Summer 2003 Volume 12, Number
2
AMERICAN WOODCOCK FACTS
Source: Ruffed Grouse Society
RANGE
As a migratory bird, the American woodcock
lives in the North during spring and summer but spends the cold months in the
South. Although a few from the farthest regions may wait out an exceptionally
mild winter in some states along the way, most woodcock will continue the
journey south to traditional wintering grounds. The bird's primary breeding
range takes in southern Canada, Maine and the Great Lakes region, dropping down
as for as central West Virginia. The woodcock's wintering range includes
Virginia, North and South Carolina, Georgia, Florida, Alabama, Mississippi,
Louisiana, Arkansas and Texas.
Woodcock migrate at altitudes of about 50
feet, flying at night and resting or feeding in secluded thickets during
the day. The birds travel alone or in loose flocks called 'flights.' Migration
usually peaks in late October and early November in more northern areas, but the
process sometimes starts as early as September and lasts until the end of
November. With the coming 'of autumn, strong northwest winds and cold nights
push large numbers of woodcock south.
There are two major woodcock populations in
North America, with each inhabiting a separate region: the Eastern Region is
from the Appalachian Mountains east; and the Central Region is from west of the
Appalachians to the Great Plains.
DESCRIPTION
The American woodcock (Scolopox minor) is
known by a host of colloquial names, the most common being timberdoodle. Other
colorful nicknames include Labrador twister, bogsucker and mudsnipe.
Woodcock are about the size of robins, and their plumage is an overall mottled
russet or brown. Males and females are similar in appearance, although females
generally average a bit heavier than males - 7.6 ounces vs. 6.2 ounces - with
the weight of each sex varying depending on the time of year.
The bird's bill, which looks too long for its body, is used to probe rich soils
for earthworms. Eyes are large, set well back and high on the sides of a
timberdoodle's head. Naturalists have speculated that this positioning lets the
bird look to all sides while it probes for food. Nostrils are located high on
the bill, close to the skull. A woodcock's ears are ahead of its eyes, between
the base of the bill and the eye sockets.
The brain of an American woodcock is unique
among birds. The cerebellum, which controls muscle coordination and body
balance, is below the rest of the brain and above the spinal column. (in most
birds, the cerebellum occupies the rear of the skull.) One theory holds that as
the woodcock evolved: the eyes moved back in the skull, the bill lengthened and
the nostrils approached the base of the bill, allowing for enhanced
ground-probing abilities. As a result, the brain was rearranged, and the modern
bird, in essence, has an upside-down one. The booklet A Woodcock in the Hand
provides sexing and aging details.
BIOLOGY
Earthworms provide about 60 percent of the
bird's diet. The worms are high in fat and protein, they provide the necessary
nutrients to help keep woodcock healthy and strong. An additional 30 percent of
a woodcock diet consists of insects such as ants, flies, beetles, crickets,
caterpillars, grasshoppers and various larvae. They've also been known to eat
crustaceans, millipedes, centipedes and spiders.
Woodcock primarily feed in early evening and just before down. Because they have
a quick digestive system, an adult woodcock may eat its weight in worms every
day.
When woodcock flush, air passes through their
rapidly beating wings and produces a trilling or whistling sound. The birds
usually flutter up out of cover, level off and fly for distances ranging from
ten to several hundred yards before setting down.
During the mating season, a male timberdoodle
on the ground will sound a nasal, buzzing insect-like note usually described as
a peent. Preceding each peent is a two-syllable gurgling note known as a
tuko. While the peent carries several hundred yards, the much softer tuko
is audible up to about 10 yards from the bird.
Some examples of the different woodcock
sounds include: the flight song - a series of liquid, gurgling chirps - which is
sounded on the wing by a male trying to attract a mate, while a male defending
his breeding territory against another male calls coc-coc-coc-coc as he flies
toward his rival. A female will squeal and often feign a broken wing to lure
intruders away from her young. In the spring, males establish territories known
as singing grounds, where they can perform the flight song and a ground display.
While on the ground, a male peents to attract females. He next takes off to
ascend 200 or 300 feet on twittering wings. Then, sounding his liquid chirps, he
spirals downward. Displays and mating occur during short periods of dawn and
dusk, usually from early March to mid-May when temperatures are above freezing
and winds are calm.
Males may mate with several different females
during the mating season. They play no role in next selection, incubation or
rearing of the young. Although in the more southern areas, woodcock no doubt at
times nest earlier, they usually nest from early March into June. A typical
timberdoodle nest is a slight depression on the ground among some dead leaves. A
female lays one egg a day until she completes the normal clutch of four. The
eggs, which are oval, have a slight gloss to them and may vary from a pinkish
buff to cinnamon with brown blotches and darker speckling.
