Examinando por Autor "Medina-Vogel, Gonzalo"
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Ítem A global review of the American mink (Neovison vison) removal techniques – Patagonia as a case study for their potential application(Universidad de Concepcion, 2023-06) López, Ronar; Clapperton, B. Kay; Medina-Vogel, GonzaloAmerican mink (Neovison vison) represents a threat to both biodiversity and economy in various regions of the world, including Patagonia. This invasive species has been successfully removed from many areas of Europe. In Chile and Argentina there have been only patchily distributed attempts of local control to date and large-scale removal has been considered unfeasible. We analyzed available scientific information, to determine best-fit strategies and improved methodologies that increase efficiency (capture per unit of effort) in American mink control. We reviewed published papers about programs that aimed at local control, functional or total eradication of minks in the Web of Science (WoS) database. Based on accessible information, the influence of some field variables on capture efficiency was determined through a General Lineal Model. From 1525 results in the WoS search, 51 papers refer to mink control action carried out in 28 areas of Europe and South America since 1992. Trapping has been the most used and efficient capture method. Short trapping periods that cover larger lineal distances per control program, and the use of attractants, specifically pheromones, have led to improved control efficiency. Chilean, Scottish and English experiences showed among the highest trapping efficiency values. We identify areas of research needed on mink ecology and behavior and trapping techniques that could improve trapping efficiency. A control program that incorporates the outcomes of this data assessment has the potential to improve feral mink removal. But further research is required to ensure that these efficiency measures result in cost-effective control in Patagonia. © 2023 The author(s).Ítem Analysis of trophic interactions of large oceanic predators as an indicator of the stability of marine ecosystems(Universidad Andrés Bello, 2019) Canales Cerro, Carlos Alberto; Klarian Klarian, Sebastián Alberto; Medina-Vogel, GonzaloEl aumento en la actividad pesquera ha provocado un importante aumento en las poblaciones de especies marinas que se encuentran sobreexplotadas a niveles no sostenibles. Esto ha llevado a una preocupante pérdida de biodiversidad lo cual puede favorecer el colapso de la actividad pesquera, con importantes consecuencias ecosistémicas, económicas y sociales. Un manejo pesquero adecuado, que asegure la sustentabilidad del recurso pesquero, requiere conocer el estado del ecosistema. Una forma de conocer el estado de un ecosistema explotado es por medio del análisis de su estabilidad, estado en el cual el ecosistema tiene las condiciones adecuadas para regresar a un estado inicial después de una perturbación. Un elemento fundamental para que el ecosistema tenga esta capacidad y sea estable, es la diversidad de sus componentes. De esta forma, la asimetría en los nichos entre y dentro de las especies permite un mayor número de opciones que ayudan a las comunidades a responder y recuperarse de las perturbaciones. Por este motivo, la presencia de nichos muy similares (o simétricos) sugieren que un ecosistema está siendo impactado a un nivel donde su estabilidad puede verse comprometida. En el caso de los depredadores de alto nivel trófico, su plasticidad trófica les permite adaptarse a los cambios en las condiciones del ambiente. En condiciones normales, sus nichos están segregados, con una baja superposición y alta asimetría, sin embargo, frente a perturbaciones, como la reducción en los recursos o de otro depredador, su plasticidad permite modificar sus nichos, favoreciendo la superposición y simetría de éstos, afectando la estabilidad del ecosistema. En Chile una de las pesquerías más importantes es la del pez espada (Xiphias gladius) donde, de forma secundaria, son capturados tiburones (Isurus oxyrinchus y Prionace glauda) y como fauna acompañante atunes y escolares. Esta actividad, de más de 40 años, se ha caracterizado por iniciar como una pesca sin control hasta que fue regulada, manteniendo una tendencia creciente. Si bien el análisis de las poblaciones de estos depredadores sugiere una estabilidad del stock entre los años 2009 al 2017, la población del azulejo tuvo una reducción en su rendimiento, lo que se suma a la alteración de la productividad del ecosistema pelágico evidenciado a través de la disminución del nivel trófico. Esta situación supone un gran riesgo para la actividad pesquera nacional, por la posible pérdida de elementos clave del ecosistema, promoviendo la reducción en su estabilidad. Para estudiar la estabilidad del ecosistema oceánico centro-norte de Chile, con datos obtenidos entre los años 2012 y 2017, se analizaron, por un lado, los grados de superposición de los nichos isotópicos de nueve depredadores de alto nivel