Contributed by Robert S. Woods
[Published in 1968: Smithsonian Institution United States National Museum Bulletin 237 (Part 1): 290-314]
The house finch, more familiarly known as the linnet, is a species whose repute varies according to the interests and point of view of those who regard it. To the average city dweller, its domestic tastes, cheerful song, amiable manner, and the bright coloring of the male make it a pleasing adjunct to the dooryard or window sill; but a grower of the softer varieties of fruit who watches flocks of these birds descend like locusts upon his ripening crop finds difficulty in appreciating their esthetic values. ***
Most numerous about towns and cultivated lands, this species is by no means a stranger to uninhabited wastes and deserts. However, competent observers agree that the sight of a house finch is one of the surest signs that water is near; hence the linnet cannot be considered a characteristic or generally distributed bird of the desert regions. In California and New Mexico the species is reported to breed at altitudes as high as 8,000 feet, but in California, at least, the mountains are not a favored habitat, and it is not among the birds that one ordinarily expects to encounter in the higher country. In the United States its centers of greatest abundance are the valleys of the Pacific slope of central and southern California, but its natural range extends north to Washington and East into Wyoming, Colorado, and western Texas.
In recent years extensions of territory have occurred. Ralph C. Tate (1925) reported an apparently permanent incursion into the Oklahoma Panhandle, approximately 40 miles southeast of the border of the previously known breeding range. Ian McTaggard Cowan (1937) found a pair nesting at Victoria, British Columbia, in 1937, and stated that the species had been noted as a regular breeding resident in the interior of the same province for the previous 3 or 4 years. Most striking was the establishment in the early 1940s of a population of house finches on the eastern seaboard. As Austin (1961) describes it: "In 1940 cage-bird dealers in southern California shipped numbers of these birds, caught illegally in the wild, to New York dealers for sale as 'Hollywood finches.' Alert agents of the Fish and Wildlife Service spotted this violation of the International Migratory Bird Treaty Act and quickly put an end to the traffic. To avoid prosecution the New York dealers released their birds. The species was soon noted in the wild on nearby Long Island, and it has slowly been increasing its range ever since. The Mexican House Finch has now pushed northward into Connecticut and southward into New Jersey. It has also been introduced to Hawaii." On Feb. 26, 1963, a young male was collected at Zebulon, N.C., a considerable southward extension of the range.
The house finch has not only expanded the boundaries of its range in some degree, but to a much greater extent the coming of civilization has enabled it to occupy new habitats and to increase the density of its population within its original range. In reporting on a visit to the Farallone Islands near San Francisco, Milton S. Ray (1904) tells of discovering house finches, "several pairs of which, for the first time, were nesting here and challenging the Rock Wren's long-defended title of being the island's only song bird. Were it not for the grove of friendly evergreens, where these birds would have nested is a puzzle." In his comprehensive account of the species in Colorado, Dr. W. H. Bergtold (1913) says: "Previous to the advent of the English Sparrow in Denver (about 1894, according to the writer's notes) the only bird at all common about the buildings of Denver was this finch. Before the present extensive settlement of Colorado, the House Finch was, so far as one can gather from the reports of the various early exploring expeditions, to be found mainly along the tree covered 'bottoms' of the larger streams, along the foot hills, to a small extent up the streams into the foot hills, and possibly along the streams as they neared the east line of the state." He estimated the population of house finches in Denver at the time of writing to be at least four for each of the 35,000 houses or other buildings, and possibly much higher.
That the adaptation of the species to civilized environments was not, however, an instantaneous process is indicated by a statement of Charles E. H. Aiken (Aiken and Warren, 1914): "I found none nesting in those early days in Canon City, Pueblo, Colorado Springs, or Denver, but at Trinidad, in July, 1872, I first saw them utilizing human habitations. It was many years before the northern birds took up the advance of civilization and made their homes in towns. When I returned to Colorado, in December, 1895, after some years absence, I found them frequenting the city." ***
Courtship.--In the spring the male linnet may often be seen following the female, signing and fluttering his wings. Ralph Hoffmann (1927) says: "At the height of the breeding season the male hops about the indifferent female with tail up, wings drooping, head up and crest feathers raised, singing and making a sound like a sharp intake of breath. The female in the height of the mating period utters a few notes that suggest the male's song."
Various writers have referred to "courtship feeding" of the female by the male, but these incidents are usually described as occurring during incubation, and Anders H. and Anne Anderson (1944) state that at Tucson, "No 'courtship feeding' was noted during nest building or before. The nest building is done entirely by the female. The male follows, singing frequently from perches close to her work. At intervals both of the birds search for food in the vicinity." However, in the following description by Laurence M. Huey (1925) of "pre-nuptial" feeding at a feeding table in San Diego, the date mentioned is presumptive evidence that incubation had not yet commenced:
On the afternoon of March 19, 1925, a pair alighted on the edge of the table and my attention was soon attracted by a peculiar twittering call given by the female. It was rather unusual, so I watched them carefully and observed the male feed the female regurgitated food several times. His actions were much the same as those of any bird raising partly digested food from its crop; the head was bent sharply downward several times and the pellet was seen to rise up through the gullet. At the moment the female, with much twittering and flipping of wings, would open her beak to receive the tidbit. . . .
After the performance was over, they both ate freely of the damp, broken dog biscuit that was on the table.
Bergtold (1913) "suspects that this species mates permanently: it is apt, in all seasons of the year, to come to the food and drinking dishes in pairs." This is a question which their social disposition makes more difficult to determine.
Nesting.--The greater part of the nesting activities occur in April and May, but are continued in some degree through June and July. In one of the earliest detailed studies of the species, Charles A. Keeler (1890b) says: "During the month of February the males sing more or less constantly, but it is not until a month later that love-making begins. . . . By the middle of March they are nearly all mated and by the latter part of the month nest-building is fairly under way. During the early part of April both sexes are busy in constructing a home, the male merely assisting by bringing material and finding abundant opportunity to sing while his mate is at work."
Extreme dates for fresh eggs in southwestern California as listed by George Willett (1933) are March 22 and August 1. Although Philbrick Smith (1930) reports the discovery of eggs under incubation in Contra Costa County, Calif., on November 24, it appears from available data that nesting of the house finch in California is confined rather closely to the four months first mentioned. While Bergtold (1913) also found April and May to be the most active nesting months, the following quotation indicates that early nesting may be more frequent in Colorado than in California, notwithstanding the colder winters: "Cold weather has a positive deterrent effect on egg laying, a fact clearly established by the writer's records. On the other hand, pairs of House Finches, unquestionably mated, have been observed looking for eligible nesting sites every month of the year, not excepting the period from September to February. The earliest active nest building noted by the writer was on January 30, and the latest July 23; while pairs have been noticed gathering material as late as December 22, these attempts have been classed, however, by the writer as due to a fleeting spell of warm weather."
