Woodpecker facts for kids
Quick facts for kids Woodpecker |
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| Pileated woodpecker |
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Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Piciformes |
| Infraorder: | Picides |
| Family: | Picidae Leach, 1820 |
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Woodpeckers are part of the bird family Picidae, which also includes the piculets, wrynecks, and sapsuckers.
Members of this family are chiefly known for their characteristic behaviour. They mostly forage for insect prey on the trunks and branches of trees, and often communicate by drumming with their beaks, producing a reverberatory sound that can be heard at some distance. Some species vary their diet with fruits, birds' eggs, small animals, tree sap, human scraps, and carrion. They usually nest and roost in holes that they excavate in tree trunks, and their abandoned holes are of importance to other cavity-nesting birds. They sometimes come into conflict with humans when they make holes in buildings or feed on fruit crops, but perform a useful service by their removal of insect pests on trees.
Contents
General characteristics
Size
Woodpeckers include the tiny piculets, the smallest of which appears to be the bar-breasted piculet at 7.5 cm (3.0 in) in length and a weight of 8.9 g (0.31 oz). Some of the largest woodpeckers can be more than 50 cm (20 in) in length. The largest surviving species is the great slaty woodpecker, which weighs 430 g (15 oz) on average and up to 563 g (19.9 oz), and measures 45 to 55 cm (18 to 22 in), but the extinct imperial woodpecker, at 55 to 61 cm (22 to 24 in), and ivory-billed woodpecker, around 48 to 53 cm (19 to 21 in) and 516 g (18.2 oz), were probably both larger.
Plumage
The plumage of woodpeckers varies from drab to conspicuous. The colours of many species are based on olive and brown and some are pied, suggesting a need for camouflage. Others are boldly patterned in black, white, and red, and many have a crest or tufted feathers on their crowns. The plumage is moulted fully once a year apart from the wrynecks, which have an additional partial moult before breeding.
Feet
Woodpeckers, piculets, and wrynecks have feet that are good for grasping the limbs and trunks of trees. They can walk vertically up tree trunks. In addition to their strong claws and feet, woodpeckers have short, strong legs. This is typical of birds that regularly forage on trunks. The tails of all woodpeckers, except the piculets and wrynecks, are stiffened, and when the bird perches on a vertical surface, the tail and feet work together to support it.
Bills
Woodpeckers have strong bills that they use for drilling and drumming on trees. Woodpecker bills are typically longer, sharper, and stronger than the bills of piculets and wrynecks, but their morphology is very similar. The bill has a chisel-like tip. It is kept sharp by the pecking action.
To prevent brain damage from the rapid and repeated powerful impacts, woodpeckers have a number of physical features that protect their brains.
Distribution, habitat, and movements
Global distribution
Woodpeckers can be found worldwide, although they are absent from Australasia, Madagascar, and Antarctica. They are also absent from some of the world's oceanic islands.
Most woodpeckers are sedentary, but a few spieces are migratory. The woodpeckers that do migrate, do so during the day.
Habitat requirements
Overall, woodpeckers live in wooded habitats. They reach their greatest diversity in tropical rainforests, but occur in almost all suitable habitats, including woodlands, savannahs, scrublands, and bamboo forests. Even grasslands and deserts have been colonised by various species. Some species are able to adapt to forest clearance by exploiting secondary growth, plantations, orchards, and parks. In general, forest-dwelling species need rotting or dead wood on which to forage.
Several species are adapted to spending a portion of their time feeding on the ground, and a very small minority have abandoned trees entirely and nest in holes in the ground. The ground woodpecker is one such species, inhabiting the rocky and grassy hills of South Africa, and the Andean flicker is another.
Behavior
Most woodpeckers live solitary lives, but their behavior ranges from highly antisocial species that are aggressive towards their own kind, to species that live in groups. Aggressive behaviors include bill pointing and jabbing, head shaking, wing flicking, chasing, drumming, and vocalizations.
Group-living species tend to be communal group breeders. Most birds roost alone and will oust intruders from their chosen site, but the Magellanic woodpecker and acorn woodpecker are cooperative roosters.
Drumming
Drumming is a form of nonvocal communication used by most species of woodpeckers, and involves the bill being repeatedly struck on a hard surface with great rapidity. After a pause, the drum roll is repeated, with each species having a pattern that is unique in the number of beats in the roll, the length of the roll, the length of the gap between rolls, and the cadence. The drumming is mainly a territorial call, equivalent to the song of a passerine. Woodpeckers choose a surface that resonates, such as a hollow tree, and may use man-made structures such as gutters and downpipes. Drumming serves for the mutual recognition and plays a part in courtship rituals.
Calls
Calls produced include brief, high-pitched notes, trills, rattles, twittering, whistling, chattering, nasal churrs, screams, and wails. These calls are used by both sexes in communication and are related to the circumstances of the occasion; these include courtship, territorial disputes, and alarm calls. Each species has its own range of calls. Mated couples may exchange muted, low-pitched calls, and nestlings often issue noisy begging calls from inside their nest cavity.
Diet and feeding
Most woodpecker species feed on insects and other invertebrates living under bark and in wood, but overall, the family is characterized by its dietary flexibility. The diet includes ants, termites, beetles and their larvae, caterpillars, spiders, other arthropods, bird eggs, nestlings, small rodents, lizards, fruit, nuts, and sap. Crustaceans, molluscs, and carrion may be eaten by some species, including the great spotted woodpecker, and bird feeders are visited for suet and domestic scraps.
