Bent Life History of the House Finch
Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.
Bent Life History for the House Finch - the common name and sub-species reflect the nomenclature in use at the time the description was written.
CARPODACUS MEXICANUS FRONTALIS (Say)
Contributed by ROBERT S. WOODS
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. Because of these destructive tendencies, the house finch has long been denied the protection of the law in California, at least, but nevertheless continues to be the most abundant species of bird throughout much of its range, which consists in general of the Upper and Lower Sonoran Zones of the Pacific and southwestern States, together with Mexico.
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 McTaggart 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 1940's 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 coining 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 Cafion 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 with 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."
According to the fifth edition of the A.O.U. Check-List (1957), the other subspecies of Carpodacus rnexicanw~ are mostly confined to Mexico, with the exception of clemerais, an inhabitant of islands off southern California. The present widely distributed subspecies is characterized by a great amount of variation, but Ridgway (1901) pronounced these differences individual rather than geographical, and they have been generally so regarded. This decision was based on an examination of adults only. In view of the striking differences in the natal covering as described hereinafter (p. 302), it may be pertinent to note the conclusion of Aiken (1914) "that the House Finches of Colorado east of the mountains and probably of southeastern Wyoming are subspeciflcally distinct from those of California, An: zona and New Mexico as far east as the Rio Grande River. If further investigation proves this conclusion correct the more western and southern form becomes Carpodacus mexicanus obscurus McCall. Local birds are true frontalis since Say's type locality is the Arkansas Valley."
In a review of the house finches, Robert T. Moore (1939) goes much farther and divides that portion of the species north of the Mexican border into the subspecies (1) frontalis Say, centering in southern Colorado and New Mexico, (2) smithi Figgins, farther to the north, (3) solitudinis Moore, in Nevada and adjacent arid regions, (4) grinnelli Moore, on the Pacific coast, and (5) clement'is Means, on San Clemente Island, the birds of the remaining territory being considered intengrades or undetermined.
Courtship: In spring the male linnet may often be seen following the female, singing 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 Phllbrick 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 band, pairs of House Finches, unquestionably mated, have been observed looking for eligible nesting sites in 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 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 Californian 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 o[ growth provides snug nesting sites and its nusnerous 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 loc&tion in both years being under a bridge. D.I. Shephardson (1915) citee 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 Alired M. Bailey and Robert J. Niedrach (1936) in Denver:
Two instances of Western Robins (Turdus migratorius pro pinquus) and House Finches (Carpodacus mexicanus frontalis) 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 net 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 wer5 the only ones noted feeding them from that time on, 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 branchtips of an cverlasting 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% 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. flenshaw (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 about 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 Car podacus 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 he 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% 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 (1957) found nest construction in the region of Sacramento, Calif., took as long as 2 to 3 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 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 (p. 292). 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 t.he 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 ofï 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 impluse 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 sucessfully 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 for 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. Tbey 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 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 (192~5a) 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 16.2, 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 the 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 Benecia, 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 (MS.) thus describes the behavior of a brood of house finches found in a nest built in the top of a 15foot 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 while 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 rot seen. On 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 on 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 he 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. Woodhury. 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. m 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 mtermediate 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 vermilion than any in my series of Colorado specimens. This may be the result of the intense sunlight." Even in a single locality and 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 H. 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 (l9lla) 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 Cerpodacus purpureus and C. cossini, where the post-juvenal molt of the male leads into an uncolored first annual 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 Itidgway'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 and 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.
Weights: J. L. Partin (1933) made more than 1,000 weighings of 800 individuals to determine the possible influence on weight of season, time of day, sex, and age, with the following results:
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 te~ndency 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, from 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 tregus). 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 used 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 that 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 back. ward 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, how. ever, 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, whicb is one of the primary conditions necessary for any species to become injurious.
