Assessment of the efficiency in trapping North American mink (Neovison vison) for population control in Patagonia

Indexación: Web of Science; Scielo.BACKGROUND: Introduced species can have a major negative impact on biodiversity; an example is the American mink, which was introduced in the 1930s in Patagonia. While there is a consensus that reversing alien mustelids continental scale invasions remains unfeasible, there is little consensus, given a maximum cost or investment, on the feasibility and efficiency of region-wide control or eradication. Thus, our goal was to provide information about efficiency for mink control in Patagonia METHODS: Between January 2009 and February 2013 this study was conducted in ten study sites (4 km to 15 km long) between 39°S to 45°S latitude. Minks were trapped using cage traps operated by two trappers. We estimated the population density at each study site assuming they were close populations, exhibit intrasexual territoriality and the home range of females were smaller than those of males. We obtained a theoretical population and a modeled population from our trapping results. Sixty five minks were trapped over 2190 trap nights (0.03 mink/trap night). Mink captures were higher in the first six days and in the first trapping campaigns. A two person team was able to control a maximum distance of approximately 6 km of river shore by foot and 15 km of sea and lake shores by boat. There was an over linear increase of operational costs as time passed. Our modeled population was 91% of the theoretical population CONCLUSIONS: We believe that to trap and remove a minimum of 70% of the mink population in a region under ideal circumstances, traps should be deployed every 200 m and after the sixth day should be moved to another new transect. We suggest an annual repetition of this strategy as the more efficient for controlling mink populations in terms of trapping success and reduced costs. The number of traps will depend on the number of trappers participating and also on habitat characteristicshttp://ref.scielo.org/qcr5j

Importance of infectious disease for the conservation of Chilean threatened wildlife

Indexación: Web of Science; Scielo.En conservación biológica existe un incremento en los antecedentes de que las enfermedades infecciosas (EIs) pueden afectar especies silvestres causando mortalidades que pueden aumentar el riesgo de extinción. Es así que para conseguir metas en conservación animal hoy se estima necesario conocer el rol de los patógenos en las poblaciones silvestres. En concordancia con lo anterior, los objetivos de este trabajo fueron: 1) determinar la contribución de las EIs a la declinación de las especies amenazadas de la fauna silvestre presente en Chile, de acuerdo a lo señalado por la Lista Roja de la UICN, 2) evaluar la evidencia existente en la literatura científica del impacto de las EIs en estas especies, y 3) proponer el nivel de riesgo para cada especie animal amenazada de Chile de ser impactada por EIs que podrían provocar potenciales declinaciones poblacionales o extinción. En Chile, 105 especies animales se encuentran en alguna categoría de amenaza. En el 16,2 % (N=17) de estas especies se menciona, según la Lista Roja de la UICN, alguna EI como principal amenaza para su conservación. Pese a esto, no existe evidencia en la literatura científica indexada (ISI-wok) de alguna EI provocando declinaciones poblacionales en el país. Se sugiere que los anuros Telmatobius zapahuirensis y T. pefauri, y el cánido Lycalopex fulvipes requieren esfuerzos urgentes de investigación epidemiológica debido a su categoría de conservación y distribución restringida, lo que podría aumentar el riesgo de extinción mediado por EIs. Finalmente, se plantean direcciones futuras en el estudio de las EIs que contribuyan a alcanzar la meta de la conservación biológica en Chile.There is evidence that infectious diseases (IDs) can directly affect wildlife even causing catastrophic died-offs, which increase extinction risk. In this way, to achieve the biological conservation goal we should know the role of IDs on wild populations. The aim of this work was 1) to determine the contribution of IDs in Chilean wildlife declination, according to the IUCN Red List, 2) to evaluate the level of scientific evidence of this threat on wildlife from Chile, and 3) propose a risk level (for each threatened wildlife species) of become threatened by an ID with potential to leading population decline or extinction. In the country, 105 species are in some category of threat, of which 16.2% (N=17) have IDs as potential major threat. Despite this, no evidence is available into scientific literature about an ID producing population declines in Chile. We suggest that anuran species Telmatobius zapahuirensis and T. pefauri, and the canid Lycalopex fulvipes, need urgent efforts in epidemiological research; due in part by its restricted distribution and conservation status, which could increase risk of extinction driven by IDs. By the end, we suggest future directions to enhance the biological conservation in Chile.http://ref.scielo.org/tfbpf

