Пуэрто-Риконың эндемикалық попугайы

Parrot endemic to the archipelago of Puerto Rico

The Puerto Rican amazon (Amazona vittata), also known as the Puerto Rican parrot (Puerto Rican Spanish: cotorra puertorriqueña) or iguaca, is the only extant parrot endemic to the archipelago of Puerto Rico, and belongs to the Neotropical genus Amazona. Measuring , the bird is a predominantly green parrot with a red forehead and white rings around the eyes. Its closest relatives are believed to be the Cuban amazon (Amazona leucocephala) and the Hispaniolan amazon (Amazona ventralis). The Puerto Rican amazon reaches sexual maturity at between three and four years of age. It reproduces once a year and is a cavity nester. Once the female lays eggs she will remain in the nest and continuously incubate them until hatching. The chicks are fed by both parents and will fledge 60 to 65 days after hatching. This parrot's diet is varied and consists of flowers, fruits, leaves, bark and nectar obtained from the forest canopy. The species is the only remaining native parrot to Puerto Rico and has been listed as critically endangered by the World Conservation Union since 1994. Once widespread and abundant, the population declined drastically in the 19th and early 20th centuries with the removal of most of its native habitat; the species has completely vanished from Vieques and Mona Island. Conservation efforts commenced in 1968 to save the bird from extinction.

The various native parrot species in the West Indies are assumed to be descended from a singular group that immigrated to the Caribbean at some point. Some small species would have encountered problems traversing large bodies of water, but parrots have flight strength and various behavioral characteristics that would facilitate "over water" dispersion. Most Caribbean bird species originate from Central, North and South America. The Amazona species found in the Caribbean are divided in two groups: five mid sized species found in the Greater Antilles and seven large species in the Lesser Antilles. All the Greater Antillean amazons display characteristics leading to suppositions of relatedness, including predominantly green toned color patterns and white rings around the eyes. British ornithologist David Lack considered that the Puerto Rican amazon had evolved from the Hispaniolan amazon (A. ventralis) found in Hispaniola, but it has since been argued that he omitted some elements in his analysis, including the similarities found between the black billed amazon (A. agilis) of Jamaica and the Puerto Rican amazon. Subsequent studies showed that size and color patterns were not sufficient to assess evolutionary relationships, and that patterns changed with relative ease even within members of the same species. However, recent phylogenetic studies show that the Puerto Rican amazon is more closely related to the Hispaniolan amazon and the Cuban amazon than to the black billed amazon.

The Puerto Rican amazon measures and weighs , or on average. Although small compared to amazons in general, it is similar in size to other Greater Antilles Amazona species. Sexual dimorphism is not present. Both males and females have predominantly green plumage, though their feathers have blue edges. The primary flight feathers of the wings and the main covert feathers are dark blue. The color of the feathers on the underside varies depending on the body part: the feathers on the underside of the wings, which can be seen during flight, are bright blue; those in the tail have yellow green tone. Their underparts are paler and yellow tinged, their foreheads are red, and they have white ovals around the eyes. The iris is brown, the bill a horn color, and the legs yellow tan. Aside from DNA tests, males and females can only be distinguished by behavioral differences during the breeding season. Immature birds have plumage similar to adults. There is also evidence the species may have inhabited other nearby islands, such as Antigua, Barbuda and the Virgin Islands. Estimates of the parrot's early numbers vary greatly. Some authorities claim that there were once more than a million individuals, while others suggest a more modest population of 100,000. During the first 150 years of Spanish rule the human population was small, and in 1650, when the population of the island was 880 people, the species was still abundant throughout the archipelago. After 1650, human habitation increased exponentially, and by the 18th century the Puerto Rican amazon population started to be affected. Heinrich Moritz Gaede, a German naturalist, declared that by 1836 the parrot population had noticeably declined. At first, human activity had not posed a significant threat to the Puerto Rican amazon. The Taíno hunted the parrot but without much effect on its population. In the past 200 years, however, many factors have led to a drastic decrease in the birds' numbers: agricultural development, the construction of roads, hydroelectric development, and the adoption of young chicks as pets. Especially during the latter half of the 19th century, most of Puerto Rico's virgin forests, a historical habitat of the species, were cleared for agricultural development, primarily for the production of sugar, cotton, corn and rice. The amazon quickly came to rely on these crops as its main food source and so became seen as a pest; local farmers repelled or hunted the bird if possible. As agriculture expanded, the amazon's habitat disappeared further and its population declined. The species was historically found in mature or old growth forests in Puerto Rico at all elevations, and in holes, cliffs, and other diverse habitats at lower elevations. The species could be found at medium elevations in the Guajataca State Forest (until 1910) and the Rio Abajo State Forest (until the 1920s), and at high elevations in the Carite State Forest (until the 1930s). Accounts from the early 1900s describe the parrots traveling away from the Luquillo forest and the Sierra de Cayey towards the main island's coast to find food. The species is currently found at elevations between Since the species requires mature forests with open cavity trees for reproduction, it does not occur in dwarf and secondary forests. By the 1950s, there were only 200 parrots in the wild, and in 1975 the population reached an absolute low of 13 individuals. Numbers then recovered, and in August 1989 there were an estimated minimum of 47 individuals. But on September 18, 1989, Hurricane Hugo struck the northeast coast of Puerto Rico inflicting heavy casualties on the remaining birds. In the aftermath of the hurricane the population was estimated at 23 individuals. In 2004, the wild population was 30–35 individuals, and the long term trend appears to be stable albeit with some fluctuations. The current range of the species is , 0.2% of what it once was. Recovery programs continue and as of 2021 the total population is around 500 including those in captivity and in the wild.