Seeds of plants, mostly those of noxious weeds, constitute about seveneighths 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, hut 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 5, 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 band, 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 found 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 in 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, axe 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. Irom 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 the Point Lobos Reserve, Grmnell and Linsdale (1936) made the following observation: "Ordinarily linnets exhibited a marked preference for open places, expose.d 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 390 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 200 down to 60 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 mapressive 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 distinct 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 tdy3 tdtdtdt4 tdy6 tlt~t1t~ t~~ip3tIfft. The number of short notes in the series varied from 2 to 10, but was most frequently 4. The pitch varied from D5 to A6, the slurred notes mainly dovnward from 13~ to 23~ 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 ascendency 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 8pleri~d1~da.
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. Sef ton, Jr., of an adult female linnet fluttering helplessly 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, Depart.. ment 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 (iSV,) spoke of them as "very abundant at Camp Apache the first of December, frequenting the ravines and hill sides covered with piflons 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.
Range: British Columbia, Idaho, and Wyoming to Baja California, Sonora, Chihuahua, and Texas. Also (introduced) Connecticut to North Carolina; Hawaii.
Breeding range: The common house finch breeds, and is largely resident, from southwestern and south central British Columbia (Victoria, Williams Lake, Okanagan Landing), central, western, and southern Idaho (Moscow, Boise, Pocatello), central, northern, and and southeastern Wyoming (Big Horn Valley, Torrington), and western Nebraska (Kimball County, Haigler) south through California, including the northern Channel Islands, to central Baja California (Todos Santos Islands, Cedros Island, Santana), central Sonora (Tibur6n Island, San Pedro MArtir Island, Oposura), northwestern Chihuahua (Chihuahua), and western and south central Texas (Boquillas, Somerset, Austin). Introduced in Hawaii, and on Long Island, N.Y., from where it has spread as a breeding species north to southwestern Connecticut (Greenwich Township, Fairfield County) and south to New Jersey, eastern Pennsylvania, and northern Maryland (Towson).
Winter range: In winter to the Gulf coast of southern Texas. Descendents of the birds released in New York migrate south regularly to Maryland and have been recorded south to the District of Columbia, Virginia, and central North Carolina (Zebulon), and north to Massachusetts.
Casual records: Casual north to Alberta (Topaz Lake) and Montana (Santon Lake), east to central Kansas (Cloud County), and northeastern Texas (Fort Worth), and south to southern Sonora (Chinobampo).
Migration: Early dates of spring arrival are: New Jersey: Oakhurst, February 19. Texas: northwestern Atascosa County, February 2; Haskell County, March 28. New Mexico: Clayton, February 26. Montana: Stanton Lake, February 11. Nevada: Carson City, March 9. Washington: Pullman, March 16. British Columbia: Okanagan Landing, March 21.
Late dates of spring departure are: Texas: Haskell County, May 8; Rockport, April 26. Nebraska: Red Cloud, February 26. New Mexico: Clayton, May 3. Colorado: Platteville, March 17.
Early dates of fall arrival are: Washington: Camas, September 11. Nevada: Clark County, October 5. Texas: El Paso, August 7.
Late dates of fall departure are: British Columbia: Okanagan Landing, October 24. Nevada: Clark County, December 5. Wyoming: Laramie, November 25. Utah: Pine Valley, December 31. Colorado: Platteville, December 27. Arizona: Tombstone, December 20. New Mexico: Clayton, December 13. Kansas: Morton and Hamilton counties, November 19.
Egg dates: Arizona: 37 records, March 16 to June 30; 20 records, May 10 to May 26.
British Columbia: 50 records, April 13 to July 18; 25 records, April 22 to May 23.
California: 268 records, February 28 to August 7; 104 records, May 1 to May 17; 72 records, April 6 to April 26.
Colorado: 16 records, April 24 to July 22; 9 records, May 13 to May 26.
New Mexico: 12 records, April 12 to June 26. Oregon: 31 records, April 7 to July 25; 16 records, May 6 to May 22. Texas: 9 records, April 5 to July 12.
Utah: 37 records, April 16 to July 4; 19 records, April20 to June 1.
Washington: 23 records, April 15 to June 30; 13 records, April 25 to June 13.