tróficos que co-habitan, y por otro lado, se estudiaron las superposiciones entre las dietas, así como los cambios en la posición trófica de los tiburones azulejo y mako, y del pez espada. Con esta información, se analizó la correlación entre los valores de superposición (de nichos isotópicos y dietas) con factores pesqueros (esfuerzo, rendimiento y desembarcos) para evaluar el impacto de esta actividad sobre la estabilidad del ecosistema. De forma complementaria, debido a que la pesquería puede verse afectada por variaciones en el ambiente, se incorporó factores oceanográficos (SST y Clorofilaa) para analizar su posible efecto. En el estudio de los nichos isotópicos, los resultados sugirieron que las interacciones entre los depredadores fueron variables en el tiempo, con promedios y proporciones de superposición entre las Especies y Grupos de Depredadores para cada año que no permitieron indicar de forma robusta que existió una menor estabilidad en el ecosistema evaluado. Sin embargo, el registro de superposiciones significativas todos los años y ausencia de diferencias significativas en los valores isotópicos en algunas de las interacciones, sugiere posibles alteraciones en la estabilidad del ecosistema. En el estudio de las dietas, los análisis de superposición a nivel de macro-grupo de presas con SCA y a nivel de grupo de presas y macrogrupo de presas con SIA entregan indicios que la estabilidad del ecosistema puede estar siendo afectada negativamente. De forma similar, la tendencia decreciente de la posición trófica, especialmente para el azulejo y el mako, sugieren un impacto negativo sobre el ecosistema en sus tramas tróficas. Finalmente, en el estudio de la correlación, los resultados no permitieron, de forma robusta, vincular el grado de superposición entre depredadores (nicho isotópico o dieta) con alguno de los factores pesqueros y oceanográficos considerados, de todos modos, las observaciones permiten sugerir que los factores oceanográficos, por sobre los factores pesqueros, tuvieron una mayor influencia en los proxy de estabilidad del ecosistema aquí estudiados. Sin embargo, las escasas correlaciones detectadas no permiten dar resultados concluyentes. Los resultados sugieren que en el ecosistema oceánico frente a las costas centro-norte de Chile están ocurriendo eventos que causan el incremento en la superposición de los depredadores, disminuyendo la asimetría y desfavoreciendo la capacidad de resiliencia del ecosistema frente a perturbaciones. Sin embargo, este trabajo no puedo correlacionar de forma robusta la actividad pesquera con el incremento en las superposiciones. De todos modos, los datos otorgados por esta investigación parecieran ser la antesala de futuras consecuencias mayores sobre el ecosistema, en especial si las medidas de manejo pesquero permanecen iguales. Por lo que no deben ser desconocidos y se requiere de un seguimiento del estudio, que permita analizar cambios futuros, para poder generar proyecciones que contribuyan a la implementación de planes de gestión adaptativos en función de las necesidades del ecosistema, para de esta forma asegurar, la sustentabilidad de la actividad, prolongando los beneficios para las personas.Ítem Assessment of the efficiency in trapping North American mink (Neovison vison) for population control in Patagonia(Sociedad de Biología de Chile, 2015) Medina-Vogel, Gonzalo; Barros, Macarena; Monsalve, Rene; Pons, Daniel JBACKGROUND: 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 characteristicsÍtem Assessment of toxoplasma gondii exposure in carnivores of the Valdivian temperate Rainforest, Chile : insights from marine otters (lontra felina), american mink (neogale vison), and domestic cats (felis catus)(Universidad Andrés Bello, 2023) Calvo Mac, Carlos Luis Gabriel; Medina-Vogel, GonzaloToxoplasma gondii es un parásito protozoario de distribución global de importancia en salud pública y conservación de la biodiversidad. Comprender los factores que influyen en la exposición de los animales a T. gondii es crucial para una gestión efectiva de la enfermedad y los esfuerzos de conservación. Esta tesis doctoral tiene como objetivo evaluar la exposición de carnívoros, específicamente nutrias marinas (Lontra felina), visones americanos (Neogale vison) y gatos domésticos (Felis catus), a T. gondii en el Bosque Lluvioso Valdiviano en Chile. El primer capítulo examina la exposición a T. gondii en nutrias marinas. Se capturaron un total de 30 nutrias marinas entre 2013 y 2021 a lo largo de la costa chilena. Específicamente, 20 fueron obtenidas de las regiones costeras áridas del norte y centro, mientras que 10 fueron muestreadas en la región sur lluviosa y templada, que abarca el Bosque Lluvioso Valdiviano. Se emplearon muestras de suero de nutrias marinas para evaluar la exposición a través de un método de ELISA indirecto comercial, realizado de acuerdo con las instrucciones del fabricante. Los resultados revelan una exposición menor (10%, 95% CI: 2.1-26.5%) en comparación con otros mustélidos acuáticos en Chile: 