Dispersión de semillas por murciélagos a través de cuatro estados sucesionales de un paisaje subandino

The mutual relationships between bats and vegetation, in addition to the individual benefits, are significant contributors to the tropical forest regeneration through seed dispersal. As the bats eat the fruits of pioneer plants they provide secondary succession dispersing the ingested seeds into the forest as well as in the degraded areas. This study compared the structure and composition of the fruit bats and the seeds dispersed in different successional habitats (mature forest, secondary growth with seven years of regeneration, secondary growth with one year of regeneration and pasture) in the Forest Reserve Bremen-La Popa (Filandia-Quindío, Colombia). Mist nets were used to capture the bats and samples of their feces were also obtained. Abundance, richness and equity of the fruit bats and the seeds dispersed were higher in those habitats with older regeneration. The bats Artibeus lituratus and Sturnira lilium were more abundant in the pasture and in the early successional stages of one and seven years. The seeds most dispersed by bats were Cecropia telealba, Solanum undullata, Solanum aphydendron and Solanum acerifolium.La relación mutualista entre murciélago-vegetación, además de los beneficios individuales, contribuye de manera importante a la regeneración de los bosques tropicales a través de la dispersión de semillas. Los murciélagos al consumir los frutos de plantas pioneras facilitan la sucesión secundaria, dispersando las semillas que ingieren tanto en bosques como en áreas degradadas. En este estudio se comparó la estructura y composición del conjunto de murciélagos frugívoros y las semillas que dispersaron en hábitats con diferente estado sucesional (bosque maduro, crecimiento secundario con siete años de regeneración, crecimiento secundario con un año de regeneración y pastizal) en la Reserva Forestal Bremen-La Popa (Filandia, Quindío). Se utilizaron redes de niebla para la captura de los murciélagos y se obtuvo muestras de materia fecal. La abundancia, riqueza y equidad del conjunto de murciélagos frugívoros y de las semillas que dispersaron fue superior en los hábitats con mayor edad de regeneración. Artibeus lituratus y Sturnira lilium fueron los murciélagos más abundantes en pastizales y en los estados sucesionales tempranos de uno y siete años. Las semillas más dispersadas por los murciélagos fueron de Cecropia telealba, Solanum undullata, S. aphydendron y S. acerifolium

DIETA DEL CORRELIMOS DIMINUTO (CALIDRIS MINUTILLA) EN CULTIVOS DE ARROZ ORGÁNICO DE COLOMBIA

RESUMEN ∙ El arroz es uno de los principales alimentos para el ser humano y su área cultivada global se aproxima a los diez millones de hectáreas. Muchos ecosistemas naturales, en especial humedales, han sido modificados para realizar este cultivo. Sin embargo, el desarrollo de este cereal requiere de etapas de anegamiento que permiten que varios organismos, entre estos las aves playeras, obtengan recursos alimenticios. En los cultivos orgánicos de arroz del Valle del Cauca, Colombia, se han registrado doce especies de aves playeras migratorias provenientes principalmente de Norteamérica y se ha encontrado la mayor concentración de individuos del Correlimos Diminuto (Calidris minutilla) en Colombia. En los sitios de reproducción, C. minutilla se alimenta principalmente de invertebrados bentónicos y terrestres mientras que para los sitios de invernada se ha registrado una mayor gama de presas. Con el fin de determinar la dieta del C. minutilla en arrozales orgánicos, entre octubre y diciembre de 2012 se capturaron 50 individuos con redes de niebla y se les indujo a regurgitar con solución salina. Las presas identificadas en los regurgitados indican que en los arrozales orgánicos del Valle del Cauca, C. minutilla se alimenta principalmente de insectos, arañas y material vegetal. Además, usa pequeñas piedras para triturar presas con exoesqueletos duros como coleópteros y hemípteros. Dado el porcentaje de consumo de larvas y adultos de coleópteros que son considerados una plaga en los cultivos de arroz, C. minutilla puede ser uno de los principales controladores naturales de estos insectos. Esta información contribuye a entender porque C. minutilla utiliza los arrozales y resalta la importancia de este agroecosistema para la migración de esta ave playera.ABSTRACT ∙ Diet of Least Sandpipers (Calidris minutilla) in organic rice fields of ColombiaRice is one of the most important food sources for humans, and its global cultivated surface reaches ten millions of hectares. Many natural ecosystems, especially wetlands, have been modified or destroyed due to conversion to rice fields. However, rice crops require flooding, and the wetlands thus created can provide food for several organisms including shorebirds. In the organic rice fields of Valle del Cauca, in Colombia, twelve species of Nearctic migrant shorebirds have been recorded, including the highest numbers of Least Sandpipers (Calidris minutilla) in Colombia. On their breeding grounds in North America, Least Sandpipers feed on benthic and terrestrial invertebrates, while on the wintering grounds they ingest a wider range of prey. To determine the diet of Least Sandpipers in this type of cultivation in Valle del Cauca, from October 2012 to December 2012 we caught 50 individuals using mist netting and obtained regurgitates induced with saline solution. The identification of prey found in regurgitates indicates that Least Sandpipers feed on insects, spiders, and vegetable material in the study site. In addition, they use small stones to crush prey with hard exoskeleton, such as Coleoptera and Hemiptera. Given the relatively high levels of consumption of beetle larvae and adults, which are considered pests for rice crops, Least Sandpipers could be one of the main biocontrol agents of these insects. This information contributes to understand why Least Sandpipers use organic rice fields and highlights the importance of this agroecosystem for the migration of this shorebird

Tracking extinction risk trends and patterns in a mega-diverse country: A Red List Index for birds in Colombia.

