This is the largest parrot commonly seen in the SSR. Except at night roosts, they are typically seen flying in pairs or small family groups. Occasionally larger flocks will be seen congregating at favored food trees . The bright green coloration and yellow on the nape of the neck are distinctive markers.The sexes are the same. |
Yellow-naped Amazons live in the dry forests from SW Mexico to the southern parts of Guanacaste, Costa Rica. They are part of a large complex of similar amazon species with various amounts of yellow on the head or nape that extend from Mexico into South America. |
| Natural History: Diet:This species is a major predator of large seeds in SSR. It typically finds unripe fruit, tosses away the fruit flesh, opens the seeds with its hooked bill, and after eating only preferred portions of each seed, tosses it away to begin the next. Favored species include. | Species | Season | | | Guanacaste Tree (Enterolobium cyclocarpum) immature seeds | Dry | | | Albizzia adinocephala seeds | Dry | | | Oak (Quercus oleodes) acorns | Both | | | Hymenaea courbaril seeds | Wet | | | Mango (Mangifera indica) fruit | Wet | | | Night Roosts: This is the only one of the four common SSR parrots to have traditional and fixed communal night roosts. There are several that house the Yellow-napes seen in the Park: one just south of the escarpment on the property of Hacienda Pelon and another near the coast by Playa Naranjo. Night roosts are typically separated by 10-30 km. Hundreds of birds home in on these sites every evening. Although a few pairs come as early as 5 PM, the major bulk of the aggregation arrives between 5:30 and 6:30 PM. Unlike the smaller parrots, Yellow-napes seem to feel little pressure to settle down before dark. Most birds arrive as single pairs homing in from every direction. They are extremely noisy and one hears a large fraction of the vocal repertoire at the night roosts. Finally, birds aggregate into a few tall but usually bare trees and quiet down for the night. They are often the first parrots to leave the night roosts in the morning: Yellow-nape pairs can often be seen radiating out again as early as 5:00 AM. | Nesting: Yellow-naped Amazons nest in natural tree hollows and rotten palm tree trunk holes. Unlike the Conures and Parakeets, they do not excavate their own nesting cavities. Mated pairs will actively defend these sites and often engage in counter-duets with invading pairs. As with all the resident SSR parrots, nesting occurs in the dry season. The female incubates the eggs and both parents feed the nestlings. Parents remain with their offspring in the general vicinity of the nest for several weeks post-fledging and eventually lead their fledglings to their regular communal night roosts. Here fledglings gradually become increasingly independent and join juvenile flocks that radiate out each day on their own to forage. Juvenile dispersal may occur as these flocks move between different night roosts. | Predators: There are few hawks currently resident in the SSR that are large enough to take an adult Yellow-naped Amazon. The major predator faced by Yellow-naped Amazons is man. Because of their desirability as talking pets, poaching of nestling is an extremely serious problem throughout their range. Poaching has been reduced significantly within the SSR, but even just outside the Park, it remains a serious problem. Poachers often open up the nesting cavities to get at the chicks, ruining them for future breeding attempts. Since hole nesters are often limited by suitable nest sites, the birds lose both their current nestlings and the chance for future breeding in that site. Yellow-nape offspring are vulnerable to many of the snake, monkey, and small mammal predators that attack nests of other parrot species. | Flock Structure: Yellow-naped Amazons are the least social of the SSR parrots during the daytime. One typically encounters single pairs or at most, two mated adults and their recent fledglings. Partly, this is because birds are most vocal around an active nest or at the night roost. At other times of the day they may be found in larger aggregations at feeding sites, but rarely use vocalizations other than the soft contact calls. Close association and allopreening tends to be reserved for mates and family members. Unlike the three smaller species, pairs of Yellow-napes rarely exchange contact calls with conspecifics that move nearby. Instead, they appear to use contact calls as part of pair duets to announce their presence in an area, particularly in early morning and late afternoon. On some occasions, such duets are given by pairs in isolation and do not provoke responses from other pairs. On other occasions, two pairs will sit high in nearby trees and counter-duet back and forth for an extended period. In these cases, the two pairs are clearly interacting. However, such contests never seem to result in closer approach or fusing of groups as is typical when smaller species exchange vocalizations. Instead these exchanges are reminiscent of song duels in territorial male songbirds, with the obvious difference that birds of both sexes are engaging in joint displays. | |
