my husband, and I found a nest near a forest edge in Lauder Township, Nipissing District, Ontario, on June 21, 1945 (Speirs and Speirs, 1947). The nest was 55 feet up in a white pine and very well concealed. It contained at least three young and through a 47X telescope we were able to watch the young being fed. I spent 3 days observing this nesting. After the young left we collected the nest, which is now in the Royal Ontario Museum of Zoology and Palaeontology. Its measurements are: Inside of cup--longest diameter, 3.7 in.; shortest diameter, 3.2 in; Outer diameters--longest, 5.9 in.; shortest, 4.3 in.; Depth of cup--2.8 in.; Total depth--5.1 in. to supporting limb; 5.9 ins. including twigs below limb. Most of the foundation of the nest is of twigs from deciduous trees (maple, birch, viburnum, red-osier, dogwood), a piece of vine (possibly bittersweet), twig of raspberry. Many of the twigs are opposite branching (maple, viburnum, dogwood). The smaller twigs are from coniferous trees, mostly from spruce, some from balsam fir, and one from tamarack. The edge of the nest is of rootlets interwoven with Usnea lichen. The innermost lining is of what appears to be black moss--the dead stage of threadlike lichens. Dr. C. H. D. Clarke assisted with the identification of the nest material.
The following summer (1946) grosbeaks were found nesting some 10 miles south of Lauder Township in Algonquin Park. Says C. E. Hope (1947):
During the last week of May, a road, about one and one-half miles in length, was bulldozed through a mixed forest of second-growth white pine, black and white spruce, balsam and birch. The action of the scraper exposed a myriad of rootlets which, after a few days, became dry and brittle. Coinciding with this period at least ten pairs of Evening Grosbeaks established themselves in what might be termed a loose colony, in woods adjacent to a section of this road. Pairs were frequently seen on the freshly graded earth. On June 10, a female, accompanied by her mate, was observed to carry off rootlets in her bill. On June 12, a similar observation was made and on this occasion we were fortunate enough to see where the material was taken and deposited. The performance was repeated several times, with only the female carrying the material but always accompanied by the male. The nest, situated 28 feet from the ground in a black spruce, was left undisturbed until June 22 when it was collected. It was found to be placed close to the trunk some six or seven feet from the top of the tree and almost entirely hidden by dense foliage. It contained four slightly incubated eggs.
On June 21 a second nest was discovered 30 feet 5 inches up in a balsam. Like the first, it was invisible from the ground and was situated close to the trunk, six or seven feet from the top. It contained three eggs on the date mentioned. This nest was left undisturbed until July 6. It was then found to contain three partially fledged young. One, taken for a specimen, proved to be a male. . .The remaining two young left the nest on July 8. . . .
A point of interest concerning the structure of the two nests found is that from seventy-five to ninety percent of the materials used consisted of rootlets such as were exposed in the newly made road. Oddly enough, the taking up of nesting territories adjacent to the road coincided with the exposure of unlimited nesting material.
Marjory B. Sanger reported in a letter to me the first nesting I have heard of for the Province of Quebec. Between May 26 and May 30, 1955, she watched a pair of evening grosbeaks gathering nesting material and carrying it into a 60-foot white birch that stood in a fairly open spruce and maple glade near St. Charles de Mandeville, Conte Berthier. The nest was about 30 feet up and the female seemed to be doing all the nest-building. The male, however, "observed her actions with obvious interest. . . supervising with care and staying close at all times."
Evening grosbeak nests have three outstanding characteristics: they are loosely constructed "stick-nests"; some moss or lichen is woven into the structure; and the cup is not really round (as has been reported) but oblong or elliptical. They have been reported in seven species of coniferous trees: balsam-fir, red spruce, black spruce, white pine, Norway (or red) pine, jack pine, and white cedar. The species has also nested in at least seven species of deciduous trees: willow, aspen, white (or paper) birch, elm, Saskatoon (Amelanchier), and in hard and soft maples. One nesting was in an orchard.
Eggs.--The evening grosbeak lays from two to five eggs in a set, usually three or four. The eggs are ovate or, rarely, pointed ovate, thin shelled, and of smooth texture with little gloss. The ground color is usually deposited as a clear blue or bright blue-green, which during incubation changes to "pale blue-green" or "pale glaucous-green." They are blotched and spotted, particularly at the larger end, with "olive-brown," "lilac gray," or "light Quaker drab." Fine pencilled markings in black occur on a number of eggs. One with a "pale glaucous-green" shell was stippled all over with "olive-gray" and "pale mouse gray." The eggs resemble rather strikingly those of the red-winged blackbird.
The measurements of 23 eggs average 24.5 by 17.5; those showing the four extremes measure 28.0 by 18.0, 26.8 by 19.0, 21.0 by 16.0, and 21.0 by 16.0 millimeters.
Incubation.--One egg is laid each morning until the set (usually of three or four eggs) is complete. Incubation has been observed to start on the second day and is performed by the female alone. There is no record of incubation by the male, and but one observation of a male brooding a 3-day old nestling (H. R. Ivor Journal). At times during the incubation period the male feeds his mate both on and off the nest.
No data on the length of the incubation period in the wild are available, but we have several measurements from aviary nestings. A. G. Lawrence reported to Mr. Bent periods from 11 to 12 days in his aviary. Paul Kuntz (1939) writes from Winnipeg: "The bird sat steady for twelve days. On the thirteenth two young were hatched." J. H. Fleming (1903) observed in his aviary: "About the 16th of July three eggs of a second set were noticed in the nest; one had disappeared before my return, and on the 30th one of the two remaining eggs hatched." The incubation period in this case was at least 14 days. In the Ivor bird observatory at Erindale, Ontario, the incubation periods for three marked eggs were 12, 13, and 14 days, respectively.
One of Ivor's birds laid a second clutch; the first egg appeared when the only nestling of the first set was 11 days old and still in the same nest. Young birds recently fledged have been seen as late as mid-August in Ontario and on August 30 in Vermont, according to Elizabeth Holt Downs. B. M. Shaub (1958) reports a young male still in juvenal plumage at his Northampton, Mass., feeding station on Oct. 26, 1957. These records suggest the possibility of two broods occasionally in the wild.
At hatching, the nestling is much like the young of the rose-breasted grosbeak, but the skin is darker. The little bird appears very red with damp gray feathers on its head. These neossoptiles are about a quarter-inch long and dry within 25 minutes. Paul Kuntz (1939) gives his impression of the young: "They are strong and healthy chicks, all black with a fluffy down. They looked exactly like young Bullfinches." My own notes read: "The white natal down sticks out from the top of the head. The membrane covering the eye looks purplish and very large. The bill is yellow. The egg-tooth is like the tiniest white bead on the upper mandible. The gape is white. The mouth and pharynx have an iridescent appearance--tones of violet and carmine." My notes for the second day state: "When the babies are not raising their heads, they throb with every 'peep' they utter. The natal down is perfectly placed to cover them as a blanket while in the nest. They lie bellies down. Bellies and throats are bare, but down grows on head, wings, and tract down the back."