Monitoring trends in the extinction risk of species is important for tracking conservation effectiveness. The Red List index (RLI) reflects changes in aggregate extinction risk for sets of species over time (a value of zero means that all species are extinct, a value of one means that all species are categorized as Least Concern). We calculated the first national RLI for birds in Colombia for the period 2002-2016, and disaggregated indices by ecosystems, regions, and species groups. Overall, the status of birds in Colombia has moderately deteriorated during 2002-2016, declining by 0.0000714% per year (the global RLI for birds declined by 0.0297% per year). High Andean forest, paramo, and freshwater are the ecosystems in worst condition. The two regions with the greatest avian diversity contrasted: the Andes has the lowest RLI, and the Amazon the highest. Among species groups, gamebirds, parrots, large frugivores, and forest raptors are the most threatened. Habitat loss from expansion of illicit crops and population declines from hunting were the most important threats. Agricultural expansion, invasive alien animal species, illegal logging and illegal mining are significant threats for some species. Tracking species' extinction risk is important in a country with the highest bird species richness in the world, dynamic spatial patterns of habitat loss, and high levels of endemism. Recent developments provide reasons for both hope and despair. In 2016, a peace agreement ended 50 years of armed conflict. New opportunities for biodiversity conservation, local development based on bird-watching tourism, and advancement in scientific knowledge of birds now occur alongside dramatic increases in deforestation. These new conservation opportunities and challenges provide strong motivation to take advantage of the fact that the overall risk of extinction of birds in Colombia is still relatively low and stable. Effective action is urgently needed while there still is the opportunity to prevent extinctions and safeguard species, particularly those in higher risk categories

Seed dispersal by bats across four successional stages of a subandean landscape

The mutual relationships between bats and vegetation, in addition to the individual benefits, are significant contributors to the tropical forest regeneration through seed dispersal. As the bats eat the fruits of pioneer plants they provide secondary succession dispersing the ingested seeds into the forest as well as in the degraded areas. This study compared the structure and composition of the fruit bats and the seeds dispersed in different successional habitats (mature forest, secondary growth with seven years of regeneration, secondary growth with one year of regeneration and pasture) in the Forest Reserve Bremen-La Popa (Filandia-Quindío, Colombia). Mist nets were used to capture the bats and samples of their feces were also obtained. Abundance, richness and equity of the fruit bats and the seeds dispersed were higher in those habitats with older regeneration. The bats Artibeus lituratus and Sturnira lilium were more abundant in the pasture and in the early successional stages of one and seven years. The seeds most dispersed by bats were Cecropia telealba, Solanum undullata, Solanum aphydendron and Solanum acerifolium

Lista de chequeo de las aves de Colombia: Una síntesis del estado del conocimiento desde Hilty & Brown

The taxonomy and knowledge of the distribution of Colombian avifauna has undergone great changes since the publication of “A Guide to the Birds of Colombia” by Hilty & Brown (1986) to the extent that we are unaware of how many and which species inhabit the Colombian territory. Here, we present a checklist of the birds of Colombia updated to August 2017 with a review of 340 references dealing with the distribution of Colombian birds. In sum, we report 1909 species for continental and insular Colombia, 216 of which have been added mainly since 1986. Although there are new data on distribution from 66% of the Colombian avifauna, most publications (87%) and new records (53%) are concentrated to the west of the Eastern cordillera (trans-Andean region). Based on the data we identify those regions of the country with knowledge gaps, which deserve more interest from researchers. Moreover, we encourage the ornithological community to publish their unpublished data and to improve the evidence supporting future new records for the country.La taxonomía y conocimiento de la distribución de la avifauna colombiana ha sufrido grandes cambios desde la publicación de “A Guide to the Birds of Colombia” por Hilty & Brown (1986), a tal punto que hoy no se sabe con precisión cuántas y cuáles especies de aves existen en el territorio colombiano. Presentamos la lista de chequeo de la avifauna de Colombia a agosto de 2017 con base en la revisión de 340 referencias relacionadas con la distribución de la avifauna colombiana. En total, reportamos 1909 especies de aves para el territorio continental e insular del país, de las cuales 216 han sido adicionadas principalmente a partir de 1986. Aunque existe información novedosa sobre distribución para cerca del 66% de la avifauna colombiana, la mayoría de las publicaciones (87%) y registros (53%) se concentran al occidente de la cordillera Oriental (región transandina). Con base en esta información identificamos aquellas áreas del país con vacíos de conocimiento que ameritan mayor interés por parte de los investigadores. Además, estimulamos a la comunidad ornitológica a publicar la información inédita represada, al igual que mejorar la evidencia que soporta los registros novedosos para el país

