Sonographic analysis shows that many local vocal dialects occur within the total range of the species. These dialects are distinct and reflect the general reluctance of these parrots to venture far away from their home areas; consequently geographic vocal variance occurs within subgroups. The vocalizations are innate, but parrots that do venture into new areas rapidly learn the dialects they encounter and thereby avoid being shunned as outsiders.
Red-lored amazons (Amazona autumnalis) are about 14 inches long; the striking plumage is mainly green with red speculum, forehead and lores.
These are vigilant birds, and often quite nervous, spooking noisily at the approach of human or other intruders. But, in the Selva Verde area, most are quite approachable–except in the vicinity of nests. Recent studies confirm that one of the most critical factors contributing to the breeding success of this species is its overall shyness and wary aloofness, and in particular, its inconspicuousness around the nest site. Such behavior minimizes the chances that a nest will be discovered, and potentially destroyed by predators.