Nuevas amenazas para la recuperación de la población de oso pardo cantábrico

Trabajo presentado al: Congress on “New challenges for the management and conservation of bear and Wolf population”. XII Symposium International-WAVES, Zamora, 28 Septiembre-1 Octubre.Peer reviewe

Dung removal increases under higher dung beetle functional diversity regardless of grazing intensification

Dung removal by macrofauna such as dung beetles is an important process for nutrient cycling in pasturelands. Intensification of farming practices generally reduces species and functional diversity of terrestrial invertebrates, which may negatively affect ecosystem services. Here, we investigate the effects of cattle-grazing intensification on dung removal by dung beetles in field experiments replicated in 38 pastures around the world. Within each study site, we measured dung removal in pastures managed with low- and high-intensity regimes to assess between-regime differences in dung beetle diversity and dung removal, whilst also considering climate and regional variations. The impacts of intensification were heterogeneous, either diminishing or increasing dung beetle species richness, functional diversity, and dung removal rates. The effects of beetle diversity on dung removal were more variable across sites than within sites. Dung removal increased with species richness across sites, while functional diversity consistently enhanced dung removal within sites, independently of cattle grazing intensity or climate. Our findings indicate that, despite intensified cattle stocking rates, ecosystem services related to decomposition and nutrient cycling can be maintained when a functionally diverse dung beetle community inhabits the human-modified landscape

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Notes about copulation and nesting of White-Cheeked Pintail (Anas Bahamensis l. 1758) on the island of Margarita, Venezuela.

The breeding status of White-cheeked Pintail (Anas bahamensis L.) in Venezuela has been anecdotal. On the island of Margarita, in the water treatment plant "Los Cerritos" (11° 0'35.19"N - 63°49'4.96"O), in a two-month period in September 2009, we monitored a breeding pair of White-cheeked Pintail from their copulation until the chicks reached the juvenile stage. When accepting the male, the couple went to the water, the male climbs on female back and clings to the neck feathers; the female dips its body into the water, raises the tail exposing the cloaca, and the male, with vigorous movement, copulates. The copulation in the water is an unreported behavior in this species. The nest is a hemispherical structure placed on the ground among vegetation in a clump of down, twigs and leaves of Philoxerus vermicularis (L.) Mears 1814 (Amaranthaceae). By 04 November the white-cheeked pintail female hatched twelve young, which at 22 days exhibited the typical adult coloration, but without the orange beak or the green wing mirror. The fledgling period spanned two months. The young of the species lack the red colouration in the maxilla or bill base and also have a much less green speculum and a yellow tinge over their body. Later it was found that the White-cheeked pintail reproduced regularly throughout the year on the premises of the treatment plant in "Los Cerritos", on the island of Margarita.La información sobre el estatus reproductivo del Pato Malibú (Anas bahamensis L.) en Venezuela ha sido anecdótica. En la isla de Margarita, en las instalaciones de la planta de tratamiento "Los Cerritos" (11° 0'35.19"N - 63°49'4.96"O), en septiembre del año 2009, durante un período de 2 meses, se le hizo seguimiento a una pareja reproductiva, desde la cópula hasta que las crías alcanzaron la fase juvenil. Al aceptar al macho, la pareja se dirigió al agua; el macho sube al dorso y aferra con su pico las plumas de la nuca; la hembra sumerge su cuerpo bajo el agua, y eleva su cola exponiendo la cloaca, y el macho, con un movimiento vigoroso, copula. La cópula dentro del agua es por primera vez documentada fotográficamente para esta especie. El nido constituye una estructura semiesférica tapizada con plumón, y hojas y talluelos postrados de Philoxerus vermicularis (L.) Mears, 1814 (Amaranthaceae). El 4 de noviembre ya habían eclosionado las doce crías, las cuales a los 22 días exhibían la coloración adulta típica, pero aún sin el color naranja del pico, ni el espejo alar verde. El período de volantones abarcó dos meses. Posteriormente se ha constatado que el Pato Malibú se reproduce regularmente durante todo el año en las instalaciones de la planta de tratamiento de "Los Cerritos", en la isla de Margarita

Elaenia Ruficeps (Aves: Tyrannidae, Elaeniinae): Nuevo indicio de la interconexión biogeográfica de las avifaunas del Macizo Guayanés y la Cordillera Nororiental de Venezuela

