Deterministic population growth models and conservation translocation as a management strategy for the critically endangered Blue-throated Macaw (Ara glaucogularis): A critique of Maestri et al (original) (raw)
Management and Conservation of the Large Macaws in the Wild
2004
Resumo.-Manejo e conservação das grandes araras na natureza.-Araras e papagaios (Psittaciformes) representam um dos grupos de aves mais ameaçados do mundo. Por séculos, araras foram capturadas por suas penas e para serem usadas como animais de estimação. Os principais fatores que ameaçam as araras são a destruição de habitat (perda e fragmentação), caça clandestina ou captura para o comércio (penas, ovos, filhotes, adultos). Outros fatores importantes são endogamia e distribuição geográfica restrita, especialmente para populações pequenas, especialização da dieta e hábitos, baixa taxa reprodutiva e grande tamanho corporal que os predispõe à extinção. O objetivo deste trabalho é resumir alguns dos estudos de campo conduzidos com grandes araras da América Central e do Sul durante os últimos anos, e descrever as atuais atividades de manejo e conservação conduzidas com araras azuis (Anodorhynchus hyacinthinus) no Pantanal Sul, através do Projeto Arara Azul.
Lear's Macaw Anodorhynchus leari is currently listed as "Endangered" by IUCN. Although it only breeds on cliffs at two protected sites in Bahia State, Brazil, there is no accurate information on population parameters such as the number of breeding pairs and their breeding performance. Between 2009 and 2010, we sought to quantify, for the first time, breeding population size and the main breeding parameters for the species in the two known breeding sites, by quantifying the number of active nests and monitoring 75 breeding attempts. Overall, 80% of the breeding attempts were successful with 1.33 (± 0.86 SD) fledglings/breeding attempt (productivity) and 1.67 (± 0.60 SD) fledglings/ successful nest (brood size). Breeding success and productivity were higher in 2010, while brood size did not vary between years and breeding sites. By adding 73 estimated nests to the 41 nests monitored, 228 individuals were estimated to be reproductively active in 2010, representing c.20% of the population (1,125 individuals). Given that the species is confined to a single population, further population increases could provoke overcrowding and negative density-dependent effects if it does not expand geographically. Therefore, long-term population monitoring focusing on the fraction of the population that is actually breeding and its breeding performance, rather than solely on the whole population size, is important for a better understanding of the population dynamics and conservation of this species.
DOAJ (DOAJ: Directory of Open Access Journals), 2010
Quando uma extensa reserva não é grande o bastante para proteger parte de uma população: Araras-canindé (Ara ararauna) no Brasil central. Este estudo teve como objetivo examinar movimentos de araras-canindé (Ara ararauna) através de fronteiras entre o Parque Nacional das Emas e paisagens adjacentes, no Brasil central. Dois locais de estudo foram selecionados para observações conduzidas em outubro de 2006 e fevereiro de 2007. Grupos de araras foram observados deixando o parque e voando sobre extensas áreas agrícolas, em direção a remanescentes de vegetação nativa, evidenciando que estas aves utilizam recursos localizados na matriz de entorno da reserva. Estas observações sugerem que a conservação de parte da população de A. ararauna encontrada no Parque Nacional das Emas exigirá expansão desta reserva e/ou ações conservacionistas por fazendeiros da região.
Biotemas, 2010
Quando uma extensa reserva não é grande o bastante para proteger parte de uma população: Araras-canindé (Ara ararauna) no Brasil central. Este estudo teve como objetivo examinar movimentos de araras-canindé (Ara ararauna) através de fronteiras entre o Parque Nacional das Emas e paisagens adjacentes, no Brasil central. Dois locais de estudo foram selecionados para observações conduzidas em outubro de 2006 e fevereiro de 2007. Grupos de araras foram observados deixando o parque e voando sobre extensas áreas agrícolas, em direção a remanescentes de vegetação nativa, evidenciando que estas aves utilizam recursos localizados na matriz de entorno da reserva. Estas observações sugerem que a conservação de parte da população de A. ararauna encontrada no Parque Nacional das Emas exigirá expansão desta reserva e/ou ações conservacionistas por fazendeiros da região.
