Animal Diversity Web

Diversity

Woodcreepers are in the order Passeriformes, suborder Furnarii and family Dendrocolaptidae. There are 13 genera and 50 species within the family. Woodcreepers are small to medium sized birds. Most have brown plumage with some white spots or streaks. Their tails usually have rigid shafts and spiny tips that help the birds climb trees. They are Neotropical birds found from Mexico to central Argentina. Woodcreepers live primarily in lowland tropical forests and are mainly insectivores. Some species follow swarms of army ants and eat the insects that are flushed by the ants. Most species are monogamous although some form dispersed leks. Woodcreepers are poor dispersers and, like many bird species, they are suffering from habitat loss and fragmentation. Some species are better able to cope with human disturbance than others, but preservation of their habitat is crucial. (Campbell and Lack, 1985; Dickinson, 2003; Marantz and Hutson, 2003; Marantz, et al., 2003; Wetmore, 1972)

Geographic Range

Woodcreepers are Neotropical birds; their range extends from Mexico south to central Argentina. The highest diversity of woodcreepers occurs in the lowlands of the Amazon Basin. (Campbell and Lack, 1985; Marantz and Hutson, 2003; Marantz, et al., 2003; Wetmore, 1972)

• Biogeographic Regions
• neotropical
  • native

Habitat

Most woodcreepers live in lowland tropical rainforest. However, some species can be found in forest edge habitats, semi-open habitats, cloudforest, savanna or arid scrub. Most species are found below 1000 m, but some can be found in the mountains up to 3600 m. Species that have been able to adapt to human disturbance can be found in some suburban and urban areas. (Marantz and Hutson, 2003; Marantz, et al., 2003)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• forest
• rainforest
• scrub forest
• mountains

• Other Habitat Features
• urban
• suburban

Physical Description

Woodcreepers are small to medium sized birds (13 to 36 cm and 11 to 160 g). They are typically brown, olive or rufous colored with white spots, streaks or bars. Species that live in open areas are lighter colored underneath. Their broad, rounded wings and specialized tail are often rufous colored and the tips of their remiges (flight feathers) are usually darker. Woodcreepers molt once each year, however, molting does not change their appearance. Most species are not sexually dimorphic. However, in some species the males are larger and some males are able to raise their crown feathers while females are not. Different species of woodcreepers are often very difficult to tell apart. Many species have similar behaviors, colors and shapes. Often they can only be told apart by their calls. Juveniles generally have more barring than adults, a shorter tail and a darker, shorter bill.

Bill size and shape is variable in woodcreepers and reflects foraging strategy. Bills range from long to short, thick to thin and straight to very decurved. Long-billed woodcreepers (Nasica longirostris) have a bill that is one quarter of their body length.

Woodcreepers’ tails are specialized to help them climb trees; the tail feathers have stiff, spiny shafts that are claw-like. Their foot and leg morphology also help them climb and their claws are very curved. (Campbell and Lack, 1985; Marantz and Hutson, 2003; Marantz, et al., 2003; Wetmore, 1972)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike
• male larger

Reproduction

Most woodcreepers are monogamous and some species remain in their pairs throughout the year. Some (from the genus Dendrocincla) may be polygynous with a dispersed lek system. (Marantz and Hutson, 2003; Marantz, et al., 2003)

• Mating System
• monogamous
• polygynous

Some woodcreepers are year-round breeders and others are seasonal. Those that breed seasonally breed in the summer. They nest in cavities, but do not excavate their own sites. Instead they use woodpecker cavities, holes in stumps, abandoned termite mounds, or man-made structures. Most nests are within 5 m of the ground and may have a long, narrow nest entrance. Nests are lined with bark chips or wood shavings or are a shallow cup made of roots, leaves and other plant fibers.

