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1.
PLoS One ; 18(9): e0291234, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37682943

RESUMEN

Large forested tracts are increasingly rare in the tropics, where conservation managers are often presented with the challenge of preserving biodiversity in small and isolated fragments. The Atlantic Forest is one of the world's most important biodiversity hotspots, jeopardized by habitat loss and fragmentation. The Pernambuco Endemism Center (PEC) is the most degraded of the Atlantic Forest regions and because of the dramatic levels of deforestation, fragmentation, and ongoing species losses, studies on the distribution and configuration of the PEC's forest cover are necessary. However, across dynamic tropical landscapes, investigating changes over time is essential because it may reveal trends in forest quality attributes. Here, we used Google Earth Engine to assess land use and land cover data from MapBiomas ranging from 1985 to 2020 to calculate current landscape metrics and to reveal for the first time the spatiotemporal dynamics of the PEC's forests. We identified a forest cover area that ranged from 571,661 ha in 1985 to 539,877 ha in 2020, and about 90% of the fragments were smaller than 10 ha. The average fragment size was about 11 ha, and only four fragments had more than 5,000 ha. Deforestation was mostly concentrated in northern Alagoas, southern Pernambuco, and non-coastal Paraíba and Rio Grande do Norte. On average, borders represented 53.6% of the forests from 1985 to 2020, and younger forests covered 52.3% of the area in 2017, revealing a vegetation rejuvenation process 2.5 times higher than in total Atlantic Forest. In 2017, older forest cores in fragments larger than 1000 ha (i.e., higher-quality habitats) represented only 12% of the remaining forests. We recommend that the amount of forest cover alone may poorly assist conservation managers, and our results indicate that ensuring legal protection and increasing surveillance of the PEC's few last higher-quality habitats is urgently needed.


Asunto(s)
Bosques , Rejuvenecimiento , Brasil , Benchmarking , Biodiversidad
2.
Ecology ; 100(6): e02647, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30845354

RESUMEN

Scientists have long been trying to understand why the Neotropical region holds the highest diversity of birds on Earth. Recently, there has been increased interest in morphological variation between and within species, and in how climate, topography, and anthropogenic pressures may explain and affect phenotypic variation. Because morphological data are not always available for many species at the local or regional scale, we are limited in our understanding of intra- and interspecies spatial morphological variation. Here, we present the ATLANTIC BIRD TRAITS, a data set that includes measurements of up to 44 morphological traits in 67,197 bird records from 2,790 populations distributed throughout the Atlantic forests of South America. This data set comprises information, compiled over two centuries (1820-2018), for 711 bird species, which represent 80% of all known bird diversity in the Atlantic Forest. Among the most commonly reported traits are sex (n = 65,717), age (n = 63,852), body mass (n = 58,768), flight molt presence (n = 44,941), molt presence (n = 44,847), body molt presence (n = 44,606), tail length (n = 43,005), reproductive stage (n = 42,588), bill length (n = 37,409), body length (n = 28,394), right wing length (n = 21,950), tarsus length (n = 20,342), and wing length (n = 18,071). The most frequently recorded species are Chiroxiphia caudata (n = 1,837), Turdus albicollis (n = 1,658), Trichothraupis melanops (n = 1,468), Turdus leucomelas (n = 1,436), and Basileuterus culicivorus (n = 1,384). The species recorded in the greatest number of sampling localities are Basileuterus culicivorus (n = 243), Trichothraupis melanops (n = 242), Chiroxiphia caudata (n = 210), Platyrinchus mystaceus (n = 208), and Turdus rufiventris (n = 191). ATLANTIC BIRD TRAITS (ABT) is the most comprehensive data set on measurements of bird morphological traits found in a biodiversity hotspot; it provides data for basic and applied research at multiple scales, from individual to community, and from the local to the macroecological perspectives. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or teaching and educational activities.

