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Papers by Marcelo Hurtado

Entre las tres especies de ciervos chilenos, el Pudú (Pudu puda, Molina, 1782) es uno de los cier... more Entre las tres especies de ciervos chilenos, el Pudú (Pudu puda, Molina, 1782) es uno de los ciervos mas pequeños del mundo con 40 cm de altura (Hershkovitz, 1982). Este habita los bosques templados lluviosos del sur de Chile y Argentina, lugar del cual es endémico (Wemmer, 1998). Su distribución geográfica abarca desde los 36º a los 49º S en Chile (Miller et al., 1973) y desde los 39º a los 43º S en Argentina (Meier & Merino, 2007) (Figura 1). El Pudú prefiere sotobosque denso, bosques secundarios, y lugares con abundante presencia de quila (Chusquea quila) (Eldridge et al., 1987; Meier & Merino, 2007). Sin embargo, la ecología de la especie aun permanece pobremente entendida. El Pudú esta categorizado como Vulnerable por la IUCN Red List (Jiménez & Ramilo, 2008) y esta incluida en el Apéndice I de CITES (Wemmer, 1998; Weber & González, 2003). Se le considera vulnerable debido al continuo descenso y reducción poblacional, causado por el deterioro y disponibilidad de su hábitat, deb...

Quaternary glacial cycles have shaped the geographic distributions and evolution of numerous spec... more Quaternary glacial cycles have shaped the geographic distributions and evolution of numerous species in the Arctic. Ancient DNA suggests that the Arctic fox went extinct in Europe at the end of the Pleistocene and that Scandinavia was subsequently recolonized from Siberia, indicating inability to track its habitat through space as climate changed. Using ecological niche modeling, we found that climatically suitable conditions for Arctic fox were found in Scandi-navia both during the last glacial maximum (LGM) and the mid-Holocene. Our results are supported by fossil occurrences from the last glacial. Furthermore , the model projection for the LGM, validated with fossil records, suggested an approximate distance of 2000 km between suitable Arctic conditions and the Tibetan Plateau well within the dispersal distance of the species, supporting the recently proposed hypothesis of range expansion from an origin on the Tibetan Plateau to the rest of Eurasia. The fact that the Arctic fox disappeared from Scandinavia despite suitable conditions suggests that extant populations may be more sensitive to climate change than previously thought.

Island–continent isolation scenarios have played major roles in the understanding and development... more Island–continent isolation scenarios have played major roles in the understanding and development of evolutionary theories. During the last glacial maximum (LGM) in southern Chile, ice sheet advances and retreats formed the Patagonian archipelago along the southern Pacific Ocean. Chiloé Island is the largest island from the archipelago isolated from the continent by a narrow and shallow stretch of ocean. Pudu puda is a species endemic to Chile and part of Argentina, distributed along the Valdivian Temperate rainforest. We used mtDNA control region (654 bp) and cytochrome b (734 bp) sequences to understand the consequences in the evolutionary history and population structure of Pudu puda island–continent isolation. Bayesian and Maximum Likelihood phylogenetic analysis revealed two divergent clades corresponding to the continent and Chiloé Island. The Median Joining Network also supports these findings with an isolation of 10 mutational steps between Chiloé and the continent. We also found a significant high genetic structure (Φst = 0.75) and a sequence divergence percentage of 2.3% between the two clades. On the other hand, on the continent we found high haplotype genetic diversity (H = 0.9790 ± 0.0103) but no clear geographical population structure or phylogenetic clades. Our results suggest that the southern Pudu deer populations were isolated since the interglacial period (less than 0.5 million years ago) from the continent leading to two reciprocally monophyletic clades. We propose two subspecies to be considered in the development of future conservation programs for the species.

The southern pudu (Pudu puda) is a threatened deer that is endemic to the South American temperat... more The southern pudu (Pudu puda) is a threatened deer that is endemic to the South American temperate forests. Despite its assumed threatened status, there is relatively little understanding on the ecology and conservation of this species. Considering this situation and the fact that there are some research groups currently working on this species, we organised a symposium to discuss research and management priorities – as well as to coordinate efforts – to move forward on the conservation of the pudu. We agreed that main research priorities should be to increase the understanding of the threats that jeopardize the viability of pudu populations, with a strong emphasis on research questions that will provide information for the management of these threats. The main management recommendations were to implement monitoring of pudu populations at least in protected areas, to implement specific actions to remove threats from protected areas and to start following internationally-accepted guidelines for the management of rescued and confiscated animals.

