A technique to estimate density and monitor populations of the Spotted Nothura (Nothura maculosa) in grasslands habitats

En este trabajo se propone una técnica para estimar la densidad del Inambú Común (Nothura maculosa) y evaluar cuantitativamente sus tendencias poblacionales en ambientes de pastizal. Se estimó la densidad del Inambú Común en la sierras de Tandil, provincia de Buenos Aires, mediante dos técnicas: transectas de ancho variable y transectas de ancho fijo. Para este último caso, se evaluó el supuesto de que la probabilidad de detección dentro del ancho de la transecta es igual a 1. Las estimaciones de densidad obtenidas con ambas técnicas fueron similares (1.20 ind/ha para transectas de ancho variable y 1.16 ind/ha para transectas de ancho fijo). No se encontraron diferencias significativas en la frecuencia promedio de detecciones a distintas distancias de la línea de marcha dentro del ancho de faja. Se concluye que la utilización de transectas de ancho fijo es confiable y eficiente para evaluar, con un mínimo costo, las tendencias poblacionales del Inambú Común en áreas de pastizal y campos de cultivo. La densidad estimada se encuentra entre las más altas reportadas para la provincia, sugiriendo que las sierras de Tandil podrían estar actuando como un refugio para la especie.In this paper we present a technique to estimate densities and quantitatively evaluate population trends of Spotted Nothura (Nothura maculosa) in grasslands habitats. We evaluated Spotted Nothura density in the hills of Tandil, Buenos Aires Province, using two techniques: line transects with variable width and strip transects. For the latter, we also evaluated the assumption that the probability of detecting an individual within the strip was 1. Density values obtained with both techniques were similar (1.20 ind/ha for variable width transects, and 1.16 ind/ha for strip transects). We did not find significant differences among frequencies of individuals detected at different distances within the strip. We conclude that strip transects constitute a robust and efficient technique to evaluate, with a minimum cost, population trends of Spotted Nothura in grasslands and agricultural habitats. Our density estimates are among the highest reported for Buenos Aires Province, suggesting that the hills of Tandil could represent a refuge for this species.Facultad de Ciencias Naturales y Muse

Sub-Antarctic Biocultural Conservation Program

Poster presented at the 2013 Ecological Society of America (ESA) Annual Meeting. This poster discusses research on assessing habitat preference of invasive American minks (Neovison vison) using trap-cameras in Navarino Island, Chile

A technique to estimate density and monitor populations of the Spotted Nothura (Nothura maculosa) in grasslands habitats

En este trabajo se propone una técnica para estimar la densidad del Inambú Común (Nothura maculosa) y evaluar cuantitativamente sus tendencias poblacionales en ambientes de pastizal. Se estimó la densidad del Inambú Común en la sierras de Tandil, provincia de Buenos Aires, mediante dos técnicas: transectas de ancho variable y transectas de ancho fijo. Para este último caso, se evaluó el supuesto de que la probabilidad de detección dentro del ancho de la transecta es igual a 1. Las estimaciones de densidad obtenidas con ambas técnicas fueron similares (1.20 ind/ha para transectas de ancho variable y 1.16 ind/ha para transectas de ancho fijo). No se encontraron diferencias significativas en la frecuencia promedio de detecciones a distintas distancias de la línea de marcha dentro del ancho de faja. Se concluye que la utilización de transectas de ancho fijo es confiable y eficiente para evaluar, con un mínimo costo, las tendencias poblacionales del Inambú Común en áreas de pastizal y campos de cultivo. La densidad estimada se encuentra entre las más altas reportadas para la provincia, sugiriendo que las sierras de Tandil podrían estar actuando como un refugio para la especie.In this paper we present a technique to estimate densities and quantitatively evaluate population trends of Spotted Nothura (Nothura maculosa) in grasslands habitats. We evaluated Spotted Nothura density in the hills of Tandil, Buenos Aires Province, using two techniques: line transects with variable width and strip transects. For the latter, we also evaluated the assumption that the probability of detecting an individual within the strip was 1. Density values obtained with both techniques were similar (1.20 ind/ha for variable width transects, and 1.16 ind/ha for strip transects). We did not find significant differences among frequencies of individuals detected at different distances within the strip. We conclude that strip transects constitute a robust and efficient technique to evaluate, with a minimum cost, population trends of Spotted Nothura in grasslands and agricultural habitats. Our density estimates are among the highest reported for Buenos Aires Province, suggesting that the hills of Tandil could represent a refuge for this species.Facultad de Ciencias Naturales y Muse

