The Puerto Rican amazon (Amazona vittata), also called the Puerto Rican parrot (Spanish: cotorra puertorriqueña) or iguaca (Taíno), is the only parrot species that lives only in Puerto Rico. It grows to be 28–30 cm (11.0–11.8 in) long and is mainly green with a red forehead and white rings around its eyes. It belongs to the Neotropical genus Amazona, and its closest relatives are the Cuban amazon (Amazona leucocephala) and the Hispaniolan amazon (Amazona ventralis).

The Puerto Rican amazon becomes sexually mature between three and four years old. It breeds once each year and nests in tree cavities. After laying eggs, the female stays in the nest and keeps the eggs warm until they hatch. Both parents feed the chicks, and the young birds leave the nest 60 to 65 days after hatching. The parrot eats a variety of foods, including flowers, fruits, leaves, bark, and nectar from the forest canopy.

This parrot is the only native parrot species in Puerto Rico and has been listed as critically endangered by the World Conservation Union since 1994. Once common, its population dropped sharply in the 19th and early 20th centuries due to the loss of its natural habitat. The species no longer lives on Vieques and Mona islands. Conservation efforts began in 1968 to prevent the bird from going extinct.

Taxonomy and evolution

The Puerto Rican amazon was first described in 1780 by the French scientist Georges-Louis Leclerc, Comte de Buffon, in his book Histoire Naturelle des Oiseaux. The bird was also illustrated in a hand-colored drawing by François-Nicolas Martinet, which appeared in Planches Enluminées D'Histoire Naturelle. This work was created under the guidance of Edme-Louis Daubenton to accompany Buffon’s text. Neither the illustration’s caption nor Buffon’s description included a scientific name. However, in 1783, the Dutch naturalist Pieter Boddaert gave the bird the two-part scientific name Psittacus vittatus in his catalog of Planches Enluminées. Buffon incorrectly believed his specimen came from the French colony of Saint-Domingue (modern Haiti) instead of Puerto Rico. Today, the Puerto Rican amazon is classified in the Neotropical genus Amazona, which was introduced by the French naturalist René Lesson in 1830. The specific name vittatus means "banded" in Latin.

Birds in the genus Amazona are commonly called amazons. The American Ornithologists’ Union also refers to them as "parrots," so "Puerto Rican parrot" is another accepted name in North America. The indigenous Taíno people called the bird iguaca, a name that imitated the parrot’s flight call.

There are two known subspecies:
– A. v. vittata is the main subspecies still living today. It is found in Puerto Rico and once lived on nearby Vieques Island and Mona Island.
– A. v. gracilipes lived on Culebra Island but is now extinct. It is unclear if it was significantly different from the main subspecies.

Scientists believe the parrot species in the West Indies originated from a single group that migrated to the Caribbean. While some small birds might struggle to cross large bodies of water, parrots have strong flight abilities and behaviors that help them travel across water. Most Caribbean birds come from Central, North, and South America. The Amazona species in the Caribbean are divided into two groups: five medium-sized species in the Greater Antilles and seven large species in the Lesser Antilles. All the Greater Antillean amazons share traits, such as green coloring and white eye rings, suggesting they are closely related. Research by Russello and Amato suggests all Greater Antillean Amazona species descended from Amazona albifrons, with A. vittata, A. leucocephala, and A. ventralis forming a closely related group.

British ornithologist David Lack once thought the Puerto Rican amazon evolved from the Hispaniolan amazon (A. ventralis) in Hispaniola. However, later studies found he missed some similarities between the Puerto Rican amazon and the black-billed amazon (A. agilis) in Jamaica. Later research showed that size and color patterns alone are not enough to determine evolutionary relationships, as these traits can change easily even within the same species. Some studies suggested the Puerto Rican amazon might share a common ancestor with the Jamaican A. agilis. However, recent genetic studies show the Puerto Rican amazon is more closely related to the Hispaniolan amazon and the Cuban amazon than to the black-billed amazon.

