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A
chapter from the electronic book:
Life Histories of Familiar North American
Birds
Northern
Mockingbird
Mimus polyglottos [Eastern
Mockingbird]
Contributed by Alexander Sprunt, Jr.
[Published in 1948:
Smithsonian Institution United States National Museum Bulletin
195: 295-315]
If Mark Catesby had accomplished nothing else in his pioneer
work of ornithological discovery in Carolina over 200 years ago
but introduce the mockingbird to science it would have been a
fitting memorial. Had Linnaeus been capable of slang, he might
have expressed the opinion, when receiving Catesby's notes on the
species, that the collector "had something there!"
Truly, that field worker of other days did have something when he
heard his first mockingbird, and from his far-off day to this the
bird has held primary affection in the minds of thousands who
thrill to its matchless ability of song.
Audubon expatiated upon the advisability of hearing the mocker only
amid the magnolias of Louisiana. Since he knew Carolina later, a
native of the latter state would have expected Audubon to change
that setting, but doubtless he never found time to rewrite his
history of the bird! Seriously, however, everything in his opening
paragraphs on this species, in which he dilates upon the botanical
glories of the Pelican State, could have been written with equal
accuracy of the Carolina Low Country. Charleston, the center of
that favored region, and the mockingbird are inseparable, for that
is where it was first seen and made known to science by an
ornithologist.
Linnaeus described the bird from notes furnished by Mark
Catesby on what the latter called the "Mock-Bird of
Carolina" and whose own account of the species appears in his
"Natural History of Carolina, Florida and the Bahama
Islands," published in 1731, and accompanied by a drawing.
Carolinians, then, have a proprietary interest in the mockingbird.
Actually it occurs much farther afield, of course, but at the same
time, wherever the name is mentioned, the hearer inevitably thinks
of the South as the typical habitat.
Surely, this is as it should be. Can anyone visualize the
gray-clad aristocrat amid snow and ice, amid spruces and hemlocks,
or upon cliffs battered by the might of the north Atlantic? Can
one visualize it, indeed, without mental pictures of moss-bannered
live oaks or towering magnolias, where the yellow jessamine climbs
aloft to burst in golden glory among the pines and cypresses and
the immaculate disks of Cherokee roses reflect the moonlight?
Here, along the coasts fringed with semitropical jungles of
barrier islands, where the slow heave of rollers out of the Gulf
Stream thunders slowly upon yielding sands, is the mocker's home.
Here, amid the crimson clusters of cassina and holly the mocker
lives, or is equally at home in a moon-drenched old city whose
garden walls and graceful spires reflect the golden civilization
of a vanished era. Yes, to Charlestonians and other Carolinians,
the entire scope of ornithology might be summed up and typified in
a single species, and that species . . . the mockingbird!
Spring.--Almost universally
considered a southern bird, the mocker has undoubtedly been
increasing its range northward and westward in recent years. It is
now well known in New England and as far west as Knox County,
Ill., and parts of Iowa (Monroe County). Possibly this spreading
population might be considered as an "overflow" from the
normal range, somewhat like certain other species that have
apparently thrived upon the march of civilization and increased
rather than decreased in numbers. While most mockingbird
populations in the South appear to be largely stable (the writer
is unable, for instance, to note any annual shifting of numbers in
South Carolina), certain concentrations in parts of the southern
range indicate that there may be a short migration in fall and an
early return in spring.
In Florida, where the bird is abundant the year round, there
are times when many more are to be seen in certain places in
winter than occur in summer. This is certainly the case in the
Keys, where the writer has, in winter, noted the mocker in greater
abundance than anywhere else in the entire South. Through six
years of fall and winter trips in the Keys he has, time and again,
been impressed with the presence of the bird on Key Largo.
Counting completely at random, he has seen the bird average seven
individuals to a mile along the Overseas Highway for as much as 15
miles. All these, of course, were on conspicuous perches; no
search was made, for the birds were seen from a moving car.
Increasing records from far northern points are evident. Even
in Maine the mocker is now beginning to show itself, and winter
records from various parts of New England are not the uncommon
events they once were. Indeed, in southern New England the mocker
is now resident (E. H. Forbush, 1929). One of the most remarkable
northern occurrences is that of an individual seen on Mount Desert
Island, Maine (Acadia National Park), by Maurice Sullivan (1940)
in the winter of 1940. As an added touch of complete incongruity,
an ivory gull (Pagophila alba) was seen at the same time,
February 10. Thus, the far north and the deep south were brought
together in as strange an avian mixture as perhaps has ever been
noted in this country.
Definite evidence of some movement on the part of individual
birds has been secured by banding. F. C. Lincoln (1939) lists an
instance of a mocker banded at Haddonfield, N.J., on November 25,
1932, being found dead at Shadyside, Md., on May 25, 1935. This
was a northerly banded winter bird found in spring some distance
to the southward. Another specimen, banded at Nashville, Tenn., on
May 26, 1934, was killed at Fulton, Miss., on January 29, 1936.
This represents a directly westward movement.
Frank L. Farley, of Camrose, Alberta, contributes the following
note: "The nesting of a pair of mockingbirds in central
Alberta during the summer of 1928 was one of the most remarkable
ornithological discoveries since the country was first opened to
settlement. That season a pair of these southern birds nested in
the garden of Mr. McNaughton, on the western edge of the town of
Didsbury. This is about 200 miles north of the Montana border and
roughly between 50 and 60 miles east of the Rockies. The unusual
'find' was published in the local paper, The Pioneer, issue
of June 21, 1928. Later that summer when returning from a trip I
called at Mr. McNaughton's home to get further particulars, but
unfortunately the family was absent. However, I talked with
neighbors who were familiar with the circumstances, and they
verified the statements that appeared in the paper. This is, I
believe, the most northerly point at which the mockingbird has
been recorded on the continent."
