Browsing by Author "Rau, Jaime R."
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- ItemDensity, abundance, and activity of the chilla or grey fox (Lycalopex griseus) in Isla Grande de Tierra del Fuego, Chile(2024) Zurita Redón, Carlos Nicolás Felipe; Oporto, Javier; Valverde, Ignacio; Bernales, Borja; Soto, Nicolás; Rau, Jaime R.; Jaksic Andrade, FabiánBackground: The chilla or grey fox (Lycalopex griseus) is a native species from continental Chile and neighboring areas of Argentina. It was introduced to Isla Grande de Tierra del Fuego in 1951 and began to increase its abundance, to the chagrin of local sheep ranchers. Since 1998, its hunting has been authorized. Here we update information on the density, abundance, and activity of this fox in the Chilean sector of Tierra del Fuego Island, to evaluate its population trend since the last census conducted by the Servicio Agrícola y Ganadero (SAG) in 2007. Methods and results: We carried out two fox censuses on a 941-km transect on public roads, divided into eight routes, from October to November (spring) of 2021 and 2022, following the same design used by SAG for the fox assessments carried out from 1999 to 2007. We report a reduction of>50% in the density and abundance of chilla foxes with respect to the 2007 estimate, which could be attributed to the interference by free-ranging dogs (Canis lupus familiaris), through restricting the use of space by the fox, while transmitting diseases and parasites, and to human hunting pressure and vehicle collisions. Discussion: The chilla fox decline highlights the need for an in-depth study to determine the ecological and socioeconomic impact of this exotic species on the ecosystems of Tierra del Fuego Island and the desirability of its management, if needed.
- ItemPopulation status of the Peruvian Pelican (Pelecanus thagus) in Chile: initial survey(NEOTROPICAL ORNITHOLOGICAL SOC, USGS PATUXENT WILDLIFE RESEARCH CTR, 2018) Cursach, Jaime A.; Rau, Jaime R.; Gelcich, Stefan; Rodriguez Maulen, JuanThe Peruvian Pelican (Pelecanus thagus) is an endemic seabird of the Humboldt Current System in South America, inhabiting the Pacific coast from the south of Ecuador, Peru to the south of Chile. In Peru it is classified as an Endangered species, while globally it is considered Near Threatened. Although more than 50% of the habitat used by the Peruvian Pelican occurs on the coast of Chile, its population trends and conservation status remain unknown in this country. For this reason, the objective of the present work was to diagnose the population situation of the Peruvian Pelican in Chile, through the analysis of databases and perceptions of local ornithologists. Between the years 2010 and 2015 the abundance of Peruvian Pelican in Chile decreased significantly in the central zone of the country. There is seasonality in its presence, with greater abundances during the winter season. The perception of local ornithologists indicated a population increase towards the south of the country. Along the Chilean coast, 24 nesting sites of the Peruvian Pelican have been described, of which 29.1% are located inside of protected areas. Finally, we identify future research questions, suggest the need to apply a meta-population approach, and establish international collaboration frameworks for the study and conservation of the Peruvian Pelican.
- ItemWorld-level ecologists in Chile : oldtimers, newcomers, and the bypassed(2022) Rau, Jaime R.; Jaksic Andrade, FabiánBackground: A team of 3 scientometrists led by John Ioannidis published in 2020 an extensive and updated database (ca. 6.9 million researchers in 22 disciplines and 176 sub-disciplines), ordering them according to a composite bibliometric index that measures their whole trajectory (career-long) impact and their annual impact at year 2019. They reported the top 100,000 scientists (1.45% across all disciplinary felds) or the top 2% of each subfeld discipline, thus publishing the ranking of ca. 150,000 researchers worldwide. Methods and fndings: We fltered that information for the disciplinary and sub-disciplinary areas corresponding to Ecology and identifed a total of 14 ecologists with residence in Chile that appear in either of those two worldwide rankings. We report their measured productivity as both whole trajectory (career-long) and as annual impact at year 2019. We attribute their high registered productivity to their training at the doctoral level in prestigious foreign universities, their academic positions in internationally recognized Chilean universities, and their participation in statefunded research centers of scientifc excellence. Exceptions to the rule are presented. Conclusions: The 14 ecologists identifed with the scientometric algorithm proposed by Ioannidis and coworkers include, but are not restricted, to the most cited ecologists in Chile. We put forth possible reasons for some puzzling omissions from these rankings.