Bird Conservation International, 2014
Lear's Macaw Anodorhynchus leari is currently listed as "Endangered" by IUCN. Although it only breeds on cliffs at two protected sites in Bahia State, Brazil, there is no accurate information on population parameters such as the number of breeding pairs and their breeding performance. Between 2009 and 2010, we sought to quantify, for the first time, breeding population size and the main breeding parameters for the species in the two known breeding sites, by quantifying the number of active nests and monitoring 75 breeding attempts. Overall, 80% of the breeding attempts were successful with 1.33 (± 0.86 SD) fledglings/breeding attempt (productivity) and 1.67 (± 0.60 SD) fledglings/ successful nest (brood size). Breeding success and productivity were higher in 2010, while brood size did not vary between years and breeding sites. By adding 73 estimated nests to the 41 nests monitored, 228 individuals were estimated to be reproductively active in 2010, representing c.20% of the population (1,125 individuals). Given that the species is confined to a single population, further population increases could provoke overcrowding and negative density-dependent effects if it does not expand geographically. Therefore, long-term population monitoring focusing on the fraction of the population that is actually breeding and its breeding performance, rather than solely on the whole population size, is important for a better understanding of the population dynamics and conservation of this species.
The Blue-throated Macaw in the Wild: a Cause for Concern
AFA Watchbird, 1997
Globally restricted to an area in central Beni department, Bolivia, measuring hardly 15,000 square km. (9,300 sq. miles) and moreover bearing the unenviable status of a globally threatened species (Collar et al., 1992), the Blue-throated Macaw (Ara glaucogularis) calls for long overdue attention from the conservation world. Until quite recently the only information available on Ara glaucogularis was mainly morphological data from five museum skins and from observations of the various captive individuals dotted around the globe. In terms of wild studies, however, Ara glaucogularis still remains one of the most mysterious birds in the world. Since the last reported sighting of the species in the wild over a century ago, various investigators reported dubious findings of the macaw as far south as southern Bolivia and northern Argentina and Paraguay (see in Ingels et al. 1981), although these were probably due to confusion with the superficially similar Blue and Yellow Macaw (Ara ararau...
Rediscovered in the wild twenty years ago, the breeding biology of wild Blue-throated Macaws remains largely unexplored, yet is essential to its effective conservation and recovery. Here, we analyse reproductive parameters in an intensively managed wild population of Blue-throated Macaws, providing the first data on the breeding biology of this critically endangered species. During the six-year study period, 2007-2012, the number of active breeding pairs either remained constant or decreased, depending on the site, and no new breeding pairs were discovered despite extensive searching. We documented nesting attempts in natural cavities in dead palms or live hardwoods, and artificial nest boxes. Egg-laying was concentrated during the end of dry season and the beginning of the wet season, August through December. Hatching failure was the greatest cause of egg losses. Half of the breeding attempts of Blue-throated Macaws produced at least one fledging, on average two, after a 85 days nestling period. An average of 4.3 nestlings per year fledged from all known wild nests combined. Each pair lost roughly 65% of its initial reproductive investment at each nesting attempt. In most successful nesting attempts of individualized pairs, a new nesting attempt was not detected the following year. All monitored breeding pairs showed high nest site fidelity, reusing hardwood-tree cavities and nest boxes. Our findings will aid conservation efforts by refining current actions and prompting new approaches towards the conservation and recovery of the Blue-throated Macaw.
NR, 2014
The Great Green Macaw Ara ambiguus is an endangered species whose most important food resource and nesting site in Costa Rica is the mountain almond tree Dipteryx panamensis, threatened mainly by deforestation. In this study, we analyse the suitability of reintroducing A. ambiguus in the South Caribbean Coast of Costa Rica by examining whether the ecological and socio-cultural conditions required for the reintroduction are met in the area. The methods developed in this work include biological sampling, cartographical analysis and semi-structured interviews, among others. We set La Ceiba Nature Reserve as study unit and starting point of the analysis due both to its conservation status, favouring the potential release of individuals, and its ecosystem representativeness. Our results suggest that the habitat is suitable for reintroduction, with frequent presence of D. panamensis in the region, as well as other feeding options and potential nesting sites in the study area. The cartographic study reveals that the species could rely on a forested surface of up to 7000 hectares, which would be sufficient for sustaining a viable population. As for the socio-cultural analysis, illegal logging and low protective frameworks were identified as the main potential threats for the species. Nevertheless, we perceived positive conservation attitudes among local people and a pro-active commitment of political stakeholders. We conclude that a viable South Caribbean reintroduction of A. ambiguus is possible in conjunction with a threat mitigation programme.