Nesting sites chosen by house finches are of such infinite variety that it is useless to attempt to mention all the diverse situations that have been reported. Any cavity or projection on a building which is capable of holding a nest may be utilized, provided that some concealment is afforded if near the ground; higher up, nests are often placed in plain sight on lookout timbers. About orange groves, the trees are often used as nesting sites, and in this case certain generalizations may be made. The nests are not placed in the dense outer foliage, as is the custom of the brown towhee and the lark sparrow, nor in the upper branches, as favored by the goldfinch and the phainopepla, but rather in the more open interior of the tree, often in the fork of an upright limb. The usual height of the nests is from 5 to 7 feet, but when favorable sites do not occur within these limits, they may be located at slightly less or much greater heights.
Of the house finches of Santa Fe County, N. Mex., J. K. Jensen (1923) says: "They are not at all particular about a nesting site as they build in the branches of a tree, in cavities of trees and walls, in tin cans hanging on fenceposts, and I have even seen a nest on the ground under a rabbit weed. It is one of the few birds that will use a 'cholla' cactus for a nesting site." At the writer's home in the San Gabriel Valley, where there is no scarcity of nesting sites, a specimen of a "cholla" cactus, Opuntia tunicata, at one time contained four occupied linnet's nests, showing that they have an actual preference for these spiny plants. From his observations in San Diego County, Calif., H. W. Henshaw (1894) wrote:
So tame and confiding have these pretty Finches become that I am persuaded that the larger proportion of their nests are built not in trees and bushes as formerly, but in all sorts of odd nooks and crannies about the house and barn; and even when they are compelled by the lack of facilities to resort to bushes and shrubbery, they choose those as close to the house as possible.
The pertinacity with which the House Finch clings to a chosen nook about a house when their nests are destroyed is amazing, and is equalled only by the English Sparrow. I have known five nests with their contents to be destroyed one after another, and each time the same pair set to work with apparent unconcern to build anew.
Writing from San Jose, Calif., Ernest Adams (1899) summed up the matter thus: "Experience has taught me that the House Finches may nest anywhere. I have found them occupying nests of orioles, towhees, grosbeaks, cliff swallows, blackbirds and portions of hawks' abodes; besides tin cans, old hats and stove pipes and now I shall add hollow limbs. One bird entering the opening of a small cavity actually squeezed her way back for two and a half feet to sit on her eggs in total darkness. Another reared her brood in the deep cavity of a California Woodpecker in an oak while a third selected a similar hole in a telegraph pole. The latter contained six eggs." F. C. Willard (1923) discovered a nest in a woodpecker hole about 30 feet up in a large sycamore in southern Arizona, but in this case the nest was placed so that the bird could look out while incubating. In the vicinity of Salt Lake City and Ogden, Utah, states Howard Knight in an as yet unpublished manuscript, the Colorado blue spruce appears to be the house finch's favorite nesting tree, probably because its form of growth provides snug nesting sites and its numerous sharp needles discourage predators. Knight also found a nest at the unusual height of 35 feet in a Carolina poplar, where it was situated in a cup-shaped depression in the broken end of a vertical limb, surrounded by a circle of erect branches.
Old oriole nests are frequently used by the house finches, according to Willard and others, and in California nests of the black phoebe are often appropriated, a layer of new material being added in some, at least. Harold M. Holland (1923) relates one instance in which the linnets did not wait for the phoebe's nest to be vacated, but alternated with the rightful owners in the deposition of eggs until the nest contained six eggs of the phoebe and five of the house finch, after which it was deserted by both pairs. In two different years Wilson C. Hanna (1933) found a recently built phoebe's nest occupied by linnets, while the phoebe had rebuilt a few feet away, the location in both years being under a bridge. D. I. Shephardson (1915) cites instances of the invasion of newly built or occupied nests of Arizona hooded orioles, cliff swallows, and black phoebes. That the house finch may occasionally assume the role of benefactor rather than that of usurper is indicated by the observations of Alfred M. Bailey and Robert J. Niedrach (1936) in Denver:
Two instances of Western Robins and House Finches using the same nests have come to our attention during the past three years. In May, 1934, we were informed that House Finches were feeding young robins in a nest on a front porch in east Denver, Colorado. On investigation we found four half-grown robins, two newly hatched finches and four finch eggs. There were two female finches apparently with the same mate, and the three finches and the two adult robins fed the young regularly. Unfortunately, however, the large robins smothered their small nest mates. We did not determine whether the four remaining eggs hatched. All three adult House Finches fed the young robins in the nest, and after the young had left the nest.
On May 15, 1936, in a similar instance, the nest was on the back porch of Bailey's home, 2540 Colorado Blvd., Denver. The young robins were nearly ready to leave the nest, and there was no evidence that the pair of House Finches had laid eggs. However, both adult finches and robins fed the young regularly. The male finch was particularly solicitous and would alight on a wire a few feet from the nest and sing whenever one of the other birds brought food. The young robins left the nest May 20, and the finches were the only ones noted feeding them from that time one, although the adult robins were about and no doubt shared the responsibility.
The building of the nest is accomplished by the female with little or no practical assistance from her mate, who, however, follows solicitously and lightens her labors with song. The materials used of course vary according to the resources of the locality, but the nests observed by the writer in southern California were composed principally of slender, dry stems, often with small leaves attached. In this particular locality the linings usually consisted of the soft, woolly branch tips of an everlasting plant, Stylocline gnaphalioides. In outside dimensions the nest is about 5 inches in diameter by 3 inches in depth; inside, the diameter is about 2 1/2 inches, the depth perhaps 2 inches. When new, the nest is neat and attractive in appearance, but it soon becomes fouled around the edges after the hatching of the brood.