Description

The Puerto Rican amazon is 28–30 cm (11.0–11.8 in) long and weighs 250–300 g (8.8–10.6 oz), with an average weight of 275 g (9.7 oz). Though smaller than most amazons, it is about the same size as other Amazona species in the Greater Antilles. There are no differences in appearance between males and females. Both have mostly green feathers with blue edges. The main feathers on the wings and the feathers covering the wings are dark blue. The color of the feathers on the underside depends on the body part: the feathers under the wings, visible during flight, are bright blue, while those in the tail have a yellow-green color. The bird’s underparts are lighter and have a yellow tint, the forehead is red, and there are white oval shapes around the eyes. The eyes are brown, the beak has a horn-like color, and the legs are yellow-tan. Except for DNA testing, males and females can only be told apart by their behavior during the breeding season. Young birds have feather colors similar to adults.

Population and distribution

The exact places where the Puerto Rican amazon lived before Spanish colonists arrived are unknown because there are no records from that time, and the Taíno people, who lived there, were wiped out. However, the parrot was likely widespread and numerous. Some evidence suggests it may have lived on nearby islands, such as Antigua, Barbuda, and the Virgin Islands. Experts disagree about how many parrots there were in the past. Some say there were more than a million, while others believe there were about 100,000. During the first 150 years of Spanish rule, the human population was small. In 1650, when only 880 people lived on the island, the parrot was still common throughout Puerto Rico. After 1650, human populations grew quickly, and by the 18th century, the parrot’s numbers began to drop. In 1836, a German naturalist named Heinrich Moritz Gaede noted that the parrot population had decreased. Even in 1864, a British scientist named Edward Cavendish Taylor reported that the parrots were still common near San Juan, the island’s capital.

At first, human activity did not harm the parrot much. The Taíno people hunted the parrot, but this did not greatly affect its population. However, in the past 200 years, many factors have caused the parrot’s numbers to drop sharply. These include farming, building roads, creating dams for electricity, and taking young parrots as pets. In the second half of the 19th century, most of Puerto Rico’s forests, which were the parrot’s natural home, were cleared for farming crops like sugar, cotton, corn, and rice. The parrot began to rely on these crops for food and was seen as a pest by farmers, who tried to drive them away or hunt them. As farming expanded, the parrot’s habitat shrank, and its population declined.

The parrot lived in mature forests across Puerto Rico at all elevations, as well as in caves, cliffs, and other areas at lower elevations. It was found in the Guajataca State Forest until 1910 and the Rio Abajo State Forest until the 1920s. At higher elevations, it lived in the Carite State Forest until the 1930s. In the early 1900s, people reported seeing parrots moving from the Luquillo forest and the Sierra de Cayey toward the coast to find food. The parrot was no longer found on Culebra by the early 1900s. A region called Valle de las Cotorras (Valley of the Parrots), located between San Sebastián and Morovis, was home to a large population. Over time, the parrot’s natural habitat was reduced to the Cordillera Central. By 1960, the parrot was only found in the Luquillo Mountains within El Yunque National Forest. Today, the parrot lives at elevations between 396 and 823 meters (1,299 and 2,700 feet). It needs mature forests with open tree cavities to breed and does not live in smaller or younger forests.

By the 1950s, only 200 parrots remained in the wild. In 1975, the population dropped to 13 individuals. Numbers then began to rise, and in August 1989, there were about 47 parrots. However, on September 18, 1989, Hurricane Hugo hit Puerto Rico’s northeast coast, killing many of the remaining parrots. After the storm, only 23 parrots were estimated to survive. In 2004, the wild population was between 30 and 35 parrots, and the trend has been stable with some changes. The parrot’s current range is 16 square kilometers (6.2 square miles), which is 0.2% of its original area. After Hurricane María, it was estimated that only 3 of 50 parrots survived in the wild, a loss of 90%. Recovery programs continue, and by 2021, the total population was about 500, including those in captivity and in the wild.