State of the world's birds

We present an overview of the global spatiotemporal distribution of avian biodiversity, changes in our knowledge of that biodiversity, and the extent to which it is imperilled. Birds are probably the most completely inventoried large taxonomic class of organisms, permitting a uniquely detailed understanding of how the Anthropocene has shaped their distributions and conservation status in space and time. We summarize the threats driving changes in bird species richness and abundance, highlighting the increasingly synergistic interactions between threats such as habitat loss, climate change, and overexploitation. Many metrics of avian biodiversity are exhibiting globally consistent negative trends, with the International Union for Conservation of Nature's Red List Index showing a steady deterioration in the conservation status of the global avifauna over the past three decades. We identify key measures to counter this loss of avian biodiversity and associated ecosystem services, which will necessitate increased consideration of the social context of bird conservation interventions in order to deliver positive transformative change for nature

How many bird and mammal extinctions has recent conservation action prevented?

Aichi Target 12 of the Convention on Biological Diversity (CBD) aims to ‘prevent extinctions of known threatened species’. To measure its success, we used a Delphi expert elicitation method to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993 - 2020 (the lifetime of the CBD) and 2010 - 2020 (the timing of Aichi Target 12). We found that conservation prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and 2–7 mammal extinctions since 2010. Many remain highly threatened, and may still become extinct in the near future. Nonetheless, given that ten bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions

How many bird and mammal extinctions has recent conservation action prevented?

Aichi Target 12 of the Convention on Biological Diversity (CBD) contains the aim to ‘prevent extinctions of known threatened species’. To measure the degree to which this was achieved, we used expert elicitation to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993–2020 (the lifetime of the CBD) and 2010–2020 (the timing of Aichi Target 12). We found that conservation action prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and two to seven mammal extinctions since 2010. Many remain highly threatened and may still become extinct. Considering that 10 bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions.https://wileyonlinelibrary.com/journal/conlMammal Research Institut

Tracking extinction risk trends and patterns in a mega-diverse country: A Red List Index for birds in Colombia.

Monitoring trends in the extinction risk of species is important for tracking conservation effectiveness. The Red List index (RLI) reflects changes in aggregate extinction risk for sets of species over time (a value of zero means that all species are extinct, a value of one means that all species are categorized as Least Concern). We calculated the first national RLI for birds in Colombia for the period 2002-2016, and disaggregated indices by ecosystems, regions, and species groups. Overall, the status of birds in Colombia has moderately deteriorated during 2002-2016, declining by 0.0000714% per year (the global RLI for birds declined by 0.0297% per year). High Andean forest, paramo, and freshwater are the ecosystems in worst condition. The two regions with the greatest avian diversity contrasted: the Andes has the lowest RLI, and the Amazon the highest. Among species groups, gamebirds, parrots, large frugivores, and forest raptors are the most threatened. Habitat loss from expansion of illicit crops and population declines from hunting were the most important threats. Agricultural expansion, invasive alien animal species, illegal logging and illegal mining are significant threats for some species. Tracking species' extinction risk is important in a country with the highest bird species richness in the world, dynamic spatial patterns of habitat loss, and high levels of endemism. Recent developments provide reasons for both hope and despair. In 2016, a peace agreement ended 50 years of armed conflict. New opportunities for biodiversity conservation, local development based on bird-watching tourism, and advancement in scientific knowledge of birds now occur alongside dramatic increases in deforestation. These new conservation opportunities and challenges provide strong motivation to take advantage of the fact that the overall risk of extinction of birds in Colombia is still relatively low and stable. Effective action is urgently needed while there still is the opportunity to prevent extinctions and safeguard species, particularly those in higher risk categories

Diversidad composicional y funcional de aves en diferentes tipos de vegetación durante el periodo de lluvias en el Enclave Seco del Cañón del Río Chicamocha - Santander

La marcada estacionalidad del bosque seco favorece un alto número de endemismos y especies de distribución restringida. Sin embargo, en las aves algunas especies pueden tener una distribución más amplia, aprovechando recursos de ecosistemas cercanos. Este estudio tiene como objetivo estudiar las variaciones de la avifauna en nueve tipos de vegetación distintos. El sitio de estudio se encuentra en el enclave seco del cañón del Chicamocha en Santander, Colombia. Se usaron unidades de muestra simultáneas para avifauna y vegetación para comparar la composición y estructura de diferentes tipos de vegetación. Se encontró que la zona alta corresponde con un bosque seco premontano, tiene mayor riqueza de avifauna y menor riqueza florística, mientras que la zona baja representa un bosque seco tropical, tiene menor diversidad de avifauna y alta diversidad florística. Los resultados de este estudio muestran las variaciones en la composición y estructura de las aves en diferentes tipos de vegetación, las mayores diferencias se presentaron entre las fisionomías de vegetación: bosques riparios, bosques de ladera y matorrales, las que además comparten comunidades de aves en un gradiente de altura dado entre un bosque seco tropical y un bosque seco premontano.