Chemical immobilisation of the wild Patagonian otter (Lontra provocax) and the North American mink (Neovison vison)

The Patagonian otter (Lontra provocax) is an endangered species endemic to southern Chile and Argentina. Most of its distribution range has recently been occupied by the American mink (Neovison vison). As part of a long-term study on the impact of mink in Patagonia, we assessed five reversible anaesthetic combination protocols in different doses on wild L. provocax and N. vison, and described the occurrence of any adverse effects. We assessed 16 anaesthetic procedures with a combination of ketamine-medetomidine (KET-MED; 6.0±2.8-0.05±0.01 mg/kg IM, respectively) or ketamine-dexmedetomidine (KET-DEX; 4.1±0.9-0.02±0.004 mg/kg IM) in L. provocax and 23 anaesthetic procedures with KET-MED (13.3±4-0.1±0.04 mg/kg IM), KET-DEX (4.8±0.3-0.024±0.001 mg/kg IM) in a low dose of ketamine (LDK) or KET-DEX (10.2±0.9-0.025±0.002 mg/kg IM) in a high dose of ketamine (HDK) in N. vison. Reversal was accomplished using atipamezole at 5 times the dose of MED or 10 times the dose of DEX. All anaesthetic combinations produced complete immobilisation and rapid anaesthetic induction, except for two otters anaesthetised with KET-MED which exhibited a longer time to initial effect. Hypothermia was commonly observed at the end of the anaesthetic procedures. Due to the hypoxemia presented in four otters at the beginning of anaesthesia, it is recommended to use additional oxygen when possible

Wildlife veterinarians rabies vaccination in Chile: a survey

Indexación: Web of Science; Scielo.Introduction: Rabies is a lethal but preventable disease. Knowing the extent of immunization coverage among at risk populations, may help to guide immunization efforts, as well as increase the effectiveness of rabies control and prevention programs. Aim: To determine the proportion of wildlife veterinarians in Chile, as part of a group at risk of rabies transmission. Methods: An electronic survey was sent to wildlife veterinarians in Chile. Results: We found that veterinarians in Chile work mainly with carnivores and deer compared to other mammals (p < 0.001), rarely works with bats (p = 0.6572). Most of the participants had been bitten by domestic animals, while a lesser proportion (29%) by wild animals. Most of the participants never received rabies vaccination (53%), while within the group that had started a rabies vaccination scheme, a substantial proportion (39%) did not complete it. Discussion and conclusion: Identify the vaccination status of risk groups is important for infectious disease control and prevention programs, as this information helps to identify priority groups during outbreaks or vaccine scarcity. Wildlife veterinarians in Chile are at risk of rabies transmission and should be included in rabies prevention programs, especially considering their vulnerability and lack of biosafety practices. Increasing education in rabies epidemiology and prevention is urgently needed in veterinary faculties in Chile.Introducción: La rabia es una enfermedad infecciosa mortal pero prevenible. Establecer si existe una adecuada inmunización pre-exposición contra la rabia en un grupo de riesgo, puede ayudar a enfocar los esfuerzos de inmunización para hacer efectivos los programas de control y prevención de la enfermedad. Objetivo: Determinar mediante una encuesta la proporción de veterinarios de fauna silvestre como grupo de riesgo que han recibido inmunización contra la rabia. Métodos: Se realizó una encuesta electrónica a veterinarios de fauna de vida silvestre de Chile. Resultados: Los veterinarios encuestados tienden a trabajar con carnívoros y ciervos en comparación con otros mamíferos (p < 0,001), rara vez con murciélagos (p = 0,6572). La mayoría de los encuestados había sido mordido por animales domésticos y una proporción menor (29%) por animales silvestres. La mayoría nunca había sido vacunado contra la rabia (53%), mientras que del grupo que sí había recibido vacunación anti-rábica, una importante proporción (39%) no completó el esquema de vacunación. Sorprendentemente, este grupo de profesionales rara vez trabaja con murciélagos (p = 0,6572), lo que puede reducir su exposición a linajes de rabia transmitida por murciélagos. Discusión y Conclusión: Identificar el estado de inmunización contra la rabia en grupos de riesgo es una información importante para evaluar los programas de prevención y control de enfermedades infecciosas y podría ayudar a identificar grupos prioritarios en situaciones de brote o escasez de vacuna. Los veterinarios de fauna de vida silvestre en Chile constituyen un grupo vulnerable: no mantienen prácticas de bioseguridad necesarias y tienen riesgo de adquirir la encefalitis rábica por lo que deberían ser considerados en los programas de prevención pre-exposición de la enfermedad. La educación sobre la epidemiología y prevención de la rabia es urgente en las facultades de medicina veterinaria en Chile.http://ref.scielo.org/c5d5b