Courtship.--As might be expected
in so individualistic a species as the mocker, its courtship
procedure is a spectacular performance. At least that is what many
have taken its characteristic actions to be. These have been
described as a "dance" and have been witnessed by
hundreds of observers all over the bird's range. It is well
described by Mrs. A. B. Harrington, of Dallas, Tex. (1923), as
follows: "It was a curious and most interesting performance.
The first time they danced exactly opposite each other. They faced
each other about a foot apart, hopped up and down, moving
gradually to one side, then back again, and so on. A second pair
began their dance in the same position, but first one hopped twice
to one side, then the other followed the first, which hopped again
sideways and the other followed, always facing each other, then
they repeated the performance. After each dance was finished the
birds flew off a short distance in opposite directions."
W. M. Tyler describes a similar performance witnessed near Lake
Okeechobee, Fla., in April 1941. He saw "two mockingbirds in
the roadway, standing facing each other, close together, that is,
a step or two apart, with heads and tails held up high and
feathers depressed so that the legs looked very long and slim.
They made dashes at each other over and over with tense little
darts, the attacked retreating a step or two each time with prim,
ballet-dancer-like movements. They gave the impressions of putting
on an act. Finally both flew off, one following the other to a
tree near at hand."
In these two descriptions the dance terminated in one case by
the birds flying off in opposite directions, while in the other
one bird followed the other. The writer has witnessed this
nonuniformity of termination frequently, one occurring about as
often as the other. Many other written descriptions of this dance
are available, but all agree so closely that further repetition is
without value.
The long-accepted belief that the dance is a courtship
proceeding is challenged, however, by Amelia R. Laskey, of
Nashville, Tenn., who has the following to say about it: "I
hope when you write about this interesting bird you will mention
the 'dance' which bird books continue to describe as a part of the
courtship behavior. However, in the years since I have been using
color bands for sight identification and have therefore been able
to distinguish sexes, this dance has never occurred except as a
territory boundary-line demonstration, when the occupants of
adjoining territories are defending their respective domains. It
usually occurs between two males but may take place with a male
and a female as participants when each is holding fall and winter
territory. I have never observed a mated pair performing together
during the mated season or during the winter season if they
remained together on a common territory. I saw it once in fall
between a pair that mated for three consecutive seasons but that
separated and defended individual but adjoining territories in
fall and winter. The dance in the latter case seemed to be the
severing ties for that season as they did not trespass on each
other's territory. In spring, when he resumed singing, they used
the two areas together."
Probably such a statement will be productive of argument.
Certainly it is an original belief, but one held by an observer
who has put much time and study on the species, as her "Fall
and Winter Behavior of Mockingbirds" (1936) will testify. Her
"territory boundary-line demonstration," however,
appears never to result in actual combat, which might reasonably
be expected on some occasions if an act of defense was the basis.
It is difficult to see exactly how the tactics employed could be
very effective in a combative sense, while it is easy to
understand that the display of wings and tail, which accompanies
the dance, could be an effort to impress a female with the charms
of the prospective consort. Lack of actual contact in a
demonstration is not, of course, conclusive by any means of the
performance's not being a territory defense, but it is suggestive.
Nesting.--Domestic duties with the
mocker are a serious undertaking and never marked with the
slackness characteristic of some avian species. The nest is
constructed by both sexes, and usually the male works as hard as
the female. The materials used vary considerably, being for the
most part small dead twigs. Grass and rootlets form the lining.
String is frequently used and sometimes skeletonized leaves.
Cotton is often found in the nest, depending on locality. The
completed nest is a rather bulky affair and lasts well; old nests
of two or three seasons past still retain their shape to a
surprising degree. Some nests are rather small in circumference.
The site is almost invariably at low elevations, with the great
majority being 3 to10 feet above ground. The writer cannot recall
any nest found by him (and he has seen them literally by the
hundred) that was over 20 feet high. Nonetheless, the mocker at
times breaks custom and ascends to elevations greater than 25
feet. E. H. Forbush (1929), for example, gives the range as
"from 1 to 50 feet from ground." In Florida, the mocker
occasionally builds in clumps of Spanish moss (Tillandsia
usneoides), such sites being noted by A. H. Howell (1932). The
writer has never seen an example of such a site in South Carolina,
the nest usually occupying a small bush or tree, such as various
oaks, or other stiff-twigged growth.
The mocker is strongly partial to human habitation as a nesting
site. Garden vegetation, vines that climb about porches, shrubbery
actually against a house, and decorative plantings in the yard are
often used. It is fairly safe to say that, in parts of the South,
the majority of the mockingbird population nests in towns or
cities. Wild sites along open woodland edges, pastures, wood lots,
and prairielike stretches, which show occasional bushes or small
trees, are situations chosen away from mankind.
Nest-building consumes two days at the minimum, but probably
not many nests are finished in so short a time. This would take
pretty constant and unremitting toil on the part of the birds, but
it certainly has been done. Incubation,
as given by various authorities, differs by several days. Thus,
Wilson and Bergtold (quoted by Forbush, 1929) give 14 days; F. L.
Burns, 10 days. In coastal South Carolina it is usually between
these two estimates, averaging 11 days. Some specific notes
furnished by E. B. Chamberlain are typical of the Charleston
region. He says that "a 4-foot-high spirea bush transplanted
to my yard on May 7 had a pair of mockingbirds begin building in
it the next morning. Both sexes built. Completed in 3 days (May
10). First egg by 8 a.m. May 11, fourth by the same time on May
14. (Thus nest built and eggs laid within a week.) Three eggs
hatched between 11 a.m. and 3 p.m. on May 25, the fourth between 8
a.m. and 6 p.m. May 26. On June 2 (8 a.m.) the young were on the
edge of the nest or on nearby twigs. By 6 p.m. the same day all
had left the bush, some to return occasionally over a period of 2
or 3 days. Thus in 26 days this pair of mockers built their nest
and reared a brood to the nest-leaving stage."