Parents of newly hatched aviary nestlings at Erindale, Ontario, fed them a gruel of masticated earthworms and mealworms, which they first chewed for some time until a dark liquid stained their bills. We watched wild adults in the Nipissing District of Ontario feeding the young similarly on the masticated larvae of the spruce budworm (Choristoneura fumiferana Clem.). When the greenish bills of the adults become stained dark brown from masticating insect larvae, it is a sure sign they are feeding their young. The spruce budworm in all stages of development is the main item of insectivorous food for nestling evening grosbeaks wherever both the insect and the bird occur together. Moreover, the birds often appear for the first time or in unusual numbers wherever there is an outbreak of spruce budworm during the breeding season.
A number of evening grosbeak stomachs from the collection of the Royal Ontario Museum of Zoology, including those of juvenals, were analyzed by J. M. McGugan, Micro-Analyst of the Dominion Department of Agriculture in Toronto, and Ronald N. Root, of the U.S. Fish and Wildlife Service. Their analyses showed the most important vegetable food in the juvenal diet to be the pit of the pin- or bird-cherry (Prunus pensylvanica). Seeds of other native fruits such as the hawthorn (Crataegus sp.) blackberry (Rubus sp.), and blueberry (Vaccinium sp.) were taken to a lesser extent; also birch (Betula sp.) seeds. Weed seeds in the diet included those of sedge (Carex sp.), dock (Rumex sp.), bindweed (Polygonum sp.), goosefoot (Chenopodium sp.), crowfoot (Ranunculus sp.), wild geranium (Geranium sp.), and violet (Viola sp.)
Mr. Bent writes: "Mr. Lawrence has sent me some clippings from his articles in the Winnipeg Free Press, in which he describes how the grosbeaks fed their young in the box elder tree in Selkirk. Both adults helped in feeding the young by reguritation of semidigested food while the nestlings were too young to take solid food. It was difficult for the old birds to insert their heavy bills into the mouths of the nestlings, but his sketches, based on photographs, show that the adults accomplished this by twisting their heads to one side. After the young were a week old they were fed caterpillars and small soft green seeds. The young were fed at irregular intervals, and, when very young, were brooded by the female between feedings."
Foraging parents usually, but not invariably, leave and return to the nest together. When they arrive simultaneously both perch on the rim of the nest and the female feeds one nestling. Then she often takes food from the male's bill and feeds another. Finally the male may give any remaining food directly to the young.
I watched one nest with young 5 or 6 days old in Lauder Township, Ontario, on June 23, 1945, from 4:45 a.m. until 8:01 p.m. when it was getting too dark to see, except for a half-hour absence from 6:30 to 7:00 a.m. During this time the young were fed 34 times. Starting at 4:50 a.m. when both parents arrived with food, there were 14 feeding periods between dawn and noon. For 10 feedings the adults came together or nearly so. Once the mother came alone and remained to repair the nest lining and brood the young. Twice the father brought food when the mother was on the nest, and once unattended by his mate. Intervals between feedings in the morning varied from 7 to 54 minutes, averaging one feeding period every 21.5 minutes. Intervals between the 20 feeding periods from noon to the last one at 7:50 p.m. ranged from 1 to 97 minutes and averaged one every 24 minutes.
The father seemed to attend to the nest sanitation more assiduously than did the mother; he removed fecal sacs eight times, the mother only twice. In each case nest sanitation followed a feeding. The nestling on my side of the nest raised its uropygium, which was covered with white down, as if to help the father remove the fecal sac.
Both parents defend the nest and young. On July 4, 1946, at the Algonquin Park nesting, I watched the pair drive off a gray jay by dashing at it, giving rough buzzing notes. They treated a bronzed grackle and a robin in the same manner, and threatened a young hermit thrush. They tolerated the following species near or even in the balsam fir that held the nest: golden-crowned and ruby-crowned kinglets, a myrtle warbler, Blackburnian and Canada warblers, and a purple finch. They chased no other evening grosbeaks and seemed tolerant of the few that appeared in the nesting vicinity.
The young birds grow quickly. An aviary nestling measured 50 millimeters when 51 hours old and 57 millimeters when 78 hours old. The eyes begin to open on the fourth or fifth day and are fully open on the fifth or sixth day. The sex of a healthy nestling can be determined by the ninth or tenth day. Thus H. R. Ivor wrote in his journal of a 9-day old bird: "The nestling definitely seems to be a male. The tail feathers have barely broken and show all black. The white of the middle secondaries are very pure white."
C. E. Hope found a fledgling male about 12 days old from a nest in Algonquin Park, Ontario, on July 6, 1946 to weigh 32 grams. A second young male collected on August 9 weighed 61.5 grams. The Shaubs have reported on weights of juveniles trapped at their feeding station at Saranac Lake, N.Y. in the summer of 1952 (Shaub and Shaub, 1953). "Two females weighed 52.6 and 49.6 grams respectively. A juvenal male weighed 55.2 grams and an adult male weighed 51.2 grams."
The young normally leave the nest on the 13th or 14th day. One fledgling male, that had left the nest prematurely in Algonquin Park, Ontario, was fed exclusively by its father until independent. A young aviary male at 36 days from hatching was being fed from time to time by its mother, although able to feed itself as well.
Juvenal males have golden heads, and when they raise the crest to beg for food, as I have seen them do in Muskoka, they are very handsome. My husband watched a juvenal female with a peach-colored breast following and begging from an adult in Muskoka on August 5, 1951. The young bird looked as big or bigger than the adult and had a full-grown tail. Elizabeth Holt Downs recorded the dates of the arrival of the first young at her feeding station in Vermont for the years 1953-1957. In 1953, 1954, and 1955 the first young appeared on June 26. In 1956 the arrival date was July 6; in 1957, June 17. Juveniles out of the nest have been reported as early as the first week in July in Ontario. The latest dates of juvenile feeding is a young male Mrs. Downs saw an adult male feeding in Vermont the third week in November.
Plumages.--The natal down is white. The neossoptiles are on the capital tract and on spinal, femoral, humeral, and alar tracts. Clifford E. Hope describes a nestling about 12 days old, taken in Algonquin Park, Ontario, on July 6, 1946: "Pin feathers of forehead, crown, occiput, and cervix 'clove brown'; back 'olive'; circle of whitish natal down above eye to nape; bare skin side of neck and center of breast, dark red; feathers side of breast shading from 'broccoli brown' to 'pinkish buff'; scapulars 'olive'; rump covered with natal down. Wing: lesser coverts, sepia; middle coverts, black, edged with gray. Yellow and black feathers with white shafts forming pattern on inner edge of greater coverts and tertials; yellow mark on primaries and secondaries. Tail, black; undertail coverts, whitish. Down on tibia, over pale yellow and black feathers."
