Woodcock are migratory. While a few birds from farther north may wait out an exceptionally mild winter on Pennsylvania's southern fringe, most timberdoodles pass through our state. They spend the cold months in the South -- the Carolinas, Georgia, and northern Florida west to eastern Texas and Arkansas, concentrating in Louisiana and southwestern Mississippi. In spring, woodcock return north.

Taxonomically, the species is placed in Order Charadriiformes, which includes gulls, oystercatchers, plovers, stilts, curlews, sandpipers, snipe, phalaropes and others. Within this large order, the woodcock belongs to Family Scolopacidae, a group of snipe and sandpipers with more than 80 species distributed over most of the world.

The American woodcock is closely related to the European woodcock (Scolopax rusticola). The Old World bird resembles its American counterpart and has a similar life history, but it's larger and almost twice as heavy.

Biology

A timberdoodle's plumage is an overall mottled russet and brown. The beige breast, back and sides are overlaid with black and browns; the forehead and crown are ashy gray to black, barred with gold. The short tail is a combination of brick-red and black, tipped with gray. Feet and toes are bare and gray- to flesh-colored.

A woodcock is 10-12 inches in length (a little longer than a bobwhite quail), has a standing height of about 5 inches and a wingspread to 20 inches. Body conformation could be described as "chunky" -- short and heavy, with a short, thick neck and a large head. Wings are short and bluntly rounded. Sexes look alike, although females generally average a bit heavier than males (7.6 vs. 6.2 ounces). Weights for both sexes vary according to time of year.

A woodcock's bill is long and thin. A female's bill measures 2 3/4 inches or slightly longer, while a male's is usually less than 2 1/2 inches. Sensitive nerve endings in the lower third of the bill help a woodcock locate earthworms. A special bone-muscle arrangement lets the bird open the tip of its upper bill, or mandible, while it's underground. The long tongue and the underside of the mandible are both rough-surfaced to grasp and pull slippery prey out of the ground.

Eyes are large and set well back and high on the sides of a woodcock's head. Naturalists have speculated that this positioning lets the bird look all around -- behind, above and to the sides, as well as ahead -- while it probes for food. Nostrils are set high on the bill, close to the skull. A woodcock's ears are ahead of the eyes, between the base of the bill and the eye sockets. Hearing and sight are acute.

The woodcock's brain is unique among birds. Its cerebellum -- which controls muscle coordination and body balance -- is located below the rest of the brain and above the spinal column. (In most birds, the cerebellum occupies the rear of the skull.) One theory suggests that as the woodcock evolved, the eyes moved back in the skull, the bill lengthened, and the nostrils approached the base of the bill -- adaptations that permitted ground-probing. As a result, the brain was forced back, and the mid-brain and hind-brain were pushed down and slightly forward. The woodcock of today, in essence, has an upside-down brain.

When woodcock flush from the ground, air passing through their rapidly beating wing primary feathers produces a whistling sound. The birds usually flutter up out of cover, level off and fly from 10 to several hundred yards before setting down. Being migratory birds, they are capable of sustained flight.

Food

Earthworms, high in fat and protein, make up about 60 percent of a woodcock's diet. An additional 30 percent is insects (ants, flies, beetles, crickets, caterpillars, grasshoppers and various larvae), crustaceans, millipedes, centipedes and spiders. About 10 percent is plant food, mostly seeds from bristlegrass, panicgrass, sedge, ragweed, knotweed and blackberry. Timberdoodles do most of their feeding in the early evening and just before dawn. Digestion is rapid; an adult may eat its weight in worms each day.

Woodcock are quite vocal; naturalists have recorded and interpreted at least 10 separate calls. During the mating season, a male timberdoodle on the ground will sound a nasal, buzzing, insect-like note usually described as peent. Preceding each peent is a two-syllable gurgling note, tako. While the peent carries several hundred yards, the much softer tako is audible only within about 15 feet of the bird.

The flight song -- a series of liquid, gurgling chirps -- is sounded on the wing by a male trying to attract a mate. A male defending breeding territory against another male calls cac-cac-cac-cac as he flies toward his rival. A female will squeal and often feign a broken wing to lure intruders away from her young. Other calls express alarm or provide communication between hens and offspring. Migrating woodcock have turned up in Pennsylvania as early as February 25, but most don't arrive until the last two weeks in March. Migration is complete by mid-April.

Reproduction

In spring, males establish territories known as "singing grounds." These are woodland clearings spotted with low brush, or open fields next to brush or woods; they vary in size, but a quarter-acre seems big enough. While on the ground, the males peent to attract females. A male will take off and fly upward 200 to 300 feet on twittering wings; then he'll spiral or zig-zag back to earth, sounding a liquid, warbling song as he descends. Courtship occurs for short periods at dawn and dusk; it's most active when temperatures are above freezing and winds are calm.

Females seek out males on the singing grounds. Males may mate with several females. In Pennsylvania, most breeding takes place from early March to mid-May. Both sexes breed in their first year on the breeding grounds (before they're a year old).

Hens usually nest within 150 yards of the singing grounds where they mated; males play no role in nest selection, incubation or rearing of young. 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. There may be little overhead cover (old fields) or up to 50 feet of vegetation (hardwood stands). The average cover height is 12 feet.

A typical timberdoodle nest is a slight depression on the ground in dead leaves. Some nests are rimmed with twigs or lined with pine needles. An egg-laying or incubating hen is difficult to spot, as her mottled, brown plumage usually blends with the background.