Other nesting materials mentioned by Mrs. Florence Merriam Bailey (1928) as used in New Mexico are grass stems, plant fibers, leaves, rootlets, twigs, hairs, string, and wool. Ray (1904) describes a nest discovered in the Farallone Islands as "closely made of island grass, with an occasional feather intermixed, and lined with bits of string, cotton and mule hair." In the Point Lobos Reserve, on the coast of central California, where the trees are hung with lichens, this material was used in the construction of nests mentioned by Grinnell and Linsdale (1936), who state that these nests are unusually well concealed when built into masses of the same vegetation. As proof of the ability of the house finch to resort to "new and ingenious expedients," H. W. Henshaw (1894) tells of a nest built "in the corner of the piazza of a country store" in San Diego County:
Viewed from below, the nest was seen to be balanced rather than firmly placed upon a narrow joist, and I was at a loss to comprehend how it was maintained there even in calm weather, to say nothing of the high winds that prevail in this locality. By means of a step-ladder I was soon able to solve the problem. Having one-half finished the structure, the birds evidently recognized the insecurity of its position, and the location being in every other respect eligible they hit upon the following remedy. Procuring a long piece of white string they carried one end well into the body of the nest and twined it around several sticks. Thence it was carried out like a guy rope to a nail that chanced to have been only half driven home, about six inches beyond the outer rim. Two turns were taken about the nail and the string then passed back to the nest and firmly interlaced with the twigs. The nest was then completed.
The string thus attached protected the nest from pitching forward--though the wind rocked it continually--while the wall protected it behind.
The work was not so deftly done as not to betray the novice in the weaving art, and a yearling Oriole might have smiled at the crude effort to steal its trade by its thick-billed relative. However, the evident purpose of Carpodacus was to tie down its nest so that it would stay, and appearances were but a secondary consideration. That the nest was securely anchored was evidenced by the fact that it contained five eggs upon which the female was peacefully setting quite regardless of the fact that it was within three feet of the head of every passer by.
The observation in the preceding sentence regarding the nesting bird's obliviousness to the near approach of persons is confirmed by Dr. Bergtold's (1913) statement: "The birds grow very tame if the nest be closely associated with man and his doings: they seem to be bothered in no way by slamming of doors or by passers in and out of a door close to a nest." Nevertheless it must be placed on record that those that have nested for years about the present writer's home in southern California do not show that philosophical disposition. Though they have never been persecuted, and they seem to prefer to build around the house, and often near doors which are in frequent use, if anyone passes through the doorway or approaches the nest, they invariably leave precipitately, with every indication of great alarm.
That the social tendencies of the linnet may be retained in some degree even during the breeding season could be inferred from the following instance cited by Grinnell and Storer (1924): "A rather unusual case was that of partnership nesting, noted at Dudley, 6 miles east of Coulterville, on July 14, 1920, where two nests had been built on one beam inside a barn. The nests were placed so close to one another that the constituent materials were interwoven on the adjacent sides. The centers of the two nests were but 4 1/2 inches apart. Each nest contained 4 fresh eggs, and so far as could be seen the householders were deporting themselves with model comity."
F. G. Evenden (1945) found nest construction in the region of Sacramento, Calif., took as long as 2 weeks in March or April, the chief cause for delay appearing to be weather conditions and competition with the house sparrow. In July, a nest was completed in 2 days. Between completion of the nest and the beginning of egg laying, 1 to 4 days' time elapsed, with the greatest time lapses coming early in the nesting season. In all recorded observations, eggs were laid in the early morning hours. Disturbance, as by a cat or house sparrow, might result in the skipping of a day.
The eggs are usually deposited daily until the full complement of four, or sometimes five, is reached. Incubation may begin at least a day or two before the completion of the set, so that all the eggs are not hatched on the same day. To atone for his dereliction in the matter of nest building, the male undertakes the support of his mate while she alone incubates the eggs and broods the young. He feeds her by regurgitation, in the manner described under Courtship. The feeding usually takes place while the female incubates, but she sometimes receives food away from the nest, after fluttering her wings and begging in the manner of the fledglings. While the female ordinarily attends to her duties quite faithfully, Bergtold (1913) says: "The eggs sometimes undergo a surprising amount of cooling without being spoiled. One set, when partly incubated, was successfully hatched after being uncovered all of a cold rainy night, the female having been frightened from the nest at about 11 p.m., not returning until daylight."
F. G. Evenden (1957) points out that early during the egg-laying period the female was found at the nest only early and late in the day, with the length of her visits increasing as the clutch was laid. Very little of the male was seen until the young hatched. Although he stayed in the area during the day, there was evidence that he joined other males in flights to a night roost. In one instance the roost was a mile and a half distant.
The house finch shows a marked tendency to return to the same nest, not only for the second brood, but in subsequent years. In this connection, Willard (1923) writes: "On the San Pedro River are some large ranches where much hay is raised. At one of these a large stack is always built in a certain deserted ranch yard and a pair of House Finches have had their nest in it every time I have visited the spot. This season, after a lapse of six years, I visited the place again, in company with Mr. A. C. Bent, and remarked as we came to the stack that I always used to find a finch's nest in it 'just about here,' and, as I touched the hay, out flew Madame Finch from her nest, which held five eggs. In passing, may I remark that this was one of the few places where I could count on getting a set of five eggs. Most of the finches in that region lay four." Nests are quickly prepared for reoccupancy by adding a layer of nesting material to the top and interior to cover the filth left by the preceding brood. The second brood often follows the first with very little delay, and instances in which the broods actually overlapped were cited by Aiken (1914):
When the young in this nest were half grown the parents built a second nest under my neighbor's porch and while the male was attending the first brood the female raised another. In 1898 the breeding impulse was even stronger. The male was first noticed December 27 of the previous year to come and inspect the old nest. At intervals of ten days he came after that for several weeks before he brought his mate. In March the pair cleaned and relined the old nest and the female began incubating. Soon after the young were hatched a second nest was built adjoining the first and attached to it in which a second complement of eggs was laid and the female sat on these while the young were growing in the first nest beside her. When the second brood were hatched a third clutch of eggs was laid in the nest now vacated by the first brood and a third brood successfully reared.
While two broods seem to be normal in the house finch, the number may be greater, or at times less. Aiken (1914) suggests an explanation of this variation, based on his observation of one pair through a period of 10 years: "I assume and am convinced that the birds were in their first reproductive year when they built the first nest. They reached the height of reproductivity in the third year when they raised three broods. In succeeding years they dropped to two broods and then to one. This may be accepted as a law or a rule applicable to other species whose habit is recorded of producing two or more broods in a season. We may conclude that the more vigorous pairs produce two or more broods some seasons but other pairs may produce but one."
Supplementing the instance of polygamy cited by Bailey and Niedrach is the following case witnessed by Harold Michener (1925a) in southern California: "On April 22, 1912, one male and two females began building a nest on top of one of the beams supporting the roof of the front porch. This position was sheltered by a wisteria vine. All three birds worked together in building the nest. Two eggs were in the nest on April 28. Ten eggs were laid, one being crowded out of the nest. After the first part of the incubation period, during which there were frequent contests between the females for the privilege of sitting on the eggs, one of the females apparently disappeared and was seen no more. The eggs had begun to hatch on May 12, but only six of them hatched."
