Long‐term monitoring of Yellow‐naped Amazons ( Amazona auropalliata ) in Costa Rica: breeding biology, duetting, and the negative impact of poaching

Abstract

The population of Yellow-naped Amazons (Amazona auropalliata) declined by an estimated 50% between 1980 and 2000, and the current population is estimated to be between 10,000 and 50,000. Poaching of young has been a persistent problem, but the species is also threatened by habitat loss and degradation. Because most aspects of their life history, behavior, and ecology have not been examined in wild populations, we studied Yellow-naped Amazons with the following objectives: (1) identify the species of trees used for nesting, (2) determine the size and potential function of breeding territories, (3) determine nesting success, and (4) examine their duetting behavior. We located nests at 16 sites on the Pacific Slope of Costa Rica from 1999 to 2008. We searched for nests from January to May. Every nest was visited at least once and some nests were visited every 2-3 weeks throughout the breeding season. We also collected territory and duetting data at one site (Ahogados). The breeding season of Yellow-naped Amazons was during the dry season (January-May). Yellow-naped Amazons nested in 21 species of trees, but 68% of nests were located in only five species, and cavities in dead coyols (Acrocomia aculeata) were used most often. We found no association between breeding success and the species of tree in which birds nested. Mean territory size was 25,578 m 2 , and these small areas generally consisted of several trees surrounding a nest tree. Pairs continued to duet throughout the breeding season, suggesting that duetting is important for territory defense. The nest failure rate in our study was 89%, and most nest failures (64%) were due to poaching for the pet trade. We recommend immediate population management and conservation actions, including increased law enforcement to reduce nest poaching, protection of key nesting areas, educational programs, and habitat conservation. RESUMEN.Monitoreo a largo plazo del lora de nuca amarilla en Costa Rica: biolog ıa de la reproducci on, duetos vocales y el impacto negativo de la caza furtiva Entre los loros (orden Psittaciformes), hay m as especies amenazadas que cualquier otro orden de aves. Una de estas especies es el lora de nuca amarilla (Amazona auropalliata); que tiene una poblaci on actual de entre 10,000 y 50,000 individuos y una disminuci on poblacional estimada del 50% entre 1980 y 2000. El saqueo de cr ıas ha sido un problema persistente, y es una de las principales amenazas para la especie, junto a la p erdida del h abitat por destrucci on y degradaci on. La mayor ıa de las etapas de la historia de vida, el comportamiento y la ecolog ıa en poblaciones silvestres de esta especie no se han evaluado sistem aticamente, y por ende se necesitan estudios adicionales. Estudiamos esta especie en la vertiente del Pac ıfico de Costa Rica de 1999 a 2008 con los siguientes objetivos: (1) identificar las especies de arboles utilizados para la anidaci on, (2) determinar el tamaño y la funci on potencial de los territorios de reproducci on, (3) determinar el exito de anidaci on y (4)...

Yellow-naped AmazonAmazona auropalliatapopulations are markedly low and rapidly declining in Costa Rica and Nicaragua

“…While our observations suggest this is often the case, this estimate is best viewed as a theoretical best estimate of reproductive success. Our own data on nesting success from nest monitoring conducted from 1999 to 2008 in some of the same Costa Rican populations surveyed here found that only 11% of nests successfully fledged young, with most of the mortality arising from nest poaching (Dahlin et al 2018). Nesting success is higher in populations of the sister species the Yellow-headed Amazon, Amazona oratrix, where 49 of 155 (31%) of nests monitored within or adjacent to protected areas over two nesting seasons from 2016-2017 successfully fledged young, but only limited roost surveys have been conducted in these populations due to an absence of stable roosting sites (C. Britt unpubl.…”

“…Yellow-naped Amazons appear quite tolerant of low-level disturbance; in our surveys most roosts were found in secondary deciduous forest, and many were in close proximity to human habitation; we actually found that mean roost size was larger for roosts located within 100 m of human habitation than for those located farther away. Furthermore, our observations suggest that Yellow-naped Amazons are capable of, and may actually prefer, to nest in more open landscapes such as those maintained by cattle ranching or controlled burns (Dahlin et al 2018). Thus it is not human activity in general, but rather specific forms of human activity that are driving the observed declines in the Yellow-naped Amazon.…”

“…Reports from elsewhere in its range note declining populations, loss of key habitat, and large numbers of birds exported for the pet trade (Wiedenfeld 1993, Grijalva 2008, BirdLife International 2016b. Costa Rica is generally held to be a stronghold of the species, but small-scale studies of nesting success have reported high levels of nest poaching (Wright et al 2001, BirdLife International 2017, Dahlin et al 2018) and this species is commonly found as pets in Costa Rican households (Drews 2003). Overall, current estimates of the total population of the Yellow-naped Amazon vary widely from 10,000 to 50,000 individuals, reflecting considerable uncertainty in the status of different populations (BirdLife International 2017).…”

Exotic parrots breeding in urban tree cavities: nesting requirements, geographic distribution, and potential impacts on cavity nesting birds in southeast Florida

“…Other parrot species are reported to breed in palm snags in their native ranges (Berkunsky et al 2014;Dahlin et al 2018). Amazona parrots are increasing in population and expanding their range in the southern United States, particularly Florida and California, where palm trees are common (Mori et al 2017).…”

Long-term monitoring of a hyacinth macaw Anodorhynchus hyacinthinus (Psittacidae) roost in the Pantanal, Brazil

“…Our findings at this site show an encouraging and positive trend, unlike that found for many other psittacines. For example, the population of yellow-naped parrots Amazona auropalliata has declined by nearly 50% since 1980 because many of these birds are caught illegally for the pet trade (Dahlin et al 2018). Marsden & Royle (2015) carried out a survey of density and abundance changes among 356 parrot species.…”