77% (95% CI: 46-95%) en el huillín (Lontra provocax), 59% (95% CI: 47-70%) y 70% (95% CI: 51-85%) en el visón americano. Se necesitan investigaciones adicionales para explorar los factores asociados con la exposición a T. gondii en las nutrias nativas y evaluar sus posibles efectos en las poblaciones de vida silvestre, en especial del huillín en los hábitats de agua dulce del Bosque Lluvioso Valdiviano. Tomando en cuenta las dificultades en el muestreo de nutrias silvestres, el visón americano, una especie alóctona de mustélido semiacuático, se propone como un indicador para evaluar la amenaza de contaminación patogénica en las nutrias nativas en este ecosistema. El segundo capítulo investiga la exposición a T. gondii y los hábitos alimenticios de visones americanos y gatos domésticos mediante el análisis de isótopos estables. Al explorar las relaciones estadísticas a través de modelos logísticos, este capítulo revela que la proporción de presas con valores δ15N altos y pollos (Gallus gallus domesticus) tuvo una asociación positiva y significativa con la exposición a T. gondii en visones americanos. Además, observamos que la exposición de los gatos domestico a T. gondii no tiene asociación significativa con ningún valor isotópico o presa en la dieta en el Bosque Lluvioso Valdiviano. El tercer capítulo explora las variables del paisaje asociadas con la exposición a T. gondii en visones americanos y gatos domésticos a través de modelos de máxima entropía (MAXENT). Los hallazgos resaltan la asociación entre hábitats de agua dulce de baja altitud, paisajes antropogénicos y un mayor riesgo de exposición. Se requiere investigación adicional para investigar el papel de los felinos silvestres nativos en la diseminación de ooquistes de T. gondii en bosques nativos y en plantaciones de coníferas en el Bosque Lluvioso Valdiviano. En general, este estudio mejora la comprensión de la epidemiología de T. gondii en el ecosistema del Bosque Lluvioso Valdiviano, proporcionando información sobre la exposición a T. gondii en nutrias marinas, visones americanos y gatos domésticos. Los hallazgos enfatizan la importancia de los factores sociales, ecológicos y ambientales en la dinámica de transmisión de T. gondii, especialmente en áreas de alto riesgo como las cuencas de los ríos Valdivia y Toltén. La investigación contribuye al desarrollo de estrategias de salud pública y gestión de la conservación destinadas a mitigar el riesgo de infección por T. gondii en poblaciones de vida silvestre y humanas en el Ecosistema del Bosque Lluvioso Valdiviano.Ítem BAT-BORNE RABIES IN LATIN AMERICA(Instituto de Medicina Tropical, 2015) Escobar, Luis E.; Townsend Peterson, A.; Favi, Myriam; Yung, Verónica; Medina-Vogel, GonzaloThe situation of rabies in America is complex: rabies in dogs has decreased dramatically, but bats are increasingly recognized as natural reservoirs of other rabies variants. Here, bat species known to be rabies-positive with different antigenic variants, are summarized in relation to bat conservation status across Latin America. Rabies virus is widespread in Latin American bat species, 22.5%75 of bat species have been confirmed as rabies-positive. Most bat species found rabies positive are classified by the International Union for Conservation of Nature as “Least Concern”. According to diet type, insectivorous bats had the most species known as rabies reservoirs, while in proportion hematophagous bats were the most important. Research at coarse spatial scales must strive to understand rabies ecology; basic information on distribution and population dynamics of many Latin American and Caribbean bat species is needed; and detailed information on effects of landscape change in driving bat-borne rabies outbreaks remains unassessed. Finally, integrated approaches including public health, ecology, and conservation biology are needed to understand and prevent emergent diseases in bats.Ítem Characterization of Campylobacter spp. isolated from wild birds in the antarctic and Sub-Antarctic(Public Library of Science, 2018-11) Johansson, Håkana; Ellström, Patrik; Artursson, Karin; Berg, Charlotte; Bonnedahl, Jonas; Hansson, Ingrid; Hernández, Jorge; Lopez-Martín, Juana; Medina-Vogel, Gonzalo; Moreno, Lucila; Olsen, Björn; Engvall, Eva Olssond; Skarin Hanna; Troell, Karin; Waldenström, Jonas; Ågren, Joakim; González-Acuña, DanielA lack of knowledge of naturally occurring pathogens is limiting our ability to use the Antarctic to study the impact human-mediated introduction of infectious microorganisms have on this relatively uncontaminated environment. As no large-scale coordinated effort to remedy this lack of knowledge has taken place, we rely on smaller targeted efforts to both study present microorganisms and monitor the environment for introductions. In one such effort, we isolated Campylobacter species from fecal samples collected from wild birds in the Antarctic Peninsula and the sub-Antarctic island of South Georgia. Indeed, in South Georgia, we found Campylobacter lari and the closely related