Mrs. Downs observes: "The juvenals have a small yellowish patch composed of the four inner secondary coverts, which I call a birthmark because they lose it during their postjuvenal molts." The postjuvenal molt is not complete until the juvenal is nearly a month old. At 24 days a young male still had a small tuft of down above the eyes on either side of the crown.
Despite J. Dwight's (1900) statement: "The sexes are similar in juvenal plumage," I have found that the fledgling male can be distinguished by its tail feathers; these are usually black when they break from their sheaths and lack the series of white spots which characterize the female rectrices. Also, the male's primaries are black, while the female's are black and white, and the male has a prominent whitish patch on the inner flight feathers which the female lacks.
My notes contain the following description of a month-old female. Crown, occiput, nape, auriculars, and side neck, olive-gray. Upper mandible, greenish gray; tip greenish. Lower mandible, pinkish, dark gray at gape. Throat, pale gray, edged with dark malar stripes. Back, olive-gray. Rump, olive-gray tinged with peach. Rectrices, with series of white spots near tips. Undertail coverts, pinkish gray. Breast, light gray washed with peach. Side and flank, gray tinged with peach. Belly, gray, washed with pale peach; dark down exposed in places. Wings: fist three primaries at leading edge, black; the remaining six edged with white and with yellowish patch forming square on wing. Wrist with pale yellow edge. Scapulars, olive gray. Greater secondary coverts with patch of yellow on three feathers, the rest black. Middle coverts, black, with light edgings. Lesser coverts, black with olivaceous edgings. Underwing coverts, lemon yellow.
I described a 2-month-old male as follows: Crown and cheek, "light olive brown." Supra-auricular region "light olive-brown" with dusky line. Auriculars, "light brownish olive"; greenish on outer webs. Upper mandible, "drab," greenish at gape. Throat, "sulphur yellow." Malar stripes, dusky. Side neck, "cinnamon-buff." Back, "Saccardo's olive." Tail, black. Undertail coverts, whitish, tinged with "cinnamon-buff." Wing, black; inner secondaries and their greater coverts, white, tinged with pale yellow and edges with pale buff. Feet, "army brown." At 3 months, the yellow frontal band of this juvenile male becomes conspicuous. As the patchwork of black and fawn spread over its crown, the cheeks were darkening, though not yet of the "bister" color of the adult.
Mrs. Downs, who has banded so many juvenals in Vermont, writes me that "there is considerable difference in the color of juvenal females and juvenal males--body color that is. Both are tan but the females are a gray-tan and the males a yellow-tan. Even without seeing their wing markings we can tell a female from a male by the color of their bodies." (For further descriptions of the young, see Shaub and Shaub, 1953.)
The first winter plumage is acquired by a partial postjuvenal molt in the autumn. Of this E. H. Forbush (1929) writes: "the first winter plumage by partial postjuvenal molt of body feathers and wing coverts, juvenal flight feathers and tail retained, tertials may be shed in some cases." J. Dwight (1900) states that "Young may be distinguished usually by the dusky inner margins of the tertiaries but differ very little from adults."
Of the first nuptial plumage J. Dwight (1900) writes that it is "acquired by wear which removes much of the wing edgings. Browner more worn remiges and especially primary coverts with distinct edgings distinguish young birds." According to M. J. Magee (1928a) some and possibly all evening grosbeaks have a very slight spring molt. Of 93 grosbeaks he examined between April 15 and May 13, 24 showed signs of molt. These included both adults and young. The molt was most pronounced on the nape, and one to several new feathers were seen on crown, occiput, cervix, side of neck, and throat. We noted a male in partial prenuptial molt at North Bay, Ontario, as early as Mar. 4, 1944. In 1929, M. J. Magee (1930) continued his study of the spring molt. On the 50 grosbeaks he banded from April 13 to May 17, he noted signs of molt on 31. The molt was largely confined to the front of the head, including the chin and the neck.
In spring the bill color changes gradually from the winter "horn-color" (but sometimes "ecru-olive" with "citron yellow" at the gape, or bright "wax yellow" or pale pink) to light green or pea green in late spring, and in June to light bluish green. It is possible to tell summer birds in collections by the bluish green color of the bills.
G. Hapgood Parks, who has banded more than 5,000 evening grosbeaks in Connecticut, wrote to Mr. Bent in 1947: "During the winter we made a study of the color the birds' bills and learned that by late February (Feb. 28) the bills began to show signs of peeling from the tip and edges. An apparent loosening of the surface membranes gave the upper mandibles of some of the birds a whitish and swollen appearance across the base of the bill near the feathers. This latter condition became more apparent on more birds during the first week of March." In 1951 he added the following: "The actual color change of the bill is apparently due to pigmentation. The mottled stage, in which many bills are seen, bears evidence of this fact. Bills showing no peeling at all are not infrequently partly green with areas which retain the 'bone' color typical of the bills in winter. The peeling off of a colorless surface layer apparently helps to promote the 'new' polished appearance of the bill.
"The peeling is much more conspicuous on the upper mandible, although some peeling of the lower mandible also occurs. I find that my notes about the bills say, most frequently, 'bill green and peeling.' About as often the entry is, 'blue-green lower, peeling upper,' or, 'mottled lower, peeling upper.' I feel certain that the entire surface of the upper mandible peels; I am not at all sure that the same condition holds for the lower mandible. I would not dare to say the bills of all of the birds peel, although I feel very strongly that such is the case."
The adult winter plumage is produced by a complete postnuptial molt. The earliest date for the beginning of the molt I have noted is June 28, when a female (one of a nesting pair at the Ivor Bird Observatory) molted a first primary and the male molted the first primary of both wings. On August 25 the male's new tail was half grown. L. H. Walkinshaw (1936) tells of a captive bird that started to molt on July 16 and did not finish until after November 1.
M. J. Magee (1926b) writes:
. . .After molting, the feathers in the white wing patches of both males and females are distinctly edged with yellow. All of the descriptions of the plumage that I have seen, from Audubon down, are very much as given by Professor Barrows in "Michigan Bird Life," in which for the the male it is said "most of the secondaries and their coverts snow white," and of the female, "primaries and secondaries black, boldly spotted with white." This limited description may be due to the fact that only specimens taken in spring were examined. Practically all of my banding of these grosbeaks had been done in the spring, until last fall (1925); and then from November 11 to March 1 I banded eighty-four, forty males and forty-four females. The males had nearly all the feathers in the white wing patch edged with yellow on the outer webs, except the tips. This was true of the great majority of females as well. . . .
Either from wear or fading the yellow edging lightens; in the males first on the white secondaries; in the females, on the white patches of the primaries. This fading of the yellow edging has been particularly noticeable since the first of March. . . .
According to Dwight (1900) the adult nuptial dress is acquired by wear.