On the south Atlantic coast the mocker usually begins nesting
late in April or early in May. Three broods are often raised.
Early and late extremes, of course, occur now and then. About
Charleston the earliest nesting on record concerns a nest that
must have been started in early March. The writer was then
connected with the Charleston Museum, and a fully fledged young
mockingbird was brought to him on April 9, 1928. The bird was at
least 10 days old then. If we allow a 12-day incubation period and
one day for the laying of each of four eggs (average), March 15
would be the day the first egg was laid. With three days added for
nest construction, March 12 results as the day the nest was begun.
This is a month earlier than is customary and probably constitutes
the earliest record for the state. Regarding late nesting, on
September 10, 1910, a young bird just out of the nest was seen
being fed by a parent in Charleston by A. S. Sloan. This is a very
late date indeed.
Nesting in Florida appears to be only slightly earlier than in
Carolina. A. H. Howell (1932) gives dates of fresh eggs on March
19 at Sebring and quotes F. M. Weston on a nest at Pensacola in
which the eggs hatched on March 20. Both of these were begun early
in March, and no doubt occasional birds nest as early as late
February. Weston has furnished additional notes as follows:
"Earliest known nesting at Pensacola, Fla. (Escambia County),
March 3, 1932. First egg of a set of three laid this date. The
nesting survived a low temperature of 23o
F. on March 10 and hatched in due time. Latest known nesting at
Pensacola, August 13, 1923 (young birds almost ready to leave
nest). Lowest known nesting site at Pensacola, a nest containing
three small young in brush pile on May 24, 1928. Rim of the nest
only 18 inches from ground (measured)."
It is not uncommon to find several mockers' nests in fairly
close proximity. Two and three pairs often nest on an acre of
ground. An interesting record count is furnished by M. G. Vaiden
who found 14 nests on a tract of 22 acres near Rosedale, Miss.
A detailed study of a mocker nesting at Dudley, Tenn., is given
by A. V. Goodpasture of Nashville (1908). He summarizes his
observations in a table as follows:
| |
Days |
| Building |
2 |
| Laying |
4 |
| Incubating |
10 |
| Care of young |
5 |
Thus, from start of nest to flight of young was 21 days,
exactly 3 weeks, being a 5-day variation in the case of the South
Carolina birds noted by E. B. Chamberlain. In the notes on the
Tennessee pair it was stated that "both sexes labored
diligently."
Rarely, the mockingbird will use a nesting-box. It is a very
uncommon procedure, however, and the writer has never seen it, but
the habit must be recognized in any account of its domestic life.
Illustrative of it was a nest found and photographed by H. O.
Todd, Jr., on June 9, 1940, near Murfreesboro, Tenn. The box had
been erected for bluebirds but was taken by a pair of mockers and
contained four eggs when found. The box had been placed on top of
a fence post about 6 feet from the ground, and it was the second
time that Mr. Todd had seen such a location used.
Penetrating into the Midwest one finds the mocker listed as an
"uncommon breeder" by B. F. Stiles, of Monona County,
Iowa. He has seen but two nests in that locality, both of these
having been found at Sergeant Bluff in 1938. H. M. Holland relates
his experience with the mocker in west-central Illinois for 33
years. He states that his earliest acquaintance with it was in
1908, when two nests were found in Knox County, which
"probably constitute the first local breeding records."
The next 12 years passed without any more nests being found. In
the early 30's, however, the birds increased and several nests
were found. The westward spread of the mocker apparently dates (as
far as his locality is concerned) from the late 20's. There is one
record already of the bird spending the winter, and nesting pairs
have become "very noticeable."
As noted above, the mocker has become an uncommon resident in
southern New England and, of course, nests there.
An instance of bigamy in the mockingbird is reported by Amelia
R. Laskey, of Nashville, Tenn. She states that it is "a
surprising situation in a species where both sexes are strong
defenders of territory. A male that occupied one portion of our
lot since 1936 had a certain mate from February 1938 until her
probable death this past December (1939). She remained in his
territory with him throughout the winter also. In April 1937,
while she was incubating eggs across the road, he acquired another
mate. He was seen carrying nesting material for the second nest,
250 feet from the other, and very close to our house. The male
watched both nests, appearing at both just as soon as I went near
for observation. The young of mate No. 1 were several days old and
the eggs of No. 2 were due to hatch when the nest was robbed; the
second female then disappeared."
Arthur T. Wayne (1910) mentions an apparent instance of a
mockingbird mating with a brown thrasher (Toxostoma rufum),
as both species were seen feeding young in the same nest. This
strange occurrence was noted in Charleston County, S.C.
Frederick V. Hebard sends us the following notes on the nesting
sites chosen by the mockingbird in the Okefenokee: "A decided
preference was shown for the holly (Ilex opaca), eight
nests being found in the planted hollies at Camp Cornelia. Four
were found in live oaks (Quercus virginiana), although
magnolias (Magnolia grandifolia), in which three were
found, seem preferred if present. Other nests were found in bamboo
brier (Smilax sp.) 2; blackberry bushes 2; saw palmetto (Serenoa
repens) 2, waxmyrtle (Myrica cerifera) 1; water oak (Quercus
sp.) 1; and unknown deciduous bushes 2. The first brood is
usually raised in May and the second by the end of July. Some
birds build their nests with incredible rapidity. Layton Burch saw
one bird start and complete her nest on July 9; lay her eggs one a
day, July 10, 11, 12, and 13; and begin incubating on July 15. The
first young hatched on July 24, and hatching was completed by the
next morning. The young had all left the nest by August 4.
