Raptors provide critical ecosystem services, yet there is currently no systematic, global synthesis of their conservation status or threats. We review the International Union for the Conservation of ...Nature's Red List to examine the conservation status, distributions, threats, and conservation recommendations for all 557 raptor species. We further assess the significance of Important Bird and Biodiversity Areas (IBAs) for raptor conservation. We also determine which countries contain the most species listed under the Memorandum of Understanding on the Conservation of Migratory Birds of Prey in Africa and Eurasia (Raptors MoU). Raptors, especially Old World vultures, are more threatened than birds in general. Eighteen percent of raptors are threatened with extinction and 52% of raptors have declining global populations. South and Southeast Asia have the highest richness and the largest number of threatened raptor species. By country, Indonesia has the highest richness of raptor species (119) and most declining species (63). China and Russia contain the most Raptors MoU species, although they are not yet signatories to the agreement. Raptor species that require forest are more likely to be threatened and declining than those that do not. Agriculture and logging are the most frequently identified threats, although poisoning is especially detrimental to Old World vultures. Of the 10 most important IBAs for raptors, six are in Nepal. Highest priority conservation actions to protect raptors include preventing mortality and conserving key sites and priority habitats. Improved long-term monitoring would allow for conservation to be appropriately targeted and effectiveness of interventions to be assessed.
Understanding parasite-host ecology is increasingly important for conservation efforts in a changing world. Parasitic nest flies in the genus
Philornis
(Diptera: Muscidae) have been implicated in the ...decline of endemic island species and are also known to negatively impact breeding success of the critically endangered Ridgway’s hawk (
B. ridgwayi
) on the island of Hispaniola. Despite the importance of these effects on hosts, and extensive research of
Philornis downsi
in the Galápagos, the ecology of most species of philornid nest flies is poorly understood. We examined biotic factors related to
Philornis pici
infestations of nestling Ridgway’s hawks in the Dominican Republic, where both fly and hawk are native. We found grass-cover was negatively associated with
P. pici
infestations, while coverage and height of other vegetation classes (tree, shrub, herbaceous, and bare ground) had no association, which is interesting considering recent landscape-level changes to Ridgway’s hawk habitat. Anthropogenic activities in Los Haitises National Park, the last strong-hold of Ridgway’s hawk, have shifted the landscape from primary forest to a fragmented secondary forest with smallholder or subsistence farms and grassy patches. New information on the ecology of nest flies in their native habitat can inform conservation efforts and allow us to make recommendations for future research.
Context
The vast majority of the global population of Eleonora’s falcon overwinters in Madagascar, where the natural environment is threatened by human-induced habitat changes, particularly intensive ...forest degradation.
Objectives
We described Eleonora’s falcon phenology and habitat use based on fine-scale telemetry data and field surveys, and investigated which environmental parameters shape the observed patterns, to obtain a better insight into the species’ ecological requirements during the wintering season.
Methods
We used high resolution GPS telemetry and remotely sensed data to establish bird–habitat associations and investigate spatiotemporal activity. We also verified habitat composition through ground surveys.
Results
Eleonora’s falcon exploits a variety of habitats, exhibiting a distinct phenological pattern in their use. The species exhibits high site fidelity, moving progressively from more open areas towards landscapes with denser tree cover, possibly as a response to spatiotemporal patterns in food abundance. Time budget analysis revealed that Eleonora’s falcon dedicates just about 15% of its daily activity to foraging, which is performed almost exclusively during daylight hours, with a greater tendency to forage at higher elevations with denser tree cover. On-site assessment of habitat composition revealed that existing habitat maps overlook small fragments of habitat and land use. However, the species’ overall preference for humid forest suggests ongoing deforestation would adversely affect the availability of preferred habitat.
Conclusions
Our findings suggest that GPS logger technology, when combined with ground surveys, can enhance our understanding of long-distance migratory bird species’ ecology at finer and more ecologically relevant scales.