Food.--The most important native food for the evening grosbeak is the fruit of maple trees and especially of the Manitoba maple or box elder (Acer negundo). A. G. Lawrence of Winnipeg sent the following note to Mr. Bent: "From fall to early spring the seeds of the Manitoba maple (Acer negundo) form their chief food, but ash seeds and chokecherries, both green and dried, are also eaten. They have also been reported as feeding on low-growing weeds, and on the buds of the Manitoba maple. They eat snow, scooping it up and swallowing it in large quantities after feeding on seeds. In feeding on the maple seed keys, the bird snips off the pod at the basal end, manipulates the winged portion between the mandibles to express the seeds from their compartments, swallows or presents the seeds to a young one and allows the winged pod to flutter to the ground. The operation is performed so rapidly that the eye can hardly follow the action."
Winsor M. Tyler (1916) describes in more detail the skill and precision with which the grosbeaks perform this operation, with their apparently clumsy beaks. He concludes:
Upon examining the wings which the birds had clipped off, it was apparent that the birds had bitten directly over the kernel itself at a point rather nearer the wing than the kernel. But, although by this incision the kernel was exposed, it was never severed and allowed to fall with the wing, as would have been the case had the beak been closed and bite completed. The cutting process was always arrested at the point after the casing had been divided, but before the meat had been severed. All this, although the process involved the nicest precision, was accomplished with great rapidity, the wing fluttering to the ground within a second or two after the fruit was plucked from the stem.
E. L. Brereton, of Barrie, Ontario, wrote on Apr. 11, 1937: "I have always associated the evening grosbeak with the Manitoba maple and always found them there, the sugar maple seeds being just a change of diet, but this year found that they prefer the sugar maple seeds when such can be obtained."
Fred W. Behrend (1946) tells of their feeding habits in the south. He writes (in part) from Elizabethton, Tenn.:
The budding of the maple trees and subsequent shedding of the bud scales as winter was on the way out, provided a plentiful supply of food for the Evening Grosbeaks who seemed to be very fond of this vegetal matter. . . .
As spring advanced, the feeding habits of the Evening Grosbeaks underwent, by necessity, a change. No longer did the bud scales of maple trees cover the ground as they had been cleaned up methodically in one area after another, and therefore less frequently were the birds seen on the ground. They now fed on the fresh seed pods of the maple trees, and most of their time was spent in the trees. . . .
With respect to the most often referred to favorite food of the Evening Grosbeak, the seed of the box elder tree, the latter was non-existent in this community. . . . The writer observed them feeding on the seeds of mimosa and locust trees, on the hulls embedding the blossoms of the catawba tree and on the buds or bud scales of elm trees, all in addition to their most abundant food in the locality, the bud scales and seeds of the maple tree.
While south in the spring of 1952, we were surprised to come upon a little flock of evening grosbeaks at Windsor, N.C., on April 30. At first we saw the birds on green lawns eating maple seeds. Then we saw several feeding in and under a pecan tree decorated with green catkins, which they seemed to be eating. At Yorktown, Va., the next day, we found several in a huge chinaberry tree and heard the cracking sound as they lived up to their name of "berry-breaker."
B. R. Chamberlain (1952) quotes from a letter written by J. W. E. Joyner from Rocky Mount, N.C., which tells of their eating conifer seeds during the 1952 grosbeak invasion: "When the birds first came here they were never far from the pines, the seeds of which were apparently their chief food. Some seed from tulip poplars were also eaten. . . . In gleaning seeds from the pine cones they deliberately and slowly plucked the seed out, the discarded wings floating, rather than swirling, downward. For the past month they have continued to feed on pine mast but have also been seen eating elm, maple, and oak buds. They have become regular visitors to feeding trays, consuming quantities of sunflower seeds; the seeds going in one side and the hulls drooling out of the other."
O. A. Stevens, of Fargo, N. Dak., wrote Mr. Bent: "We usually find them feeding on fruits of Russian Olive (Elaeagnus angustifolia)." In February 1929, T. M. Shortt saw evening grosbeaks eating the seeds of the buffaloberry (Shepherdia argentea), at St. James, a suburb of Winnipeg, Manitoba. The meaty fruit has a stone in the center, and Shortt told me the birds were biting the meat off the sides of the stones. Richard J. Eaton wrote Wendell Taber, that he had "seen these birds working on hybrid crabapples (Malus sp.?) much after the fashion of cedar waxwings, pine grosbeaks, and robins." Frere Marie-Victorin (1935) tells us that in Quebec, the fruits of the red ash (Fraxinus pennsylvanica) which form in June and persist on the tree during most of the winter, are a preferred food of migrant winter birds, including the evening grosbeak. When evening grosbeaks visited St. John's, Newfoundland, from Nov. 18, 1951, to May 3, 1952, Leslie M. Tuck informs me they fed on the seeds of snowberry and beech.
Mary S. Shaub (1956) has contributed an important paper on the effect of native foods on evening grosbeak incursions:
The great adaptability of this species within its winter range to extremes of climate and topography is evidenced by its appearance in the Adirondacks, the White Mountains of New Hampshire, and all the way down the Appalachians to Rome, Georgia, as well as at many coastal points from Halifax, Nova Scotia, to Wilmington, North Carolina. It is also most adaptable in its acceptance of a vast array of native and cultivated seeds and fruits.
In the course of our study of the Evening Grosbeak since 1947, and in connection with our publishing of the Evening Grosbeak Survey News during five winters from 1950 to 1955, we have received a large number of reports dealing with foods eaten by this species. These are summarized in the accompanying list of seeds, fruits, and buds. . . .
The box elder is without doubt the most acceptable native food, and in many reports the Evening Grosbeaks are noted on these trees and not at feeders, even though sunflower seeds are available there. This pertains especially to southern Ontario. In several New York and New Jersey localities the birds were first noted on box elders and could not be enticed to feeding stations until the maple keys had been devoured.
Of the numerous fruits taken by the Evening Grosbeaks, they seem to favor the various cherries, apples, crabapples, and sumac to all others. . . . Even where the Evening Grosbeaks have settled down to a routine of daily feeder attendance, now and then for no apparent reason they will fly off to a stand of sumac for a meal, or at least a snack, even before the supply of sunflower seeds has been exhausted. . . .
This variation in diet of the Evening Grosbeak has been noted over a period of years by Mrs. Gerald Fitzgerald of Amsterdam, New York, where her fine plantings of Washington hawthorn, crabapples, red and black chokecherries and cotoneasters have been attractive to the Evening Grosbeak despite her generous supplying of over 1300 pounds of sunflower seeds in the winter of 1949-50 and of over 900 pounds during 1954-1955.
Every spring evening grosbeaks may be observed "budding" in various trees. I have seen them budding in our elms, in the Rouge Hill area west of Pickering, Ontario. On Mar. 11, 1958, a female was budding in a tall elm, high up. My notes read: "She reached for the end bud of a twig, then bit off each lateral bud. Then to the next twig, taking the end bud first then each lateral bud within reach on that twig. And so to the leading bud of the next twig." The following day I watched two females budding in our lilacs: "Each reached forward and took the nearest bud within easy reach, bit it off, ate it and reached for the next nearest bud. These were not terminal but lateral buds in each case." Mrs. Shaub (1956) lists numerous different kinds of trees and shrubs in which grosbeaks have been seen budding.