Eggs.--[AUTHOR'S NOTE: The
mockingbird lays beautiful eggs, with much variation in color and
markings. Three to six eggs may constitute a set, but four or five
is the usual number. The prevailing shape is ovate, with
variations toward short-ovate or elongate-ovate. The ground varies
from bluish white or greenish white, through various shades of
bluish green or greenish blue, to some of the richer shades of
blue or green; "Nile blue" is a common shade. Most of
the eggs are heavily marked with spots and blotches, more or less
evenly distributed, of various shades of brown, such as
"hazel," "russet," "tawny," or
"cinnamon." One very odd egg before me is a spotless,
very pale blue, except for a dense solid cap at the larger end of
"cinnamon-rufous" overlaid with a ring of
"hazel." Another is heavily capped with "Kaiser
brown" over "cinnamon-rufous."
The measurements of 50 eggs in the United States National
Museum average 24.3 by 18.3 millimeters; the eggs showing the four
extremes measure 27.4 by 18.8, 25.9 by 19.8, 22.4
by 17.8, and 24.1 by 17.2 millimeters.]
Young.-- The incubation period of
the mockingbird is variously stated as from 9 to 12 days, but
there is very little definite information on the subject; it is
probably more than 12 days on the average.
As we found practically nothing in the literature about the
nest life of this well-known bird, which was quite surprising, Mr.
Bent asked Mr. Frank W. Braund, of Gulfport, Fla., to make some
observations on this point and send us some information. Mr.
Braund interested various members of the Gulfport Garden and Bird
Club in the subject, and they made a number of observations and
reported the results. Following are some extracts from Mr.
Braund's report: "Of the eight nests under observation, only
two records of the male entering the nest to incubate were
recorded, and both of these were for a very short duration of
time. H. R. Myers reports the female leaving the nest and
observing the male fly from a nearby singing perch to the nest and
squat in the incubating position. The female reappeared in
approximately 2 minutes and drove the male from the nest. F. W.
Braund observed a female leave her nest. The male, who had been
singing on a nearby perch, flew to the nest and incubated the eggs
until the female returned 4 minutes later and drove him off. I
have, however, observed the nest and eggs unoccupied by either
bird for long periods of time. I do not believe the male makes a
practice of incubating when the female leaves the nest exposed.
"Robert Fredricks observed a nest on his own property.
While working in the vicinity of the nest, located 8 feet up in a
Mexican flamevine, both parent birds would appear with grubs in
their bills and perch on a close by wire. As long as he remained
in the vicinity of the nest the parents made no effort to feed.
When he moved away from the nest, one parent would leave the perch
and feed, the other following to feed when the first parent
left."
F. C. Clayton and Mr. Braund both noted that the young were fed
by both sexes; the latter reports: "I watched for several
hours over a period of 10 days through 3x glasses both parents
feeding the young in the nest. At times one would be at the nest
feeding when the second parent would appear with food. This latter
parent would patiently wait until its mate finished feeding, then
fly to the nest to deposit its contribution.
"Robert Fredricks reports observing the parents feeding a
green and brown larva. F. C. Clayton states that the parents
follow the rake or the cultivator, picking up crickets,
grasshoppers, and grubs, and carry them to the nest and feed them
to the young. Observing through 3x glasses I have seen them feed
cutworms and cabbage worms at a ratio of six cabbage worms to one
cutworm. I have also observed them feeding crickets and
grasshoppers. The legs are removed from the latter two before the
insects are carried to the nest. The amputation is performed
usually on the alighting perch, which in this case was a white
fence between cottages."
The length of time that the young remain in the nest was not so
easily determined, but he obtained two records on this point. Mrs.
D. M. Morrison gave him the following data from her notes:
"Nest of mockingbird started March 13, 1931. March 25, 2
eggs; March 27, 4 eggs; April 7, first downy young. April 8, 4
downy young; April 21, young left the nest." In this case the
nest life of the young was 13 days.
In 1942, Mr. and Mrs. H. R. Myers and Mr. Braund watched a nest
closely. "This nest contained four eggs, one of which did not
hatch. All young hatched between 9:00 p.m. on June 6 and 11:00
a.m. on June 7. The young were dry at this latter time. One of the
young left the nest at 4:00 p.m. on June 20, the second at 5:00
p.m. on June 20, and the third at 9:00 p.m. on June 20. Deep
twilight was 9:00 p.m., Eastern War Time. Using the 11:00 a.m.
June 7 date would establish the nest-life cycle of these young at
13 days 5 hours, 13 days 6 hours, and 13 days 10 hours,
respectively."
William G. Fargo writes to Mr. Bent from Pass-a-Grille, Fla.,
that a pair of mockingbirds, nesting in his seagrape, began
incubating on a set of five eggs during the morning of April 7,
and that the eggs were hatched on the morning of April 19, showing
an incubation period of about 12 days. He never saw any evidence
of more than one bird incubating, but Dr. Eugene E. Murphey, of
Augusta, Ga., states that "he has seen the male relieve the
female at the incubation duties, and take his turn at sitting on
the eggs."
Mr. Braund reports the following interesting observation, made
at the residence of L. A. Kosier of Gulfport: "On April 19,
1942, the nest with four eggs and the parent incubating were
reported by Miss Kosier. We visited the nest daily until April 24,
when a painter appeared to paint the cottage and the birds
abandoned the nest. The nest was visited each day to April 30. The
adult birds were not seen; the eggs were cold. On May 6 Braund
returned to the nest to collect the abandoned eggs. This
revisitation disclosed a fifth egg in the nest and either the same
pair or another pair of mockingbirds about the location. On May 7
the nest contained 6 eggs, May 8 seven eggs and a parent bird
incubating the eggs at 3:00 p.m. This nest was visited each day to
May 27, a period of 19 days, when the parent birds again abandoned
the nest. The nest was watched each day to May 30, when the eggs
were collected and blown. All seven eggs were found
infertile."