Breeding
All members of the family Picidae nest in cavities, nearly always in the trunks and branches of trees, well away from the foliage. Where possible, an area of rotten wood surrounded by sound timber is used. Where trees are in short supply, the gilded flicker and ladder-backed woodpecker excavate holes in cactus, and the Andean flicker and ground woodpecker dig holes in earth banks. The campo flicker sometimes chooses termite mounds, the rufous woodpecker prefers to use ants' nests in trees and the bamboo woodpecker specialises in bamboos. Woodpeckers also excavate nest holes in residential and commercial structures and wooden utility poles.
A pair works together to help build the nest, incubate the eggs, and raise their young. In most species, though, the male does most of the nest excavation and takes the night shift while incubating the eggs. A clutch usually consists of two to five round, white eggs. Since these birds are cavity nesters, their eggs do not need to be camouflaged and the white color helps the parents to see them in dim light.
The eggs are incubated for about 11–14 days before they hatch. About 18–30 days are then needed before the chicks are fully fledged and ready to leave the nest. In most species, soon after this, the young are left to fend for themselves. In general, cavity nesting is a successful strategy and a higher proportion of young is reared than is the case with birds that nest in the open. In Africa, several species of honeyguide are brood parasites of woodpeckers.
Relationship with humans
In general, humans consider woodpeckers in a favourable light. They are viewed as interesting birds and fascinating to watch as they drum or forage, but their activities are not universally appreciated. Many woodpecker species are known to excavate holes in buildings, fencing, and utility poles. Such activity is very difficult to discourage and can be costly to repair.
Woodpeckers sometimes cause problems when they raid fruit crops, but their foraging activities are mostly beneficial as they control forest insect pests such as the woodboring beetles that create galleries behind the bark and can kill trees. They also eat ants, which may be tending sap-sucking pests such as mealybugs, as is the case with the rufous woodpecker in coffee plantations in India.
Woodpeckers can serve as indicator species, demonstrating the quality of the habitat. Their hole-making abilities make their presence in an area an important part of the ecosystem, because these cavities are used for breeding and roosting by many bird species that are unable to excavate their own holes, as well as being used by various mammals and invertebrates.
In culture
One of the accounts of the founding of Rome, preserved in the work known as Origo Gentis Romanae, refers to a legend of a woodpecker bringing food to the boys Romulus and Remus during the time they were abandoned in the wild, thus enabling them to survive and play their part in history.
The Pokémon Pikipek was introduced in the seventh generation games Pokémon Sun and Moon. In addition to being a visual homage to a pileated woodpecker, entries in the game's Pokédex encyclopedia describes the small Flying-type as analogous to its real-world counterpart. Its later forms (called "evolutions" in the series) Trumbeak and Toucannon resemble a honeyguide and toucan, respectively, perhaps as a tongue-in-cheek reference to the phylogenetic relationship woodpeckers share with these Piciformes families.
Status and conservation
Several woodpeckers are under threat as their habitats are destroyed. Being woodland birds, deforestation and clearance of land for agriculture and other purposes can reduce populations dramatically. Some species adapt to living in plantations and secondary growth, or to open countryside with forest remnants and scattered trees, but some do not. A few species have even flourished when they have adapted to man-made habitats. There are few conservation projects directed primarily at woodpeckers, but they benefit whenever their habitat is conserved. The red-cockaded woodpecker has been the focus of much conservation effort in the southeastern United States, with artificial cavities being constructed in the longleaf pines they favour as nesting sites.
Two species of woodpeckers in the Americas, the ivory-billed woodpecker is critically endangered and the imperial woodpecker is classified as extinct in the wild, with some authorities believing them extinct, though possible but disputed ongoing sightings of ivory-billed woodpeckers have been made in the United States and a small population may survive in Cuba. A critically endangered species is the Okinawa woodpecker from Japan, with a single declining population of a few hundred birds. It is threatened by deforestation, golf course, dam, and helipad construction, road building, and agricultural development.
Bio-inspired ideas
The spongy bones of the woodpecker's skull and the flexibility of its beak, both of which provide protection for the brain when drumming, have provided inspiration to engineers:
- A black box needs to survive intact when a plane falls from the sky, and modelling the black box with regard to a woodpecker's anatomy has increased the resistance of this device to damage 60-fold.
- The design of protective helmets is another field being influenced by the study of woodpeckers.
- Bio-inspired honeycomb sandwich beams are inspired by the woodpecker's skull design; this beam's goal is to withstand continuous impacts without the need of replacement.
Interesting facts about woodpeckers
- Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions.
- Most species live in forests or woodland habitats, although a few species are known that live in treeless areas, such as rocky hillsides and deserts.
- The Gila woodpecker specialises in exploiting cacti.
- The family Picidae includes about 240 species arranged in 35 genera.
- Almost 20 species are threatened with extinction due to loss of habitat or habitat fragmentation, with one, the Bermuda flicker, being extinct and a further two possibly being so.
- Woodpeckers tend to be sexually dimorphic, but differences between the sexes are generally small.
- They have long, sticky tongues for extracting food (insects and larvae).
- Many of the foraging, breeding, and signaling behaviors of woodpeckers involve drumming and hammering using their bills.
- The pecking causes the woodpecker's skull to heat up, which is part of the reason why they often peck in short bursts with brief breaks in between, giving the head some time to cool.
See also
In Spanish: Pájaro Carpintero para niños