Vocalizations (Click on underlined terms to hear call): | Loud Contact Call: This is usually given as a successive duet by the two members of a mated pair, but one can also hear it given singly by solitary birds. Over their range in Guanacaste, the loud contact calls of Yellow-napes occurs in three contiguous dialects (Wright 1996). One dialect just gets into the very north-west of Costa Rica and extends north into Nicaragua. The central dialect (the example given here and phonetically named the "wawa" call) covers the SSR populations and extends south to about Liberia. From there to the most southern limit of the species' range in Costa Rica, one finds a third dialect. These dialects are so different that a naive listener might think the birds from different species. Birds that have night roosts close to a dialect boundary can produce both adjacent dialects as necessary, but they never meld them. Recent work has shown that there is gene flow across dialect boundaries (Wright and Wilkinson 2001). This means that birds must migrate across these boundaries. Since one never hears birds using out-of-place dialects, migrants must quicky learn the local dialect as part of the settling process. Loud contact calls are typically given when pairs are flying between feeding or roosting sites and as part of pair duets (see below). They are most often heard between dawn and 8 AM and again later between 3 and 6:30 PM, but can in fact be heard at any time of day if pairs move locations. | | Soft Contact Call: This call is given by pair members and individuals in close proximity, often while foraging in dense foliage. | | Preflight Call: Birds will give these calls at a high frequency and repetition rate just before and during takeoff. They will also use it at the initiation of a long string of contact calls leading to duet, perhaps as means of alerting receivers that more complex calls are to follow. This call is a shortened form of the contact call, and shows the same dialect characteristics. | | Pair Duet: Pair duets follow a common general syntax with each member of a pair contributing according to rules. However, the exact form of each phase of a duet can vary resulting in each pair having a number of different duet "motifs" they can produce. The first part begins with both members making the usual loud contact call in alternation. After a variable number of contact calls, the female begins a second phase called the "squeal". These are rough raspy calls. Finally, the male finishes the duet with several very musical "yodels". Yellow-napes will produce duets wherever they happen to be foraging each morning whether other pairs are nearby or not. If other pairs are sufficiently close, or when a pair is near to its nest, pairs may engage in counter-duets in which each pair replies to the other's duet with its own version. Pair duets also exhibit dialectical differences, with duet notes changing at the same boundaries as contact calls. The basic syntax of duets, however, seems to be preserved across dialects. | | Warbles: Yellow-naped Amazons give a variety of warbling calls of great acoustical diversity (i.e. a great number of different notes). Warble calls termed gurgles are usually given as duets between mated pairs, and are often interspersed with the loud pair duets described above. The function of these warble calls may well be different than that of the loud pair duets, as warbles are typically much softer calls that would not propagate as far as they loud pair duets. A related call class is the squeal, which is also given by pairs as an acoustically diverse duet, but is only seen in highly aggressive situations when resident pairs attack other pairs that have closely approached their nests. Squeals are accompanied by aggressive approaches and displays. Squeals can also be elicited by playbacks of pair duets from speakers mounted at nests. | |
| Where to Find Them in SSR/ACG: Yellow-naped Amazons are found throughout the SSR. At all times of year, at least one pair can be heard in the early morning duetting within hearing of the central Park complex. Others appear to be regular visitors to the trees around Pocosol. They particularly like to eat ripe mangos and old farm sites such as Finca Jenny and Finca Centeno are visited in the late dry and rainy seasons nearly every morning by one or more pairs in succession. They are often silent when actually foraging, making them more difficult to see than the three smaller parrot species. However, when they are duetting, they often move to the top of a bare tree where their sounds can carry long distances. This is the best time to get a close look. One can also try to visit one of the traditional night roosts to see large numbers of pairs coming in to sleep at dusk. |
| References: Forshaw, J. M. 1989. Parrots of the World. London: Blandford.
Juniper, T. and M. Parr (1998). Parrots: A Guide to Parrots of the World. New Haven: Yale University Press. Stiles, F. G. and A. Skutch. 1989. A Guide to the Birds of Costa Rica. Ithaca, NY: Comstock Publishing Associates. Wright, T. F. 1996. Regional dialects in the contact call of a parrot. Proceedings of the Royal Society of London, Series B 263: 867-872.
Wright, T. F. 1997. Vocal Communication in the Yellow-naped Amazon (Amazona auropalliata), University of California, San Diego.
Wright, T. F. and M. Dorin. 2001. Pair duets in the yellow-naped amazon (Psittaciformes: Amazona auropalliata): responses to playbacks of different dialects. Ethology 107: 111-124.
Wright, T. F. and G. S. Wilkinson. 2001. Population genetic structure and vocal dialects in an amazon parrot. Proceedings of the Royal Society of London, Series B 268: 609-616. Wright, T.F., C.A. Toft, and 23 others. 2001. Nest poaching in Neotropical parrots. Conservation Biology 15:710-720.
South, J. and T.F. Wright. 2002. Nestling sex ratios in the Yellow-naped Amazon: no evidence for adaptive modification. Condor 104:437-440.
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