The female usually lays 2 (sometimes 3) white, unmarked eggs. Incubation and nestling periods are not well known, however, the available information suggests that incubation lasts 14 to 16 days and fledging occurs 17 to 25 days after hatching. Young may be dependent on adults for up to one year after hatching, although many remain with their parents for only a few months. (Campbell and Lack, 1985; Marantz and Hutson, 2003; Marantz, et al., 2003; Wetmore, 1972)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• oviparous

Incubation and nestling periods are not well known, however, the available information suggests that incubation lasts 14 to 16 days and fledging occurs 17 to 25 days after hatching. Species with bi-parental care have shorter times to fledging than species with only female parental care. In monogamous species, both the male and female build the nest, incubate eggs, brood young and feed nestlings and fledglings. In the polygynous species of the genus Dendrocincla, usually only the female provides parental care.

The altricial chicks are fed primarily insects, beetle larvae, grasshoppers, spiders and small lizards. Young may be dependent on adults for up to one year after hatching, although many remain with their parents for only a few months. Woodcreepers are often found in family groups. (Campbell and Lack, 1985; Marantz and Hutson, 2003; Marantz, et al., 2003; Wetmore, 1972)

• Parental Investment
• altricial
• male parental care
• female parental care

Lifespan/Longevity

Like most small birds, woodcreepers probably live on average only two to five years. (Gill, 1995)

Behavior

Woodcreepers are found alone, in pairs, small family groups, or mixed species flocks. The mixed-species flocks usually include other insectivorous species that some species of woodcreepers join as they follow swarms of army ants and catch insects that the ants flush as they move through the forest.

Most species are sedentary, although some make nomadic wanderings and altitudinal shifts in response to food availability. They have an undulating flight and sing at dawn and dusk. They roost alone in cavities at night. Woodcreepers will not cross large, unforested gaps; this may become a problem for their survival as their habitat becomes increasingly fragmented.

Woodcreepers spend most of their time in trees and are morphologically adapted for tree climbing (see Physical Description). They creep or “hitch” up trees using their tail as a brace. They are very aggressive and larger species are dominant over smaller species. They defend territories, but their defensive behavior usually entails chasing intruders out of flocks rather than out of a defended area. Woodcreepers sunbathe and have been seen anting, a behavior that is thought to help prevent or remove ectoparasites. (Marantz and Hutson, 2003; Marantz, et al., 2003)

• Key Behaviors
• arboreal
• flies
• glides
• diurnal
• motile
• nomadic
• sedentary
• solitary
• territorial
• social
• dominance hierarchies

Communication and Perception

The songs of woodcreepers are simple and unmusical. They often consist of a single repeated note or whistle, creating a rattle or trill. A few species have more complex calls and mates have contact calls that they use to communicate with each other. The frequency of woodcreeper calls is between 840 to 8830 Hz; larger species with longer bills have lower frequency songs.

Woodcreepers sing at dawn and dusk; they sing to mark their territories and to maintain contact with mates. Lekking species sometimes sing in choruses. Geographic variation exists in woodcreeper songs. Different species of woodcreepers are often very difficult to tell apart; many have similar behaviors, colors and shapes. Often they can only be told apart by their calls. (Marantz and Hutson, 2003; Marantz, et al., 2003)

• Communication Channels
• acoustic

• Other Communication Modes
• choruses

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Woodcreepers have diverse bill morphologies that reflect their diverse foraging strategies. Some of the foraging strategies include: gleaning, flycatching, probing and chiseling. They often poke through vegetation (including epiphytic plants), pry off bark, and probe along tree surfaces in search of insect prey. Most species find food while climbing on tree trunks or branches. They begin foraging at the base of a tree, work their way up and then fly to the base of another tree and begin again. Some species of woodcreepers forage by following army ant (subfamily Ecitoninae) swarms to catch the prey that are flushed by the swarms.