Conservationists often face tradeoffs. We present a tradeoff that we recently faced involving nest management of the endangered Puerto Rican Sharp-shinned Hawk (Accipiter striatus venator). Given our ...logistical constraints, we determined we were able to either continue our ongoing efforts to induce laying of a second clutch (hereafter, double clutching) of four nests per year, or we could stop double clutching and apply insecticide for parasitic nest flies (Philornis spp.) to as many nests as possible. Observed fledging rates justified our assumptions that the fledging rate of unmanaged nests was approximately one young per nest per year, whereas nests sprayed with insecticide for flies fledged two young, and double-clutched nests fledged three young. These three young from double-clutched nests were a combination of the young from both the parent-raised and hand-raised clutches. Although double clutching is more effective than spraying nests, it is also more labor intensive. We developed a model to determine how many nests we would need to spray to produce the same number of fledglings as if we continued the ongoing double clutching regime. Modeling revealed that if we could find and spray at least eight nests, then cessation of double clutching was justified. We also performed sensitivity analysis and determined that our management conclusion was robust to uncertainty in the assumed values of fledging rates. Our modeling exercise presents an example of informed decision making in the face of uncertainty. Los conservacionistas a menudo se enfrentan a soluciones de compromiso. Presentamos una solución de compromiso que tomamos recientemente asociada al manejo de nidos de Accipiter striatus venator, una especie en peligro de extinción. Dadas nuestras limitaciones logísticas, determinamos que podíamos o bien continuar con nuestros esfuerzos en curso para inducir la puesta de una segunda nidada (en adelante, nidada doble) de cuatro nidos por año o, alternativamente, podíamos detener la nidada doble y aplicar insecticida para las moscas parásitas del género Philornis a tantos nidos como fuera posible. Las tasas de emplumamiento observadas justificaron nuestras suposiciones de que la tasa de emplumamiento de los nidos no manejados fue de aproximadamente una cría por nido por año, mientras que los nidos rociados con insecticida para moscas produjeron dos crías y los nidos con nidada doble produjeron tres crías. Estas tres crías de nidos de nidada doble eran una combinación de las crías de las nidadas alimentadas por los progenitores y alimentadas a mano. Aunque la nidada doble es más efectiva que rociar los nidos, también requiere más trabajo. Desarrollamos un modelo para determinar cuántos nidos necesitaríamos rociar para producir la misma cantidad de polluelos que si continuáramos con el régimen de nidada doble en curso. La modelización reveló que, si podíamos encontrar y rociar al menos ocho nidos, entonces se justificaba el cese de las nidadas dobles. También realizamos un análisis de sensibilidad y determinamos que nuestra conclusión de gestión era robusta a la incertidumbre en los valores supuestos de las tasas de emplumamiento. Nuestro ejercicio de modelización presenta un ejemplo de toma de decisiones informada frente a la incertidumbre. Traducción del equipo editorial
Potential extinction of raptor species is especially important given their outsized roles in ecosystems and human cultures. We examined Red List data for raptor species listed as critically ...endangered by the International Union for the Conservation of Nature. Our goal was to highlight the plight of these critically endangered raptor species while identifying the reasons for their imperiled status, the most important countries for their conservation, and the actions needed for their persistence. We categorized the 17 critically endangered raptor species into two groups—Accipitrid vultures and species with small populations. Accipitrid vultures had relatively large populations and ranges, and were listed under Criterion A due to precipitous population declines. The threat listed for the most Accipitrid vultures was “pollution,” reflecting poisoning as the principal cause of declines. Conversely, the small population species were listed under Criteria C and D and were most threatened by “agriculture and aquaculture.” Countries in Africa and south Asia were hotspots of critically endangered raptors. The conservation action listed for the most species was “education and awareness” followed by “land protection” and “law and policy.” The most-listed monitoring category was “population trends.” The Multi-species Action Plan to Conserve African-Eurasian Vultures should be implemented to prevent extinction of Accipitrid vultures. Conversely, species with small populations are generally isolated and must be managed individually. Conservation of the world's most imperiled raptor species is an important facet of assuaging the sixth mass extinction. La extinción potencial de las especies de rapaces es especialmente importante debido a su papel principal en los ecosistemas y las culturas humanas. Examinamos los datos de la Lista Roja de especies de rapaces catalogadas en peligro crítico por la Unión Internacional para la Conservación de la Naturaleza. Nuestro objetivo fue resaltar la difícil situación de estas especies de rapaces en peligro crítico al tiempo que identificamos las razones de su estado de amenaza, los países más importantes para su conservación y las acciones necesarias para su persistencia. Clasificamos las 17 especies de rapaces en peligro crítico de extinción en dos grupos: buitres accipítridos