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.

The Puerto Rican amazon was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1780 in his Histoire Naturelle des Oiseaux.

[3] The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text.

[3][6] The Puerto Rican amazon is now placed in the large Neotropical genus Amazona that was introduced by the French naturalist René Lesson in 1830.

[11] There are two recognized subspecies: A. albifrons A. agilis A. collaria A. ventralis A. leucocephala A. vittata 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.

[15] All the Greater Antillean amazons display characteristics leading to suppositions of relatedness, including predominantly green-toned color patterns and white rings around the eyes.

[20] The precise distribution of the Puerto Rican amazon before the arrival of Spanish colonialists is uncertain, because of a lack of contemporary records and then the extermination of the indigenous Taíno people, but the species was apparently widespread and abundant.

[27] Even so, as late as 1864, British ornithologist Edward Cavendish Taylor noted that the parrots were still common near the island's capital, San Juan.

[29] 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.

[31] 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.

In particular, a region named Valle de las Cotorras (Valley of the Parrots), located between San Sebastián and Morovis, was home to a sizable population.

But on September 18, 1989, Hurricane Hugo struck the northeast coast of Puerto Rico inflicting heavy casualties on the remaining birds.

Amazons can fly moderately fast, reaching a top speed of approximately 30 km/h (19 mph), and are fairly agile when evading predators in mid-air.

[48] 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.

[50] 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.

[51] Females only leave the nest on rare occasions involving repelling predators or if the male has not brought food in an extended time frame.

[56] On March 11, 1967, the Puerto Rican amazon entered the United States Fish and Wildlife Service list of endangered species.

[58] 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.

[25] Early settlers of Puerto Rico, such as the Taíno, hunted it for food consumption but managed to maintain a healthy ecological balance.

[25] Another was established in 1993 when some individuals were transferred from the Luquillo Aviary to the Rio Abajo State Forest under the administration of the Puerto Rican Department of Natural Resources (Departamento de Recursos Naturales y Ambientales).

[66] 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.

[69] 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.

[76] 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.

[76] To assist in improving the understanding of the overall population health of this species and aid in captive breeding programs the genome was sequenced by researchers at University of Puerto Rico, Mayagüez.

[78] 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.

[79] The data were used to produce microsatellite marker sets to aid captive breeding efforts and population monitoring studies by providing unique identifiers for individual birds.