Carnivore-Livestock Conflicts in Chile: Evidence and Methods for Mitigation

Human population growth and habitat loss have exacerbated human–wildlife conflicts worldwide. We explored trends in human–wildlife conflicts (HWCs) in Chile using scientific and official reports to identify areas and species with higher risk of conflicts and tools available for their prevention and mitigation. The puma (Puma concolor) was considered the most frequent predator; however, fox (Lycalopex spp.) and free-ranging or feral dog (Canis lupus familiaris) attacks were also common. Our results suggest that the magnitude of puma conflicts may be overestimated. Domestic sheep (Ovis spp.) and poultry (Galliformes) were the most common species predated. Livestock losses were widespread across Chile but were highest in San Jose de Maipo, located in central Chile, and Cochrane, La Unión, and Lago Verde in south Chile municipalities. Livestock guardian dogs and the livestock insurance, as a part of the Agriculture Insurance of Chile, were identified as the most promising tools to mitigate HWCs, short- and mid-term, respectively. However, longer-term strategies should focus on improving livestock management through extension (i.e., farmer education) programs for local communities. In Chile, HWCs negatively impact small farmers and wild carnivore populations. An interinstitutional and interdisciplinary strategy integrating input from government and nongovernmental organizations, farmers, and academia is needed to achieve effective carnivore conservation in the long-term

Ecology and Geography of Transmission of Two Bat-Borne Rabies Lineages in Chile

Rabies was known to humans as a disease thousands of years ago. In America, insectivorous bats are natural reservoirs of rabies virus. The bat species Tadarida brasiliensis and Lasiurus cinereus, with their respective, host-specific rabies virus variants AgV4 and AgV6, are the principal rabies reservoirs in Chile. However, little is known about the roles of bat species in the ecology and geographic distribution of the virus. This contribution aims to address a series of questions regarding the ecology of rabies transmission in Chile. Analyzing records from 1985–2011 at the Instituto de Salud Pública de Chile (ISP) and using ecological niche modeling, we address these questions to help in understanding rabies-bat ecological dynamics in South America. We found ecological niche identity between both hosts and both viral variants, indicating that niches of all actors in the system are undifferentiated, although the viruses do not necessarily occupy the full geographic distributions of their hosts. Bat species and rabies viruses share similar niches, and our models had significant predictive power even across unsampled regions; results thus suggest that outbreaks may occur under consistent, stable, and predictable circumstances.Universidad Andres Bello supported the PhD scholarship and provided an international internship grant at the University of Kansas for LEE

Primer reporte de mortalidad de murciélagos en Granjas Eólicas en Chile

In Latin America there is a lack of scientific reports of bat mortality caused by wind farms operation. We report for the first time, clear evidence of bat mortalities from wind farms in Chile. We generated an ecological niche model of the affected species, Tadarida brasiliensis, to explore areas of potential species distribution overlapping with areas with distribution of wind farms in Chile. We found that T. brasiliensis potential distribution overlaps with the current and future distribution of wind farms in Chile. Rapid developments are currently being made within the wind energy industry in Chile. Future research should quantify the impact patterns of wind farms on wildlife, explore mitigation methods, and determine the areas with high biodiversity vulnerability in Chile.En América Latina hay una falta de reportes científicos sobre la mortalidad en murciélagos causada por la operación de granjas eólicas. Reportamos por primera vez evidencia clara de la mortalidad de murciélagos causada por granjas eólicas en Chile. Generamos un modelo de nicho ecológico para la especie afectada, Tadarida brasiliensis, con el fin de explorar la coincidencia entre las áreas de distribución potencial de la especie y la distribución de granjas eólicas en Chile. Encontramos que la distribución potencial de T. brasiliensis traslapa con la distribución actual y futura de granjas eólicas en Chile. En Chile existe un rápido desarrollo de la industria eólica. Futura investigación debe procurar cuantificar el impacto de las granjas eólicas sobre la vida silvestre, explorar métodos de mitigación y determinar las áreas con alta vulnerabilidad para la biodiversidad en Chil