3.
Zootaxa ; 4442(4): 551-571, 2018 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-30313951

RESUMEN

Seed-finches are small-sized Neotropical granivorous birds characterized by extremely strong and thick beaks. Among these birds, the Great-billed Seed-Finch Sporophila maximiliani has been selectively and intensively trapped to the extent that has become one of the most endangered bird species in South America, yet its taxonomy remains complex and controversial. Two subspecies have been recognized: S. m. maximiliani (Cabanis, 1851), mainly from the Cerrado of central South America, and S. m. parkesi Olson (= Oryzoborus m. magnirostris), from northeastern South America. Originally, S. m. parkesi was diagnosed as being larger than the Large-billed Seed-Finch, S. c. crassirostris (Gmelin, 1789), but proper comparisons with S. m. maximiliani, which is larger than S. c. crassirostris, were never performed. Here we provide a review of the taxonomic and nomenclatural history of S. maximiliani, reevaluate the validity and taxonomic status of the subspecies based on morphological characters, and significantly revise its geographic distribution. Analyses based on plumage patterns and a Principal Component Analysis of morphometric characters indicated that S. m. parkesi is most appropriately treated as a synonym of the nominate taxon, which results in a monotypic S. maximiliani comprising two disjunct populations. Further, we conducted systematic searches for S. maximiliani in Brazil, in an attempt to obtain natural history information. After more than 6,000 hours of fieldwork in 45 areas of potential and historical occurrence, S. maximiliani was located only in two sites, in marshy environments called veredas, confirming the critical conservation status of this species, at least in Brazil. We discuss the conservation potential for, and the problems involved with, captive breeding of S. maximiliani for reintroduction into the wild.


Asunto(s)
Especies en Peligro de Extinción , Passeriformes , Animales , Brasil , América Central , Pinzones
4.
Biota Neotrop. (Online, Ed. ingl.) ; 18(1): e20170373, 2018. tab, graf
Artículo en Inglés | LILACS | ID: biblio-951144

RESUMEN

Abstract Here we inferred about the effectiveness of a buffer zone composed by an Agroforestry System (AS) for providing reproductive conditions for Atlantic Forest birds by comparing artificial nest predation rates between a buffer zone, a primary forest area, and a set of small and isolated Atlantic Forest fragments. We have used 237 nests throughout the three areas, of which 100 (42.2%) were depredated. Predation frequencies were 28.6% in the continuous forest, 100% in the AS, and 51.9% in the fragments, differing significantly. We could detect nest predators in 48 of the 100 depredated nests (48%) using camera traps. Differences between areas may be attributed to changes in nest predator species. We support previous evidences that the conservation of bird communities may not rely on buffer zones as an extension of their breeding habitats.


Resumo O presente estudo teve como objetivo avaliar a efetividade de uma zona tampão composta por um sistema agroflorestal (SA) para a reprodução de aves da Mata Atlântica. Para isto, as porcentagens de predação em ninhos artificiais foram comparadas entre as zonas tampão, uma área de floresta primária e em um conjunto de fragmentos de Mata Atlântica pequenos e isolados. Um total de 237 ninhos foi utilizado nas três áreas e 100 deles (42,2%) foram predados. As porcentagens de predação foram 28,6% na área de floresta primária, 100% no SA e 51,9% nos fragmentos, havendo diferença significativa. Os predadores puderam ser identificados em 48 das 100 predações (48%) com o uso de câmeras trap, o que gerou evidências de que as diferenças possam ser atribuídas a mudanças na composição de espécies de predadores entre as áreas. Esta análise dá suporte a estudos prévios de que as zonas tampão não devam ser consideradas como extensão dos hábitats naturais para a conservação de comunidades de aves.