In Pennsylvania, woodcock nest from late March into June. Located near nesting sites are feeding areas of open woods, abandoned fields, brushy areas, and mixed forests, where incubating hens feed. Although they are solitary nesters, hens may share feeding grounds with other timberdoodles. A female lays one egg a day until she completes the normal clutch of four. Eggs are oval, 1 1/2 by 1 inch, which are large for the bird's size. The shells are smooth, with a slight gloss, colored pinkish-buff to cinnamon and covered with light brown blotches overlaid with darker speckling.

Incubation takes 19-22 days. It begins after the last egg is laid, so all eggs receive equal incubation and hatch at about 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 she will desert them. Toward the end of the incubation period, she may sit tight even when touched by a human's hand. Nest predators include domestic dogs and cats, snakes, skunks, opossums, raccoons and crows. Fires and flooding also destroy nests. Hens losing their first clutch may re-nest, often laying only three eggs. Eggs hatch from early April until mid-June, peaking in our state during the last week in April and the first week in May.

Chicks

Eggs split lengthwise (unique among birds) as the woodcock chicks emerge. Chicks are precocial, able to leave the nest a few hours after hatching. They're covered with fine down, pale brownish to buff with brown spots and stripes above, and rufous below; a dark line runs from the bill back to the eye. From the day of hatching, chicks "freeze" when threatened or in response to the hen's alarm call. During the first few days, the hen broods her chicks frequently, especially during rain, snow or cold. At first she finds worms for them, but after a few days, they are probing for and capturing worms by themselves.

Chicks grow rapidly. After two weeks they can fly short distances, and at the end of four weeks they're almost fully grown, fly strongly and look like adults. The family breaks up when juveniles are 6-8 weeks old. Adults undergo a complete feather molt during the summer; juveniles undergo a partial molt from July to October.

Migration

As days grow shorter and temperatures drop, timberdoodles begin to head south. Woodcock migrate at low altitudes (about 50 feet), flying at night and resting and feeding in secluded thickets during the day. They typically travel alone. Birds from farther north may start to pass through Pennsylvania in October; the migration peaks in late October and early November, with stragglers up until the end of November. Heavy northwest winds and cold nights may start large numbers of timberdoodles winging south.

Wildlife biologists believe that woodcock have several migration routes. Most woodcock nesting east of the Appalachian Mountains, appear to winter mainly in the south Atlantic states. Woodcock breeding west of the Appalachians are thought to winter in Arkansas, Louisiana and other Gulf States. In spring, woodcock reverse direction and return north; like many migratory birds, they home strongly to the areas where they hatched.

Woodcock are hardy and seem able to recover from injuries that would kill most other birds. If a timberdoodle reaches adulthood, its life expectancy is about 1.8 years. Banded wild birds seven years old have been recovered. Mortality factors include predators; accidents, many occurring during night flight; hunting; disease; parasites, and bad weather. Woodcock heading north too early in spring may be caught by late-season snows or hard freezes, which seal off their food supply .

As migratory birds, woodcock fall under the jurisdiction of the U.S. Fish & Wildlife Service. This agency monitors the species' population and sets the framework for hunting seasons and bag limits.

Population

Compared to most other game birds, woodcock have a low potential productivity. A female raises only one brood each year, and each brood consists of four (and sometimes only three) 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. Woodcock may be scattered, concentrated, or absent, depending on time of year, weather conditions, or habitat. In autumn, concentrated groups of woodcock may not reflect the carrying capacity of land on which they're found, as they may just be passing through. The overall population can fluctuate greatly over the years. Steady human encroachment on wet woodland, timber maturation and flooding may pose threats to the woodcock population.

Woodcock may be exposed to pesticides used to control either forest or agricultural pests. Contamination from agricultural pesticides is highest in wintering areas where woodcock feed in farm fields. Earthworms are resistant to many chemicals, so they can carry toxins. Since woodcocks are predators of earthworms, there's a chance they'll accumulate persistent toxic chemicals found in worms.

Pennsylvania's woodcock population has declined about five percent annually. That compares to a two percent average annual decrease throughout its North American range. Most biologists attribute this decline to loss of habitat quantity and quality. In Pennsylvania, intensive logging, farm abandonment and wildfires that create new and young forests -- highly desirable woodcock habitat -- are relatively rare today. Development also destroys or fragments existing woodcock habitat.

Habitat

Habitat requirements for woodcock change throughout the year. In spring, they need areas for courtship and nesting; in summer, for brood-raising; during fall and spring migrations, for feeding and resting; and they require wintering habitat in the southern states. Food must be available during all seasons.

Woodcock are attracted to moist forestland in early stages of succession. They tend to use edges rather than interiors of big, even-aged thickets. The following plants make land more attractive to timberdoodles: alder, aspen, hawthorn, gray dogwood, crab apple, blue beech and gray birch. These species can be planted, or, if they already grow in a given area, encouraged by cutting down large trees which may be shading them and stunting their growth. For courtship, males need singing grounds -- clearings a quarter-acre or larger, with a straight, unimpeded take-off strip 15-20 yards long. As trees and shrubs in the clearing grow larger, woodcock will seek out other areas; to keep a singing ground functioning, it must be cleared periodically.

Females nest and raise broods near breeding grounds. Good cover includes edges of thickets, young conifer plantations and old, brushy fields. The best feeding areas are shrub patches near streams, springs, or marshy ground; resting cover often is on high, drier ground. Feeding and resting cover is used by hens and broods, males and migrating timberdoodles.