y especies con poblaciones pequeñas. Los buitres accipítridos tuvieron poblaciones y áreas de distribución relativamente grandes, y se incluyeron en el Criterio A debido a las rápidas disminuciones poblacionales. La amenaza listada para la mayoría de los buitres accipítridos fue la “contaminación”, lo que refleja el envenenamiento como la causa principal de las disminuciones. Por el contrario, las especies con poblaciones pequeñas se incluyeron en los Criterios C y D y estuvieron más amenazadas por “la agricultura y la acuicultura”. Los países de África y el sur de Asia fueron puntos calientes de rapaces en peligro crítico. La acción de conservación enumerada para la mayoría de las especies fue “educación y concienciación”, seguida de “protección de la tierra” y “leyes y políticas”. La categoría de seguimiento más mencionada fue “tendencias poblacionales”. El Plan de Acción Multi-específico para la Conservación de los Buitres de África y Eurasia debería implementarse para evitar la extinción de los buitres accipítridos. Por el contrario, las especies con poblaciones pequeñas generalmente están aisladas y deben manejarse individualmente. La conservación de las especies de rapaces más amenazadas del mundo es una faceta importante para aliviar la sexta extinción masiva. Traducción del equipo editorial
The effects of forest fragmentation on forest bird species in the Bemanevika Protected Area (PA), northwestern Madagascar, were investigated during two breeding seasons from October 2016 to January ...2018. The forest of Bemanevika is composed of large patches of fragmented tropical rainforest. Seven forest fragments ranging from 10 to 1 050 ha were surveyed. Two methods were used to collect data along transects orientated from the forest edge toward the interior of the forest: mist-netting and point-counts. In all, 27 non-forest birds and 65 forest birds were recorded at all fragments. According to their distribution along an edge-interior gradient, these 65 forest species are classified into three main groups: 15 (23.1%) edge species, 12 (18.5%) forest interior species and 38 (58.5%) ubiquitous species. Larger forest fragments host more forest bird species than smaller forest fragments. Of the 65 forest birds, 14, including the 12 forest interior species, were not found in the four smaller fragments (10-29 ha). The density of forest interior species was positively correlated to forest fragment size. The general trend was that forest interior species were the most sensitive to forest fragmentation (e.g. Madagascar Serpent-eagle Eutriorchis astur, Pitta-like Ground-roller Atelornis pittoides and Schlegel's Asity Philepitta schlegeli). Large raptors, terrestrial species and understory species were the first to disappear from the small fragments. Fragmented forests provide habitat for bird species, even for those vulnerable to forest fragmentation, therefore the maintenance of large enough forest fragments should be considered in all conservation strategies aimed to protect forest birds.
More than one-third of the bird species found in the Caribbean are endemic to a set of neighboring islands or a single island. However, we have little knowledge of the evolutionary history of the ...Caribbean avifauna, and the lack of phylogenetic studies limits our understanding of the extent of endemism in the region. The Sharp-shinned Hawk (Accipiter striatus) occurs widely across the Americas and includes 3 endemic Caribbean taxa: venator on Puerto Rico, striatus on Hispaniola, and fringilloides on Cuba. These island populations have undergone extreme declines presumably due to ecosystem changes caused by anthropogenic factors, as well as due to severe hurricanes. Sharp-shinned Hawks, in general, and Caribbean Sharp-shinned Hawks, in particular, have not been placed in a modern phylogenetic context. However, the island taxa have historically been presumed to have some ongoing gene flow with mainland populations. Here we sequenced ultraconserved elements (UCEs) and their flanking regions from 38 samples, focusing on Caribbean taxa. Using a combination of UCEs, mitochondrial genome sequences, and single-nucleotide polymorphisms, we investigated the phylogenetic relationships among Caribbean lineages and their relationships to mainland taxa. We found that Caribbean Sharp-shinned Hawks are reciprocally monophyletic in all datasets with regard to mainland populations and among island taxa (with no shared mtDNA haplotypes) and that divergence in the NADH dehydrogenase 2 gene (ND2) between these mainland and island groups averaged 1.83%. Furthermore, sparse non-negative matrix factorization (sNMF) analysis indicated that Hispaniola, Puerto Rico, and mainland samples each form separate populations with limited admixture. We argue that our findings are consistent with the recognition of the 3 resident Caribbean populations as species-level taxa because nuclear and mitochondrial genetic data indicate reciprocal monophyly and have species-level divergences, there is no sharing of mitochondrial haplotypes among or between island taxa and those on the mainland; and they are diagnosable by plumage. LAY SUMMARY Using ultraconserved elements we reconstructed relationships among Sharp-shinned Hawk (Accipiter striatus) taxa in the Caribbean and mainland. Sharp-shinned Hawks in the Caribbean have undergone population declines and, in Puerto Rico, they are federally listed as endangered. Our analysis of both nuclear and mitochondrial genetic data supports the recognition of each Caribbean island population of Sharp-shinned Hawk as an endemic species.
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