If tree buds may be considered springtime treats for the grosbeaks, nature has other delicacies in store for them as well. Of their fondness for wild maple syrup Thornton W. Burgess (1947) writes: "Opposite the window of my room is a maple tree. Squirrels have been eating the buds and when the sun warms things up in the morning the sap drips from the twigs where the buds have been nipped off. The other morning the sun striking through these drops of sap filled the tree with glittering jewels. A male Evening Grosbeak climbed about parrot fashion from jewel to jewel drinking them." Mrs. Downs writes me: "Our front sugar maple tree has been gashed in many places by some creature. Today I saw the sap flowing from it and the EGs drinking the sap! Sometimes they even had to 'tread air' to get the sap because there was no branch handy on which to perch."
As the breeding season approaches, the grosbeaks begin to seek out insect food, of which the spruce budworm is an important item. G. H. and H. C. Parks (1963a, 1963b) describe graphically their studies of a concentration of evening grosbeaks nesting where a heavy infestation of spruce budworm was damaging the forest in the Patapedia River watershed of Quebec. In June 1962 using only two 3-cell Potter traps they captured 747 grosbeaks in 11 days. On the last day of their stay airplanes from the Quebec Department of Forestry sprayed the area with DDT. Mr. and Mrs. Parks returned the following June and, using the same traps in the same manner during the corresponding 11 days caught only five grosbeaks. During their visit to the same area in July 1964 they could not find a single evening grosbeak. Parks and Parks (1965) conclude:
To explain the dense concentration of Evening Grosbeaks which we had originally found at 39-Mile Camp let us call attention to the fact that repeated sprayings during several years had been employed in an attempt to gain mastery over a spruce budworm outbreak which involved forests in New York, Maine, Ontario, and New Brunswick, as well as in Quebec. Since the birds no longer found an adequate supply of the budworm for food in the sprayed areas they moved on to unsprayed tracts where the insect still persisted.
Examination of the maps on which the sprayed regions had been plotted shows that the effort to control a particularly obstinate budworm infestation near Quebec's Gaspe had approached, but had never quite reached, the Patapedia River prior to 1962. So, as this "island" of budworm-infested forest (with 39-Mile Camp situated very close to its center) became smaller and smaller the concentration of Evening Grosbeaks which was attracted to its abundance of edible larvae became heavier and heavier. Then 1962 witnessed the spraying of even this area and the resultant successful elimination of the pests which had been damaging the trees. Come the spring of 1963, the almost completely eradicated budworm population was no longer adequate to attract and hold more than a very few of the Evening Grosbeaks which might be returning to, or migrating through, this area.
Maurice Broun, of Hawk Mountain Sanctuary, wrote Mr. Bent in 1952: "Last May, from the 10th to the 15th, from 20 to 40 evening grosbeaks, remnants of large flocks that visited us during the winter, were observed in voracious day-long feedings on cankerworms in the tops of large oaks in front of the Sanctuary headquarters. The grosbeaks spent more time helping to clean up cankerworms than they did at the feeders, where the sunflower seeds became a minor attraction." From analyses of stomach contents of Canadian evening grosbeaks, J. McGugan states: "The animal matter of the bird's diet consisted of individuals of Coleoptera, Araneida, and perhaps others. The average amount of this material consumed was low but whole meals were enjoyed when the supply was plentiful."
Salted sand and gravel are sought both summer and winter. The birds are seen often in summer eating cinders on railroad beds, tasting the salt-impregnated dirt on gravel roads that have been spread with calcium chloride to allay summer's dust, or to melt ice in the winter. Many casualties from cars result from their craving for salt.
An important summer food is the wild cherry, which is fed to the young before they leave the nest. To the cherry groves they are taken as soon as they can fly. The cherries are eaten even before they are ripe, and cherry pits are sought for on the tree and later on on the ground until the supply is exhausted. Evening grosbeaks do not swallow berries whole, as do robins and cedar waxwings, but always break them, and their massive beaks accomplish this feat with ease. A flock may be traced to a wild cherry grove by the sound of the mandibles crushing the cherry stones. They always discard the fleshy part of the fruit, but swallow a certain amount of crushed shell with the kernel, which probably helps them digest their food.
Behavior.--Evening grosbeaks appear affable and harmonious when not overcrowded or short on food. When the conditions are reversed, they are not so attractive. Mr. Bent comments: "Although evening grosbeaks are ordinarily gregarious and sociable, feeding harmoniously when scattered openly on the ground, their behavior is quite different when crowded on the feeding trays. There they are often selfish, hostile, and belligerent, pushing their way in, sparring with open beaks, and threatening to attack or drive out a new arrival. They are bosses of the tray and are intolerant of other species, driving away even the starlings; only the blue jay seems able to cope with them. Even the females of their own species are not immune to attack by the males. But, so eager are they for their food, that the tray remains crowded full of birds as long as there is standing room. Towards human beings they are usually tame and fearless; we can almost walk among them when they are feeding on the ground; with good treatment they might learn to feed from our hands, or allow us to pick them up by hand from the feeding tray. When taken from traps, they should be handled with heavy gloves, for they can bite savagely with their powerful beaks."
G. Hapgood Parks (1946) writes of his Hartford station:
Why the flock returned morning after morning before sunrise, its population swelling until more than two hundred individuals simultaneously crowded every feeder and every shelf and filled every trap, is at least partly explained by the bushels of sunflower seed shucks which carpet our partly unspaded victory garden this spring. Only slightly less appealing to the birds seemed to be the large wooden bowl which we kept always filled with warm water. . . . As much as a gallon of water was drunk on mid-winter days when the Grosbeak traffic was at its height. Not one of the birds, however, was ever observed in an attempt to bathe in the bowl.
Later, Parks wrote to Mr. Bent: "We observed our first evening grosbeak in the act of bathing on January 15, 1947. It was a rainy day and 12 of the birds bathed briefly in puddles of water which had formed in depressions in the ice of our driveway. Three others bathed in the bird bath on sunny, mild January 18. A half-dozen isolated instances of bathing were observed during the following weeks."
Forbush (1929) says: "They are fond of bathing even in winter, and visit unfrozen parts of swift streams at this season to bathe and drink. . . . ."
Mrs. A. O. Pendleton (B. R. Chamberlain, 1952), writing from North Carolina, tells of a remarkable invasion of evening grosbeaks on January 26, 1952, into her garden and her bird bath. She writes: "We heard a great chattering of birds. . . . There must have been 500 of them. Surely they must have just come in from a very long flight because the bird bath was full of them standing as close to each other as baby chicks, all drinking and bathing at once. Hovering above the bath like hummingbirds, there were dozens of them awaiting a vacant spot to alight in the water. . . ."