Invasive expansion of the American Mink (Neovison vison) in the Cape Horn Biosphere Reserve, Chile

This article reports the continued expansion of the American mink to new sites in the Cape Horn Biosphere Reserve

Capturing and radio ear-tagging neonatal vicuñas

We used and evaluated the effectiveness of a hand-capture technique to capture and mark neonatal vicuñas (Vicugna vicugna) at San Guillermo National Park, west-central Argentina. We captured and marked 98 neonates during 5-31 January, 2008-2010. Capture success was 92% (106 attempts), with stationary marking teams being 2.5 times as successful in detecting and capturing neonates as mobile ones. Of neonates captured, 99% were 20 minutes old typically were too mobile to capture. Sex ratio at capture was biased toward males (1.5:1), while mean body weight and neck circumference were similar between sexes. Generally, mothers remained in sight during, and immediately reunited with their neonates after, capture. Four percent of the mothers ran out of sight but then returned, while 2% failed to return. Capture-related mortality was 5%, with maternal abandonment in response to capture activities (n = 3) the leading cause. Ear-tag transmitter had minimal effects on subsequent ear position. The success of our technique likely was based on terrain (flat) and vegetative conditions (short grass), high densities of animals for monitoring (particularly in a meadow), and a predictable, pulsed birth season. This hand-capturing method was efficient for handling and marking neonatal vicuñas. Combined with the use of ear-tag transmitters, it allows the study of important perinatal processes, including movement and mortality.Facultad de Ciencias Naturales y Muse

Enhancing animal movement analyses: spatiotemporal matching of animal positions with remotely sensed data using Google Earth Engine and R

Movement ecologists have witnessed a rapid increase in the amount of animal position data collected over the past few decades, as well as a concomitant increase in the availability of ecologically relevant remotely sensed data. Many researchers, however, lack the computing resources necessary to incorporate the vast spatiotemporal aspects of datasets available, especially in countries with less economic resources, limiting the scope of ecological inquiry. We developed an R coding workflow that bridges the gap between R and the multi-petabyte catalogue of remotely sensed data available in Google Earth Engine (GEE) to efficiently extract raster pixel values that best match the spatiotemporal aspects (i.e., spatial location and time) of each animal’s GPS position. We tested our approach using movement data freely available on Movebank (movebank.org). In a first case study, we extracted Normalized Difference Vegetation Index information from the MOD13Q1 data product for 12,344 GPS animal locations by matching the closest MODIS image in the time series to each GPS fix. Data extractions were completed in approximately 3 min. In a second case study, we extracted hourly air temperature from the ERA5-Land dataset for 33,074 GPS fixes from 12 different wildebeest (Connochaetes taurinus) in approximately 34 min. We then investigated the relationship between step length (i.e., the net distance between sequential GPS locations) and temperature and found that animals move less as temperature increases. These case studies illustrate the potential to explore novel questions in animal movement research using high-temporal-resolution, remotely sensed data products. The workflow we present is efficient and customizable, with data extractions occurring over relatively short time periods. While computing times to extract remotely sensed data from GEE will vary depending on internet speed, the approach described has the potential to facilitate access to computationally demanding processes for a greater variety of researchers and may lead to increased use of remotely sensed data in the field of movement ecology. We present a step-by-step tutorial on how to use the code and adapt it to other data products that are available in GEE

Spatiotemporal dynamics of wild herbivore species richness and occupancy across a savannah rangeland:Implications for conservation

Private lands are critical for maintaining biodiversity beyond protected areas. Across Kenyan rangelands, wild herbivores frequently coexist with people and their livestock. Human population and livestock numbers are projected to increase dramatically over the coming decades. Therefore, a better understanding of wildlife-livestock interactions and their consequences for biodiversity conservation on private lands is needed. We used a Bayesian hierarchical, multi-species and multi-year occupancy model on aerial survey data of 15 wild-herbivore species, spanning 15 years (2001–2016) to investigate a) spatiotemporal trends in species occurrence and richness across a mosaic of properties with different land uses in Laikipia County, central Kenya; and b) the effects of distance to water, vegetation and livestock relative abundance on species occurrence and richness. Although mean herbivore species richness varied little over time, we observed high spatial variation in species occurrence across Laikipia, mainly driven by negative effects of high livestock relative abundance. As expected, ‘wildlife friendly’ properties had higher herbivore species richness than other areas. However, high variability suggests that some pastoral properties support rich herbivore communities. The area occupied by five species with global conservation concerns (reticulated giraffe, Grevy's zebra, Beisa Oryx, Defassa waterbuck and gerenuk) and for which Laikipia County is one of the last refuges was <50% across years. We conclude that ‘wildlife friendly’ properties remain crucial for conservation, although some pastoralist areas offer suitable habitats for wild herbivores. Effective management of stocking rates is critical for maintaining ecosystems able to sustain livestock and wildlife on private lands, ensuring protection for endangered species