Behavior

The Puerto Rican amazon is active during the day, usually starting its activities about half an hour after sunrise. It is quiet and hidden when inside its nest, using its green feathers to blend in with the surroundings. However, it may be loud and vocal when outside the nest. When flying, its colors stand out against the forest. Its flying style is similar to other amazons, with wing movements below the body, unlike most birds that fly with wings above their bodies. Amazons can fly at moderate speeds, reaching up to about 30 km/h (19 mph), and are agile when avoiding predators. When searching for food, the parrots often travel in pairs. Mated pairs and their young tend to stay together. The parrot makes two types of flight calls: a long, repeated squawk when taking off, and a loud "bugle" used during flight, which may have different meanings depending on the situation.

Like most amazons, the Puerto Rican amazon eats plants. Its diet includes flowers, fruits, leaves, bark, and nectar from the forest canopy. It has been observed eating over 60 different materials, though its diet was more varied in the past due to a larger habitat range. It eats parts of plants such as the outer layer of sierran palm seeds, fruits from trees like tabonuco and negra lora, flowers from bejuco de rana and achiotillo, and leaves from cupeillo and laurel magnolia. It also eats bark from bejuco de rana and twigs from other trees. The parrot usually selects fruits directly in front of it, picking them one at a time. When eating, it uses a foot to grasp food and eats slowly, taking 8–60 seconds to finish each item.

The Puerto Rican amazon typically stays with a mate for life, but may find a new partner if one dies or leaves. A male may abandon a female if she is injured and then mate with another bird. How pairs form is unknown, but new pairs often perform mating dances with coordinated movements, such as bowing and spreading their tails.

The Puerto Rican amazon nests in tree cavities, both naturally formed and made by other animals. It prefers Palo colorado trees but also uses laurel sabino and tabonuco trees. These trees are mature and provide protection from predators and rain. Recently, the species has also used man-made wooden boxes as part of conservation efforts. Nests are usually built between 7–15 meters (23–49 feet) above the ground. The male often leads the search for nesting sites, but the female makes the final choice. Once a site is chosen, the pair inspects and cleans it. No nesting material is added to the nest.

The Puerto Rican amazon reaches sexual maturity at 4 years old in the wild and 3 years in captivity. It usually breeds once a year during the dry season, from January to July. Mating appears to be linked to food sharing, which may trigger reproduction. Mating behavior is similar to other parrots in the Americas, with the male holding a perch and the female allowing him to mount her. As egg-laying approaches, the pair spends more time in the nest, with the male feeding the female by regurgitating food. The female lays 2–4 eggs and incubates them alone for 24–28 days. The male stays nearby to provide food. The female rarely leaves the nest unless she needs to defend against predators or if the male does not bring food. Both parents feed the chicks until they leave the nest, usually 60–65 days after hatching. The young remain with their parents until the next breeding season.

Like other amazons, the Puerto Rican amazon is social during daily activities but protective of its nest. The area around the nest is usually about 50 meters (164 feet) wide. Pairs are cautious near their nests, moving slowly to avoid predators. They defend their territory using loud calls, though physical fights can occur. Pairs may fight to protect their nest site rather than focusing on laying eggs. Pairs in areas without other parrots are usually quiet unless other parrots enter their space. Some pairs may show mild territorial behavior even without nesting, possibly as practice for younger, less mature pairs.

Threats and conservation

On March 11, 1967, the Puerto Rican amazon was added to the United States Fish and Wildlife Service list of endangered species. At that time, there were about 70 birds left in the wild. In 1968, efforts began to help increase the number of birds in the wild. In 1972, when the population was estimated at 16 birds, the United States Fish and Wildlife Service (USFWS) started breeding the parrots in captivity at the Luquillo Aviary. These efforts were successful. In June 2006, the USFWS reported that 39 baby parrots had hatched in captivity, which is more than the usual yearly average of about 16. In 2006, 22 parrots were released into the Rio Abajo State Forest to start a second wild population. In 2008, 19 more parrots were released at the same location. By 2012, the total number of wild parrots was estimated to be between 58 and 80, while over 300 were in captivity.