Mrs. Lucie McDougall, of Port Credit, Ontario, reported to me that in late April, 1958, the grosbeaks sunbathed daily at her feeding station. She saw as many as four males sunbathing at once on her window-sill, a remarkable sight. Sunbathing grosbeaks assume most unusual postures. I watched one male sprawled on the ground looking, it seemed, right into the sun. Its 12 tail feathers were fanned out so the sun could reach each of them; its bill was open, its crown feathers erect. Another male cocked his head sideways, eyed the sun, and seemed bent on having its rays penetrate the skin beneath the gray down under its breast feathers.
The evening grosbeak has the undulating flight so characteristic of the finch family. It does not, however, dip in such deep loops as does the pine grosbeak, nor does the flight pattern follow the bouncing bends of the goldfinch. The undulations are definite but not deep. As a flock moves in flight in the pathway of the sky, a ringing note, p-teer, p-teer, is heard with each dip, proclaiming to the listening ear below that a flock of evening grosbeaks is flying by. We watch the swift but wavy line of flight, punctuated by wild cries, until the flock disappears in the distance.
During migration evening grosbeaks fly high. At times their voices are heard when we are unable to discern the flock in the sky. Robert Ross Taylor writes me that at Scarborough, Ontario, he heard the call notes of grosbeaks high over his head flying west at about 11:00 p.m. on Oct. 6, 1957. During the same autumn, W. W. H. Gunn heard evening grosbeaks flying high above Toronto in the very early hours of the morning when he was on a rooftop observing Sputnik I. The birds were calling and moving westward. In both of these cases the night was clear. These are the first reports I have heard indicating that the species sometimes migrates at night.
Of their manner of flying in wooded country, S. E. White (Butler, 1892) remarked: "Their flight through the woods is very swift, reminding one, by the dexterity with which they avoid branches, of a Pigeon; when in the open, however, it is more like that of a Blackbird." He also notes that when on the ground they "move by hopping, holding themselves like Robins, and turn over the leaves with great dexterity, picking up the seeds from under them."
Very rarely is the bird ever seen by anyone in the evening. Ada Clapham Govan (1940) comments: "Where the grosbeaks spent their afternoons, no one in Massachusetts knew--or why the left all feeding stations by twelve or one each day."
In April 1940 I received a pair of live evening grosbeaks from Norwood, Manitoba. After a few days I noticed how early they roosted for the night. I then noted their times of retirement and measured the light intensity with a Weston illuminometer. In May they roosted on an average 45 minutes before sunset, in their 9-foot aviary spruce tree when the light intensity varied between 180 and 60 foot-candles, averaging 135 foot candles. They always fed heavily before retiring.
As the breeding season advanced, the birds became suddenly insectivorous. Departing from their usual habits, they looked continuously for insects. After June 1, although the female might retire fairly early, the male often kept up his vigilance until after dark. This might not have happened under natural conditions, where insects are more readily available than in an aviary.
In autumn I made daily observations. About November 1 the birds roosted on an average of 57 minutes before sunset, while various other fringillids in the garden--cardinals, white-throated sparrows, juncos, and tree sparrows--were still active and feeding, and robins, starlings, and the icterids in the district had not yet flown to their roosts. In December, January, and February the pair often retired shortly after 1 p.m. and hid in their spruce, sound asleep throughout the afternoon and evening. Rarely did they ever leave their roosting place unless badly disturbed.
Evening grosbeaks roost in a variety of places. Edward R. Ford wrote me in 1942 that in the sand-dune country of northern Indiana in February: "The temperature must have been near zero and there was some wind. . . . The bird took its station on one of the small twigs of a small pine, in the lee of the trunk which was not more than 5 or 6 inches in diameter. It assumed at once an attitude of sleep with the head turned to the rear and apparently resting between the scapulars." Marcia B. Clay (1930) tells of a male evening grosbeak that passed the night near her house at North Bristol, Ohio, "on the ground where the slope of the ravine and the projecting roots of an apple tree afforded protection from wind and snow." On Dec. 28, 1956, Louise de Kiriline Lawrence and Sheldon McLaren saw five evening grosbeaks flying to a roost in white pines at Mattawa, Nipissing District, Ontario at 3:30 p.m. At 8:30 a.m. on January 31, 1957, Mrs. Lawrence saw a flock of about 40 grosbeaks at Mattawa, mostly males, "coming off the night roost in a grove of tall pines." H. R. Dean of Highland Creek, Ontario, tells me grosbeaks roosted in white pines and cedars there throughout the winter of 1956-57.
Lucie McDougall wrote me that on March 31, 1947, she had "brought an injured bird around" into her house and released it at 5:00 p.m. It "flew up into a big elm next door and to my amazement I saw two others up there sleeping." Late in the evening she went out with a flashlight and found the birds still there. Again early in the morning the three grosbeaks were still high up in the big bare elm tree. She told me of other grosbeaks roosting at Port Credit in a row of tall spruce trees. We observed several evening grosbeaks roosting in just such a long row of spruces near Lake Ontario at Oakville on Mar. 2, 1958. We discovered the birds in the thick crowns of the trees at 3:40 p.m., when a squirrel frightened them into momentary flight.
Voice.--Aretas A. Saunders sent the following note to Mr. Bent: "In recent years, when evening grosbeaks have become more frequent in occurrence, I have recorded some of the sounds they produce, but I am not satisfied that any of these are songs. The commonest calls are shrill piping sounds, somewhat suggestive of spring Hylas. These are alternated with a lower pitched trilly sound. The sounds are like peet peet kreek peet peet, etc. The peets in my records are pitched on A''' and the kreeks on F#'''. Another sound that is occasional is like tchew tchew tchew and is used by birds feeding in a flock. The pitch is G'''."
Keyes (1888) describes his impressions: "As spring advanced they were usually seen, especially early in the morning, in the top of some tree, singing or chattering noisily, thus attracting the attention of nearly every passer-by. Their loud, clear, rather harsh, piping notes, uttered in concert, reminded one forcibly of the familiar chorus of a flock of Rusty Blackbirds in the spring, and have also been likened to the shrill piping arising from some frog pond on a quiet summer evening."
Francis H. Allen contributed the following to Mr. Bent. "The most characteristic call note I describe is a sort of prrrreep, or rolling whistle, with a clear ringing quality. This note, when heard in chorus, strongly suggests sleigh bells." Harrison F. Lewis adds: "A note resembling that of the cedar waxwing, although somewhat louder. This is uttered when the birds are quiet and at ease."
Butler (1898) gives the male birds the credit for most of the noise: "The males have a loud call-note, a sharp, metallic cry like the note of a trumpet, which they utter frequently when excited. The females chatter like Bohemian Waxwings." My own observations force the conclusion that the female is more loquacious than the male and is often the noisier of the two. Once when I listened to a pair for half an hour, all the sounds, the shrill piping grosbeak notes, came from the female.