Plumages.--[AUTHOR'S NOTE: I have
not seen the natal down, but Dr. Dwight (1900) describes it as
pale sepia-brown. Unlike most of the family, the young mockingbird
in juvenal plumage is quite unlike the adult. The upper surface is
browner, grayish "sepia" rather than deep "smoke
gray," with indistinct streaks of darker brown on the back;
the wings and tail are much like those of the adult, but the
greater wing coverts and secondaries are broadly edged with pale
"wood brown"; the most conspicuous difference is on the
underparts where the chest, breast, sides, and flanks are spotted
with dusky.
A partial postjuvenal molt, which involves the contour plumage
and the wing coverts, but not the rest of the wings and tail,
takes place mainly in September. This produces a first winter
plumage which is practically adult. Adults have a complete
postnuptial molt at about the same time, but no spring molt; the
nuptial plumage is acquired by wear and is paler and grayer than
the fall plumage.]
Food.--The diet of the mockingbird is
the one phase of its existence that does not entirely redound to
its credit, at least in the opinion of some. Until detailed
studies were made of its food there was considerable doubt as to
which side of the economic scale was tipped by it. The whole
question hinged on the bird's fondness for fruit. In the southern
orange groves and vineyards, much complaint from growers of citrus
and grapes was directed against the mocker, and many took it into
their own hands to reduce the species about their own particular
properties. It is to be hoped, however, that the grape grower
mentioned by G. C. Taylor (1862) as having killed 1,100
mockingbirds at his place near St. Augustine, Fla., is
exceptional. This man was said to have buried the bodies of that
many birds at the roots of his grapevines!
The report of extensive stomach analyses by Prof. F. E. L. Beal
(Beal, McAtee, and Kalmbach, 1916) still stands as the most
complete study on record. Recent attempts to obtain more
up-to-date information have proved that there is little, if
anything, that can be added to it in the files of the Fish and
Wildlife Service. Therefore, for a general digest of the food
habits over the main part of the range the Beal report is
summarized as follows:
Stomachs of 417 specimens were available for study, and these
proved that 47.81 percent animal matter and 52.19 percent
vegetable matter were consumed. Most of the animal matter is taken
in May, amounting to 85.44 percent. December and January are the
greatest vegetable-consuming months, with 86.55 percent each. The
proportion of beetles and grasshoppers appearing in the insect
list shows that the bird feeds to a considerable extent on the
ground. This habit must have been noted by anyone who has watched
the bird much, or indeed, even casually. Six stomachs contained
nine specimens of the cotton-boll weevil. Ants form 4.48 percent
of the animal food and were found in 75 stomachs, another
ground-feeding proof. Bees and wasps composed 3 percent. Though
only two stomachs contained that notorious pest the chinch bug,
Professor Beal says that "any bird which eats this pest
deserves honorable mention." Grasshoppers composed 14.85
percent. Among "a host of others" appeared the
cotton-leaf worm, spiders, crawfish, sowbugs, and snails. Peculiar
items were a few lizards (3) and a small snake.
In the vegetable line wild fruit is the item. It is
eaten every month and totals 42.58 percent, more than four-fifths
of all vegetable matter. Maximum consumption occurs in October,
amounting to 76.91 percent. Wild fruit was found in 246 stomachs,
and 76 contained nothing else. Thirty-five species were
identified, and among the most frequently eaten were various kinds
of holly, smilax, woodbine, blackberry, pokeberry, elderberry,
mulberry, and sourgum. Domestic fruit comprised only 3.35 percent,
the bulk of it being either raspberries or blackberries. Since
both of these grow wild in abundance, the berries eaten by mockers
"are as apt to be taken from thickets and briar patches as
from gardens." Figs were found occasionally. A few grapes,
which might have been wild species, were identified. As long as
wild fruits are available the mocker will probably never do much
harm to cultivated varieties. Certainly, the above would indicate
that the mocker is not a heavy consumer of domestic fruit, as was
thought by many. Professor Beal sums up his account by the
statement that "there appears to be nothing to prove that the
Mockingbird eats domestic fruit to an injurious extent."
A. H. Howell (1932) gives some interesting information in
regard to the mocker's diet in Florida. He adds to the berry list
above the sumac, poison ivy, Virginia-creeper, red cedar, black
alder, and bayberry, by which last is probably meant the waxmyrtle,
as it is abundant in the Southeast and the bayberry is not. He
quotes C. J. Maynard (1896), as saying that at Key West mockers
eat the fruit of the pricklypear cactus (Opuntia)
extensively in fall and winter. H. H. Bailey (1925) says that the
fruit of the wild fig and seagrape (Coccolobis) are eaten.
He was told by the late Charles Torrey Simpson that mockers at
Lemon City (near Miami) consume the berries of a nightshade (Solanum
seaforthianum) and become intoxicated therefrom. D. J.
Nicholson found the birds feeding on berries of the waxmyrtle (Myrica
cerifera) and French mulberry (Callicarpa) as well as
those of the cabbage palm (Sabal palmetto). This last is a
frequent food item on the South Carolina coast, where the writer
has often seen the mocker as well as numerous other avian species
indulging on it. The ring-billed gull (Larus delawarensis)
also often eats the berries of the palmetto!
Lester W. Smith writes that about Sarasota, Fla., he has found
mockers eating the pods of the yucca, or Spanish bayonet. They
"feed on the upper ripe pods while the lower mass, still
green, is untouched." Miss Clara Bates (1940), of Fort
Pierce, Fla., writes that "like all birds, the Mockingbird is
partial to the small red pepper (C. frutescens)."