5.
Biota Neotrop. (Online, Ed. ingl.) ; 17(4): e20170391, 2017. tab, graf
Artículo en Inglés | LILACS | ID: biblio-951129

RESUMEN

Abstract The availability of suitable cavities and substrate for hole construction can limit the populations of birds that rely on tree hollows to reproduce. Several studies have focused on the effects of types of habitats, and types of human disturbances on cavities abundance, but the effect of successional stages in the Atlantic Forest has been poorly addressed. In this study we aimed to compare the availability and biometric characteristics of tree cavities between primary and mid-successional stage sites in an Atlantic Forest area from southeastern Brazil. Based on nest characteristics described in the literature, we inferred if hollows present in secondary sites could harbor the large secondary-nester Atlantic Forest birds, with special attention to toucans and hawks. From September 2016 to April 2017, 96 cavities were sampled, 67 in the primary, and 29 in the secondary plots. Our data revealed that the communities of cavity-nester birds in mid-successional stage areas may be more affected by the reduced cavity availability than by cavities quality, as the number of cavities in these sites was less than half than that found in mature forests. We also provide evidences that the largest cavity nesters, such as the biggest hawks, might have limited nesting possibilities in mid-successional stage areas especially due to small cavity entrances, which may have important reflects in conservation strategies.


Resumo A disponibilidade de cavidades adequadas e o substrato para a escavação de ocos podem limitar as populações de aves que dependem das cavidades de árvores para se reproduzir. Vários estudos se concentraram nos efeitos dos tipos de habitats e em tipos de distúrbios antrópicas sobre a disponibilidade de cavidades, mas o efeito da sucessão ecológica na Mata Atlântica é muito pouco investigado. Neste estudo, buscamos comparar a disponibilidade e algumas características biométricas das cavidades de árvores entre áreas em estágio primário e secundário-médio na Mata Atlântica do sudeste do Brasil. Baseado nas características dos ninhos das espécies que ocorrem na área de estudo, também deduzimos se as cavidades que estão presentes em áreas secundárias poderiam abrigar as maiores aves que nidificam em cavidades, mas que são incapazes de escavá-las, com atenção especial aos tucanos e falcões. De setembro de 2016 a abril de 2017, 96 cavidades foram amostradas, 67 em áreas primárias e 29 em parcelas em locais de floresta secundária. Nossos dados revelaram que a comunidade de aves dependentes de ocos para nidificação em áreas em estágio médio de sucessão podem ser mais afetadas pela baixa disponibilidade de cavidades do que pela qualidade das cavidades, já que o número de cavidades nesses locais foi menos da metade do que o encontrado em florestas maduras. Também evidenciou-se que os nidificadores de cavidades de maior porte, como os grandes falcões, podem ter possibilidades de nidificação limitadas nas áreas de estágio médio de sucessão, especialmente devido ao tamanho reduzido das entradas de cavidades, o que pode ter importantes reflexos em estratégias de conservação.

6.
Genet. mol. biol ; 26(3): 283-287, 2003. ilus
Artículo en Inglés | LILACS | ID: lil-346317

RESUMEN

Neotropical parrots are among the most threatened groups of birds in the world, and many species are facing extinction in a near future. At the same time, the taxonomic position of many species remains unclear. Karyotype analysis has been used to elucidate the phylogenetic status of many bird groups, also providing important information for both in situ and ex situ conservation plans. The objective of the present study was to describe for the first time the karyotypes of the endangered Hyacinth Macaw, Anodorhynchus hyacinthinus, and of the Hawk-headed Parrot, Deroptyus accipitrinus. A diploid number of 2n = 70 and a karyotype similar to the main pattern previously found for the genera Ara, Cyanopsitta, Aratinga, Propyrrhura, Pionites, Pionopsitta, Nandayus, and Guaruba were found for both species. These karyotype descriptions can be a starting point for the genetic monitoring of these two declining species


Asunto(s)
Animales , Masculino , Femenino , Aves , Cromosomas , Conservación de los Recursos Naturales , Variación Genética , Citogenética , Genética de Población , Cariotipificación
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