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 . Pairs are extremely cautious near their nest, usually moving in a slow manner when leaving the nest to avoid the attention of predators. 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. Some pairs may display moderate territoriality even when not apparently intending to nest, with these tendencies beginning in the latter half of the breeding season. One hypothesis is that this would occur in young pairs that had still not reached full maturity, serving as "practice territoriality". 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. The World Conservation Union (IUCN) lists the Puerto Rican amazon as a critically endangered species since 1994. The species is regulated under Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), rendering illegal international trade in specimens or parts. Human activity is arguably the main reason for the population decline of the Puerto Rican amazon. Early settlers of Puerto Rico, such as the Taíno, hunted it for food consumption but managed to maintain a healthy ecological balance. Later, habitat destruction, capture of immature individuals for the pet industry, hunting and predation contributed to the sharp population decline.