Eggs.--The eggs of the house finch number from two to six, with four or five comprising the usual set. They are ovate, sometimes tending toward the elongated-ovate or short-ovate. The ground of the egg is bluish white and they are delicately spotted, speckled, and streaked, with comparatively few well-defined markings of "dark olive," "mummy brown," or black. In most cases the spots are confined to the top half of the egg, and often they form a very fine loose ring around the large end. Occasionally an egg may be unmarked.
The measurements of 50 eggs average 18.8 by 13.8 millimeters; the eggs showing the four extremes measure 22.4 by 15.2, 16.7 by 13.7, and 17.5 by 11.5 millimeters.
Young.--The incubation period as determined by Dr. Bergtold (1913) in Denver averaged 14 days, but Chas. A. Keeler (1890b) reported it as 13 days (presumably in northern California), while in southern California three sets most accurately timed by the present writer agreed at 12 days. It thus appears possible that the incubation period is shortened by a warmer climate. Evenden (1957) says the incubation period, timed from the laying of the last egg to the hatching of the last egg, was 12 days each for two nests in June, 13 days each for six nests, 14 days for two nests, and 16 days for one nest in late April, early May. Hatching varied from one or two birds per day for 3 days, to five young hatched in 1 day. Hatching dates were between May 1, 1954, and July 29, 1951. Circumstantial evidence indicates that the first egg laid hatched first., Hatching took place both during the night and in the daytime. Significant differences in size of the young in the nests were observed infrequently. The female carried eggshells at least 20 feet away almost immediately--in fact, in one instance carried away one part of an eggshell while the young bird was still in the other part.
The development of the young is not quite as rapid as in some other small passerine birds. Not until they are about 10 days old do the young habitually hold their eyes open with an expression of alertness. The female broods them rather closely for the first few days, after which both parents bring food, which is imparted by regurgitation. The intervals between feedings, though irregular, average longer than in those species which carry food in the bill. Emerson A. Stoner (1934), in front of whose bedroom window at Benicia, Calif., a pair of linnets accommodatingly raised their brood, makes these comments on their family life:
. . .Aided by a flashlight, the beams directed out through the window, I found that the female invariably slept with her head under one wing. Although this is what might be expected, I had never before had the opportunity of looking into a bird's nest so conveniently situated to allow night investigation without fear of disturbing the sitting bird. The female had become so accustomed to motion and noise in the room that considerable rather vigorous tapping on window failed to arouse her.
The mother did not brood her young on the final nine nights the young were in the nest. During this period it was interesting to note that the fledglings, on the last six nights prior to their departure, also tucked their heads under their wings.
Bergtold (1913) says: "The young remain about fourteen days in the nest, which is kept perfectly clean by the old birds for four or five days after the eggs are hatched." In southern California I have found the period spent by the young in the nest to range from 14 to 16 days, with the latter figure predominant. Evenden (1957) says 11 to 19 days. Howard Knight thus describes the behavior of a brood of house finches found in a nest built in the top of a 15-foot blue spruce at Salt Lake City: "On the first day of observation the birds were not active nor did they have much muscular control. Most of the movement was of the feet and legs which were being flexed and stretched almost constantly. The toes were curled and then extended fully almost without cessation, and the writer believes this exercise serves to develop adequate strength in the feet and legs for perching will still quite young. These birds leave their nests and perch on limbs for a few days before they fly.
"As with the young of many birds when handled, they almost always voided feces when first taken from the nest. The distended appearance of the abdomen suggests that this is a reaction to pressure on the abdomen while being lifted from the nest. During the first 3 days of observation there was no fecal soiling of the nest, so it is concluded that during this time the adults dropped the fecal sacs out of the nest, though this was not seen. One the fourth day of observation, there was considerable soiling of the edge of the nest and voiding over the edge. Very little goes over the edge, however, so in a few days the rim of the nest is a filthy mess. The purpose of this behavior is well served as the interior of the nest stays quite clean.
"Warmth is essential to these nearly naked nestlings, and they constantly seek it. When being handled they lie close to the hand holding them, and if the fingers are closed over them they are content to remain motionless until disturbed. When lying on an open hand they lie with their bare abdomen pressed to the warmth of the hand, but if the fingers are slightly curved over them, the birds struggle to get their entire bodies under the fingers. When put back into the nest there is quite a commotion and jockeying for position as each one burrows in among the others in an effort to find suitable contact positions and a comfortable temperature.
"Until the third day of observation the eyes were closed, with only a very narrow slit showing where the lids separated in the fourth day. On the third day the birds could open their eyes a tiny bit, but seemed to prefer to keep them closed. By the fourth day the eyes were open more of the time than they were closed. Bergtold reports that the eyes of the birds he observed opened on the third day.
"Most of the observations made by the present writer were made between the hours of 5 p.m. and 7 p.m. At this time the crops of the birds were greatly distended, and the contents could be seen to be largely dandelion seeds, which suggests the importance of this bird in control of this weed. The skin of the neck is very thin, loosely folded, and almost transparent. A full crop makes a large bulge on the right side of the neck. In the morning this bulge is scarcely noticeable.
"By the fourth day the birds could hold their bodies off the ground for short periods. In doing so, the wings were used as anterior props to assist the legs. They became progressively more active with each passing day. On the fifth day they developed a technique for resisting being taken from the nest. When touched they immediately cowered among their siblings and locked their toes around some of the nesting materials or the handiest part of the nearest nestling. This gripping became more tenacious on succeeding days, and it frequently took a minute or two to disengage the feet and lift the birds free of the nest." This brood had left the nest by the 11th day of Knight's observations, which would indicate that the time spent in the nest might be less than that recorded in Colorado or California.
Evenden (1957) states young never returned to the nest after the initial flight, which ranged from 12 to 125 feet in distance and up to 9 feet in height.
He (1957) also describes at length an instance of one female, in 1951, presumably with the same male, maintaining two nests, 16 feet apart, at the same time. Timing was such that the second clutch hatched the day before four of the five young in the first nest departed. A year later, "double nesting" was observed again. Other instances are suspected.
Plumages.--As it lies in the nest with head and wings retracted, the newly hatched house finch, as observed in California, appears rather uniformly covered with fairly long grayish-white filaments, which stand erect and distinct. The concealed portions of the body, including the neck, are nearly or quite bare. Keeler (1890b), who studied these filoplumes with considerable care, described them as consisting of a straight, slender, solid stem 8 or 10 mm. in length, with very fine alternate branches or barbs, placed at considerable intervals apart. From the third day on, he found, the growth of the feathers is continuous. At that time the wing quills first make their appearance, and by the sixth day nearly all the feathers have sprouted, the ear coverts being last.