SAN LUIS HOUSE FINCH
CARPODACUS MEXICANUS POTOSINUS Griscom
Ludlow Griscom (1928) gave the above name to this subspecies and selected an adult male from San Luis Potosi, Mexico, as the type. He gave it the following subspecific characters: "Similar to Car: podacu8 mexicanus rhodocolpus Cabanis, but adult male in breeding plumage a darker bird throughout, the red areas more crimson or carmine, less scarlet; brown of upperparts darker, and brown streaking below heavier, darker and more distinct; adult male in winter plumage with the red areas a rose purple shade as in rkodocolpu.s, but more heavily and darkly streaked below, and underparts with pronounced gray edgings, giving almost a hoary effect, particularly noticeable on the hind-neck and auricular region; females darker above and more heavily streaked below."
For a further discussion of this subspecies, the reader is referred to a review of the house finches by Robert T. Moore (1939).
Range: The San Luis house finch is resident from south central and eastern Chihuahua (Chupadero) and the middle Rio Grande Valley of Texas (50 miles northwest of Comstock, Fort Clark), south to Zacatecas (Sombrerete, Lulu), San Luis Potosf (San Luis Potos~), and Nuevo Le6n (Linares).
SAN LUCAS HOUSE FINCH
CARPODACUS MEXICANUS RUBERRIMUS Ridgway
Ridgway (1887a) proposed the above name for the house finch of the southern half of Lower California. He says in a footnote: "A considerable percentage of the specimens which I have been able to examine are so peculiar that nothing approaching them can be found m the very large series from other localities. These peculiarities consist, (1) in the smaller general size, (2) rather more swollen bill, and (3) greater extension of the red. This last peculiarity is carried to such an extreme that in all of the 'Cape St. Lucas~ specimens the under tail-coverts are deeply tinged with pink, while in some even the wing-bands are pinkish; in several the pure deep madder-pink of the breast is continued backward over the belly and flanks, where the usual dusky streaks are entirely obliterated."
William Brewster (1902) writes:
This is one of the most abundant birds of the Cape Region, throughout which it is very generally distributed, save on the higher mountains, where it was not seen by either Mr. Belding or Mr. Frazar. The latter found it building at Triunfo the last week in April. Young of the first brood were on the wing and their parents laying a second time by the last week in June. One pair had taken possession of an old nest of the Arizona Hooded Oriole, which was attached to the under side of a palm leaf.
Mr. Bryant says that most of the nests of the St. Lucas House Finch which he found at Comondu "were in palm trees and well nigh inaccessible"; but one was on the "under side of a veranda awning of an cdobe house" among the branches of a vine.
In central Lower California, Griffing Bancroft (1930) found this finch to be a "common and conspicuous bird about houses and gardens, but rare in natural surroundings. * * * " The nesting sites "most frequently chosen are on the outsides of occupied houses. Where the walls are of tub stems the linnets work their way between the upright stalks. The beams under the eaves and even the thatched roofs of adobes are also favored spots. We found many nests in olive trees and in various odd locations. On the desert, mistletoe in mesquites or flicker holes in cardon are most frequently used."
The eggs are practically indistinguishable from those of the species elsewhere. The measurements of 40 eggs average 18.9 by 13.9 millimeters; the eggs showing the four extremes measure 20.9 by 14. 9, 19.5 by 15.0, 17.5 by 13.0, and 19.4 by 12.9 millimeters.
The plumage changes, food, voice, and other habits probably do not differ from those of other races of the species.
Range: The San Lucas house finch is resident in the southern half of Baja California (33 miles west of Calmalli, Cabo San Lucas, offshore islands), southern coastal and central interior Sonora (Guaymas, Rio Sonora north to lat. 30~ N., San Esteban Island), northern Sinaloa (Rio Fuerte), and southwestern Chihuahua (Barranca do Cobre).
Egg dates: Baja California: 4 records, April 26 to May 18.
SAN CLEMENTE HOUSE FINCH
CARPODACUS MEXICANUS CLEMENTIS Mearns
Edgar A. Mearns (1898) described and named this finch, based on a specimen taken on San Clemente Island, Calif. He gave it the following diagnosis: "Similar to Carpodacus mexicanus Jrontali8 (Say), but with larger legs and feet and heavier coloration. The striping of the under surface is much broader than in typical specimens of Jron.ta,lia from the eastern base of the Rocky Mountains. The wings are shorter, the tail perhaps a trifle longer, and the bill much larger and more convex above. It is, in fact, intermediate between the form of frontalis inhabiting the neighboring mainland of California and Carpodacus mcgregori Anthony, from San Benito Island, about twenty miles west of Cerros (or Cedros) Island, Lower California, which latter (C. megregori) is but another step towards Carpodaeu,s amplu8 Ridgway of Guadalupe Island."
