No abstract

El bosque seco tropical es uno de los ecosistemas más amenazado del planeta y los reptiles que alberga han sido pobremente estudiados. En seis fragmentos de bosque seco tropical (con un área entre 7 y 84 ha) rodeados por potrero, se muestrearon reptiles durante el día y la noche, en tres temporadas a lo largo de 120 transectos lineales. Se encontró mayor riqueza de especies en los fragmentos de mayor área pero la relación “número de especies-área del fragmento” se perdió a medida que los estimadores de riqueza predijeron mayor número de especies en el ensamble. La abundancia total de reptiles y la composición de especies no varió en relación al área del fragmento pero el fragmento de mayor área presentó el mayor número de especies exclusivas. El mayor recambio de especies se dio entre los fragmentos grandes y los pequeños. El tamaño del fragmento claramente afectó a Anolis vittigerus, lagarto que hasta el momento no se encuentra incluido en las categorías de riesgo de la UICN. Más del 70% de las especies encontradas son raras (abundancia < a 4 individuos) por lo cual es necesario realizar estudios poblacionales intensivos para poder conocer la respuesta de las especies crípticas a la pérdida y fragmentación del hábitat.

Magnolia pajarito, a new species from the Andean slopes of the Eastern Cordillera of Colombia, is described and illustrated, and its morphological relationships with other similar Magnolia species are discussed. This new species is a tree between 9 and 30 m tall from montane forest remnants and pasture lands with dispersal trees (1500–1700 m), and it does not appear to be closely allied to any particular Magnolia species. This new species shares several features with four other species (M. arcabucoana, M. caricifragans, M. santanderiana, and M. virolinensis) in section Talauma. Morphologically it has some similarity to M. arcabucoana, but it differs in the length of the adaxial scar of the petiole, the size and shape of the leaf blade, the sepal and inner petal, and in the number of secondary veins, vaginal hypsophyl, and stamens. Additionally, habitat information, a distribution map, and data on Magnolia conservation status are included. An identification key of species of Magnolia found in Colombia is also provided. This new species elevates to 40 the number of Magnolia taxa for the flora of Colombia, of which 31 are endemic. Colombia has the highest diversity of the genus in the neotropics.

We evaluated the taxonomic and functional diversity of birds in a rural landscape in the north-eastern Andes of Colombia. We carried out seven field trips and used transects of 300 m, separated from each other by 500 m in the dominant plant cover of the rural landscape. We measured alpha (α) and beta (β) diversity at both the taxonomic and functional levels. We registered 10 orders, 21 families, 56 genera and 63 species of birds. In wooded pasture, we recorded 55 species and a relative abundance of 66% and 44 and 34% for an Andean forest fragment. The species that contributed the most to the dissimilarity between the covers were Zonotrichia capensis, Turdus fuscater, Mecocerculus leucophrys, Atlapetes latinuchus and Crotophaga ani. We identified nine functional types, where G1 was made up of small species with anissodactyl and pamprodactyl legs that were insectivorous, frugivorous and nectarivorous as the best represented. The FEve and FDiv were 0.51 and 0.74, respectively in the Andean forest fragment plant cover and, for the wooded pasture, the FEve was 0.45 and the FDiv was 0.81. Both cover types contributed to the diversity of the rural landscape and the dynamics that existed between them formed a complementary factor that favoured the taxonomic and functional richness of the characterised rural landscape.