The call or flocking note, pete or p-teer, is the most characteristic note the species utters. It is very shrill and has considerable carrying power, which must help the various members of the flocks to keep in touch with one another. Individual birds feeding as units of a widely scattered flock call p-teer frequently, thus revealing their positions to their companions.
The evening grosbeak's chirp resembles the house sparrow's and many times I have been fooled by this resemblance. Sometimes there is quite a similarity between the grosbeak note and the peet call note of the robin.
The chorus-song is a purple finch-like chip-chip-choo-wee, or chip-ip-chu-wee-er. A surprisingly lovely harmony comes from a mixed choir, as both sexes join in the singing. On the day that I saw my first evening grosbeaks and heard their music, I wrote: "Now the grosbeaks are talking together with a tender, tinkling sweetness, very musical and gentle, a liquid loveliness."
Usually in March individual males are heard singing their whisper-song, chip-ip-chu-wee-er. As the season advances, the phrases are heard many times in full strength and sung by both sexes. For several years we considered this the true song of the evening grosbeak. Then, one day in late April of 1941, at the University of Illinois Vivarium, our male bird, "Vesper," sang a song which we had not noticed before. After some introductory passages, he gave a high note that seemed to come from his nostrils, whizz-whizz-tee-ee. He seemed to like this new phrase in his musical repertoire and repeated it a number of times. The tee-ee is very high, yet it carries well. From then on we detected this song often during his periods of singing. J. Murray Speirs (1950) writes of a March flock in Ontario: ". . .if I listen hard I can make out their very high pitched, rather starling-like squeaky song, Swi-swi-tsiee."
H. R. Ivor writes of a 3-month old male raised in his bird observatory: "Today I heard him singing--the first time I have ever heard an evening grosbeak sing. The song was very low and some of the notes seemed quite sweet, but were intermixed with some of the harsher evening grosbeak notes. I felt that there was some resemblance between his sweeter notes and those of the autumn song of the young rose-breast." The next year, Ivor heard the same bird singing a song like a catbird's, also some notes similar to the bluebirds, as well as to the high-pitched notes of the mating song of the rose-breasted grosbeak.
The warning note of the species, given more often by a female, is quoit; the scold note is dzee; the male's invitation to nest, bzzt; the nestling's food-call, see-see-see; the fledgling's call, bee? bee, bee?, bee, etc.; and the parent's call to the fledgling that has left the nest is chu-hee-chu, chu-hee-chu.
Field marks.--The evening grosbeak is a heavily-built yellow, black, and white finch between the size of a house sparrow and a robin with a very large, light-colored beak. The adult male has a brown head and neck, a black crown and a band of bright yellowish-green over the eyes. The body is mainly yellow and the tail is short, forked, and black. The wings of males of all ages are black, each with a conspicuous large white wing patch. Young males have a golden crown. The body of the female is gray, suffused with yellowish green about the nape; wings and tail are black with white markings.
The flight is undulating, and the black and white wings are conspicuous in flight. When newly arrived in a locality, they are sometimes described as "wild canaries," "little parrots," or "oversized goldfinches." Reports of orioles seen in the north in winter usually turn out to be this species.
Enemies.--Evening grosbeaks are comparatively fearless in the presence of man and have proved to be attractive and easy targets. The first evening grosbeak known to science was the specimen an Indian boy shot near Sault Ste. Marie, Michigan Territory, in 1823 (William Cooper, 1825). When they appeared for the first time in the east during the great invasion of 1889-90, D. G. Cox (1891-92) wrote from Toronto, Ontario, "numbers of them were killed by boys with sticks and catapults in the streets of our city." This remarkable tameness contributes greatly to their destruction. His report concludes: "The birds freely entered the residential parts of the city. . . . They were quite unsuspicious and tame, and were unmercifully and wantonly killed with clubs, catapults, revolvers, pea-rifles, and many were taken alive with a slip-noose attached to the end of a long stick. . . ." The birds continue to be attractive targets for the irresponsible young.
In Ontario and elsewhere, evening grosbeaks are sometimes highway casualties, owing to their previously mentioned fondness for chlorided gravel with which many of the roads are sanded in winter.
The domestic cat also takes its toll. M. J. Magee (1932) writes: "With the number of birds around I found it practically impossible to keep the cats away. One time I found a place in a thicket not 100 feet away from my traps where a nice little 'house cat' had been devouring its kills. Quite a lot of feathers were scattered around and nine bands were found, two from Evening Grosbeaks. . . ."
Shrikes, also, are enemies of this species. Mrs. Govan (1940) writes:
The fifth day of the evening grosbeak invasion dawned as a smiling but raw winter's day. With snow everywhere, my birds were awaiting me anxiously. Apparently the grosbeak flock had reached its peak. . . . At seven in the morning a shrike drove the terrorized flock before him in a madly dashing wave. . . . Then, one day, while thirty grosbeaks were feeding on the porch, a shrike cut across the yard. Shrieking their wild alarm, the grosbeaks hurtled upward in a blind panic. My last sight of them that day showed them being followed in close pursuit by the butcher bird.
Occasionally grosbeaks have been killed by striking the windows of houses. Often this has occurred at feeding stations when a bird has been stampeded by a hawk or a shrike.
To date there is but one report of the evening grosbeak parasitized by the cowbird. Near Saranac Lake, New York, in mid-June, 1949, a young grosbeak was reported at a feeding station. B. M. Shaub writes in part: "It was said to be very much grayer than the previous ones. This young remained in the tree near the house and was frequently fed by the male grosbeak. It was not until July 7 that I saw this bird and at once recognized it as a young cowbird (Molothrus a. ater), at least a week out of the nest. . . . On July 11 the male grosbeak and the young cowbird were seen again, but at this time the grosbeak's interest in the cowbird had greatly lessened and he was reluctant to feed it and only did so after much begging for food on the part of the cowbird."
Florence Huestis Simpson gave me an evening grosbeak killed at a window in Todmorden, Ontario, in March 1958. On it were several bird lice (Mallophaga) which were identified for me by K. C. Emerson, who wrote: "The two specimens you enclosed are Philopterus citrinellae (Schrank, 1776). The long, thin specimen mentioned in your letter was Bruelia sp. Also found on the host are species of the genera Myrsidea, Menacanthus, Ricinus, and Machaerilaemus."
Evening grosbeaks, however, seem to be remarkably free from bird lice. During the winter of 1945-46, G. Hapgood Parks (1947) banded 874 evening grosbeaks at Hartford, Conn. "The physical condition of most of the birds which we trapped was excellent," he writes. "They were very uniformly plump and vigorous. . . . Although a quick examination was made of every bird we were able to discover only one parasite. . . ." Although the parasite was not identified, he states that its characteristics "were very similar to those of the common chicken-louse." A nestling my husband found under a nesting tree in Ontario in June 1945 had white eggs of a dipterous parasite in the mouth and on the dorsal feather tracts and also a deposit of eggs over the left eye.