The Family Tyrannidae represents one of the most complex phylogenetic groups and the highest species richness of Neotropical avian fauna. Tyrant flycatchers have a Pan-American distribution and occur in almost every continental and insular habitat. We obtained for the first time a photographic record of Elaenia ruficeps in mountain forest habitat (ca. 800 m) in the Peninsula de Paria in northeastern Venezuela. On the one hand, this record attracts attention given that E. ruficeps is considered a savannah specialist, and, on the other hand, it revisits the controversy, until recently, about origin and biogeographical radiation of Pantepui avifauna and their ornithological relations with Paria-Turimiquire Mountains. The occurrence of E. ruficeps in the Peninsula of Paria highlights the necessity to undertake detailed ecological and phylogeographic studies about the movements of species with disjunct distributions in the circumequatorial region of South America.La familia Tyrannidae representa uno de los grupos filogeográficamente más complejos y el de mayor riqueza de especies en la avifauna de la Región Neotropical, con distribución panamericana, continental e insular, y dentro de una gran variedad de hábitat. Un registro fotográfico de Elaenia ruficeps se obtuvo por primera vez para el nororiente de Venezuela, en un hábitat boscoso montano (ca. 800 msnm) de la península de Paria. El hallazgo llama la atención, pues se ha considerado a E. ruficeps como un especialista de sabana; por otra parte, el avistamiento de E. ruficeps retrotrae las polémicas que, desde hace algún tiempo, se vienen suscitando acerca del origen y radiación biogeográfica de la avifauna de la formación Pantepuy, en el escudo guayanés, y su relación ornítica con la formación Paria-Turimiquire. La presencia de E. ruficeps en la cordillera nororiental venezolana vuelve a poner de relieve la necesidad de estudios ecológicos y filogeográficos más pormenorizados acerca de los movimientos de especies con distribución disyunta en la región circunecuatorial de Sudamérica

Dung removal increases under higher dung beetle functional diversity regardless of grazing intensification

Dung removal by macrofauna such as dung beetles is an important process for nutrient cycling in pasturelands. Intensification of farming practices generally reduces species and functional diversity of terrestrial invertebrates, which may negatively affect ecosystem services. Here, we investigate the effects of cattle-grazing intensification on dung removal by dung beetles in field experiments replicated in 38 pastures around the world. Within each study site, we measured dung removal in pastures managed with low- and high-intensity regimes to assess between-regime differences in dung beetle diversity and dung removal, whilst also considering climate and regional variations. The impacts of intensification were heterogeneous, either diminishing or increasing dung beetle species richness, functional diversity, and dung removal rates. The effects of beetle diversity on dung removal were more variable across sites than within sites. Dung removal increased with species richness across sites, while functional diversity consistently enhanced dung removal within sites, independently of cattle grazing intensity or climate. Our findings indicate that, despite intensified cattle stocking rates, ecosystem services related to decomposition and nutrient cycling can be maintained when a functionally diverse dung beetle community inhabits the human-modified landscape.info:eu-repo/semantics/publishedVersio

First record of bat-pollination in the species-rich genus Tillandsia (Bromeliaceae)

Background and Aims Bromeliaceae is a species-rich neotropical plant family that uses a variety of pollinators, principally vertebrates. Tillandsia is the most diverse genus, and includes more than one-third of all bromeliad species. Within this genus, the majority of species rely on diurnal pollination by hummingbirds; however, the flowers of some Tillandsia species show some characteristics typical for pollination by nocturnal animals, particularly bats and moths. In this study an examination is made of the floral and reproductive biology of the epiphytic bromeliad Tillandsia macropetala in a fragment of humid montane forest in central Veracruz, Mexico. Methods The reproductive system of the species, duration of anthesis, production of nectar and floral scent, as well as diurnal and nocturnal floral visitors and their effectiveness in pollination were determined. Key Results Tillandsia macropetala is a self-compatible species that achieves a higher fruit production through outcrossing. Nectar production is restricted to the night, and only nocturnal visits result in the development of fruits. The most frequent visitor (75 % of visits) and the only pollinator of this bromeliad (in 96 % of visits) was the nectarivorous bat Anoura geoffroyi (Phyllostomidae: Glossophaginae). Conclusions This is the first report of chiropterophily within the genus Tillandsia. The results on the pollination biology of this bromeliad suggest an ongoing evolutionary switch from pollination by birds or moths to bats