The incubation process takes 19 to 22 days.
It begins after the last egg is laid. The eggs hatch of approximately the same
time. If a hen is disturbed early in the incubation period, she may abandon the
nest. The longer she sits on the eggs, however, the less likely are the
chances she'll desert them. Toward the end of incubation, she may even stay on
the nest when touched by a human hand.
Nest predators include domestic dogs and cats, snakes, skunks, opossums,
raccoons and crows. Natural disasters, such as fires and flooding, can also
destroy a woodcock nest. Hens that lose their first clutch may nest again, often
laying only three eggs.
Eggs hatch from early April until mid June,
with the hatch normally peaking by May across the woodcock breeding range. When
the clutch starts to hatch, the eggs split lengthwise as the chicks begin to
emerge. American woodcock chicks are precocial, meaning they are able to leave
the nest within a few hours after hatching. They are covered with fine down -
pale brownish to buff with brown spots, stripes above and rufous below. A dark
line runs from the bill back to the eyes.
From the day they hatch, chicks learn to
'freeze' when threatened or in response to hearing the hen's alarm call. During
the first few days, the hen broods her chicks frequently, especially during
inclement
Chicks grow rapidly feeding on a high-protein diet of insects and earthworms.
After two weeks, they can fly short distances. And of the end of four weeks,
they're almost fully grown. Not only are they flying strongly, but they have
almost reached their adult size and weight. The family breaks up when the chicks
are six to eight weeks old. Adult woodcock molt during the summer. As fall
arrives, timber-doodles start heading south for the winter.
POPULATION
Compared to most other game birds, woodcock
have a low potential productivity. A female raises only one brood a year,
consisting of three or four young. Fortunately, the species has a high nesting
success rate - 60 to 75 percent - and low juvenile mortality.
Population densities vary in any one locale.
American woodcock may be scattered, concentrated or absent depending on the time
of year, weather conditions or habitat. In autumn, for instance, collective
flights' of woodcock may not accurately reflect the carrying capacity of an area
where they're found because the birds may simply be passing through.
Their population can fluctuate greatly over
the years. Steady human encroachment on moist woodland, timber maturation, and
flooding pose threats to the species. Mortality factors include predation,
accidents (many occurring during night flight), hunting, disease, parasites and
bad weather. Woodcock that migrate north too early may be caught in late-season
snows or freezing cold, which seal off their food supply.
If a timberdoodle reaches adulthood, its life
expectancy is about 1.8 years. However, banded birds have been recovered in the
wild at 7years of age.
HABITAT
Habitat requirements for American wood-cock
change throughout the year. Woodcock are attracted to moist, young forests and
require a young, dense woodland to provide ample cover and food resources. They
tend to use edges rather than the interior of big, even-age thickets. During
both migrations, they need sufficient food resources and layover sites.
Courtship sites in spring consist of forest clearings, abandoned fields spotted
with low brush or open fields next to forest edges. Sites vary in size, but a
quarter of an acre seems to provide adequate space for the courtship ritual.
Favored nesting habitat includes damp woods near water, hillsides above moist
bottomlands, old fields with low ground cover, briar patches, the edges of shrub
thickets and young conifer stands. Nesting habitat is also young, open, second
growth woodlands, generally within 90 meters of a singing ground. Adequate spots
for brood rearing are similar, but during the first few weeks areas with bare
ground or dense ground cover are avoided. Large fields for roosting are also
required. Finally, winter habitat must be well stocked with various foodstuffs
and provide necessary shelter.
Without quality habitat, timberdoodles will
seek more suitable sites or their populations will decline. As the cover
matures, different tree species take over and the habitat becomes less
attractive to woodcock.
MANAGEMENT NEEDS
Shrubs and trees can be planted, or if they already grow in a given area, it's
an option to periodically harvest large trees, which may be shading brush or
stunting the growth of younger trees. Periodic regeneration of maturing alder
and aspen or other hardwood stands -through cutting or controlled burns - will
result in a renewed, healthier habitat for not only woodcock but many other
forest wildlife species.
The goal is to provide a diverse-age forest canopy. A lush, thick area of shrub
and tree growth that is exposed to full sunlight is one of the best habitats
because a variety of food supplies and shelter will be available. But it's
necessary to take an active role in managing these areas, or they may no longer
contain the wildlife species we hold so dear.
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