By Alan Mowbray and Felipe Cano

Puerto Rican Parrot (USFWS)

HISTORY
On his second voyage to the New World in 1493, Christopher Columbus dropped anchor off the Caribbean island he named San Juan Bautista. He and his crew of Spanish explorers saw white sand beaches bordered by high mountains covered with lush forests. They were warmly greeted by the native Taino people who gave them gifts of gold nuggets plucked from the island’s rivers. During their two-day stay, Columbus most likely saw hundreds of noisy bright-green parrots with beautiful white-ringed eyes swooping overhead. The Taino called these birds “Iguaca.”

At the beginning of the sixteenth century, Spanish colonists estimated that there were nearly a million of these beautiful birds living in the island’s remaining forests. Today there are estimated to be less than fifty Amazona vittata living in the wild on the island we now know as Puerto Rico. Although the wild Puerto Rican parrot population has expanded to other locations on the island, at the moment, the 28,000 acre (19,650 hectare) El Yunque National Forest is the genesis of the renowned cooperative effort to save one of the 10 most endangered birds in the world.

Amazona vittata’s near disappearance is not unique. Of the three parrot species that are known to have inhabited U.S. territory at the turn of the twentieth century, all but one, the Puerto Rican Parrot became extinct or extirpated by the 1940’s. There are 332 known psittacine (parrot) species. Approximately 31 of them are of the Neotropical Amazona genus that inhabits central and South America and the Caribbean islands. Of these, 11 are considered threatened or endangered. Amazona vittata is the only Neotropical parrot that barely survives within the United States and its territories.

The decline of the island’s parrot population over five centuries is directly related to the rise in human population. As more colonists arrived, they cut-down forests and converted land for agriculture. The habitat on which the species depended began to disappear. The remaining parrot population which had retreated to the Luquillo Mountains was further threatened when the cutting of forest timber for charcoal production was encouraged beginning in the 1900’s.

The story of the last-ditch recovery effort to save this extraordinary bird from extinction illustrates a unique amalgamation of scientific intervention, agency cooperation and management strategy that began as a gamble with no guarantee of ultimate success.

In 1968 when the Puerto Rican parrot population had dwindled to around two dozen individual birds in the wild, a concerted mutual effort to save the species was launched. Christened the Puerto Rican Parrot Recovery Plan, it brought together scientists and managers from the US Fish and Wildlife Service, the US Forest Service and the Puerto Rico Department of Natural and Environmental Resources, with added support provided by the World Wildlife Fund.

By 1989, the Puerto Rican Parrot Recovery Plan had been in operation for over a decade. Through scientific intervention the parrot population in the wild had increased to 47 birds. Then suddenly disaster struck. On September 18th of that year, hurricane Hugo roared across the Luquillo Mountains destroying more than half the parrots in the wild. By year’s end a small population of 22 birds remained. By early 1994, the wild population had again risen to 39 birds and 6 breeding pairs. Today’s parrot population on the El Yunque National Forest continues to hover near to that level. Intense research and unswerving management strategies by the three cooperating agencies over the ensuing years have prevented the ultimate extinction of the Puerto Rican Parrot.

Illustration of improved nest cavity

US Forest Service
In collaboration with the Fish and Wildlife Service, US Forest Service biologists and technicians have created and managed nesting sites in the parrot’s habitat within the National Forest. Their efforts ensure the availability of nests for the wild parrot flock, construction and maintenance of canopy platforms and blinds for ongoing flock research, development and maintenance of service trails into the nesting areas and the control of some parrot flock predators and nest competitors. Forest Service experts also train Fish and Wildlife and Puerto Rico Department of Natural and Environmental Resources personnel in how to safely climb-up trees into the forest canopy. The conservation education program on the El Yunque National Forest provides information about the Puerto Rican Parrot and the vital parrot recovery program to over 600,000 visitors to the forest each year.

The overall achievement of the program consists of detailed control of the limiting factors to parrot population growth. El Yunque National Forests technicians deploy rat-bait boxes at the bases of trees in the nesting area to discourage the scavenging of parrot eggs from nests. Alternative nesting boxes are used for the Pearly-eyed Thrasher (Margarops fuscatus) an aggressive resident bird that if not prevented from doing so will lay its own eggs on top of the parrot eggs when the nest is untended causing the nest to be abandoned by the parrot parents. Mongooses (Herpestes auropunctatus), are introduced exotic predators that are trapped in the area surrounding the parrot habitat just prior to breeding season to ensure protected reproduction. During breeding season, artificial cardboard bee hives are also set as a substitute dwelling for exotic bees, another increasingly common parrot nest competitor. Forest Service and Fish and Wildlife Service biologists and technicians take a type of census of the wild parrot flock before and after each year’s breeding season, climbing 60 feet to the top of the forest’s canopy at dawn and dusk counting the individual birds to determine if the wild flock has increased, decreased or remained stable.