Behavior.--As individualistic as
the mocker is, its actions and behavior are replete with vigor and
vivacity. There seems to be no condition under which the bird does
not appear keenly alive. One of its marked traits is its alert
defense of territory against all comers, and in this it rivals the
kingbird (Tyrannus tyrannus) in attacking anything that
violates it. At times it seems that a spirit of innate pugnacity
prompts attacks, for these are by no means limited to the nesting
season, or even winter territorial defense. Encounters among
themselves are frequent and as many as six, eight, or even more
birds will indulge in a battle royal. The writer once saw a group
of 12 in his yard engaged in a pitched combat of determined
proportions, this being the largest avian "mass attack"
of which he has knowledge.
The spirit of play appears well developed in the mocker also.
It is somewhat reminiscent of the duck hawk (Falco peregrinus
anatum) in this respect. It seems to delight in bedeviling
dogs and cats and puts either to flight. A neighbor of the writer
in Charleston maintained a kennel of hunting dogs for some years,
and the mockers of the neighborhood would often
"dive-bomb" these dogs, plunging upon them as they
slept, or else they roamed about the enclosure and frequently
drove them to the shelter of the kennels, tails between legs! At
times they would actually alight on a dog's back and peck
savagely. M. G. Vaiden, of Rosedale, Miss., says that "I have
seen the mockingbird ride my Belgian shepherd's back more than
once, near the nesting site, and usually the dogs find some other
places to ramble than those near a mocker's nest." It often
attacks snakes also, and an instance of this is related by Mrs. J.
L. Alley (1939), of Tavernier, Fla. She states that she witnessed
an attack on a coachwhip snake (Masticophis flagellum) near
St. Petersburg in the summer of 1939. The bird repeatedly alighted
on the head of the snake and pecked it viciously. The encounter
was watched for a considerable time, the snake finally seeking
sanctuary under some bushes.
The flight of the mocker is well sustained but appears somewhat
labored at times, particularly in heavy winds, probably on account
of the long tail. It is often the case that, when alighting on the
ground, where it spends much time, the bird elevates its wings and
holds them high, after the manner of some of the shorebirds,
before folding them. Also it will often continue such behavior
with a series of opening and closing the wings, fanning them
gently, running a few feet then stopping abruptly with head high.
This may be done as many as five or six times, the whole
performance illustrating the trim, alert character of the bird.
When two or three are going through such actions it reminds one of
a sort of avian gymnastic drill. It is thought by some that these
performances are indulged in to startle unseen insects into
betraying their whereabouts, but this needs more definite study
and proof than are now available.
Though a low-ranging species, generally, as regards feeding and
nesting, the mocker often selects an elevated perch for singing,
or even resting. Telephone wires, chimney tops, or the top twigs
of trees are frequently used. To watch one atop a tall yucca,
outlined against the sky, amid the sand dunes of a barrier beach,
or the flaming colors of a city garden, is as characteristic a
sight as anything could be in a southern state. When a bird
chooses a chimney for a singing perch, the effect of its song
coming down into the rooms below is a most striking auditory
experience, muted as it is by perhaps two or more floors of flues.
This is often heard on moonlight nights, when it is the more
remarkable.
The ready willingness of the mocker to attack anything about
its nest or territory is proverbial. Occasionally, however, it
meets a match in such species as the loggerhead shrike (which it
superficially resembles). In the files of the Charleston (S.C.)
Museum are some notes by Francis M. Weston as follow: "March
3, 1907, St. Andrew's Parish, S.C. Mockingbird chased by
Loggerhead." Again, on March 17, same year, the same
observation was made at 4-Mile House, Charleston County. On the
other side of the ledger appear such notes from the same observer
as "Dec. 24th, 1906, Pee Dee River, S.C. Mocker chasing
Phoebe" and "Dec. 27th, 1906, Pee Dee River, S.C. Mocker
chasing Red-bellied Woodpecker." H. R. Sass, of Charleston,
notes that a mocker was "worrying Robins" in his garden
on January 9, 1906.
As is the case with several other species of the mocker
frequently attacks its own image in polished, reflecting surfaces.
This has been commented on by numerous observers. M. G. Vaiden
writes: "In June 1933, my car was parked at the side door of
the residence when I observed a mockingbird pecking at the highly
polished radiator. I scared the bird away and returned to the
house; the bird came back and again started pecking and
occasionally striking with wings, whereupon I concluded that it
was fighting its shadow (reflection) in the radiator. This
continued for an hour or more until I moved the car. The next day
I noticed the bird doing the same thing and covered the radiator
with a towel to prevent any possible damage to the mocker."
A friend of the writer had much the same experience near
Georgetown, S.C., when a mocker made persistent attacks on its own
image in the surface of a car's hubcap. The owner of the car
finally covered the cap with moss when he parked it! A mockingbird
living in the yard of the writer fought itself literally for days
in the window of the cellar, which was almost on a level with the
ground. This is almost certainly a territorial defense action, as
the image is taken by the bird for an intruder on its domain and
treated accordingly.
The immense popularity of the mocker throughout its range has
resulted in its being chosen as state bird by no less than five
commonwealths!
Voice.--There is no possibility of
doubt that the vocal attainments of the mockingbird are its
primary characteristic. Its voice overshadows its every other
trait, habit, and even appearance. Recognition of it is evident in
both the common and the scientific name of the species, and
neither could be more appropriate. Though its amazing powers of
imitation were not known to Linnaeus except second-hand, his
designation of Mimus polyglottos as its name was well
chosen, for as a "many-tongued mimic" the mockingbird
stands alone. Catesby's name of "Mock-bird" is
practically the same as its present-day appellation. Some years
ago Herbert R. Sass, of Charleston, S.C., referred to the
mockingbird in one of his inimitable nature articles as "Mimus
the Matchless," and it has always seemed to this writer that
no more descriptive adjective could be used in connection with it.