The filoplumes persist until all the feathers are fully grown and the filaments standing erect among the feathers of the crown furnish the last identification mark by which the more recently fledged individuals can be distinguished. After losing these vestiges of natal down, the young linnets differ in appearance from the adult females principally in the streaking, which is rather narrower and appears to stand out more conspicuously, perhaps because of the cleaner plumage. Also, the wing coverts of the young are tipped with buffy.
Surprisingly, in the cooler climate of Denver the natal covering seems to be much less developed than in southern California. Dr. Bergtold (1913), by setting up removable nest boxes outside his windows, was able to study closely the development of the young nestlings there, which he describes as follows:
. . .the young up to the fourth day seem naked, but are really partly covered by a minute down which appears in streaks, there being four lines on the head, i.e., one along the skull in the long axis of the body, one over each eye, and one over the occiput, transverse to the long axis of the head. There is also one along the dorsum of each wing, one over each scapula parallel with the vertebral column, an inter-acetabular dorsal patch, a streak down the outside of each thigh, and a sternal streak which bifurcates, one fork going under each wing, and on the second day an interscapular vertebral streak appears. All these areas grow rapidly and soon appear to coalesce; and by the fourth day the body seems to be covered all over with down except the belly, and, by this time, the wing quills are just budding.
Since available literature furnished little information concerning the finches of the Great Basin region lying between these east and west extremes of the range, an inquiry was addressed to A. M. Woodbury. This resulted in studies by Howard Knight of the University of Utah, who kindly supplied the following description of a brood of recently hatched house finches at Salt Lake City: "These nestlings did not have their eyes open, but did have several streaks of down on them. One streak was slightly crescent shaped across the occiput with the points of the crescent running forward. The top of the head or crown was bare. Between the center line of the head and either eye there were two streaks of down running from the base of the beak backward to a point just behind the eye. These last four mentioned tracts measured 6 mm. in length, and the down tufts themselves measured from 3 to 8 mm. in length.
"The cervical region and the anterior part of the back were bare. At a point between the wings the dorsal down tract began and extended posteriorly to terminate abruptly above the oil gland. The humeral down streaks were 4 mm. wide, and the tufts measured 3 to 5 mm. in length. A short femoral tract measured 10 mm. in length, while the downy tufts varied from 5 to 10 mm. in length. The wings at their widest point were 8 mm. across, and bare except for a tract of down 6 mm. long on the posterior edge. There was a little down on the shank of the legs, and it was scattered about without pattern or design. Downy tufts at the tarsus measured 3 to 4 mm. in length, and were confined to the outside of the leg.
"The abdominal region of these birds was very bare except for two lateral streaks of down appearing in narrow tracts between the legs. The tracts were 10 mm. long, and the tufts measured 3 to 5 mm. in length. There were two rows of pin holes in the skin of the lateroventral region where the feather tracts later developed."
Assuming that there had been no significant change between hatching and the discovery of the brood, this seems to represent an intermediate condition, in that the natal covering was much more conspicuously developed than in the Colorado nestlings, while on the other hand, the down of the head, though disposed in a different pattern from that described by Dr. Bergtold, still occurred in linear tufts, unlike the California birds.
The great variations which occur in the normally red portions of the male house finch's plumage have been the subject of much comment and study. It is well known that in captive birds the red color eventually changes to yellow, and this is also true of those which were introduced into the Hawaiian Islands. On the other hand, F. C. Lincoln (1917), in writing of the birds of Rock Canyon, Ariz., says: "The males of this region are remarkably brilliant; much more vermillion than any in my series of Colorado specimens. This may be the result of the intense sunlight." Even in a single locality under natural conditions, moreover, bright red may in certain individuals be replaced by tawny orange, deep yellow, or pinkish, while the extent of the reddish area is also variable. In the course of studies carried on in connection with their banding operations, Harold Michener and Josephine R. Michener (1931) discovered that the paler hues were usually replaced by red in subsequent years, and that in some individuals the red areas increased in extent with age, while the reverse changes were of much less frequent occurrence. Their conclusion was that the paler or duller coloration normally represents the first adult plumage of a substantial percentage of individuals. In a discussion of the linnet of the Hawaiian Islands, Joseph Grinnell (1911a) makes the following general observations on the plumage of the house finch:
At its post-juvenal molt the male acquires a first annual plumage not perceptibly different in matter of intensity or extent of color from that assumed at any later or more "adult" period of life. A corollary of the fact last stated is that during the winter and spring--from September until the time of appearance of full-fledged young the following season--there are no male linnets without color. This is very different from the case in Carpodacus purpureus and C. cassini, where the post-juvenal molt of the male leads into an uncolored first plumage, practically identical with the plumage of the normal adult female. The above facts are abundantly indicated by the extensive series of specimens in the California Museum of Vertebrate Zoology. . . .
In the large series of males of the California linnet, leaving out the rare examples which are distinctly yellow or orange, striking variation is shown in the tint of the red. But arrangement of the component examples by date, from September to July, shows this variation to parallel the lapse of time beyond the fall molt, and to be altogether due to the effects of wear. There is no spring molt; and the notion that an influx of new pigment into the feather towards spring serves to produce the bright colors of the nuptial dress is, of course, without foundation. In the fresh fall plumage the red is of a conspicuous pinkish cast (burnt carmine of Ridgway's Nomenclature of Colors, 1886 edition); there is thereafter a gradual change through crimson, until by summer a brilliant poppy red is displayed. . . .
Microscopical examination of various appropriate feathers shows the following conditions. In the newly acquired, unworn feather, the red pigment is restricted to the barbs of the contour portion of each feather, except for their terminal portions to a distance of one millimeter from their tips. These barb-ends, which together thus constitute a grayish band terminating each feather, and all the barbules, are white. In the extremely old abraded (summer) feather these uncolored end-portions of the barbs in the overlapping feathers, and all of the barbules, have simply been broken off or lost, thus removing the grayish obscuration from the bright red in the barbs.
The Micheners (1932) also conducted experiments on male linnets, which were frequent visitors to the traps, by plucking the feathers of the rump at intervals during the year and comparing the colors of the successive replacements. They found that red was replaced by more yellowish or brownish tones, thence through brown shades to grayish olive. However, with the renewal of the entire plumage at the time of the molt, the rump again became red. Though red coloring is very rare in the plumage of the female house finch, H. S. Swarth (1914) obtained two females which showed scattered red feathers in some of the areas where that color occurs in the male.
