PHILIPPINE CREEPERS: Rhabdornithidae

PHYSICAL CHARACTERISTICS

Philippine creepers are a small group of medium-sized, very similar looking, arboreal (living in trees) birds found only in the Republic of the Philippines. They are similar in physical appearances to treecreepers. The perching birds have long, slender bills and brush-tipped tongues. The bird group consists of three species, the greater rhabdornis, the stripe-breasted rhabdornis, and the stripe-headed rhabdornis.

As a group, Philippine creepers are very similar in size and color. However, there is little known about the specific details of the family's size and color. Philippine creepers are marked and shaded with black, brown, red-browns, gray, and white; colors that help them to blend into the forests in which they live. The birds have dark brown streaks on their upperparts, white on the under parts and flanks (with blackish streaks), and lighter streaks on the other parts of their body. They have a long, slender, pointed, down-curved bill and brush-like tongue. Philippine creepers are 6 to 7 inches (15 to 17 centimeters) long and weigh between 3 and 4 ounces (80 to 95 grams).

GEOGRAPHIC RANGE

Philippine creepers are limited to the range of the major Philippine Islands of Luzon, Samar, Leyte, Mindanao, Negros, and Panay and of the minor islands of Catanduanes, Masbate, Calicoan, Dinagat, Basilan, and Bohol.

HABITAT

Philippine creepers inhabit deep, dense, tropical primary and secondary lowland and mountainous forests, along with the edges of forests. They specifically prefer the upper levels, including the canopy (uppermost level of vegetation of the forest) and the crown (top part of the forest) of trees and the middle story (middle part) of the forest.

DIET

Philippine creepers run across the tops of tree branches, hop and jump between branches on trees, and crawl on tree bark found on the trunks and main limbs of trees during their foraging for food within the forest. They search on the bark of tree trunks and branches and even among flowers. Philippine creepers eat mostly insects, but also nectar (sweet liquid produced by flowering plants), fruits, and seeds. Their long, slender bill allows them to easily remove insects from bark, while their brush-tipped tongue enables them to quickly feed on nectar.

PHILIPPINE HABITAT DESTRUCTION

About 572 species of birds, including the Philippine creepers, are known to occur within the 7,100 islands that comprise the country of the Republic of the Philippines. Scientists believe that of these 572 species, about 172 bird species are not found in any other place on Earth. Many of these unique birds, however, are endangered as the result of high levels of habitat destruction in the Philippine forests. Their continued existence will depend in part on how successful conservation and protection measures will be in the future.

BEHAVIOR AND REPRODUCTION

In most of the recent past, these birds have been grouped with the northern creepers (family Certhidae), which is why they are often called Philippine creepers. Although they are called "creepers," their behavior is not very creeper-like. In fact, they act more like chickadees and titmice while in flocks of mixed species of birds. Philippine creepers are diurnal (active during the day) and arboreal (living in trees). They do not migrate (move between habitats) other than with regards to local movements in their permanent territory. They are very social birds, often found foraging with a flock of birds both within and outside of their family. Other specific behaviors with other birds are not known for certain due to a lack of adequate study and research. Their songs and calls are also unknown. At dusk, groups of the birds roost in the upper branches of trees. Little information is known about the reproduction activities of Philippine creepers. It is known that they nest in tree crevasses (cracks), but it is unknown what type of nesting material is used inside the nest. Also unknown is specific information about the number and coloring of eggs laid by the birds. Breeding probably begins in March but may occur at other times during the year.

PHILIPPINE CREEPERS AND PEOPLE

Philippine creepers have no special significance to people.

CONSERVATION STATUS

Philippine creepers are not threatened. The stripe-breasted rhabdornis and the stripe-headed rhabdornis are common throughout their ranges, while the greater rhabdornis is relatively rare and confined to the mountainous regions in Luzon (within the Philippines). As the native forests of the Philippines are increasingly destroyed, the size of their habitat (home environment and territory) is being decreased and the condition of their habitat is being severely degraded. Because of this, Philippine creepers have a weakened ability to grow in numbers.

STRIPE-HEADED RHABDORNIS (Rhabdornis mysticalis): SPECIES ACCOUNT

Physical characteristics: Stripe-headed rhabdornises (sometimes called the stripe-sided rhabdornises) are 5.7 to 6.2 inches (14.5 to 15.8 centimeters) long, and weigh between 2.75 and 3.00 ounces (78 to 85 grams). Both sexes are colored in a similar way, but males are larger in size than females. Generally, stripe-headed rhabdornises have black bills, dark brown eyes, and dark legs. Adult males have a blackish brown crown (top part of the head) and nape (back part of the neck) with many white streaks, a broad strip through the eye, while the face and the rest of the neck are blackish brown. Adult females differ from males in having a lighter brown crown and face. Both sexes have a striated head (marked with narrow parallel bands).

Geographic range: Stripe-headed rhabdornises range in the Philippine Islands of Luzon, Negros, Panay, Masbate, Contanduenes, Leyte, Mindanao, Samar, Basilan, Bohol, Calicoan, and Dinagat.

Habitat: Stripe-headed rhabdornises live throughout the major Philippine Islands in tropical forests from sea level up to an elevation of about 3,900 feet (1,200 meters). They generally prefer lowland forests and second growth forests, and are usually found within the canopy or middle story of the trees.

Diet: Stripe-headed rhabdornises primarily eat insects, along with nectar, fruits, and seeds found within their forest habitat. Stripe-headed rhabdornises forage (search for food) along limbs, checking crevices with their thin pointed, down-curved bills in order to remove insects from tree bark. They then use their brush-tipped tongues for the removal of nectar within flowers.

Behavior and reproduction: Stripe-headed rhabdornises are very active during the day. They occupy the canopy and middle story of primary forests, forest edges, and secondary growth. Groups of the birds themselves or groups of the birds along with other bird species often flock together in numbers up to twenty-five individuals. At dusk, they usually roost in large groups of up to several hundreds of birds. The call of the stripe-headed rhabdornises is an uninteresting, high-pitched "tsee tsee WICK tsee," with the "tsee" called out softly but the "WICK" spoken sharp and loud. The reproduction habits of the birds are largely unknown. They are believed to nest in cavities (hollow areas) and holes of trees.

Stripe-headed rhabdornises and people: Stripe-headed rhabdornises have no special significance to people.

Conservation status: Stripe-headed rhabdornises are not threatened. They are commonly found throughout a restricted range of the Philippine islands. However, as the native forests of the Philippines decrease due to increased and continuing activities of humans, the size and condition of the habitat of the birds is being negatively affected. Stripe-headed rhabdornises, thus, are less able to adequately cope with their changing environment. ∎

FOR MORE INFORMATION

Books:

del Hoyo, Josep, Andrew Elliott, Jordi Sargatal, et al, eds. Handbook of the Birds of the World. Barcelona: Lynx Edicions, 1992.

Dickinson, Edward C., ed. The Howard and Moore Complete Checklist of the Birds of the World, 3rd ed. Princeton, NJ and Oxford, U.K.: Princeton University Press, 2003.

Harrison, Colin James Oliver. Birds of the World. London and New York: Dorling Kindersley, 1993.

Forshaw, Joseph, ed. Encyclopedia of Birds, 2nd ed. San Diego, CA: Academic Press, 1998.

Perrins, Christopher M., and Alex L. A. Middleton, eds. The Encyclopedia of Birds. New York: Facts on File, 1985.

Web sites:

Birdwatch.ph. The Official Website of the Wild Bird Club of the Philippines. http://www.birdwatch.ph/gallery/stripeheadedrhabdornis.html (accessed on April 19, 2004).