PLANTCUTTERS: Phytotomidae

PHYSICAL CHARACTERISTICS

Adult plantcutters are generally between 7 and 8 inches (18 and 20 centimeters) long, and have short, thick, cone-shaped bills. Their bodies are stocky, although they weigh only 1.5 ounces (40 grams). The birds' wings and legs tend to be short, although plantcutters have long tails and strong, large feet. In the males and females of the Peruvian and red-breasted species, the head peaks in a short crest. The rufous-tailed plantcutter is similar looking, but lacks a crest and has more red in its tail.

Male plantcutters are more brightly colored than the females, and show off their cinnamon or rusty breasts and bellies and distinctive black eye stripes at mating time. Neither sex is particularly colorful, however, blending into their dry environment with ashy gray (male) and buff-brown (female) backs. Both sexes have white bars on their wings and tail ends and either yellow or crimson irises.

These birds are locally known in South America as cotarramas, cortaplantas, and raras ("rare ones"). Their name derives from the highly unusual rows of sharp, forward-leaning, tooth-like projections on the edges of their bills on both sides. Made of keratin (KARE-ah-tin), like the bill itself, these projections allow the birds to pulverize and eat the leafy foods on which they feed.

GEOGRAPHIC RANGE

The Peruvian plantcutter lives only in the dry forest and scrublands of Peru's northwest coasts. The rufous-tailed and red-breasted plantcutters occupy a larger area, and may be found in Argentina's southern temperate zone and Chile, and north to subtropical Bolivia and Paraguay.

HABITAT

The Peruvian plantcutter lives exclusively in the dry forests of Peru's northwest coast, whereas the rufous-tailed and red-breasted varieties live mainly in open farmland, grassland, open forest, and scrubland.

DIET

All three species of plantcutter are herbivores (plant eaters), eating leaves of the plants and trees found in their habitats. They also eat fruit on occasion, and since humans have occupied their territories have developed a fondness for grape and cereal-crop leaves.

Unlike other species of herbivorous birds, of which there are only a few, the plantcutter has not evolved a complex digestive system to process its tough, fibrous food. They use the tooth-like ridges on the edges of their beaks to chew their food into a pulp, which allows their digestive tracts to absorb the nutritious interiors of the plants' cells.

The plantcutter species has extremely efficient intestines that can process large amounts of vegetation in a relatively short time. This adaptation lets the birds maintain a high metabolic level, and thus a high energy and activity level.

BEHAVIOR AND REPRODUCTION

Unlike the majority of vegetarian birds, whose biology demands that they conserve energy to compensate for their low-calorie diet, plantcutters are energetic and lively. They patrol their territories throughout the day, looking for new food sources and invaders.

The reproductive life of the plantcutter species remains something of a mystery to ornithologists, although we know that the females lay two to four eggs in a loosely constructed nest.

A FAMILY NAME

Bird scientists have long debated exactly where the plantcutter belongs in the classification of all organisms. Some experts insist that the bird represents a distinct genus within the cotinga family, while others believe it forms a genus in a cotinga subfamily within the tyrant flycatcher family. Ongoing ornithological, bird science, studies hope to bring a definitive answer to the question soon.

PLANTCUTTERS AND PEOPLE

South American farmers and vintners (grape growers) often complain about plantcutter raids on their grape and cereal crops. However, tourist revenue from avid birdwatchers hoping for a glimpse of the rare Peruvian plantcutter helps to offset any animosity.

CONSERVATION STATUS

While the red-breasted and rufous-tailed plantcutters vigorously occupy a large area of South America, the Peruvian plantcutter is one of the most Endangered birds in the world, facing a very high risk of extinction, because of the rapid destruction of its small habitat for grazing, mining, and agriculture.

PERUVIAN PLANTCUTTER (Phytotoma raimondii): SPECIES ACCOUNTS

Physical characteristics: Adult Peruvian plantcutters are 7 to 8 inches (18 to 20 centimeters) in length and weigh approximately 1.5 ounces (40 grams). Both males and females have bright yellow eyes and a short crest, but the male is more colorful, with red patches on his lower breast and forehead. The birds' short wings make them agile fliers, and their strong feet allow them to grasp their leafy food tightly as they shred it with their tough, ridged beaks.

Geographic range: The Peruvian plantcutter lives only in coastal northwestern Peru, from the city of Tumbes south to the capital, Lima.