The World Conservation Union (IUCN) lists the Puerto Rican amazon as critically endangered since 1994. The species is protected under Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which bans the trade of the species or its parts.

Human activity is the main reason for the decline in the Puerto Rican amazon’s population. Early settlers, like the Taíno, hunted the birds for food but kept the ecosystem balanced. Later, habitat destruction, capturing young birds for the pet trade, hunting, and predation caused the population to drop sharply. Cutting down old forests for farming was the biggest cause of the decline.

Natural predators of the Puerto Rican amazon include the red-tailed hawk, the broad-winged hawk, the peregrine falcon, and the pearly-eyed thrasher. The thrasher arrived in Puerto Rico in the mid-20th century and became a threat to the parrot population. To help the parrots, special deep nests were built to prevent competition. Introduced species, such as honeybees and Hispaniolan amazons, compete for nesting spaces. Black rats and small Indian mongooses may eat parrot eggs and chicks.

Natural disasters, like hurricanes, were not a major threat when the parrot population was larger. However, due to habitat loss and smaller numbers, hurricanes now pose a risk. Hurricane Hugo in 1989 reduced the population from 47 to 23 birds.

In 1968, a recovery plan was created to help the Puerto Rican amazon. The goal was to reduce the species’ status from endangered to threatened by 2020. Other goals included creating two separate wild populations (each with at least 500 birds for five years), protecting their habitat, and controlling predators and competitors. A third site was planned in 2011 by the Caribbean Islands National Wildlife Refuge Complex. A captive population was started in the Luquillo Aviary in 1973. Another group was moved to the Rio Abajo State Forest in 1993 under the Puerto Rican Department of Natural Resources. In 2007, new facilities at the Iguaca Aviary in El Yunque National Forest were opened in honor of Priscilla Stubbe, who helped fund the project.

Human activity again threatened the parrots in later years. In 2012, unapproved flights of small planes from nearby islands disrupted the birds’ behavior. A proposed gas pipeline, Via Verde, raised concerns about more deforestation in their feeding areas. In 2011, researchers at the University of Puerto Rico at Mayagüez sequenced the parrot’s genome. In 2013, scientists found nests in the Río Abajo State Forest that were not assisted by humans, showing the birds were adapting to the wild. This was important because El Yunque’s high humidity can make some birds sick. Experts also noted an unmonitored group of about 50 parrots living in different parts of Puerto Rico.

Plans for a third population in Maricao State Forest were announced in 2013. Ten parrots were released at Río Abajo that year. The breeding program set a record in 2013, producing 51 baby parrots, more than the 34 from 2011. The wild population grew by 15 chicks, up from 12 the previous year. Around 500 parrots were known to exist by 2013. A severe drought caused by El Niño in 2015 helped parrots breed longer in El Yunque but also increased the number of mongooses, which threaten the birds. In 2015, 25 parrots were moved to a new site in Maricao for a year-long acclimation program before being released.

To improve breeding programs and monitor the parrots, researchers sequenced their genome. This project was funded by the community, including art and fashion events organized by students and donations from Puerto Rican citizens. The data helped create tools for breeding and tracking individual birds. In early 2020, 30 parrots were released into El Yunque rainforest.

General and cited references

• Forshaw, Joseph M. & William T. Cooper (1978). Parrots of the World (Second Edition). Melbourne: Landsdowne. ISBN 0-7018-0690-7.
• Russello, Michael A. & George Amato (2004). "A molecular phylogeny of Amazona: implications for Neotropical parrot biogeography, taxonomy, and conservation." Molecular Phylogenetics and Evolution. 30 (2): 421–437. Bibcode: 2004MolPE..30..421R. doi: 10.1016/S1055-7903(03)00192-1. PMID 14715233.
• Snyder, Noel F. R.; James W. Wiley & Cameron B. Kepler (1987). The Parrots of Luquillo: Natural History and Conservation of the Puerto Rican Parrot. Los Angeles: Western Foundation of Vertebrate Zoology. ISBN 0-935868-27-5.