Browsing by Author "Duclos, Melanie"

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    European Rabbit Invasion in a Semi-Arid Ecosystem of Chile: How Relevant Is Its Role in Food Webs?
    (2023) Gubelin, Patricia; Correa-Cuadros, Jennifer Paola; Ávila Thieme, María Isidora; Flores Benner, Gabriela Verónica; Duclos, Melanie; Lima Arce, Mauricio; Jaksic Andrade, Fabián; Torre, Ignasi; Balčiauskas, Linas
    The European rabbit (Oryctolagus cuniculus) is one of the main invasive species in Chile, where it became naturalized ca. 150 years ago. Their high reproductive capacity, lack of specialist predators, and great adaptability favored the settlement of rabbits in diverse mainland and island ecosystems of the country. Recently, rabbits have become central players in semi-arid ecosystems, such as those represented in Las Chinchillas National Reserve in north-central Chile. We undertook to analyze the place and role of rabbits in the food web of that Reserve, based on a bibliographic review and long-term annual data gathered from 1987 until 2022 (36 years). Results showed that the network comprised 77 species, where 69% were primary producers (plants), 18% were mid-level consumers (herbivores), and 13% were top-level consumers (predators). The most connected species in the food web was the rabbit, which positively or negatively affected the species interacting with it. Predators such as Galictis cuja, Geranoaetus polyosoma, Leopardus colocolo, and Puma concolor, and the scavenger Vultur gryphus, could be negatively affected by an eventual decrease (natural or human-caused) in the rabbit population of the Reserve. To the contrary, primary producers such as Oxalis perdicaria, Plantago hispidula, Schizanthus parvulus, Senna cumminggi, and Tropaeolum azureum could be positively affected by an increase in their biomass in response to a decrease in rabbits, favoring native rodents. We consider that analyzing the rabbit-centered food web and its impacts on native interacting species allows a better understanding of the relevance of invasive species in the local community, providing conceptual tools for rabbit management.
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    EVIDENCE OF HIGH CONSUMPTION OF WASTE BY THE ANDEAN CONDOR (VULTUR GRYPHUS) IN AN ANTHROPIZED ENVIRONMENT OF CHILE
    (2019) Pavez, Eduardo F.; Duclos, Melanie; Rau, Jaime R.; Sade, Soraya; Jaksic, Fabian M.
    Anthropogenic food subsidies and waste disposals have become a new food resource for wildlife, including the Andean Condor (Vultur gryphus), a situation that implies benefits and health risks. To increase understanding of Andean Condor feeding habits in the most anthropized area in Chile, we analyzed 280 pellets collected during 2016 from one roost in the Metropolitan Region, central Chile. We identified the main diagnostic elements microscopically and expressed them as percentage of occurrence (percentage of each item in relation to all pellets). We found 12 prey categories (including mammals, birds, and plant material) and 9 waste categories. Condors fed mainly on mammals (99%); livestock was their main feeding source (52%), followed by native (22%) and exotic wild species (19%). Birds were detected less frequently (8%). We found a high occurrence of waste (31%), of which plastic remains were the main item (27%). According to our results, landfills serve as a complementary food source for condors, probably a low-quality but easily accessible, and which exposes them to a variety of health and mortality risks. Despite the fact that Andean Condors can reach distant places in foraging flights to find food resources, a high proportion of the population is attracted to rubbish dumps and landfills. Despite the spatio-temporal limitations of our results, this is the first record that describes and quantifies a high presence of waste as a component of the Andean Condor diet. We recommend a more comprehensive study to assess their feeding habits and habitat preferences in a broader spatio-temporal context, and to determine the possible impact of the use of waste disposals on Andean Condor populations.