Habitat: Adapted to the dry environment known as the Tumbesian ecosystem, the Peruvian plantcutter prefers desert scrub, low woodlands (both open and dense), and occasionally thickets near or next to rivers. Its habitat is always populated with caper shrubs, acacia (uh-KAY-shah) trees, the Prosopis tree, and climbing vines in the cucumber family. The Peruvian plantcutter is notoriously sensitive to any changes in its environment, including noise, light, and contamination.

Diet: Although it eats occasional bits of fruit, the Peruvian plantcutter gets most of its nutrition from the leaves and buds of the Prosopis tree and various shrubs. In terms of diet, the bird has adapted to its dry environment by extracting most of its water from the foliage it eats.

Behavior and reproduction: The Peruvian species of plantcutter is a high-energy and active bird, patrolling its territory during the day to flush out interlopers and find new sources of food. Its throbbing, sad song has prompted locals to nickname it the "toothache bird."

Scientists know very little about the reproductive habits of the bird. However, field biologists have observed that they build loose nests and that the females lay between two and four eggs. The eggs are a mottled brown color to help camouflage (KAM-uh-flaj; hide) them from predators, animals that hunt them for food. The females incubate the eggs, keep them warm, by sitting on them for an unknown period of time.

Peruvian plantcutters and people: The Peruvian plantcutter has become a rallying symbol for Peru's emerging conservation movement. Champions of the bird have been fighting to save the estimated 500 to 1,000 remaining birds by educating the public and trying to block agricultural interests from developing the plantcutter's last population stronghold near Talara.

Conservation status: There are only four recent records of sightings of this bird, leading to its classification by the World Conservation Union (IUCN) as Endangered. The Peruvian plantcutter is extremely choosy about its habitat. The species has failed to colonize some apparently suitable territory, which has puzzled experts.

A nongovernment conservation group called ProAvesPeru is the leader in the effort to save the Peruvian plantcutter. Sponsored and supported by the Audubon Society of Latin America, ProAvesPeru's main goal is to establish the Talara Reserve. Another ally of the plantcutter is Gunnar Engblom, a Swedish ornithologist who in 1999 conducted the first ecological study of the bird's habitat.

The main threats to Peruvian plantcutters are gold mining, animal grazing, illegal logging for firewood, and the installation of new crops such as sugar cane.

FOR MORE INFORMATION

Books:

Feduccia, Alan. The Origin and Evolution of Birds. New Haven, CT: Yale University Press, 1999.

Sibley, C. G., and B. L. Monroe. Distribution and Taxonomy of Birds of the World. New Haven, CT: Yale University Press, 1990.

Skutch, Alexander F. Life Histories of Central American Birds. Vol. 3. Berkeley, CA: Cooper Ornithological Society, 1969.

Periodicals:

Lopez-Calleja, M. V., and F. Bozinovic. "Energetics and Nutritional Ecology of Small Herbivorous Birds." Revista Chilena de Historia Natural 73 (September 2000): 411–420.

Prum, R. O., et al. "A Preliminary Phylogenic Hypothesis for the Cotingas (Cotingidae) Based on Mitochrondrial DNA." Auk 117 (2000).

Web sites:

"Birder's Exchange Recipients." American Birding Association. http://www.americanbirding.org/programs/consbexr3.htm (accessed on April 27, 2004).

"Tambogrande Referendum Has Domino Effect in Peru." Americas Program. http://www.americaspolicy.org/citizen-action/focus/0207tambogrande_body.html (accessed on April 27, 2004).

"Conservation of the Critically Endangered Peruvian Plantcutter in Talara Province, NW Peru." Audubon Latin America. http://www.audubon.org/local/latin/bulletin6/initiatives.html (accessed on April 27, 2004).

"Birdlife Species Factsheet (extended): Peruvian Plantcutter (Phytotoma raimondii)." Birdlife International. http://www.birdlife.net (accessed on April 27, 2004).

"Conservation of the Threatened Peruvian Plantcutter." Communications for a Sustainable Future. http://csf.colorado.edu/mail/elan/jan99/0053.html (accessed on April 27, 2004).

"Phytotomidae." Cornell University, Department of Ecology and Evolutionary Biology. http://www.eeb.cornell.edu/winkler/botw/phytotomidae.html (accessed on April 27, 2004).

"Phytotomidae: Plantcutters." John Penhallurick's Bird Data Project. http://www.worldbirdinfo.net (accessed on April 27, 2004).