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