The Puerto Rican amazon is diurnal, typically beginning its day half an hour after sunrise. It is generally secretive when inside its nest, using its green plumage as camouflage. In contrast, it may be vocal and noisy when outside the nest. Upon taking flight, its color pattern provides some contrast to the forest. The flight mechanism of this species is similar to the one found in other amazons, and involves strokes below the body axis, unlike most birds whose wings flow above their bodies in flight. Amazons can fly moderately fast, reaching a top speed of approximately , and are fairly agile when evading predators in mid air. When in search of food, the parrots group in pairs. Couples and their fledged young display a tendency to stay together. The amazon makes two flight calls, a take off squawk which consist of a pattern of long squawks, and a loud "bugle", commonly used in flight and which may have several meanings depending on the circumstances when it is used.

Like almost all amazons, the Puerto Rican amazon is a herbivore. Its diet consists of flowers, fruits, leaves, bark and nectar obtained from the forest's canopy. The species has been recorded to consume more than 60 different materials, although its diet was historically more varied due to its larger range. Among the items it consumes are the pericarp of the seeds of sierra palm (Prestoea montana), tabonuco (Dacryodes excelsa), and negra lora (Matayba domingensis); the fruits of bejuco de rana (Marcgravia sintenisii), camasey (Miconia sintenisii), cupey de altura (Clusia gundlachii), and palo de cruz (Rheedia portoricensis); the flowers of bejuco de rana, achiotillo (Alchornea latifolia), and Piptocarpha tetrantha; the leaves and twigs of cupeillo (Clusia grisebachiana), laurel sabino (Magnolia splendens), caimitillo verde (Micropholis garciniaefolia), and Piptocarpha tetrantha; the bark of bejuco de rana, cupeillo, and cachimbo cumun (Psychotria berteriana); and the buds of cuaba (Inga vera). It normally selects the fruits positioned directly in front of its eyes, picking them one at a time with some rare exceptions. When feeding, it uses a foot to pick up the food. The amazon feeds in a slow, paused manner taking 8–60 seconds to consume separate items.

The Puerto Rican amazon usually mates for life, with pairs only changing mates if one bird perishes or abandons the nest. A male may abandon the female if the latter is injured, re mating with a more "physically perfect" subject. The Puerto Rican amazon is a secondary cavity nester, nesting in tree trunk cavities, both naturally occurring and excavated by other species. It prefers to nest in Palo colorado trees (Cyrilla racemiflora), but uses other trees, including the laurel sabino (Magnolia splendens) and tabonuco (Dacryodes excelsa), to a lesser extent. These trees are mature cavity forming trees which provide protection against predators and the entry of water. Recently, the species has also nested in artificial wooden boxes designed as part of the recovery plan for the species. Nest height varies from above ground. The male usually leads the search for nest sites, although the final decision seems to be taken by the female. Once a site is selected, the pair will spend some time inspecting and cleaning it. No lining material is added to the nest. The Puerto Rican amazon reaches sexual maturity at 4 years of age in the wild and at 3 years in captivity. The species usually reproduces once a year between the months of January and July (the dry season). Copulation between pairs seems to be closely related to food transfers, with this possibly serving as a trigger for intercourse. Amazons have a copulation pattern similar to that found in other parrots throughout the Americas, with the male gripping a perch with one leg while passively placing the other in the female's back. As the time for egg laying approaches the pair spends more time in the nest, with the male providing food to the female via regurgitation. The female lays 2–4 eggs that she exclusively incubates for a period of 24 to 28 days, while the male will be present in the vicinity of the nest when providing food. Females only leave the nest on rare occasions involving repelling predators or if the male has not brought food in an extended time frame. The chicks are fed by both parents until they leave the nest, usually 60 to 65 days after they hatch. Nonetheless, they remain dependent on their parents and travel with them until the next breeding season. Like other amazons, the Puerto Rican amazon is gregarious while performing daily activities, but territorial around its nest. The size of the territory around the nest is usually around Although territorial defense is mostly composed of loud vocalizations there are instances of actual physical combat. Pairs will defend their nest sites against invading couples, sometimes focusing on the location's defense instead of egg laying. Pairs nesting in areas uninhabited by other parrots will remain mostly silent unless other parrots enter the zone.