Campylobacter peloridis, but also distantly related human-associated multilocus sequence types of Campylobacter jejuni. In contrast, in the Antarctic Peninsula, we found C. lari and two closely related species, Campylobacter subantarcticus and Campylobacter volucris, but no signs of human introduction. In fact, our finding of human-associated sequence types of C. jejuni in South Georgia, but not in the Antarctic Peninsula, suggests that efforts to limit the spread of infectious microorganisms to the Antarctic have so far been successful in preventing the introduction of C. jejuni. However, we do not know how it came to South Georgia and whether the same mode of introduction could spread it from there to the Antarctic Peninsula. © 2018 Johansson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Ítem Detection of evolutionarily distinct avian influenza a viruses in Antarctica(American Society for Microbiology, 2014-05) Hurt, Aeron C.; Vijaykrishna, Dhanasekaran; Butler, Jeffrey; Baas, Chantal; Maurer-Stroh, Sebastian; Silva-de-la-Fuente, M. Carolina; Medina-Vogel, Gonzalo; Olsen, Bjorn; Kelso, Anne; Barr, Ian G.; González-Acuña, DanielT Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveil lance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Adélie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lin eage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment. IMPORTANCE Avian influenza viruses (AIVs) are typically maintained and spread by migratory birds, resulting in the existence of distinctly different viruses around the world. However, AIVs have not previously been detected in Antarctica. In this study, we characterized H11N2 viruses sampled from Adélie penguins from two geographically different sites in Antarctica and show that the segmented AIV genome diverged between 49 and 80 years ago from other AIVs, with several genes showing similarity and shared ancestry with H3N8 equine influenza viruses. This study provides the first insight into the ecology of AIVs in Antarctica and highlights the potential risk of an introduction of highly pathogenic AIVs into the continent.Ítem Domestic dog and alien North American mink as reservoirs of infectious diseases in the endangered Southern river otter(Universidad Austral de Chile, 2022) Barros, Macarena; Pons, Daniel J.; Moreno, Andrea; Vianna, Juliana; Ramos, Barbara; Dueñas, Fernando; Coccia, Cristina; Saavedra-Rodríguez, Roberto; Santibañez, Alexis; Medina-Vogel, GonzaloIntroduced 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. © 2022 Universidad Austral de Chile. All rights reserved.Ítem Ecological approaches in veterinary epidemiology: mapping the risk of bat-borne rabies using vegetation indices and night-time light satellite imagery(BioMed Central Ltd., 2015-12) Escobar, Luis E; Peterson, A Townsend; Papeş, Monica; Favi, Myriam; Yung, Veronica; Restif, Olivier; Qiao, Huijie; Medina-Vogel, GonzaloRabies remains a disease of significant public health concern. In the Americas, bats are an important source of rabies for pets, livestock, and humans. For effective rabies control and prevention, identifying potential areas for disease occurrence is critical to guide future research, inform public health policies, and design interventions. To anticipate zoonotic infectious diseases distribution at coarse scale, veterinary epidemiology needs to advance via exploring current geographic ecology tools and data using a biological approach. We analyzed bat-borne rabies reports in Chile from 2002 to 2012 to establish associations between rabies occurrence and environmental factors to generate an ecological niche model (ENM). The main rabies reservoir in Chile is the bat species Tadarida brasiliensis; we mapped 726 occurrences of rabies virus variant AgV4 in this bat species and integrated them with contemporary Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The correct prediction of areas with rabies in bats and the reliable anticipation of human rabies in our study illustrate the usefulness of ENM for mapping rabies and other zoonotic pathogens. Additionally, we highlight critical issues with selection of environmental variables, methods for model validation, and consideration of sampling bias. Indeed, models with weak or incorrect validation approaches should be interpreted with caution. In conclusion, ecological niche modeling applications for mapping disease risk at coarse geographic scales have a promising future, especially with refinement and enrichment of models with additional information, such as night-time light data, which increased substantially the model's ability to anticipate human rabies. © 2015 Escobar et al.Ítem Encuesta sobre vacunación anti-rábica en veterinarios de fauna silvestre en Chile(Sociedad Chilena de Infectología, 2015-06) Escobar, Luis E.; Yung, Verónica; Vargas-Rodríguez, Renzo; Medina-Vogel, Gonzalo; Favi, MyriamIntroduction: 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.