Woodcreepers are primarily insectivores, although they occasionally eat small vertebrates (such as lizards, frogs, snakes and salamanders), crabs (Decapoda) and snails (Mollusca). The most common foods consumed by woodcreepers include: grasshoppers and crickets (Orthoptera), beetles (Coleoptera), cockroaches (Blattodea), ants (Formicidae) and spiders (Araneae). Only very rarely do woodcreepers eat seeds or fruit. A notable sighting was that of a great rufous woodcreeper (Xiphocolaptes major) eating a small bat. (Campbell and Lack, 1985; Marantz and Hutson, 2003; Marantz, et al., 2003; Wetmore, 1972)

• Primary Diet
• carnivore
  • insectivore

Predation

Snakes (suborder Serpentes) are common predators of eggs and nestlings. Adults are taken by forest raptors (order Falconiformes). Woodcreepers’ coloration helps them avoid predation by blending in with their habitat. (Marantz, et al., 2003; Wetmore, 1972)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • snakes (Serpentes)
  • forest raptors (Falconiformes)

Ecosystem Roles

Woodcreepers are important members of their ecosystems. They have an impact on populations of the prey they eat and are food for their predators. They are also hosts to a number of blood parasites and feather lice. (Marantz, et al., 2003)

Economic Importance for Humans: Positive

Because encounters between woodcreepers and humans are limited, woodcreepers have no direct positive impacts on the economy other than the important ecosystem roles they play. (Marantz, et al., 2003)

Economic Importance for Humans: Negative

There are no known adverse affects of woodcreepers on humans.

Conservation Status

Habitat fragmentation and destruction for agriculture, logging, mining and the growth of urban areas are the main threats facing woodcreepers. Woodcreepers will not cross large, unforested gaps. This may become a problem for their survival as their habitat becomes increasingly fragmented. The dramatic reduction in lowland forest is also causing a reduction in the number of army ant colonies. Without the army ants, the foraging success of many species of woodcreepers will be reduced. There is a need for more preserves to protect the remaining intact forest.

Some species of woodcreepers are better able to cope with human encroachment than others. For example, some species nest in man-made structures or forage on the insects attracted to lights at night.

The IUCN lists two species of woodcreepers. Moustached woodcreepers (Xiphocolaptes falcirostris) are listed as vulnerable and greater scythbills (Campylorhamphus pucherani) are listed as near threatened. (IUCN, 2003; Marantz, et al., 2003)

• IUCN Red List [Link]

  Not Evaluated

Contributors

Alaine Camfield (author), Animal Diversity Web.

Kari Kirschbaum (editor), Animal Diversity Web.

References

Campbell, B., E. Lack. 1985. A Dictionary of Birds. Vermillion: Buteo Books.

Dickinson, E. 2003. The Howard and Moore Complete Checklist of the Birds of the World, 3rd edition. London: Christopher Helm.

Gill, F. 1995. Ornithology, Second Edition. New York: W.H. Freeman and Company.

IUCN, 2003. "2003 IUCN Red List of Threatened Species" (On-line). Accessed April 09, 2004 at http://www.redlist.org/.

Marantz, C., A. Aleixo, L. Bevier, M. Patten. 2003. Family Dendrocolaptidae (Woodcreepers). Pp. 358-447 in J del Hoyo, A Elliott, D Christie, eds. Handbook of Birds of the World, Vol. 8. Barcelona: Lynx Edicions.

Marantz, C., A. Hutson. 2003. Woodcreepers. Pp. 442-445 in C Perrins, ed. The New Encyclopedia of Birds. Oxford: Oxford Univeristy Press.

Payne, R. 2003. "Bird Families of the World" (On-line). Accessed April 09, 2004 at http://www.ummz.lsa.umich.edu/birds/Bird_Families_of_the_World.html.

Sibley, C., J. Ahlquist. 1990. Phylogeny and Classification of Birds, A study in Molecular Evolution. New Haven: Yale University Press.

Wetmore, A. 1972. The Birds of The Republic of Panama, Part 3. Washington: Smithsonian Institute Press.