North Carolina State University
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Media Contacts:
Dr. Jaime A. Collazo, 919/515-8837, or [email protected]
Kevin Potter, News Services, 919/515-3470 or [email protected]
June 8, 2000
Research by NC State Scientist Aids Recovery of Endangered Parrot
FOR IMMEDIATE RELEASE
With only 40 Puerto Rican parrots left in the wild, the species hovers precariously close to extinction. Research by an ornithologist at North Carolina State University, however, has laid the groundwork for the first large-scale release of captive-bred Puerto Rican parrots into the wild ñ a move aimed at improving the species' chance of survival.
On June 27, scientists will release 10 of the captive parrots in the Caribbean National Forest in extreme eastern Puerto Rico, and will free six more in August. Dr. Jaime Collazo, NC State associate professor of zoology, will be there.
"It may not sound like a whole lot to release that many birds, but when there are so few in the wild, this is a big deal, an important milestone," says Collazo (pronounced "co-YA-zo"), who is assistant unit leader in the North Carolina Cooperative Fish and Wildlife Research Unit at NC State. "We are finally implementing a more aggressive recovery action; up to this point, only one to three captive-bred chicks per year could be added to the wild population by way of a fostering program." While valuable, he explains, that approach is constrained by the small number of breeding pairs in the wild in any given year.
The Puerto Rican parrot (Amazona vittata) is thought to have been common before Columbus arrived in the Americas. By the 1950s, however, the population dwindled to only 200 birds, and further plummeted to 13 in 1973 - all living in the Caribbean National Forest. Researchers blame deforestation as the main reason for decline, while hunting, natural predation and the taking of the parrots as pets were contributing factors.
The species had recovered somewhat in recent years, growing to at least 47 birds in 1989. But half the birds were wiped out when Hurricane Hugo pounded the island that September. An additional 120 Puerto Rican parrots live in captivity at two aviaries.
Collazo says the releases will boost the size of the wild population - even if many of the released birds die in the wild - and will help maintain the long-range viability of the species in the face of such natural catastrophes. "The Puerto Rican parrot hasn't been able to establish a wild population of more than 40 or 50 birds," he says. "With these releases, we hope to break this demographic inertia."
To come to that conclusion, Collazo, along with Dr. Franscisco J. Vilella of Mississippi State University and Dr. Thomas H. White of the U.S. Fish and Wildlife Service, conducted two years of "dress rehearsal" releases using the Puerto Rican parrots' closest relation, the Hispaniolan parrot (Amazona ventralis). Working in Parque Nacional del Este (National Park of the East) at the southeastern tip of the Dominican Republic, the researchers released 49 of the Hispaniolan parrots from 1996 to 1998.
Collazo and his colleagues will present their findings from that research on Saturday, June 10, and Sunday, June 11, at the Society for Conservation Biology annual conference at the University of Montana in Missoula.
Their work in the Dominican Republic taught Collazo and his colleagues a number of important lessons that the researchers considered as they prepared to release the Puerto Rican parrots:
Before the release, it's highly important that the birds be taken to the release site for an "acclimation period" of two to four weeks; that they be offered natural foods to familiarize themselves with what they will encounter when released; and that they be given an "exercise regimen" that allows for the maximum development of flight muscles. Stronger birds, familiar with their surroundings and foods, were more likely to join and remain with wild birds, and to forage for food over a larger area - which is a key to their survival.
Releasing the birds as far ahead of the September hurricane season peak, preferably in June, also is important. Hispaniolan parrots released several months before Hurricane Georges hit the Dominican Republic in September 1998 were better able to survive the food shortage caused by the storm, Collazo says.
Scientists from the U.S. Fish and Wildlife Service, the U.S. Forest Service and the Puerto Rico Department of Natural and Environmental Resources are hoping to release captive-raised Puerto Rican parrots every year or every other year. Collazo and a Dominican student at the University of Puerto Rico, Jose Luis Hernandez, will monitor the released birds using radio telemetry.
Within a decade, Collazo hopes there will be at least 100 Puerto Rican parrots in the wild.
Collazo says the research in the Dominican Republic also was useful because the karst or limestone geologic formation of the park is similar to that of the Rio Abajo area in north-central Puerto Rico, where scientists hope to establish a second population of Puerto Rican parrots in three to five years. "You're not putting all your eggs in the same basket, so with the next Hugo you're more likely to have an unaffected population," he says of establishing a second population.
The federal and Puerto Rican government agencies are seeking funding to establish a large preserve in the Rio Abajo area to help ensure the success of that future reintroduction project.
Collazo will soon join Dr. Vilella of Mississippi State University to begin research to determine whether predation of Puerto Rican parrots by red-tailed hawks (Buteo jamaicensis) is suppressing parrot population growth. Before coming to NC State in 1989, Collazo worked for the Fish and Wildlife Service and the Puerto Rico Department of Natural and Environmental Resources.
-potter-
NOTE TO EDITORS: A photo of a Puerto Rican parrot is available by e-mail from NC State News Services, 919/515-3470 or [email protected],or you can download it from http://www2.ncsu.edu/ncsu/univ_relations/news_services/press_releases/00_06/137.htm.
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