Ítem Epidemiología espacial de rabia en quirópteros(Universidad Andrés Bello, 2014) Escobar Quiñonez, Luis Emilio; Medina-Vogel, GonzaloLa rabia transmitida por murciélagos es un sistema complejo de estudiar considerando la amplia diversidad de especies hospedero involucradas. Reconocer qué especies de murciélagos están implicadas en el sistema tiene implicaciones en conservación y salud pública. Los factores ambientales asociados a la actual distribución y potenciales zonas geográficas para la dispersión del virus permanecen sin una clara comprensión. En esta disertación se explora cómo factores ambientales delimitan la distribución de rabia en sus hospederos en un espacio ambiental, lo que permite su proyección a un contexto geográfico. Con la captura de un impresionante conjunto de datos disponible en el Instituto de Salud Pública de Chile, obtuvimos las coordenadas geográficas de ocurrencia de rabia a lo largo de Chile en los últimos 27 años. Primero examiné e la riqueza de especies de murciélagos que se reportan como positivas a rabia en América Latina. Luego exploré la misma situación en Chile utilizando los reportes de rabia desde 1985, cuando el primer murciélago fue detectado positivo al virus en el país, hasta 2012. Después, utilizando modelamiento de nicho ecológico, busqué similitudes ecológicas entre los principales linajes de rabia en Chile en distintas especies de hospedero para determinar si deben o no considerarse distintos ecológicamente a las escalas estudiadas. Finalmente con el conocimiento generado construí un mapa de riesgo de transmisión de rabia transmitida por murciélagos para delimitar las zonas de mayor riesgo de exposición en humanos en Chile. El mapa de riesgo puede ser una herramienta importante para guiar intervenciones para la prevención de la enfermedad.Ítem Epidemiologic evaluation for Toxoplasma gondii, parvovirus, distemper virus and leptospira in domestics pets, American mink (Neovison vison) and Souther river otter (Lontra provocax) in Southern Chile(Universidad Andrés Bello, 2017) Barros Lama, Macarena; Medina-Vogel, GonzaloThe increase in human population and domestic pets, such as dogs and cats, and introduction of species, such as American mink are generating important consequences in terms of habitat loss and pathogen pollution of ecosystems with potential to generate negative impacts in biodiversity. For this, it is essential to perform studies that illustrate the sanitary situation of Chilean native species, particularly those with serious conservation problems, like Southern river otter, to be able to understand and predict how infectious agents spread, and whether they represent a risk for the conservation of these wild species. In particular, this investigation seeks to carry out epidemiologic evaluation of four important infectious agents: Toxoplasma gondii is the etiological agent of zoonotic disease toxoplasmosis, and is associated to cat abundance and anthropogenic disturbance. The present study analyzed seroprevalence (modified agglutination test, MAT, cut-off 1:25) and presence of T. gondii DNA in American mink, Southern river otters and domestic cats in Southern Chile. Mean seroprevalence of T. gondii was 64% of 151 total animals sampled: 59% of 73 American mink, 77% of 13 Southern river otters, 68% of 65 domestic cats. Toxoplasma gondii DNA was detected in tissues from one American mink and one Southern river otter. The present study confirms the widespread distribution of T. gondii in Southern Chile, and shows a high exposure of semiaquatic mustelids and domestic cats to the parasite. Cats and anthropogenic disturbance have a role in the maintenance of T. gondii infection in ecosystems of southern Chile. 8 Parvovirus and canine distemper virus are important agents that can infect carnivores, which causes severe disease in Canidae and Mustelidae. Domestic dogs are considered a problem for public health and for conservation of endangered species, because it can transmit infections to wildlife, such as parvovirus and canine distemper virus. This study analyzed, by PCR the presence of Canine Parvovirus (CPV) and Canine Distemper Virus (CDV) in domestic dogs (n=82), American mink (n=48) and native Southern river otter (13) in the Chilean Patagonia. One dog and two minks were found positive to CPV, these samples were confirmed as CPV by sequencing; but which showed 100% identity with CPV, Feline Panleukopenia and mink Enteritis virus. Non CDV was found. Leptospirosis is an important zoonosis with worldwide distribution caused by pathogenic bacteria of the genus Leptospira. The North American mink has an important role in the environmental contamination with Leptospira, as minks live in aquatic environments and are the predators of rodents. Blood and kidney samples were obtained from 57 minks in southern Chile 39ºS to 45ºS. Pathogenic species of Leptospira were detected by PCR on 31/57 minks. To determine the species we sequenced the 16S rRNA gene on nine of the positive samples. We predicted two pathogenic species: L. interrogans (five samples) and L. borgpetersenii (four samples). 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.