In commenting on the status of this subspecies, A. J. van Rossem (1925) remarks: "For sonic years past, the standing of C7arpodacws mexicanus clementis Mearns has suffered assault by various writers," and then goes on to say: "The extent of red or yellow on the males, the proportion of red to yellow males, and the measurements of wing and tail in either sex are all items to which no diagnostic value can be attached. The tarsi and feet of dementis are slightly heavier in appearance but are not longer than in frontalis, and, considering the variation displayed, this tendency will not bear stressing. The characters which appear to provide the most secure basis for differentiating the island race are the decidedly heavier bill, the intensity or brilliancy of coloration in the males and the heavier streaking of the females."
There is very little to be said about the habits of this island form, which do not seem to differ much from those of its mainland relative.
A. Braziar Howell (1917) says of it: "The breeding season is a long one, and at least three broods must be raised each year. * * * Nesting sites originally were in cactus plants or in niches of cliffs, but the birds are now taking advantage of the chance to occupy more she]tered situations in buildings and sheds, where such occur. * * * Linnets are fond of congregating about the opuntia patches, on the ripe fruit of which they feed extensively."
Earlier he says: "Two phases of coloration occur in this form, the usual red phase and another in which the red is replaced by yellow. Every intergradation between these two is encountered. I have seen specimens in which the yellow was of very limited extent, a male marked like a female except for a faint red tinge on the chest, a female showing a trace of red, and another with a tinge of yellow."
The measurements of 40 eggs average 19.6 by 14.3 millimeters; the eggs showing the four extremes measure 2~.5 by 14.9, 19.4 by 15.3, 17.9 by 14.9, and 19.3 by 13.5 millimeters.
Range: T he San Clemente house finch is resident on Santa Barbara, San Nicolas, Santa Catalina, and San Clemente Islands off southern California and Los Coronodos Islands off northwestern Baja California.
Egg dates: Santa Catalina Islands: 12 records, March 15 to July 13; 6 records, April 8 to April 23.
San Clemente Island: 21 records, February 7 to May 30; 15 records, March 23 to March 30.
GUADALUPE HOUSE FINCH
CARPODACUS AMPLUS Ridgway
A larger house finch, with an even larger bill, lives on Guadalupe Island, off the west coast of Lower California.
Ridgway (1901) describes it as "similar to C. mexicanus mexicanus, but much larger, the bill especially; coloration darker and browner above, more broadly streaked with dusky beneath; the adult male with red (or yellow) of throat, etc., extended over breast."
It seems worthwhile to consider the environment in which the Guadalupe house finch still continues its somewhat precarious existence on an island where at least two endemic forms have already become extinct and others seem to be threatened with a similar fate. The following extracts are from a paper by John E. Thayer and Outram Bangs (1908):
Guadaloupe Island, the northern end of which lies about 160 miles southwest from San Antonio point, Lower California, is about 20 miles long and from 3 to 7 miles wide. It is of volcanic origin, and is traversed throughout its entire length by a chain of mountains, the highest of which is some 4500 feet above sea level. The western and northern sides of this range slope rapidly toward the ocean, ending in many places in high perpendicular cliffs. Toward the south the slope is more gradual and ends less abruptly. The southern part of the island, which is lowest, is rocky and barren, and during May and June, 1906, was a sun-burned waste with hardly a leaf of living verdure.