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    First Detection of Benign Rabbit Caliciviruses in Chile
    (2024) Smertina, Elena; Keller, Luca M.; Huang, Nina; Flores Benner, Gabriela Verónica; Correa Cuadros, Jennifer Paola; Duclos, Melanie; Jaksic Andrade, Fabián; Briceño, Cristóbal; Neira Ramírez, Víctor; Díaz-Gacitúa, Miguel; Carrasco-Fernández, Sebastián; Smith, Ina L.; Strive, Tanja; Jenckel, Maria
    Pathogenic lagoviruses (Rabbit hemorrhagic disease virus, RHDV) are widely spread across the world and are used in Australia and New Zealand to control populations of feral European rabbits. The spread of the non-pathogenic lagoviruses, e.g., rabbit calicivirus (RCV), is less well studied as the infection results in no clinical signs. Nonetheless, RCV has important implications for the spread of RHDV and rabbit biocontrol as it can provide varying levels of cross-protection against fatal infection with pathogenic lagoviruses. In Chile, where European rabbits are also an introduced species, myxoma virus was used for localised biocontrol of rabbits in the 1950s. To date, there have been no studies investigating the presence of lagoviruses in the Chilean feral rabbit population. In this study, liver and duodenum rabbit samples from central Chile were tested for the presence of lagoviruses and positive samples were subject to whole RNA sequencing and subsequent data analysis. Phylogenetic analysis revealed a novel RCV variant in duodenal samples that likely originated from European RCVs. Sequencing analysis also detected the presence of a rabbit astrovirus in one of the lagovirus-positive samples.
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    La invasión del conejo europeo en Chile
    (2023) Correa Cuadros, Jennifer Paola; Flores-Benner, Gabriela; Gübelin , Patricia; Ávila-Thieme, María Isidora; Muñoz, Manuel; Duclos, Melanie; Soto, Nicolás; Briceño, Cristóbal; Vásquez, Felipe; Díaz, Miguel; Jaksic, Fabián
    El conejo europeo (Oryctolagus cuniculus) fue introducido en Chile central a mediados del siglo XVIII y se encuentra entre las especies invasoras que más afectan los ecosistemas chilenos y sus usos productivos. Los impactos más negativos del conejo se han reportado en islas chilenas y en el bosque esclerófilo continental. En Chile, los impactos de esta especie han sido abordados principalmente desde una perspectiva ecológicacomunitaria. Sin embargo, hace falta investigación aplicada para mejorar las políticas públicas y el manejo eficiente del conejo, como por ejemplo determinar su distribución geográfica, el tamaño de su población, comprender mejor sus impactos en los ecosistemas naturales y agroecosistemas, y los depredadores y patógenos que los afectan. En este libro se realiza una revisión exhaustiva de los estudios existentes sobre el conejo europeo en Chile en cuanto a su historia y control, epidemiología de enfermedades virales, ecología e impactos económicos, con el fin de detectar los vacíos y desafíos resultantes y orientar los esfuerzos hacia su manejo en Chile
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    The ecological roles of the European rabbit in the Magellanic/Fuegian ecosystem of southernmost Chile
    (2024) Mann-Vollrath, Francisca; Correa-Cuadros, Jennifer Paola; Avila-Thieme, M. Isidora; Duclos, Melanie; Jaksic, Fabian M.
    The European rabbit has invaded numerous ecosystems worldwide, but rarely steppes. Since its various introduction attempts into the ecosystems of the Magallanes/Fuegian region, the rabbit has become a key player, interacting with species at different trophic levels and generating impacts on ecosystems. To better understand the role of the rabbit in steppe and scrub ecosystems, we characterised the food web in the Magallanes/Fuegian region to understand the identity of their interacting species, the mechanisms and complexities of their interactions to demonstrate that rabbit management may become more complex than just controlling a single species. Based on a bibliographic review and wildlife specialists' opinions, we built the Magellanic/Fuegian food web, evaluated their topological properties and performed a rabbit extinction simulation to assess the possible short-term ecological mechanisms operating in the community. We found that the network had 206 nodes (64% native, 13% exotic, and 22% mixed) and 535 links among nodes. The European rabbit was the most connected node of the food web, had the second largest dietary breadth, and ranked as the seventh prey item with more predators. A rabbit extinction simulation shows a possible release of herbivory pressure on plants, including that on several native plants (e.g., Gunnera tinctoria, Pratia repens, Gavilea lutea, Tetroncium magellanicus), and a possible release of competition for some herbivores that share resources with the rabbit (e.g., Ovis aries, Lama guanicoe, Bos taurus). Although rabbit predators have a broad and generalist diet, some such as the native Galicitis cuja, could face a 20% reduction in their trophic width and could intensify predation on alternative prey. These results show that the European rabbit is strongly embedded in the Magellanic/Fuegian ecosystem and linked to several native species. Therefore, rabbit management should consider ecosystem approaches accompanied by monitoring programs on native fauna and experimental pilot studies on native flora to conserve the Chilean Patagonia community.