Ítem Evaluación de la dieta y sobreposición trófica entre Lontra Provocax, Neovison Vison y Felis Catus en la cuenca del río Toltén y Allipén(Universidad Andrés Bello, 2022) Ugarte Barriga, Andrés Alejandro; Medina-Vogel, Gonzalo; Facultad de Ciencias de la VidaEl huillín, Lobito de río Patagónico o nutria de río (Lontra provocax) es una de las dos especies de nutrias que habitan en Chile, como especie presenta una situación de conservación extremadamente preocupante debido al dramático declive a un 10% de su distribución en los últimos 200 años. Esta situación es el resultado de varios factores, entre los cuales se destacan la caza ilegal, destrucción de hábitat, enfermedades infecciosas y posiblemente contaminación química y patógena, debido a esto, el huillín se encuentra en estado de “Peligro” según el UICN y el Ministerio del Medio Ambiente de Chile. Otro factor importante y más reciente es la presencia de carnívoros alóctonos invasores como los son el gato doméstico (Felis catus) y el visón americano (Neovison vison), en donde ambos casos el humano ha sido el culpable de sus introducciones. Esta situación es preocupante, debido a que ambas especies invasoras pueden llegar a tener un grado de competencia por explotación entre ellas y en particular en visón americano con el huillín, debido a que pertenecen a la misma familia, ambas son semiacuáticas, comparten hábitats y recursos alimenticios. Por lo tanto, se plantea como hipótesis: “Existe una menor sobreposición de la dieta entre visón americano y el gato doméstico, y una mayor sobreposición en la dieta entre visón americano y huillín”, esto daría indicios sobre, un potencial de competencia por explotación entre estas tres especies, para lo cual se evaluó la sobreposición trófica entre ellas. La sobreposición de nicho se evaluó con la técnica de isótopos estables, en la cuenca del río Toltén y Allipén, Región de la Araucanía. Con este fin, se capturaron individuos de las tres especies, a los cuales se les tomo una muestra de vibrisas, las cuales fueron posteriormente analizadas mediante un analizador elemental acoplado a un espectrómetro de masas “IRMS” en modo flujo continuo en el laboratorio de isotopos estables de la Universidad Andrés Bello en Viña del Mar. De este modo se obtuvieron valores de δ13C vs δ15N, los cuales permitieron representar la trama trófica de los ríos Toltén y Allipén, en donde no se presentaron diferencias significativas entre el visón americano y el huillín, no así entre visón con el gato doméstico. Luego se obtuvieron las proporciones de contribución en la dieta de los tres depredadores mediante el uso del paquete para R “SIMMR”: “Stable Isotope Mixing Models in R”, en donde el gato doméstico presentó un mayor apego por gallinas (Gallus gallus), y tanto el huillín como el visón americano, mostraron preferencias por el salmón Chinook (Oncorhynchus sp.) y el camarón de río (Samastacus spinifrons). Esto permitió generar un estimado del tamaño de nicho isotópico para gato doméstico, huillín y visón americano, mediante el paquete para R “SIBER”: “Stable Isotope Bayesian Elipses in R”, con el fin de obtener el grado de sobreposición de nicho entre estas especies. Como esperábamos (no se rechazó la hipótesis propuesta), observamos un menor grado de sobreposición entre gato doméstico y visón americano, y un mayor grado entre huillín y visón americano. Es importante mencionar que el estudio está afectado por las limitaciones de un bajo número de muestras, por lo que se propuso la adición de fuentes alimenticias tales como peces nativos y otros crustáceos como Aegla spp., lo que permitiría mejorar la precisión de los resultados para futuras investigaciones.Ítem Galictis cuja (Mammalia): an update of current knowledge and geographic distribution(Fundação Zoobotânica do Rio Grande do Sul, 2014) Poo-Muñoz, Daniela A.; Escobar, Luis E.; Townsend Peterson, A.; Astorga, Francisca; Organ, John F.; Medina-Vogel, GonzaloThe lesser grison (Galictis cuja) is one of the least-known mustelids in the Neotropics, despite its broad range across South America. This study aimed to explore current knowledge of the distribution of the species to identify gaps in knowledge and anticipate its full geographic distribution. Eighty-nine articles have mentioned G. cuja since 1969, but only 13 focused on the species. We generated a detailed model of the species’ potential distribution that validated previous maps, but with improved detail, supporting previous southernmost records, and providing a means of identifying priority sites for conservation and management of the species.Ítem High prevalence of pathogenic Leptospira in alien American mink (Neovison vison) in Patagonia(Sociedad de Biología de Chile, 2014) Barros, Macarena; Sáenz, Leonardo; LapierreII, Lisette; Nuñez, Camila; Medina-Vogel, GonzaloBACKGROUND: 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.