1. There is a seasonal variation in the weight of the House Finch; the minimum average for adults occurs during November, and is about 93.7% of the maximum, which occurs in February, while there is a tendency for a low average weight all along from May to November.
2. Immatures average lightest in June, being about 92.8% of the adult average for that month, and reach 98% of the adult weight in September.
3. There is a daily variation in the weight of the House Finch, with a decidedly uniform increase for adult birds during the morning, breaking away from a smooth curve in the afternoon, but reaching a maximum during the latter period. The average daily fluctuation for the adults amounts to about 3.5%.
4. Immatures are more erratic in weight in the forenoon but tend toward a smooth curve in the afternoon, reaching a maximum near the close of the day, with a differential of about 5% between a.m. and p.m. weights.
5. The females average heavier during the breeding season than the males, while the males are heavier during the prenuptial season, November to March.
6. There is a strong indication that territorial variations occur, possibly because of variations in food supply, or in hereditary influences, or in both.
Food.--In relation to the house finch, food is a most important, not to say controversial subject, and it is by all means unwise to arrive at any generalized conclusion. Each locality or each set of circumstances should be considered on its merits. Bergtold (1913) sums up as follows his observations on the food of house finches in Denver and its environs:
The House Finch will eat almost anything vegetable, though it prefers seeds, and experiments with different seeds show that hemp is selected to the exclusion of all others. Nevertheless it feeds in our streets and alleys, gathering bread crumbs, eating from pieces of bread, apples, oranges, and, in fact, almost any piece of table refuse. It will consume large quantities of fat, more especially suet. In winter when the ground is unusually deeply covered by snow, these birds wander far and wide over the prairie and vacant city lots, eating weed seeds, particularly those of the so-called Russian Thistle (Salsola tragus). It was, to the writer, a most satisfying discovery to find that the nestlings were, whenever possible, fed as soon as hatched and hereafter, on dandelion seeds. . . .
If not fed on dandelion seeds, the nestlings are given such food as the old ones usually consume but the writer has never detected any animal food in the crops or stomachs of House Finch nestlings. This Finch has never been seen feeding from the horse manure of the streets.
The House Finch exhibits, in common with many other birds, a fondness for maple sap, sipping it as it oozes from the cut branches of a spring pruned tree. The only objection my friends hereabout have against the House Finch is that it eats in the spring, leaf and blossom buds from bushes and trees--for example, lilac bushes and apple trees.
Insofar as the food of the adults is concerned, it is probable that the foregoing statements would apply almost equally well to the city of Los Angeles. However, in an agricultural environment in the same county, where for many years a feeding table has been maintained and sporadically supplied with such table scraps as crumbs and cheese parings, we have never known any of the numerous house finches present to show the slightest interest in these offerings, which are watched for and eagerly eaten by towhees, song sparrows, and some other birds. Apparently the diet of the house finches in this part of the San Gabriel Valley has consisted entirely of three items: soft fruits, seeds, and buds. The first of these items is seasonal, as the birds are unable to penetrate the skins of the year-round fruits, namely, oranges and avocados, and they show no taste for the berries of the pyracantha and other shrubs, highly favored by mockingbirds and waxwings. On buds their attacks are not systematic and persistent like those of the purple finches during their occasional visits. It is plain, therefore, that seeds constitute their staple food.
The fruits that suffer most severely from the linnets are peaches, apricots, nectarines, plums, sweet cherries, pears, summer apples, and loquats. Persimmons would probably be equally acceptable, but they ripen at a time when these birds are not numerous in the orchards. In the San Gabriel Valley they have shown no great interest in the berry fruits such as grapes and mulberries. The variety of seeds is undoubtedly great. Among naturalized plants, the seeds of the sweet alyssum and the tree tobacco (Nicotiana glauca) are especially popular.
The most thorough study of the house finch's diet was made by F. E. L. Beal (1907), who examined the contents of 1206 stomachs and found them to consist in the aggregate of weed seed 86.2 percent, fruit 10.5 percent, animal matter 2.4 percent, miscellaneous 0.9 percent. Excerpts from Beal's report follow:
Observations in orchards show that in the fruit season the linnet is not backward in taking what it considers its share of the crop, and as it spends much of the time there, field observations alone would lead to the conclusion that fruit was its principal article of diet. Examination of the stomach contents, however, proves that such is not the case, and when we find how small is the relative percentage of fruit eaten, it seems strange that its fruit-eating proclivities should have attracted so much attention. But it must be borne in mind that the bird is wonderfully abundant, which is one of the primary conditions necessary for any species to become injurious.
. . .Seeds of plants, mostly those of noxious weeds, constitute about seven-eighths of its food for the year, and in some months amount to much more. In view of this fact it seems strange that the house finch has acquired such a reputation for fruit eating, and it can be explained only upon the principle already laid down that in the fruit districts the bird is too numerous for the best economic interests. While each house finch eats but a small modicum of fruit, the aggregate of all that is eaten or destroyed by the species is something tremendous. . . .
Examination of linnet stomachs does not reveal any very considerable number of blossom buds, and it is probable that but little of the alleged mischief to fruit blossoms is done by this bird. Moreover, it may be stated that in most cases budding by birds does little, if any, damage. It is only in very rare instances that birds take the buds from a tree, or even enough to cause considerable loss. . . .
Before the settlement of the Pacific coast region it is evident that the linnet must have subsisted almost entirely upon the seeds of plants growing wild in the valleys and canyons. With the advent of civilization two new articles of food were presented--grain and fruit. It would seem natural for the linnet, especially equipped as the bird is to extract the kernel of seeds, to have chosen the former, as did the blackbirds, doves, and some other species; but for some reason best known to itself it selected fruit. How much the character of the food had to do with the bird's choice it is impossible to say, but it is probable that attendant conditions greatly influenced the result. Grain is grown on large, open areas, with few or no trees to afford nesting sites, while orchards offer every inducement to linnets as a permanent residence. Moreover, much of the fruit-growing section of the state is divided into small holdings, each with a dwelling with accompanying barns, sheds, and other buildings that afford ideal homes for these birds. . . .
Although the great bulk of fringilline birds normally subsist principally upon seeds, at certain times, notably in the breeding season, they eat a considerable quantity of animal food, mostly insects. Moreover, their young while still in the nest are usually fed largely, and in some cases entirely, upon insects. Quite the contrary is true of the linnet. The adults eat only a small percentage of animal food, even in the breeding period, and feed their nestlings no more, perhaps less, than they eat themselves. In this respect the linnet is probably unique in its family. Such animal food as the bird does eat, however, is much to its credit. Plant-lice (Aphidae), especially the woolly species, constitute a large portion of this part of the linnet's food; caterpillars and a few beetles make up most of the remainder.