On March 11, 1967, the Puerto Rican amazon entered the United States Fish and Wildlife Service list of endangered species. At the time of inclusion the population was estimated at 70 individuals. In 1968, recovery efforts began to increase the population in the wild. In 1972, when the estimated population was 16 individuals, the United States Fish and Wildlife Service (USFWS) at the Luquillo Aviary began efforts to breed parrots in captivity and yielded good results. In June 2006, it was reported by the USFWS that its birds in captivity had successfully hatched 39 chicks (the yearly average is around 16). In 2006, 22 birds were released in the Rio Abajo State Forest to initiate a second wild population, and a further 19 were released at the same site on 27 December 2008. In 2012, the total estimated population was 58–80 individuals in the wild and over 300 individuals in captivity. which prohibits commercial international trade in the species or its parts/derivatives.

Human activity is arguably the main reason for the population decline of the Puerto Rican amazon. Introduced species are a threat: honeybees (Apis mellifera) and related Hispaniolan amazons may compete for nesting cavities, and black rats (Rattus rattus) and small Indian mongooses (Urva auropunctata) may eat eggs and chicks.

In response to the Puerto Rican amazon's low population and endangered status, a recovery plan was drafted and implemented in 1968. Its main objective was to downlist the species to threatened status by the year 2020. As part of the conservation efforts, a captive population was established in the Luquillo Aviary in 1973. In 2007, expanded facilities at the Iguaca Aviary at the El Yunque National Forest were inaugurated and dedicated to the late Priscilla Stubbe, who was a major fundraiser for the new facility. Human activity once again threatened the amazon during the following years. In 2012, it was reported that the unsanctioned flight of light aircraft from adjacent islands was disrupting the reproductive and social behaviors of the species. Via Verde, a gas pipeline grid proposed by the Luis Fortuño administration, raised concerns among conservationists due to further deforestation of the regions where the birds feed. New conservation efforts have also begun during this timeframe. In 2011, a research team of the University of Puerto Rico at Mayagüez sequenced the amazon's genome. On August 15, 2013, the discovery of non assisted nests in the Río Abajo State Forest was announced. Experts considered this a sign of expansion, implying that the reintroduced amazon population was fully adapting to wild life and was dispersing throughout the region. This was noted as a significant advance, since El Yunque is not an ideal habitat for the bird due to its humidity, which precipitates sickness in some of the individuals. This was accompanied by a second announcement, which noted that added to the known number of amazons in the wild (fluctuating between 64 and 112 specimens) there is an unmonitored population of approximately 50 birds dispersed throughout Puerto Rico. The creation of another aviary and captive reproduction center was considered throughout 2013, with the municipalities of Maricao and Isabela being analyzed. In November 2013, plans for the establishment of a third population in the Maricao State Forest were formally announced. The following month, ten amazons were released at Río Abajo. 2013 set a new record for the reproduction program, which produced 51 fledglings and shattered the previous record of 34 that was established in 2011. A severe drought caused by the emergence of El Niño began during the spring of 2015 and extended throughout the summer, benefitting the breeding of the amazons in El Yunque by extending their reproductive season. However, this weather pattern also increased the number of mongooses present in the forest, representing a risk for the population. Each member was brought individually in order to ensure their safety while being transported and later placed in an acclimation program that is expected to last a year, before they are released to create a new population in the region. As an emblematic species of Puerto Rico, this was carried out as a uniquely community funded project. The research budget raised by student organized art and fashion shows dedicated to the effort plus small personal donations from Puerto Rican citizens who wanted to support the work. And from this data producing microsatellite marker sets to aid the captive breeding efforts and population monitoring studies by providing unique identifiers for individual birds. In early 2020, 30 parrots were released into the El Yunque rainforest.