Ítem Improving Trapping Efficiency for Control of American Mink (Neovison vison) in Patagonia(MDPI, 2022-01) Medina-Vogel, Gonzalo; Muñoz, Francisco; Moeggenberg, Meredith; Calvo-Mac, Carlos; Barros-Lama, Macarena; Ulloa, Nickolas; Pons, Daniel J.; Clapperton, B. KayTwo main challenges when controlling alien American mink (Neovison vison) in Patagonia are to maximize campaign efficacy and cost-effectiveness and to avoid trapping native species. We designed and tested new variants of collapsible wire box traps, compared the efficacy of a food-based bait and a scent lure and compared catch rates in different seasons of the year. We used the data to model the efficiency rate of the trapping and to determine the trapping effort required to remove 70–90% of the estimated discrete mink population. Between January 2018 and March 2021, we operated 59 trapping transects over 103 three-day trapping periods in southern Chile. Traps were first baited with canned fish, and afterwards with mink anal gland lure. We compared the efficacy of mink capture with that of our previous study. We trapped 196 mink (125 males, 71 females), with most captures in summer. The medium-sized GMV-18 trap caught more male mink, but the more compact GMV-13 caught fewer non-target rodents and no native mammals. The scent lure was more successful than the canned fish when the previous campaign’s data were included in the analysis. There was also a significant improvement in the proportion of female mink trapped and reduced labour compared with our previous campaign that used larger traps, fish bait and 400–500 m trap spacings. We caught relatively more females than males after the third night of trapping on a transect. Our data analysis supports the use of the GMV-13 variant of wire cage trap as the best trap size: it is effective on female mink, small, cheap and easy to transport. Combined with mink anal scent lure, it reduces the possibility of trapping native species compared with other traps tested in Chile. As the most efficient method for removing at least 70% of the estimated discrete mink population within the area covered by each trap transect in southern Chile tested to date, we recommend trapping campaigns using GMV-13 during summer, with a 200-m trap spacing, for up to 6 days before moving traps to a new site, with a combination of three days with a female scent gland lure, followed by three days with a male scent gland lure. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Ítem Potential for spread of the white-nose fungus (Pseudogymnoascus destructans) in the Americas: Use of Maxent and NicheA to assure strict model transference(University of Naples Federico II, 2014) Escobar, Luis E.; Lira-Noriega, Andrés; Medina-Vogel, Gonzalo; Townsend Peterson, A.merging infectious diseases can present serious threats to wildlife, even to the point of causing extinction. White nose fungus (Pseudogymnoascus destructans) is causing an epizootic in bats that is expanding rapidly, both geographically and taxonomically. Little is known of the ecology and distributional potential of this intercontinental pathogen. We address this gap via ecological niche models that characterise coarse resolution niche differences between fungus populations on dif ferent continents, identifying areas potentially vulnerable to infection in South America. Here we explore a novel approach to identifying areas of potential distribution across novel geographic regions that avoids perilious extrapolation into novel environments. European and North American fungus populations show differential use of environmental space, but rather than niche differentiation, we find that changes are best attributed to climatic differences between the two continents. Suitable areas for spread of the pathogen were identified across southern South America; however caution should be taken to avoid underestimating the potential for spread of this pathogen in South America.Ítem Relationships Between Off-bottom Bivalve Aquaculture and the Magellanic Steamer Duck Tachyeres Pteneres in Southern Chile(Aquaculture Environment Interactions, 2019) Medina-Vogel, Gonzalo; Pons, Daniel; Schlatter, Roberto P.The interactions between aquaculture farms and endemic marine birds in the Northern Hemisphere have been a recurrent topic in the past decades. In the Northern Hemisphere, shellfish aquaculture farms have diverse effects on wildlife populations, and the substantial predation on mussels by birds can lead to culling of the birds by farm managers. In this work, we assessed the interaction between Chilean blue mussel Mytilus chilensis farms and the Magellanic steamer duck Tachyeres pteneres, an endemic duck of southern Chile whose population is thought to be declining. In particular, we assessed the importance of the Chilean blue mussel in the Magellanic steamer duck’s diet, and we estimated the magnitude of losses to aquaculture due to predation by the ducks. Between March 1988 and February 1989, observations and sampling collections were performed around a bivalve aquaculture farm in Yaldad Bay (Chiloé Island, Chile). In contrast to what happens in the Northern Hemisphere, we infer that Chilean blue mussel farms do not promote the increase of the Magellanic steamer duck population in Chile: the population dynamics appear to be responding to other habitat variables. Moreover, our estimate for the losses due to predation was less than 1.6% of the annual farm production in Chile. Despite the fact that sampling was done almost 30 years ago, this study is the most recent one investigating the ecology and social behaviour of the Magellanic steamer duck and its relationship with bivalve aquaculture. © The authors 2019. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited.Ítem Where wilderness and humans meet : assessing interactions between people and wild and domestic carnivores in a fragmented landscape(Universidad Andrés Bello, 2015) Poo-Muñoz, Daniela Alejandra; Medina-Vogel, Gonzalo; Facultad de Ecología y Recursos NaturalesUrban sprawl and human activities are increasingly occupying and disturbing natural ecosystems, replacing pre-existing natural areas with a hostile matrix composed of human settlements, domestic animals, forest plantations, and agriculture, among others. These changes are fragmenting natural landscapes, with remaining natural areas surrounded by an anthropogenic matrix. This scenario increases interactions between humans, domestic animals, and wildlife , triggering conflicts mediated principally by resource competition . Additionally, domestic animals that accompany humans, such as domestic dogs, can actas an "extension" of human activities inside natural areas, with detrimental effects on wildlife. Domestic animals can also actas a bridge, translocating micro and macroparasites between natural areas and the anthropogenic matrix. This research aimed to determine the effects of an anthropogenic matrix on wild carnivores from a natural reserve, in terms of interactions between humans, domestic animals, wildlife, and their ectoparasites. The study was developed in the interface area between a natural reserve (NR) and the surrounding anthropogenic matrix (MA). To accomplish this aim, we developed three objectives, the first objective (Chapter 1), aimed to determine factors associated with people's recognition and attitudes towards wildlife and native carnivores (chilla fox, culpeo fox, and lesser grison), through interviews with local inhabitants. The second objective (Chapter 11), was to determine the factors influencing dogs' presence inside the NR and the effective protection of a Natural Reserve (NR), in terms of edge effects, and was based on dog's presence and movements. To achieve this goal, we developed a camera- trap survey and domestic dog fine-scale tracking through data loggers. The third objective (Chapter 111) was to characterize ectoparasitic species and Rickettsia spp. from domestic and wild carnivores collected in the NR and surrounding human settlements. We use morphological identification and molecular analysis to achieve this goal. Via interviews, we found that the species lesser grison was poorly recognized by inhabitants, with only 16% of people identifying the species. Additionally, personal attitudes towards wildlife and foxes were positively influenced by: higher education levels, closeness to the NR, and not having experiences with poultry predation/attacks. Nevertheless, for the lesser grison, negative attitudes were also reported. For this species, more negative attitudes were detected among the elderly, people that had encounters with lesser grison , and/or those who had poultry or experienced poultry predation/attacks. Models based on camera trap data detected that variables that best explained the presence of domestic dogs were the distance to houses and cattle presence, the latter a previously undescribed variable, that should be considered for dog management in rural areas. Camera trap data and dog movement confirmed that under a conservative approach, dogs are reducing the NR effective protection area, between 4-26%, depending on different scenarios. Ctenocepha/ides felis, Ct. canis and P. irritans fleas, and Rhipicephalus sanguineus tick, were detected in this study. Ctenocephalides felis was the most frequent species in carnivores, and P. irritans in wild carnivores Ctenocephalides felis, and domestic and wild carnivores shared P. irritans. A Rickettsia species, related to R. felis, was detected in ectoparasite pools (26.7%) through molecular analysis in C. felis and C. canis fleas collected from domestic dogs (one from the NR) and cats. To ensure biodiversity conservation , it is urgent to increase formal education in the area , especially related to cryptic and non- charismatic species, such as the lesser grison. Exclusion of cattle herding inside the NR will help to reduce the presence of dogs. Our ectoparasite survey suggests that dogs could translocate ectoparasites between the anthropogenic matrix and natural areas, increasing the risk of vectorborne disease transmission. Finally, the detection of a Rickettsia spp. similar to R. felis in ectoparasites from pets, represents a latent risk for human health in the area.