Woodpecker

Woodpeckers are tree-dwelling birds of the family Picidae, comprising subfamilies like Picumninae (piculets), Jynginae (wrynecks), and Picinae (sapsuckers). Their long, sharp bills that they use for pecking and drilling on trees help in distinguishing them from other bird species. They typically nest in the holes that they make in branches and tree trunks.

Physical Description and Appearance

Size: Woodpeckers vary in size, ranging from tiny piculets of length 7cm (2.8in) to the great slaty woodpecker measuring 48-58cm (19-23in). The possibly-extinct ivory-billed woodpecker and imperial woodpecker were larger than the great slaty woodpecker.

Weight: While the smallest piculets weigh just 7g (0.25oz), the largest surviving great slaty woodpeckers’ weight is 360-563g (12.7-19.9oz).

Color: Their plumage can vary from dull to conspicuous, with some species having an olive and brown base while some are pied. Many species have a bold pattern of white, black, and red, while others have tufted feathers or a crest on their crown.

Skull: They have strong, spongy, compressible bones that are mostly concentrated at the back of the skull and in the forehead.

Beak: Their bills are sharp and strong, having a chisel-like tip suitable for the pecking action on wood. The beak is made up of three layers, including a scaly outer sheath formed from keratin, a middle layer consisting of porous bones, and an inner bony layer with collagen fibers and a large cavity.

Feet: They possess zygodactyl feet, meaning they have four toes, which are arranged such that the first and fourth face backward, while the second and third face forward.

Distribution

The range of distribution of woodpeckers extends across the globe, although they are not found in Antarctica, Australasia, and Madagascar. Picumninae piculets live in Africa, Southeast Asia, and South America while the Nesoctitinae piculets occur in the Caribbean Island of Hispaniola.

The wrynecks are found in Asia, Africa, and Europe.

What kind of Habitats are they found in

Woodpeckers, being arboreal birds, occur in wooded habitats. The different habitats occupied by various woodpecker species include savannahs, scrublands, woodlands, grasslands, deserts, and bamboo forests.

Forest-dwelling woodpeckers typically need dead or rotting wood on which they can forage.

How long do they live

In the wild, the average lifespan of woodpeckers can range between 4 and 12 years. However, larger woodpecker species may live for 20-30 years when kept in ideal conditions.

What do they eat

Woodpeckers are omnivores, feeding mostly on insects like ants, beetles, termites, caterpillars, spiders, and mealybugs. They also eat fruits, nuts, acorns, pine seeds, berries, and tree sap.

However, their exact diet depends upon the availability of food in an area that they inhabit.

Behavior

• Most woodpeckers prefer living a solitary life. While some are highly aggressive
  towards members of their species, others live in groups.
• These birds remain active during the day, and they roost at night in tree cavities
  and crevices.
• Woodpeckers use ‘drumming’ as a means of non-vocal communication, for which they strike
  their bill repeatedly on wood. They use this rhythmic pattern of beats as a
  territorial call, with the males doing it more frequently than the females.
• They also use drumming for recognizing their mates during courtship.
• Each woodpecker species produces its unique range of calls, including brief
  high-pitched trills, rattles, whistling, twittering, whistling, wails, and
  screams. These calls are used during territorial disputes, courtship, and for
  raising the alarm.
• They excavate holes on living and dead trees to obtain tree saps, insects and their
  larvae.

Adaptations

• The hyoid bone or tongue-bone of woodpeckers is long and spongy, winding around
  their skull through a cavity. It helps in cushioning the brain and absorbing
  the impact of drilling.
• Their strong feet and the alignment of their toes are designed explicitly for
  clinging and grasping onto tree trunks and branches.
• Woodpeckers have feathers over their nose that helps in preventing inhalation of wood
  particles when excavating holes in trees.
• They have a long, sticky tongue, with bristles that are useful for grabbing and pulling
  out insects and their grubs from deep within a cavity in a tree.
• A translucent eyelid, called nictitating membrane, helps protect their eyes from
  all the debris when drilling holes in the wood.

How do they Reproduce and Mate

During the breeding season, woodpeckers and piculets excavate their nests while wrynecks search for pre-existing cavities. A nest typically has a round entrance and a large vertical chamber below. It takes about 30 days to finish excavating a nest.

A breeding pair usually works together in drilling the nest, incubating the eggs, and then raising their offspring. In most woodpecker species, the males perform most of the excavation and then incubate the eggs at night. After the nest is built, a clutch of 2-5 white eggs is laid, which are incubated for roughly 11-14 days. Once the eggs hatch, the chicks take approximately 18-30 days to fledge and leave the nest.

Members belonging to the family Picidae are mostly monogamous, meaning a woodpecker has one partner throughout its life. However, a few species like the West Indian woodpecker and the lesser spotted woodpecker have a polygamous mating system.

Conservation

Among the different bird families, the woodpecker is the only family to have fewer species threatened with extinction. A few species, including the red-cockaded woodpecker and the Okinawa woodpecker, are at risk as their population is reduced due to deforestation, agricultural development, and construction of roads, buildings, and golf courses.

Conservation efforts for the red-cockaded woodpecker in the US have included the construction of artificial cavities in the longleaf pines.

Woodpecker-FAQs

1. Why do woodpeckers peck wood?

They peck into trees to search for food, produce a nesting site, attract mates, and establish their territory.

2. Do woodpeckers migrate?

Most woodpeckers are sedentary birds, but a few species like the yellow-bellied sapsucker, Rufous-bellied woodpecker, and Eurasian wryneck migrate in the winter.

3. Do woodpeckers kill trees?

They can cause economic losses, as some sapsuckers excavate cavities in live ornamental or fruit trees.

4. Do woodpeckers peck at night?

No, they are diurnal birds.

5. What predators may eat woodpeckers?

Wild cats, foxes, large predatory birds, rats, and snakes are their common predators.

Interesting Facts

• A few woodpecker species, like the ground woodpecker and Andean flicker, have abandoned the trees completely and inhabit holes in the ground.
• For drumming, woodpeckers select a surface that resonates, like a hollow tree, downpipes, and gutters.
• The spongy bones of their skull have inspired engineers to design black box (flight recorders) in such a way that it can withstand a crash.