Truly, that is the word for the mocker. . . .matchless!
It is evident, of course, that there are remarkable performers
among the so-called song birds of this country, and each has
enthusiastic partisans. However, whatever can be said about each
one of them can be said of the mockingbird, plus. Always plus,
because if given the opportunity, the mocker can deliver the song
of any other bird as well as the species itself, plus the fact
that it has a wonderfully beautiful song of its own!
Ample proofs that the writer is not hopelessly biased in his
statements regarding the mocker's vocal ability are numerous.
Illustrative of what others think are quotations that follow.
Baird, Brewer, and Ridgway (1874) say:
"The vocal powers of the Mockingbird exceed, both in their
imitative notes and natural song, those of any other species.
Their voice is full, strong and musical, and capable of an almost
endless variation in modulation. . . . In force and sweetness the
Mockingbird will often improve upon the original." A. H.
Howell (1932) states that "the song of the Mocker is easily
the most prominent and best loved of southern bird voices."
John Burroughs (1895) is less qualified in his approbation than
the conservative Howell and joins with Ridgway in enthusiastic
praise. He termed the mocker "Our nightingale" and goes
on to say that it is "famed mostly for its powers of mimicry,
which are truly wonderful, enabling the bird to exactly reproduce
and even improve upon the notes of almost every other species of
songster. . . . Here is the lark and the nightingale in one."
In connection with the reference to the nightingale, probably
the most famous Old World songsters, an amusing story is even yet
related in Florida connected with this species and the mocker. It
seems that Edward Bok, who created the well-known Singing Tower
near Lake Wales, had several nightingales imported and confined
there in cages. When the strangers had settled down and had begun
to voice their famous song abroad across the orange groves, great
satisfaction was felt, of course. Before long, however,
nightingale songs were heard all over the surrounding territory!
Here, there, and yonder the foreign strains were echoing, but all
the captives remained in their cages. The mockingbirds of the area
had taken charge and were broadcasting nightingale melodies over
the countryside! It is said that the European performers were put
to silence and soon refused to sing at all. Particularly apropos
of this is R. W. Shufeldt's symposium on the mockingbird in
Newton's "Dictionary of Birds," for he says there:
"I believe were he successfully introduced to those countries
where the Nightingale flourishes, that princely performer might
some day wince as he was obliged to listen to his own most
powerful strains poured forth. . .by this king of feathered
mockers." It has happened.
The mocker begins its performance at an early age. Amelia R.
Laskey says that they start "when very young but these songs
are very soft-toned, 'whisper' songs that cannot be heard unless
one is very close to the performer. Four young birds under
observation started singing at the following ages: 30 days, 34,
57, and 73 days." This whisper song is also indulged in by
the adult and is an exquisite thing--soft, appealing, and
infinitely tender in its cadences.
Aretas A. Saunders says that "the song is long continued,
consisting of phrases with pauses between them. The mocker differs
from the catbird and the brown thrasher in a tendency to repeat a
phrase four or five more times in succession, in a richer quality,
in greater frequency of singing, tendency to sing at night,
especially when moonlight. . .frequently in fall. . . frequently
on the wing. The greatest number of different phrases I have
recorded from one bird is 30, but I have no doubt that it uses
many more than that."
That gifted ornithological writer Edward H. Forbush (1929),
speaking as a New Englander, gives the mockingbird one of the
finest of tributes when he says that "the Mockingbird stands
unrivaled. He is the king of song. . . . He equals and even excels
the whole feathered choir. He improves upon most of the notes that
he reproduces, adding also to his varied repertoire the crowing of
chanticleer, and cackling of the hen, the barking of the house
dog, the squeaking of the unoiled wheelbarrow, the postman's
whistle. . . . He even imitates man's musical inventions."
T. Gilbert Pearson (1909) writes that he has "sometimes
thought that they must be conscious of the power of their numbers.
. . . The bird revels in the glory of his vocal strength, and
shouts his ringing challenge to the trees, the flowers, the very
sky itself. . . . However, it is at night that the Mockingbird is
at his best. If he is the music-price of the grove by day, he is
the song-king of the lawn on moonlight nights."
It is not surprising that, in such a species, particular
individuals have become known for particular powers of rendition
and imitation. One of these is mentioned by Frank M. Chapman
(1912), a specimen heard by Leverett M. Loomis near Chester, S.C.
This mocker imitated 32 different birds in a space of 10 minutes.
Of it Chapman says, "This was a phenomenal performance, one I
have never heard approached, for in my experience many
Mockingbirds have no notes besides their own, and good mockers are
exceptional." In an observer and student of the wide
knowledge and experience of Dr. Chapman, this seems a strange
statement. The writer, during a lifetime with the mocker, would
observe that there is little, if any difference in the individual
powers of this bird. One is as capable as another. It would be
difficult to assign any reason why this should not be the case.
Why would one be especially gifted and another not?
As remarkable as was the performance of the South Carolina
specimen, however, its record has been eclipsed since Dr. Chapman
gave it prominence. E. H. Forbush (1929) quotes W. L. Dawson as
saying the latter heard a mockingbird change his tune 87 times
in 7 minutes and that he was able to recognize 58 of the
imitations given! Forbush had such unqualified belief in the
mocker's powers that he says, "Perhaps there is no song-bird.
. .that the Mockingbird cannot imitate to perfection."
Despite all the foregoing, it would be reprehensible not to
mention that amazing bird that has come to be known as the Arnold
Arboretum Mocker, of Boston. It has been written of at length and
in great detail by C. L. Whittle (1922). In summarizing its
astounding vocal powers, it need only be said that Mr. Whittle
lists its imitations of 39 bird songs, 50 bird calls, and the
notes of a frog and a cricket!