At the northern end of the island extending along a narrow ridge, and in some places down its perpendicular face is a fast decaying pine wood. No young trees appear anywhere and the old ones are gradually falling, the ground being strewn with decaying trunks. * * ~ Most of the higher parts of the island are open, rocky table land, but near the very highest part, north of Mt. Augusta, is a large cypress wood, occupying an area of nearly three square miles. The eastern edge of this large cypress grove ends abruptly at a ridge below which is another much lower table land. Upon this is a second hut very much smaller grove of cypress with several springs and pools of water, more or less alkaline, near by. Here Brown and Marsden made their camp. Among the cypresses of both groves there are numerous dried stumps of some shrub now extinct in Guadaloupe. No young trees could be found in or about the groves, and most of the old trees show the marks of the teeth of goats, and many are dying. Far down the northwestern slope there is a large grove of cabbage palms, and another smaller one near Steamer Point on the west shore. Among the palms are a few fine oaks, from 30 to 65 feet in height, and under a cliff east of the cabins several stunted ones that branch very lowdown like shrubs * *
The domestic goat and cat turned loose upon the island many years ago, are of course responsible for the destruction of its flora and ornis. Brown and Marsden estimated the numbers of the goat to be between six and eight thousand. It eats up every growing thing. All shrubs have long been exterminated and not a young tree, palm, oak, pine or cypress can be found in the island. The cat is also very numerous and undoubtedly has caused the extinction of two of the island's native birds: the towhee and the Guadaloupe wren: while the rock wren, junco, flicker and petrel, suffer much from its depredations.
In spite of its environment and enemies, the house finch seems to be flourishing, for the same authors say in the same paper:
The house finch is by far the commonest bird of the island. Mr. Brown has sent us the following account of it: "On our arrival: May 1: well grown young were about with the old birds, and at that time the house finches were scattered about in large numbers all over the island. On the cliffs and about the rocks near the landing there were several hundred of them. Late in June they gathered in flocks and all left the lower altitudes, even those, some thirty or forty, that had been living about our cabins. Empty nests were found in a variety of situations, in the pines and cypresses, in cactus plants, and in crevices in the rocks. Their food seemed to consist chiefly of grass seeds and insects, but the birds that lived near our cabins were very partial to goat meat and made our meat-shed their headquarters."
Nesting: Walter E. Bryant (1887) gives the following account of the nesting habits of the Guadalupe house finch:
Two nests were found in cypress trees nearly completed by February 22. A nest and set of five fresh eggs (No. 792, author's oological collection), which in consequence of a heavy storm had been deserted, was taken on the 1st of March. From this date began the nesting season of this species.
The last nest, taken April 7th, contained five eggs, with small embryos in them. In nearly every instance, the birds selected for a nesting place the upper side of a cypress branch in the angle formed by its intersection with the trunk, thus avoiding the storm-shaken foliage. They seemed to show a preference for the leeward side of a tree, where the nest would be protected from prevailing winds. One prudent couple had built in a clump of mistletoe, at a height of twenty feet.
Several pairs built in the tops of palms. The nests were ordinarily not more than ten or fifteen feet from the ground.
The birds make but slight demonstrations while their nest is being removed, uttering only a few notes of protest, or silently witnessing a wrong hitherto unknown to them.
The material used for the outer structure of the nests consisted of the dark, dead stems of weeds, only the finer ones being selected. One nest found in a pine tree, had the foundation and sides made of pine needles, with the invariable lining of goat's hair, black and white being used indiscriminately. The external diameter of the nest is about 130 mm., with a central cavity about 65 mm.
Eggs: He says of these: "The eggs, sometimes four in number, but oftener five during the early part of the season, are colored precisely like the average specimens of C. Irontalis rhodocolpus, the spots being either sparingly applied or entirely wanting. They also resemble them in general shape, but the size seems to distinguish them. The five eggs of set No. 792, measure respectively 22 X 15; 22 X 15.5; 22.5 X 15.5; 23 X 15.5; 23 >< 16.5 mm. The length measurement varies from 19.5: 24 mm., and the width 15: 16.5 mm. The average of thirty-two specimens is 21.3 X 15.5 mm."
The measurements of 50 eggs average 21.5 by 15.6 millimeters; the eggs showing the four extremes measure 24.1 by 15.7, 23.0 by 16.5, and 19.0 by 14.9 millimeters.