High prevalence of pathogenic Leptospira in alien American mink (Neovison vison) in Patagonia

Indexación: Web of Science; Scielo.BACKGROUND: Leptospirosis is an important zoonosis with worldwide distribution caused by pathogenic bacteria of the genus Leptospira. The North American mink (Neovison vison) has an important role in the environmental contamination with Leptospira, as minks live in aquatic environments and are the predators of rodents. FINDINGS: Blood and kidney samples were obtained from 57 minks in Southern Chile 39° S to 45° S. Pathogenic species of Leptospira were detected by PCR on 31/57 minks. To determine the species, we sequenced the 16S ribosomal RNA (rRNA) gene on nine of the positive samples. We predicted two pathogenic species: Leptospira interrogans (five samples) and Leptospira borgpetersenii (four samples). CONCLUSIONS: This study showed that the American mink presents pathogenic species of Leptospira and confirm important environmental contamination of Patagonian rivers and lakes with pathogenic Leptospira.http://ref.scielo.org/fkzjb

Domestic dog and alien North American mink as reservoirs of infectious diseases in the endangered Southern river otter

Introduced alien carnivores are host to infectious diseases that may become an important threat for native carnivore species conservation. Canine distemper virus (CDV) is thought to be transmitted among individuals by direct contact and to present viral dynamics associated with a density-dependent multi-host carnivore community. In contrast, Canine Parvovirus (CPV) is mostly transmitted by indirect contact and does not depend only on the density, but also on the social behaviour of infected as well as susceptible hosts. The objective of this study was to assess how introduced American mink (Neovison vison) can act as a bridge-host between domestic dog (Canis familiaris) and Southern river otter (Lontra provocax) in different dog and mink population density scenarios. Our data show that otters are seropositive to both CDV and PV, as well as a molecular identity to Parvovirus in dogs and minks. Furthermore, a strong positive correlation between dog population density and observed seroprevalence of CDV in dogs, minks, and otters was recorded. For Parvovirus, the observed seroprevalence in mink and otters was not correlated to a higher dog population density, but instead a relationship between dog and mink population densities and social behaviour. Our results suggest that introduced American mink and domestic dogs are reservoirs of CDV and PV, both being diseases of major importance for the conservation of native endangered carnivores in Patagonia

Phylogeography of the Patagonian otter Lontra provocax: adaptive divergence to marine habitat or signature of southern glacial refugia?

<p>Abstract</p> <p>Background</p> <p>A number of studies have described the extension of ice cover in western Patagonia during the Last Glacial Maximum, providing evidence of a complete cover of terrestrial habitat from 41°S to 56°S and two main refugia, one in south-eastern Tierra del Fuego and the other north of the Chiloé Island. However, recent evidence of high genetic diversity in Patagonian river species suggests the existence of aquatic refugia in this region. Here, we further test this hypothesis based on phylogeographic inferences from a semi-aquatic species that is a top predator of river and marine fauna, the huillín or Southern river otter (<it>Lontra provocax</it>).</p> <p>Results</p> <p>We examined mtDNA sequences of the control region, ND5 and Cytochrome-b (2151 bp in total) in 75 samples of <it>L. provocax </it>from 21 locations in river and marine habitats. Phylogenetic analysis illustrates two main divergent clades for <it>L. provocax </it>in continental freshwater habitat. A highly diverse clade was represented by haplotypes from the marine habitat of the Southern Fjords and Channels (SFC) region (43°38' to 53°08'S), whereas only one of these haplotypes was paraphyletic and associated with northern river haplotypes.</p> <p>Conclusions</p> <p>Our data support the hypothesis of the persistence of <it>L. provocax </it>in western Patagonia, south of the ice sheet limit, during last glacial maximum (41°S latitude). This limit also corresponds to a strong environmental change, which might have spurred <it>L. provocax </it>differentiation between the two environments.</p