The design of artificial parrot nests was a mutual effort, between Forest Service biology technicians and Fish and Wildlife biologists that evolved over the years. Early in the recovery program it was recognized that natural nesting cavities in the parrot’s preferred Palo Colorado (Cyrilla racimiflora) trees were deteriorating. Natural nests in these trees also lacked a means to protect the parrot eggs and fledglings from incursions by exotic and native predators and nest competitors. Repeated “trial and error” design efforts by biologists and technicians ultimately produced sophisticated artificial nesting cavities constructed of virtually indestructible, industrial-grade polyvinylchloride (PVC) plastic that the parrots found acceptable, especially after a section of hollowed-out tree trunk was attached to the PVC entrance tube to make it appear more natural. The artificial nests accomplished the goal of protecting parrot eggs and nestlings from predators and nest competitors until they had fledged and left the nests. The final nest design was deployed at tree nesting cavities in the El Yunque National Forest in 2001. Since 2002, all wild flock nesting pairs have used these artificial nests, and at least 28 chicks have been fledged over the ensuing breeding seasons.

Iguaca Aviary (USFWS)

US Fish & Wildlife Service
The U.S. Fish and Wildlife Service is directly responsible for biological research and the direct management and handling of both captive and wild parrot flocks. FWS scientists monitor the breeding productivity, movement, and habitat use of wild and released parrots in the El Yunque National Forest. Monitoring scientists watch from blinds to protect nesting parrots and their offspring from predators, nest competitors and parasites and provide veterinary service when it is needed. Careful observation of nesting success is key to their efforts. Every year newly fledged wild chicks are equipped with radio transmitters that allow the scientists to study their movements, survival rates, and causes of mortality.

The FWS operates the new and modern Iguaca Captive Parrot Aviary located in the El Yunque National Forest. Here captive adult parrots are trained, conditioned and released. Breeding pairs are kept in nesting cages where they mate, eggs are hatched and nestlings are fledged. Fledged chicks that show promise are transferred to a much larger “flight cage” where human interaction is restricted. Here the young parrots learn how to survive in a close approximation of their future environment before being released into the wild.

Puerto Rico Department of Natural and Environmental Resources
Biologists and technicians of the Puerto Rico Department of Natural and Environmental Resources have become increasingly involved in the PR Parrot Recovery Program. In 1989, 30 Hispaniolan parrots (Amazona ventralis) obtained from the Dominican Republic were transferred to the Jose J. Vivaldi Aviary situated on Puerto Rico’s Rio Abajo State Forest to test this facility’s suitability as an alternate PR Parrot Aviary. The program proved so successful, that in 1993, a group of PR parrots (Amazona vittata) was transferred from the El Yunque Aviary to the Rio Abajo located in western Puerto Rico. Since then, this facility has successfully produced Amazona vittata fledglings.

The Future
The US Fish and Wildlife service will continue with periodical releases of captive PR parrots for introduction into the existing wild flock in the Luquillo Mountains.  The wild flock which is being created on the Rio Abajo State Forest will also be augmented with new individuals to better secure a self-sustaining parrot population.  Before that happens, biologists and technicians from the US Fish and Wildlife Service and US Forest Service will pass-on to the DNER scientists and technicians the hard-earned lessons they have learned over the past decades in the logistical support of the El Yunque wild parrot flock so they can further plan the infrastructure for the Rio Abajo Forest. Important skills such as recommended trail building and maintenance methods and suggested predator suppression and nest competition abatement techniques will be transferred to State Forest Managers.

What Have We Learned?
Amazona vittata has been kept from the brink of extinction. The recovery process is frustrating and very difficult. It has been going on now for nearly four decades and success is still not a scientific certainty. For the most part, the program has progressed because of the unselfish, dedicated and unceasing cooperation between scientists, managers and grass-roots workers of Federal, Commonwealth and private agencies and organizations. The Puerto Rican Parrot Recovery Program owes the success it has seen to the implementation and continuity of this unique union of concerned conservationists that serves as a template for similar endangered and threatened species recovery programs throughout the world.

Related Websites and Recommended Reading:

PR Parrot website of the USFWS.

Snyder, N. F. et.al. : 1987, The Parrots of Luquillo; Western Foundation for Vertebrate Zoology.

White, T. H., et al.; 2005, Survival of Puerto Rican Parrots Released in the Caribbean National Forest, “The Condor”, © The Cooper Ornithological Society, 2005.

Memorandum of Understanding (MOU) between Federal and Commonwealth agencies on the PR Parrot Recovery Program