When Gordon Lambert and Ross Baker collected a young bird not long out of the nest in the Mattawa region of Ontario, 14 hippoboscids flew out from the bird's plumage. The fledgling was one of four being fed by an adult, and the nest must have been heavily infested. J. C. Bequaert has written me that the only bird-fly taken thus far on evening grosbeaks is Ornithomyia fringillina Curtis, and adds: "All in all, the fly is rarely seen on this species of bird and perhaps only of accidental occurrence on it." He reports (1954) that there have been six published captures from the eastern race, one of which came from Alberta (Strickland, 1938) and the others from Ontario. Mrs. Downs has found these bird-flies on 10 juvenal grosbeaks at her banding station in Vermont. One was taken from an adult. Most of the birds she has handled have been free from bird-flies.
C. H. D. Clarke (1934) collected a male in Algonquin Park that had a tapeworm (Cestoda) in its intestines and microfilaria in its bloodstream. Of six specimens taken at Brule Lake, Algonquin Park, in the summer of 1934, he found three, including the one above, parasitized by blood protozoa, the second being infested by flagellates of the genus Trypanosoma, and the third by sporozoa of the genus Leucocytozoon. Wenyon in Hamerton (1937) also lists Trypanosoma as a protozoal parasite in this species. Plasmodium, the malaria parasite, has been reported in a captive bird (Hamerton, 1939) wrongly attributed to Haemoproteus (Herman, 1944).
Despite these records, internal parasitism in the species is rare. A. M. Fallis examined blood slides from several banded Ontario grosbeaks captured in Algonquin Park, 1945-48, and the smears were negative. Mary S. Shaub of Northampton, Mass., who has banded so many of these birds, considers them "especially healthy" (letter). She has written me of another bander, Dorothy Driscoll of Brookline, Mass., who made blood smears from grosbeaks during an invasion recently and "found only one infection in 100 smears."
Age.--As yet no one has analyzed the wealth of banding data now available to determine the evening grosbeak's probable longevity or its rates of mortality and survival in the wild. M. J. Magee (1939) reported retaking three of his banded birds in their 9th year. Elizabeth Holt Downs at her home in Vermont banded a grosbeak July 11, 1956 as an adult female. This bird returned regularly and was at least 10 years old when she recaptured it June 10, 1965.
H. R. Ivor probably has the longevity record for an aviary bird of this species. Some years ago he received from Winnipeg a handsome adult female of unknown age which he named "Beauty." I knew the bird well. She lived in his bird observatory 16 1/2 years and was therefore at least 17 years old when she died.
Fall.--In the autumn, adults and young are "on the move." Their long wings--longer in relation to body-size than any other finch--make them well equipped for extensive journeyings. Until recent years, little was known about this bird's habits in the fall; but since it has moved eastward as a breeding species, it has been appearing in populated regions in some years, notably in 1957, early in the fall, and is therefore being observed more frequently. The birds show no interest in feeding stations at this time and are reported more often in box elder trees than in any other kind. K. F. Edwards reported on Grand Manan Island, New Brunswick, October 11-16, 1957, a flock of 15 was feeding on cherry pits, another favored food. Louise de Kiriline Lawrence saw five on Oct. 19, 1944, at Rutherglen, Ontario: "They were eating cone seeds in the tops of coniferous trees." On November 14, she watched two settle in an aspen and sample the buds. On Oct. 27, 1947, she saw others budding in a poplar. Thus, on occasion, this species is a fall as well as a spring budder.
Winter.--Mr. Bent has written: "It is when the grosbeaks come to our feeding trays in winter that we become intimately acquainted with them and their traits. For a number of years I have maintained a feeding shelf at my study window, almost within an arm's reach as I sit at my desk, and have kept it supplied with sunflower seed, hemp seed, cracked nuts, peanuts, scratch feed, and other mixed bird food.
"During winters that they are here they flock to the shelf, often in such numbers that there is hardly any standing room; as long as there is room for one more to crowd in they come and gobble up the food, with a decided preference for the sunflower seeds; these they crack open very skillfully with their beaks, swallow the kernel and let the shells fall where they may, which leaves quite a mess for me to clean up. When the grosbeaks are here in large numbers they consume an enormous amount of these seeds, involving considerable trouble and expense to keep the greedy birds satisfied, but they are worth it.
"Francis H. Orcutt, of Penn Yan, N.Y., writes to me on this point: 'Other bird students with feeding stations report that the grosbeaks are eating them out of house and home. At first, one or two birds began feeding, now I have 40. With sunflower seeds at 49 cents a pound, I cannot afford to feed them much longer.'
"During some winters these birds are seen in enormous numbers, hundreds or even thousands of them; some seasons, we see only a few, and in other years none at all. Probably the abundance or scarcity of food supply may explain this irregularity."
Mr. Bent refers the reader to: Butler (1892), Elon H. Eaton (1914), Arthur H. Norton (1918), Bagg and Eliot (1937), and Brackbill (1947) for records of invasions of this race from Wisconsin to New Brunswick, in the years since the discovery of the species. For a very complete picture of the years 1950-1955, the reader is referred to "Evening Grosbeak Survey News" edited by Dr. and Mrs. B. M. Shaub, which tells of the penetration of the grosbeaks south to Georgia.
Some winters, as in 1956-57, the grosbeaks stay north and only a comparatively few appear south of the 45th parallel. The evening grosbeak is well equipped to resist the cold, for beneath the contour plumage is a warm gray down. It wears its own "eiderdown" for the same reason that the eider duck wears his--insulation against the cold. The feet are very short, so short that they may be tucked under the feathers in cold weather. The unfeathered part of the leg is covered in the front with scales or scutellae. The underside of the feet, including the toes, are padded with tylari, corneous cushions in ridges, which give the feet grip on icy branches, leading J. Murray Speirs to comment: "The grosbeaks are equipped with their own snow tires."
One morning in North Bay, Ontario, when the temperature was 35o
below zero, anxious to find out what the grosbeaks did on an
extremely cold day, I went out. A flock of 12 were located,
feeding on Manitoba maples. Above each bill, the breath of the
bird could be seen like a little wreath. All were males. My notes
read: "I noted that they looked noticeably larger than usual,
as their feathers were fluffed out as far from the body as
possible, so that they were encased in warmth. Their feet were
tucked into the warm down and could not be seen at all. One of
them reached far out for a pair of the winged seeds, and broke
through the silver ice, with which the seeds were encrusted, with
a loud snap. In spite of the icy frosting over the trees and
seeds, apparently they were getting all the food they needed, and
even piped prettily, choo-wee, chorr-wee, to each
Evening Grosbeak* Coccothraustes vespertinus [Eastern Evening Grosbeak]
*Original Source: Bent, Arthur Cleveland. and collaborators (compiled and edited by Oliver L. Austin, Jr.). 1968. Smithsonian Institution United States National Museum Bulletin 237 (Part 1): 206-237. United States Government Printing Office