Conference Presentations by Marcelo Hurtado

Vianna et al. 2011 publicó un estudio filogeografico de Lontra provocax basado en región control ... more Vianna et al. 2011 publicó un estudio filogeografico de Lontra provocax basado en región control de ADNmt, ND5 y citocromo-B. En este artículo los autores describen dos clados divergentes para la especie, uno continental (hábitats de agua dulce) y otra austral (hábitats marinos). Sorprendentemente, a pesar de la extensa cobertura glacial de Patagonia durante el Último Máximo Glacial (UMG), las poblaciones australes evidenciaron gran diversidad genética y de haplotipos, los cuales además no fueron compartidos con poblaciones continentales no afectadas durante el UMG. Este patrón fue también reportado por Centrón et al. 2008 para poblaciones australes de la especie en Argentina, sugiriendo la sobrevida in situ de esta especie durante el Pleistoceno en Patagonia.
Nuestro objetivo en este trabajo es corroborar espacialmente esta hipótesis a través de un modelo de paleodistribución de la especie durante el UMG que nos permita identificar la presencia de áreas bioclimaticamente idóneas (refugios). La construcción de los modelos fue realizada a través del programa y algoritmo MaxEnt. El modelo de nicho ecológico actual fue calibrado y evaluado con 398 ocurrencias, este modelo fue posteriormente proyectado a dos simulaciones bioclimáticas del UMG (CCSM, MIROC) obtenidas desde WorldClim. El modelamiento de nicho ecológico reveló cinco áreas principales con probabilidades de idoneidad de hábitat para la especie. Dos de estas han sido reportados como refugios glaciales para diversos taxa (porción noroeste de Chiloé y costa continental sobre los 41ºS). Los otros tres sitios representarían nuevos refugios ubicados en la región de Aysén, los cuales estuvieron espacialmente correlacionados con los haplotipos australes únicos y altamente diversos reportados por Centrón et al. 2008 y Vianna et al. 2011. De esta forma, nuestros resultados sugieren el soporte espacial de la hipótesis de sobrevida in situ de la especie durante el UMG en Patagonia. Esta hipótesis, contribuye además a la evidencia molecular de diferentes Unidades Evolutivamente Significativas (ESUs) de la especie, situación clave en futuras estrategias de conservación.

Los ciclos glaciares y climáticos del Pleistoceno han modificado la distribución de diversas espe... more Los ciclos glaciares y climáticos del Pleistoceno han modificado la distribución de diversas especies. Durante el ultimo máximo glacial, los bosques templados de la Ecoregión Valdiviana fueron completamente cubiertos por glaciares, sin embargo, en la zona continental de Chile al noroeste de los 41ºS y la porción noroeste de la Isla de Chiloé los bosques permanecieron intactos, representando los principales refugios glaciares durante este periodo. El pudú Pudu puda es la especie de ciervo más pequeña del mundo y además de estar clasificado como vulnerable, es endémico de la Ecorregión Valdiviana. El objetivo de este trabajo es dilucidar si existe divergencia entre las poblaciones continentales e insulares de esta especie.

Pleistocene climatic and glacial cycles had modified several species distribution. During the lat... more Pleistocene climatic and glacial cycles had modified several species distribution. During the late period of the last glaciations (29,400-14,450 BP) South America's temperate rain forests were completely covered by glaciers, from Coastal to Andean Cordillera, but coastal areas north of 41°S and northwest area of Chiloe Island were practically intact, representing the principal refuge during glaciations. This forest represents the current distribution of the Pudu puda, one of the smallest deer species of the world. In order to evaluate the genetic structure and divergence between continental and insular populations a total of 654 bp of mitochondrial DNA control region were sequenced from 32 samples collected at different locations of southern Chile. We found a significant and high population genetic structure (Fst=0.68) between continental and insular populations. Maximum likelihood and bayesian phylogenetic analysis showed two well supported clades, continental and insular, with a sequence divergence of 2.2%, probably due to colonization from different glacial refuges after glaciers retreat. Our results suggest that no recent gene flow have occurred due to the influence of the Chacao Channel between continent and Chiloe Island. Therefore, we propose that these divergent clades represent two different Evolutionary Significant Units (ESUs) which should be considered for future management and conservation programs.