Plumage: According to C. H. Blake, the adult male has both the brown and the red darker than in the Mexican house finch (C. m. mexicanus), with the red extending in lighter shades down onto the streaked area of the breast. The distribution of color resembles the much paler San Clemente house finch. The red of the forehead and crown is less extensive than in the common house finch. The females and immature males are darker than those of the Mexican house finch, and the ventral streaks are broader, resembling in this respect the San Clemente house finch.
Food: Bryant (1887) says: "The dissection of specimens showed the food to consist chiefly of seeds from the cypress tree, mingled with green seeds of 'chick-weed.' Some of those taken near camp had their crops well filled with bits of tallow picked from the body of a goat which had been dressed and hung under a tree."
Behavior: Bryant (1887) noticed nothing in either their habits or song that differed from those of the mainland forms, and adds: "Soon after settling on the top of the island in December, 1885, the 'Gorrions' began to collect about the camp, making the mornings joyous with their song.
"By our refraining from discharging fire-arms in the immediate vicinity of the camp, they soon became quite tame, hopping about camp during the day, and roosting at night in the thickest cypress, or, during a storm, under the eaves of the palm-thatched huts."
Enemies: Bryant (1887) says: "They are easily entrapped under a box, and it was in this way that the Mexican women at the settlement succeeded in catching, during my stay, as many as two or three dozen, which they ate."
But their chief enemy is the introduced cat, and it is largely due to their nesting in the spiny chollas, or other inaccessible places, that they have survived the predation of this animal. However, A. W. Anthony (1925) makes the following statement: "Formerly one of the most abundant land birds on the island but now reduced to about 10% of its abundance 25 years ago, the destruction being due to the thousand of cats that infest all parts of the island. The species nests largely in the cactus found over most parts of the island, which fact saves the nestlings until able to flutter to the ground, where they fall an easy prey."
Range: The Guadalupe house finch is resident on Guadalupe Island off central western Baja California.
Egg dates: Guadalupe Islands: 14 records, March 21 to May 25; 7 records, March 24 to March 26.
McGREGOR'S HOUSE FINCH
CARPODACUS McGREGORI Anthony
This large-billed house finch is characterized by its describer, A. W. Anthony (1897) as "nearest C. amplus but slightly smaller, with more compressed and laterally flattened mandible, longer tail and different coloration; larger than C. mexicanus frontalis, bill much larger, its lateral outlines viewed from above, parallel for nearly half the length. Red colors replaced by orange tints."
He describes the coloration of the adult male as follows: "Above dark olive gray heavily streaked with blackish slate; rump pinkish or ; forehead, superciliary stripe, and malar region orange vermilion; chin, throat and breast lighter, approaching orange chrome; rest of lower parts whitish, heavily streaked with slaty; wings and tail dusky brown; primaries and tail feathers edged with whitish; wing-coverts edged and tipped with huffy white."
Of its habitat on the San Benito Islands off the west coast of Lower California, Anthony says: "McGregor's Finch seems to be rather rare but well distributed over the island that we explored, the largest of the group of three. There is very little vegetation on this island, which is little more than a reef less than two (?) miles in extent, and it is rather surprising that a species of this genus should be found there at all."
Richard C. McGregor (1898), for whom this species was named, writes:
We found examples of C. mcgregori distributed over the two large Benitos, but on account of their extreme shyness they were difficult to obtain. We were at the islands too late to collect eggs, but I secured three young birds about ready to leave the nest. The parents had constructed their nest about two feet above the ground in a century plant (Agave). It was made after the fashion of C. frontal is, of a miscellaneous lot of bark, twigs, and fibre. The three young are of different sizes, of which the smallest is here described.
The young plumage differs in coloration but little from that of the adult female. Upper parts heavily marked with clove brown, edges and tips of the feathers cinnamon; lower parts streaked with clove and cinnamon; tertials and rectrices broadly edged and tipped with wood brown.
One set of four eggs reported by E. N. Harrison from Lower California April 1, measures 20.0 by 15.0, 20.0 by 15.1, 20.1 by 15.5, and 19.5 by 15.5 millimeters.
Range: McGregor's house finch is resident on the San Benito Islands and, rarely, on Cedros Island off central western Baja Callfornia.