M. P. Skinner (1930) writes: "The house finches. . .of the San Joaquin Valley are certainly developing a great fondness for watermelon. On July 7 and 8, 1930, I watched them at a feeding station thirty miles north of Bakersfield. During the morning hours, and still more during the afternoon hours, there was a steady stream of these birds to some watermelon rinds for the ripe watermelon pulp still present. Most of these feasting birds were young of the year, but there was also a fair number of both adult males and adult females. At first I thought the birds were attracted because of thirstiness; but soon after that, I noted that pulp that was almost dry was taken as well." Esther Reeks (1920) noticed these birds eating regularly from a block of pressed salt and sulphur, apparently being the only birds attracted to it. Various observers have commented on the important part cactus fruit plays in the linnet's diet where other food is scarce. Some individuals, at least, show a marked liking for sugar syrup.
From available evidence, it would seem that the economic status of the house finch might be summarized somewhat as follows: In the case of fairly large commercial orchards, their depredations should not be overly serious, and in years when there is overproduction they might be actually beneficial to the grower, since the attacks of the birds, unlike many insect infestations, in no way impair the vitality and future productive capacity of the trees. It is in small home orchards that they become most annoying and destructive, especially since, as Beal points out, their concentration is greatest in such an environment. On the other hand, their consumption of weed seeds is undoubtedly of great benefit, though this cannot be expressed in terms of actual monetary value.
Behavior.--The house finch is eminently social in disposition, and outside the breeding season is usually seen with others of its kind, in numbers ranging from small groups to immense flocks. Among themselves, as well as with other birds, they are comparatively peaceable and not especially given to aggression. Bergtold (1913), whose intimate study of the birds enabled him to know many of them as individuals, stressed the high degree of variation fund among them, not only in physical characteristics such as color and markings, but in such attributes as tameness, quarrelsomeness, and gentleness. The notable differences in the timidity of nesting birds, as mentioned previously, may perhaps be taken as examples of these marked individual or clan variations. Clearly it is useless to attempt to define too closely the behavior pattern of such a species.
The linnet's flight is bounding and free, usually clearing the tops of trees and buildings rather than passing between them. Descent to the ground is ordinarily only for the purpose of feeding on weed seed, and they prefer to eat fruit still hanging on the tree rather than that which has fallen to the ground. When idle, they choose comparatively high perches, and great numbers may often be seen lined up on transmission wires. Grinnell and Storer (1924) comment on the behavior of this species in the foothills of the Sierra Nevada:
Linnets, like purple finches, when frightened usually seek safety in flight rather than dodging into the protection of trees or brush as many sparrows are wont to do. If a flock of linnets is come upon suddenly, while feeding in a weed patch or on the ground, they get up quickly with an audible whirring of wings and make rapidly off in ascending course. The flock is usually dense when it first rises. Then it opens out and the individuality of the members is expressed as each pursues its own undulating course. Linnets, more perhaps than any other of the finches, are accustomed to strike out into the open, mounting high into the sky and circling for a time, before descending again.
The song of the male linnet is heard off and on through the greater part of the year. After the annual molt begins, in late summer, singing is indulged in sparingly and the birds usually remain relatively quiet until some protracted warm spell during the late winter, or until the first days of actual spring. From then on, their voices resound, in favorable places, from early dawn until late dusk. During the courting season they are as apt to pour forth their melodies while in flight high overhead as when perched.
After the couples have become established, the male and female of each pair stay close together, both when perched or when in flight, and when alone or with other pairs. In flight, the male usually keeps a little behind and to one side of the female, and when foraging he is quick to follow any changes in her location. After she begins the work of incubation he is wont to post himself on a perch close to the nest, where he is seen and heard much of the time.
In the cool coastal climate of Point Lobos Reserve, Grinnell and Linsdale (1936) made the following observation: "Ordinarily linnets exhibited a marked preference for open places, exposed to the sunshine. Flocks were observed in winter in the dead tops of pines at the margin of the woods, on wires of telephone and power lines, in live oaks, in the dead and leafless cypresses and also in the live ones, on the ground where the cover of vegetation was sparse, in the tops of brush piles, and in extensive patches of mustard and radish. Some of these places were occupied as forage sites, but others serve only as safety refuges or as perches where, seemingly, sunshine could be absorbed."
George A. Bartholomew and Tom J. Cade (1956) showed that water consumption increased directly with increasing ambient temperatures. Mean consumption at 39o C. was over 40 percent of body weight per day. A bird might drink over 100 percent of its body weight in 24 hours. Birds were hyperactive at this temperature, and some individuals panted almost continuously. At 20o down to 6o the birds were under no apparent stress. Succulent food proved important for birds in the deserts and enabled them to maintain body weights during a 7-day test period without water.
Voice.--The linnet household furnishes an outstanding example of a "musical family." The male is an indefatigable songster, the female also sings on occasions, and the fledglings, lined up on a wire, literally "sing for their supper." To human ears, the keynote of all house finch utterances is cheerfulness. The song suggests happiness, and even the notes that express anxiety over peril to the nest have a cheerfully rising inflection. Entirely absent from their vocabulary are the strident bickering cries and harsh scolding notes that are so freely used by many other species. In the words of Myron H. and Jane Bishop Swenk (1928), "The House Finch is a joyous bird, and it expresses its joy in its rollicking, warbling song. The song itself is not long, but it is rapidly repeated many times, producing a long-continued flow of singing. The song has many variations; in fact, but rarely do you hear two songs that are exactly alike. Different individuals will sing slightly differently, and the same bird will vary his song from time to time, but the song always has the same basic structure, is rather consistently given in 6/8 time, and all of the songs share the same general quality."
To the casual observer the notes of the house finch are not impressive in their variety, but Bergtold's (1913) account indicates that this apparent limitation of expression may be attributable rather to a lack of acuteness or attention on the part of the listener:
. . .During the cold months the birds are comparatively silent but they frequently break into song on bright sunny winter days. . . . From the middle of January onward, the singing increases with the lengthening days. . . .
There is a distant and recognizable difference in the alarm note over the sight of a dog or a cat if it be near the drinking place, and the alarm when one examines the nest. The writer has learned to know when the young are ready to leave the nest by the peculiar coaxing notes of the old birds. During nest building, the male often feeds his busy mate, as he would a young bird, and at such times the notes uttered by the female are peculiar to this part of the nesting habits. During August and September the song is at ebb, but starts afresh, on a subdued scale, in October.