Field environmental philosophy: ecology and ethics in LTSER-Chile and ILTER networks

Article presents a methodological framework and applications of Field Environmental Philosophy (FEP) at Omora Park that combine ecological and philosophical research in education and biocultural conservation programs, including ecotourism

Primer registro de Vespula vulgaris (Linnaeus 1758) (Hymenoptera: Vespidae) en la isla Navarino, Chile

The common wasp Vespula vulgaris (Linnaeus 1758) is an introduced species in the Southern Hemisphere that has been reported in Australia, New Zealand, Tasmania, Argentina and South-central Chile. This report documents the presence of V. vulgaris on Navarino Island, Cape Horn Biosphere Reserve, Southern Chile.La avispa común Vespula vulgaris (Linnaeus 1758) es una especie introducida en el Hemisferio Sur que ha sido registrada en Australia, Nueva Zelanda, Tasmania, Argentina y Chile central. Este trabajo documenta la presencia de V. vulgaris en la isla Navarino, Reserva de la Biósfera Cabo de Hornos, sur de Chile

The Subantarctic Rayadito (Aphrastura subantarctica), a new bird species on the southernmost islands of the Americas

We describe a new taxon of terrestrial bird of the genus Aphrastura (rayaditos) inhabiting the Diego Ramírez Archipelago, the southernmost point of the American continent. This archipelago is geographically isolated and lacks terrestrial mammalian predators as well as woody plants, providing a contrasted habitat to the forests inhabited by the other two Aphrastura spp. Individuals of Diego Ramírez differ morphologically from Aphrastura spinicauda, the taxonomic group they were originally attributed to, by their larger beaks, longer tarsi, shorter tails, and larger body mass. These birds move at shorter distances from ground level, and instead of nesting in cavities in trees, they breed in cavities in the ground, reflecting different life-histories. Both taxa are genetically differentiated based on mitochondrial and autosomal markers, with no evidence of current gene flow. Although further research is required to define how far divergence has proceeded along the speciation continuum, we propose A. subantarctica as a new taxonomic unit, given its unique morphological, genetic, and behavioral attributes in a non-forested habitat. The discovery of this endemic passerine highlights the need to monitor and conserve this still-pristine archipelago devoid of exotic species, which is now protected by the recently created Diego Ramírez Islands-Drake Passage Marine Park.Fil: Rozzi, Ricardo. Universidad de Magallanes; Chile. University of North Texas; Estados UnidosFil: Quilodrán, Claudio S.. Universidad de Magallanes; Chile. Universite de Fribourg;Fil: Botero Delgadillo, Esteban. Max Plank Institute for Ornithology; Alemania. Universidad de Chile; ChileFil: Napolitano, Constanza. Universidad de Magallanes; Chile. Universidad de Los Lagos; Chile. Instituto de Ecología y Biodiversidad; ChileFil: Torres Mura, Juan C.. Universidad de Magallanes; Chile. Union de Ornitologos de Chile; ChileFil: Barroso, Omar. Universidad de Magallanes; ChileFil: Crego, Ramiro D.. Conservation Ecology Center; Estados UnidosFil: Bravo, Camila. Universidad de Chile; ChileFil: Ippi, Silvina Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Quirici, Verónica. Universidad Andrés Bello; ChileFil: Mackenzie, Roy. Universidad de Magallanes; ChileFil: Suazo, Cristián G.. Universidad de Magallanes; Chile. Justus Liebig Universitat Giessen; AlemaniaFil: Rivero de Aguilar, Juan. Universidad de Magallanes; ChileFil: Goffinet, Bernard. Universidad de Magallanes; Chile. University of Connecticut; Estados UnidosFil: Kempenaers, Bart. Max Plank Institute for Ornithology; SuizaFil: Poulin, Elie. Universidad de Magallanes; Chile. Universidad de Chile; ChileFil: Vásquez, Rodrigo A.. Universidad de Magallanes; Chile. Universidad de Chile; Chil