Sharpbill: Oxyruncidae

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SHARPBILL: Oxyruncidae

PHYSICAL CHARACTERISTICS

Sharpbills are small, sturdy, quiet birds 6 to 7 inches (15 to 18 centimeters) in length that live in scattered areas of South America. Sharpbills have olive green backs, black wings, and black tails. Their undersides are ivory with distinctive dark tear-shaped spots on the upper part of the breast. In the center of the head is a bright orange or red crest that is normally hidden, but is raised when the bird is excited. Males and females look similar, although the colors of the female may be duller. Some ornithologists, scientists that study birds, separate this species into five different groups based on their geographic location and small differences in color and size. However, these differences are minor.

Sharpbills get their name from the distinctive shape of their gray bill, which is sharply pointed. The bill is surrounded by rictal (RIK-tuhl) bristles, stiff stripped-down feathers consisting mainly of the feather shaft. Originally it was thought that rictal bristles helped the birds catch insects while flying, but experimental evidence disproved this theory. Ornithologists (scientists who study birds) now think the bristles may help to keep insects out of the birds' eyes as they fly.

Ornithologists have not decided exactly where sharpbills belong in the classification of bird families. Sharpbills were first scientifically described in 1820 and were put in their own family, which contains only this species. Since then, they have been reclassified by some ornithologists as contingas or as tyrant flycatchers. Genetic research started in the 1980s seemed to suggest that they could be part of the tyrant flycatcher family, but as recently as 2002, there was no firm conclusion about how they should be classified.


GEOGRAPHIC RANGE

The range of the sharpbill is unusual, because it is discontinuous, or broken. Sharpbills are found in isolated patches throughout Central and South America. They live year round in parts of Costa Rica and Panama, Argentina, Bolivia, Brazil, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, and Venezuela. The broken up nature of their range suggests that at one time they may have been found over a much greater, continuous area.


HABITAT

Sharpbills live and breed in humid mountain rainforests at elevations of 1,300 to 5,900 feet (400 to 1,800 meters) above sea level. They are found in both dense forest and along the forest edges. Although they do not migrate, or move seasonally to find food, in the traditional sense, some scientists have reported that they do move down the mountain toward lowland rainforests when they are not breeding.

WHAT IS A TAXONOMIST?

A taxonomist is a scientist who studies the orderly classification of plants and animals. Taxonomists first look to see if two groups of plants or animals can interbreed, produce living offspring. This is the main way to define separate species. Taxonomists also look at the physical and behavioral characteristics a species shares with other species in determining their genus (JEE-nus), the first grouping above individual species, and the family, a grouping of genera (JEN-uh-rah; plural of genus). Today, taxonomists use biochemical and genetic tests to determine the relationship among species, genera, and families. Single species like sharpbills that do not seem to be closely related to any other species provide a challenge for taxonomists. Often they are reclassified several times as more information becomes available.

DIET

Sharpbills eat mainly fruit, insects, and insect eggs. They get their name from their pointed bill that allows them to hunt for food using what is called "pry and gape" behavior. When a sharpbill is feeding, it often hangs upside down on a branch and uses its pointed bill to pry into fruit, tightly rolled leaves, or moss growing on the tree. It then forces its bill apart (gapes) and collects seeds or insects from inside the fruit, leaves, or moss. This type of feeding behavior is uncommon. It is an example of a physical trait, the bill, and a behavioral trait, the feeding technique, evolving, changing over time, together to give the bird an advantage over competing species.

BEHAVIOR AND REPRODUCTION

Sharpbills are quiet birds that tend to stay still, making only short flights between perches. Their coloring allows them to blend in well with the environment, making them hard to observe. They live alone, rather than in flocks.

Although sharpbills were first described in 1820, the first sharpbill nest was not found until 1980, so not much is known about the mating and nesting behavior of these birds. It is believed that sharpbills mate from late February to May. The nest that was found in 1980 contained two eggs and was a shallow cup located near the top of tree about 100 feet (30 meters) tall, making observations difficult for scientists. Much remains to be learned about the behavior of these birds.

SHARPBILLS AND PEOPLE

Sharpbills are of interest mainly to ornithologists and birdwatchers.

CONSERVATION STATUS

Not enough is known about these birds to determine their conservation status. However, the broken up nature of their range suggests that they once were found in a wider area than they are today.


FOR MORE INFORMATION

Books:

Hilty, Steven L. Birds of Venezuela. Princeton, NJ: Princeton University Press, 2003.

Ridgley, Robert S., and Guy Tudor. The Birds of South America. Vol. 2, The Suboscine Passerines. Austin, TX: University of Texas Press, 1994.

Periodicals:

Brooke, M., D. Scott, and D. Teixeira. "Some Observations Made at the First Recorded Nest of the Sharpbill Oxyruncus cristatus." Ibis (1983): 259–261.

Web sites:

"Birds Mammals and Amphibians of Latin America." NatureServe. http://www.natureserve.org/infonatura (accessed on May 4, 2004).

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