A. V. Goodpasture, of Nashville, Tenn. (1908), says:
The most obvious charms of his song, however, are the
infinite variety and range of his round, full, distinct notes, and
the rapidity and enthusiasm with which he trills his marvelous
medley. . . . Four observations of his song, taken at different
times, will convey some idea of his performance: (1) In ten
minutes he changed his song from one to four notes, forty-six
times, and repeated each from one to nine times--an average of
3.41 times. (2) In three minutes he changed his song twenty-eight
times, repeated each from one to nine times--average four times.
(3) In one minute he changed thirteen times, repeated from one to
nine times--average 6.3 times. (4) In ten minutes he changed 137
times, repeated from one to twelve times--average 3.18 times.
The call notes of the mockingbird have none of the melodious
qualities of its song; indeed the tone is quite the opposite.
There is a grating harshness about them more suggestive of the
bird's fighting temper than of any quality of musical sweetness.
Rendered into words (never satisfactory, of course) the call note
has been described as "a harsh, grating 'chair'" by R.
Hoffman; a "chuck" or "chick" and a harsh,
scolding note (almost veery-like) "whee-e-e" by J. A.
Farley. A. H. Howell calls it a "harsh chuck."
There has doubtless been speculation on the ability of memory
on the part of the mocker in reproducing the songs of other birds.
Since there is very little in the literature concerning it, the
following notes from F. M. Weston are of extraordinary interest:
"March, 1912, Charleston, S.C. Mockingbird heard giving 'tucky-tuck'
call of summer tanager (Piranga rubra), then tanager song,
then call again, showing definite association of those two sounds.
Tanager had not yet arrived in spring migration, and recollection
was at least 6 months' duration.
"May 25, 1925, Pensacola, Fla. A mockingbird that has been
singing in the neighborhood all spring imitates the full song of
the field sparrow (Spizella pusilla) more than that of any
other species. He is so persistent about it that I can recognize
him by that feature of his performance. During my 10 years'
residence here, I have yet to hear the song of the field sparrow
in this region. That particular mockingbird has spent some earlier
period of his life in some other region, and his memory is at
least eight months long."
Field marks.--Even its most
ardent admirers could hardly call the mockingbird handsome. It is
trim, alert, and clean-cut but not striking in plumage and is
quite plain in appearance. At rest, the long tail is diagnostic,
and the conspicuous white wing patches show to advantage in flight
and can also be seen while the bird is perched. There is a decided
general resemblance to the loggerhead shrike (Lanius
ludovicianus), which had led to the latter's being known in
some localities as the "French mockingbird." However,
the mocker is a darker gray and lacks the sharply contrasting
pattern of the loggerhead, as well as the black line through the
eye.
Albinism is not rare in mockingbirds, and the writer has seen
specimens ranging from totality to only a few feathers in wings or
tail. A totally albino bird was reported to the writer on May 29,
1940, as occurring in the grounds of a resident of a Charleston
(S.C.) suburb for several days. Two or three specimens were
brought into the Charleston Museum during the years the writer was
connected with that institution, and the late A. T. Wayne had at
least one specimen in his collection.
Enemies.--The mockingbird is
probably as free from natural enemies as any passerine bird could
be. Because of its pugnacious tendencies it, like the kingbird (Tyrannus
tyrannus), takes the offensive rather than the defensive
against all avian enemies, although, of course, it would be and
sometimes doubtless is a victim of such predatory species as the
accipitrine hawks.
In regard to man it is fortunate in holding a high place in
public sentiment and affection. If a census could be taken
regarding the bird most beloved by the public generally throughout
the entire country, the result would probably be a close race
between the mockingbird and the robin. Even the small boy, who
must be classed as a predatory animal of dangerous proportions at
one state of his development, usually directs his slingshot,
airgun, or .22 rifle at some other avian target than this general
favorite.
Years ago the mocker figured largely as a cage bird in many
parts of the south at least, but this practice is now all but
nonexistent except in the most remote regions where the laws
governing it are not well known. The bird's attacks on fruit
orchards and groves are not serious, and few are done away with on
such accounts.
Dr. Friedmann (1934) cites only two cases in which the
mockingbird has been imposed upon by the cowbird. E. B.
Chamberlain records a very interesting occurrence that took place
in the yard of his residence near Charleston, S.C. He had been
watching the nest of a mockingbird in a small oak, where it was
built near the end of a limb and only 4 feet from the ground. On
the afternoon of July 7, 1942, it held four pinfeathered young. As
he came into the yard that afternoon, a Cooper's hawk rose from
the nest, bearing one of the young in its claws. It stopped in a
larger oak nearby but escaped out of the far side before it could
be shot. An hour later there was an outcry from the mockers and on
rushing out, Chamberlain saw the hawk making away with a second
youngster. I "cut loose," he says, "just for the
noise effect as I had no chance to hit the hawk." The next
day passed without a repeat visit from the hawk, but on the
following day (9th) "again I met the spectacle of the hawk
leaving the nest, the third young in its talons." The adult
mockers gave chase to the marauder as it flew out over the
adjacent marshes. While at the supper table that same evening, at
7:45 p.m., Chamberlain witnessed the return of the hawk and the
departure of the last of the young by "the same well worn
route." He then closed the account with the statement that
"I was interested to note that by 8:15 p.m. the adult male
(?) mocker had recovered enough to burst into song on a nearby
perch. Perhaps he had forgotten the tragedy already."
Northern Mockingbird*
Mimus polyglottos [Eastern
Mockingbird]
Contributed by Alexander
Sprunt, Jr.
*Original Source: Bent,
Arthur Cleveland. 1948. Smithsonian Institution United States
National Museum Bulletin 195: 295-315. United States Government
Printing Office
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