Aretas A. Saunders says of the species as it sings in the eastern United States: "The following notes were obtained from a single individual that appeared in Canaan, Conn., in June 1954: The song is bright, rapid, extremely musical, consisting of series of rapid notes, with slurred notes before or between the series. An example might be written phonetically as tayo tatatata tayo titititi teeeyotitit. The number of short notes in the series varied from 2 to 10, but was most frequently 4. The pitch varied from D6 to A6, the slurred notes mainly downward from 1 1/2 to 2 1/2 tones.
"A call note recorded I wrote as queet. It was pitched on A6."
Field marks.--In the valleys of California very few species of birds have red in the plumage; there the male linnet is usually recognized at a glance. In none of its range, in fact, is it likely to be confused with any birds other than the purple finches of the same genus. From them it differs in its normally brighter and less purplish shade of red, the red areas being rather more restricted and more sharply defined, with no suffusion of red over the remaining plumage. Ralph Hoffmann (1927) says: "The darker gray of the female Purple Finch and the dark patch on the cheek bordered above by a light line distinguish her from the female House Finch. The absence of marked streaking on the flanks and the deeply notched tail distinguish the male Purple Finch from the male Linnet." This species is also noticeably more slender than the purple finches. From most of the streaked, brownish sparrows the female can be distinguished by the heavy, convex bill and the rather broad and comparatively uniform streaking of the under parts; also by the less terrestrial habits.
Oakleigh Thorne (1956) states that persons encountering difficulty in identifying finches for banding purposes, with the bird in the hand, have a number of distinguishing marks to guide them. Particularly, the bill of the house finch is very stubby as compared with that of the Cassin's finch, or other races, including the eastern purple finch. The house finch is slightly smaller than the Cassin's and has a more "round" head. Cassin's usually shows a slight crest. The house finch tends to have a square-ended tail, whereas the tail of the purple finch is rather forked. The Cassin's tends to sit rather still while feeding at a banding station and flies away silently after banding. The house finch is more noisy and nervous, and inevitably utters a chirp upon being released. The house finch has rather long, slender tarsi; those of the Cassin's are rather short and stocky.
The foregoing statements apply to both sexes and all ages. Female or young house finches have brown streakings on a buff background on the breast, Cassin's has darker brown streaking, or elongated dots, on a white background, and thus appears to be the more distinctly streaked bird. The house finch shows a uniform tone over the whole head; the Cassin's shows distinct areas of light and dark. Ear, or cheek patches, and malar stripes are darker.
The adult male Cassin's has a rose-red or "old rose" colored head. The bright red is restricted to the crown, with a wash, rather than dense color, on the face and breast. In the house finch this bright red includes most of the head and breast. Cassin's has an unmarked belly, whereas the house finch has brown streakings on the belly and breast.
Enemies.--The abundance of the house finch is evidence that it has no enemies serious enough to hold it in check where food, water, and shelter are available. Its habit of nesting around buildings protects it from many wild predators, though domestic cats take their toll of any nestlings that leave the nest before they are in full command of their wings. For some unexplained reason there are very few records of parasitism by cowbirds, despite the fact that the nests are not very well concealed.
In some parts of California poisoning campaigns have been carried on by orchardists, but the effects, if any, have been local. Bergtold (1913) expressed the fear that the house finch would ultimately be supplanted by the house sparrow in the cities, because of the latter's aggressive disposition, superior strength, and longer breeding period. However, the waning of the house sparrow's ascendancy in more recent years would seem to lessen that danger, and there is no need to fear for the future of the house finch.
As to the parasitic insects and mites, Bergtold (1913) says: "The young and nests of the House Finch are always infected by a minute parasite, some of which were collected and sent to an entomologist, who determined that they were not true bird lice (Mallophaga) but mites, probably belonging to the family Gamasidae. . . ." At a later date, Bergtold (1927) reported capturing a young finch "which seemed unusually docile. An examination of the bird disclosed a good sized swelling in the cellular tissue just below the right eye, a swelling that proved to be an abscess containing three small living larvae which were removed by expression. Thereupon the bird was liberated, was seen about my premises all that day and was much more lively than before." The flies raised from these larvae were identified as Protocalliphora splendida.
An unusual form of hazard to which these birds are subject was revealed by Clinton G. Abbott (1931), who reported the discovery on Point Loma by J. W. Sefton, Jr., of an adult female linnet fluttering hopelessly on the ground. "He picked it up and saw that the flight feathers of the left wing were securely attached by spider's webbing to the left foot. In his estimation the bird could never have disentangled itself, but with his aid it was able to proceed on its way." Abbott suggests that this "probably represents the maximum size of bird that could be so ensnared in this country."
Rudolph Donath of the Communicable Disease Center, Department of Health, Education, and Welfare, Atlanta, Ga., writes on Oct. 17, 1958, that the house finch has been found to carry antibodies of western equine and St. Louis encephalitis.
Fall.--With the close of the nesting season in late summer, house finches of all ages begin to gather in flocks and search out the larger tracts of maturing weeds, whence they flush and circle in clouds before the passer-by. Referring to the vicinity of Denver, Bergtold (1913) says: "During August and September of each year there is a noticeable diminution of Finches about the city. This is the time when the burdens of nesting and raising of young are practically over, permitting young and old to flock on the prairies to feed on weed seeds. . . ."
Winter.--Even in the mildest regions of coastal California, the numbers of the house finch are distinctly less in winter, though some remain throughout the year in almost all localities. Since H. W. Henshaw (1875) spoke of them as "very abundant at Camp Apache the first of December, frequenting the ravines and hill sides covered with pinons and cedars, as well also as the stubble fields and weeds," it seems not improbable that there is a partial migration to the desert regions where the winter sun shines warmer. That the birds are able to withstand winters of considerable severity, however, is shown by the following observations of Bergtold (1913):
Winter in Denver seems to have no terrors for this species.
It appears to the writer that the cold season does not trouble the
House Finch much as long as the bird is well fed, though many,
doubtless, suffer frosting of feet during extremely cold spells,
resulting in mutilations referred to later on. The birds roost at
night, whenever possible, close to buildings, in vines next to a
wall, in a nook or on a moulding under an overhanging eave, and in
the folds of awnings, for which places the birds have many fights
until all are located for the winter, each going to its accustomed
place a considerable time before sunset. The young birds sleep in
trees after leaving the nest. They have never been observed to
sleep two or more together, but appear, on the contrary, to desire
separate places, each by itself. It has seemed odd to find that
the birds never use the nesting boxes to sleep in, after the
nesting season is over. In December they go to roost early, 4:15
p.m., and sleep with the head under the wing, puffed up like
little feather balls.
House Finch* Carpodacus mexicanus
*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): 290-314. United States Government Printing Office