Search

La avispa común Vespula vulgaris (Linnaeus 1758) es una especie introducida en el Hemisferio Sur que ha sido registrada en Australia, Nueva Zelanda, Tasmania, Argentina y Chile central. Este trabajo documenta la presencia de V. vulgaris en la isla Navarino, Reserva de la Biósfera Cabo de Hornos, sur de Chile.

The introduction of carnivores to islands affects the conservation status of native prey. For two decades, American mink (Neogale vison) has expanded its distribution in the sub-Antarctic archipelago of Austral Patagonia, while preying on nests of solitary ground-nesting birds. Here, upland geese (Chloephaga picta) and flightless steamer ducks (Tachyeres pteneres) are naïve to such predation risk because of the lack of native terrestrial predators. We used nest occupancy models to reveal preferred breeding habitats of those two ground-nesting waterbirds to prioritize areas for future mink control programs. We searched for nests along 80 transects on Navarino Island, southernmost Chile, and 11 transects on 10 nearby islets (3 ± 2.9 ha). Our results showed that islets were essential for breeding in comparison to the main island (5.3 nests/km versus 0.8 nests/km, respectively). The occupancy models revealed that islets were particularly important for flightless steamer ducks, endemic to western Patagonia. As breeding habitat, upland geese preferred medium-dense shrubland, and flightless steamer ducks preferred rocky coastlines. Nest detection was negatively affected by dense vegetation and, in the case of the upland geese, towards the end of the survey. Ten camera traps (n = 385 trap nights) revealed mink presence on all islets, highlighting their capacity to swim in cold water, up to 340 m distance from the main island. We conclude that islets represent breeding refuges for ground-nesting waterbirds and therefore advocate allocating resources for mink control during the warm season on islets. We also provide predictive maps of nesting habitat preference of upland geese and flightless steamer ducks for conservation managers to focus their often scarce human and financial resources on areas critical for breeding. Finally, we argue that detection probability should be an integral part of bird breeding studies, which can be methodologically achieved through targeting transects, not nests, as sample units.

The Chilean Patagonia is characterized by extensive protected areas that encompass most of the region. Mammals are often among the priorities for these protected areas either as conservation targets (e.g., threatened species) or as threats (e.g., invasive species). Camera traps offer a cost-effective alternative to monitor these species, however baseline studies are scarce in the region. Therefore, our objective was to provide an assessment of camera-trapping detection rates for mammals that are present in protected areas of Magallanes, Chilean Patagonia. Between 2015 and 2022 we installed 278 camera traps (9,936 trap-days), distributed in seven protected areas. For each protected area, we calculated the detection rates and proportion of camera traps that detected each species. We recorded 18 mammalian species, including ten native, four domestic, and four invasive species. The culpeo fox (Lycalopex culpaeus) was the most frequently detected species, followed by invasive European hare (Lepus europaeus) and puma (Puma concolor). Endangered species like the huemul (Hippocamelus bisulcus) and southern river otter (Lontra provocax) were detected infrequently, whereas beaver (Castor canadensis) and American mink (Neogale vison) were only recorded in cameras that targeted them. From our data we suggest that generalist monitoring designs are likely to be effective for relatively common species like the culpeo fox. However, when species of interest are associated with specific features of the landscape (e.g., otters and water), other designs are needed. Based on our findings, we provide recommendations for the design of camera- trapping monitoring plans in protected areas.

Dogs are the most abundant carnivores on earth and, as such, negatively impact wildlife. Free-ranging dogs roam in many protected areas, which in turn are often tourist destinations. Whether tourists influence their roaming is largely unexplored but highly relevant to wildlife conservation. To address this question, we obtained (i) 81 completed questionnaires from tourists on their experience with free-ranging dogs in the remote Cape Horn Biosphere Reserve, Chile, and (ii) photographs of three camera-traps placed next to trekking trails (n = 87 trap days). A third of the participants were followed by dogs for up to four days, and 39% saw free-ranging dogs on their hikes, but neither feeding dogs nor fear of them had any influence on whether tourists were followed by dogs. Camera-traps yielded 53 independent dog sequences, recorded 32 individuals plus 14 unidentified dogs, of which only one was leashed, with a frequency of one dog every 28th person. In 17% of 53 sequences, dogs were photographed together with hikers carrying large backpacks for several-day trips. We conclude that tourists are facilitators for the movement of dogs and highlight the importance of the engagement of the tourism sector in wildlife conservation in and close to protected areas.

Background Hundreds of millions of domestic carnivores worldwide have diverse positive affiliations with humans, but can provoke serious socio-ecological impacts when free-roaming. Unconfined dogs (Canis familiaris) and cats (Felis catus) interact with wildlife as predators, competitors, and disease-transmitters; their access to wildlife depends on husbandry, perceptions, attitudes, and behaviors of pet owners and non-owners. Methods To better understand husbandry and perceptions of impacts by unconfined, domestic carnivores, we administered questionnaires (n = 244) to pet owners and non-owners living in one of the last wilderness areas of the world, the Cape Horn Biosphere Reserve, located in southern Chile. We used descriptive statistics to provide demographic pet and husbandry information, quantify free-roaming dogs and cats, map their sightings in nature, and report experiences and perceptions of the impact of free-roaming dogs and cats on wildlife. We corroborated our results with an analysis of prey remains in dog feces (n = 53). With generalized linear models, we examined which factors (i.e., food provisioning, reproductive state, rural/village households, sex, and size) predicted that owned dogs and cats bring wildlife prey home. Results Thirty-one percent of village dogs (n = 121) and 60% of dogs in rural areas (n = 47) roamed freely day and/or night. Free-roaming dog packs were frequently observed (64% of participants) in the wild, including a feral dog population on Navarino Island. Dogs (31 of 168) brought home invasive muskrats (Ondatra zibethicus) and avian prey, and over half of all cats (27 of 51) brought home mainly avian prey. Birds were also the most harassed wildlife category, affected by one third of all dogs and cats. Nevertheless, dog-wildlife conflicts were hardly recognized (

Invasive exotic species of mammalian predators represent a major cause of vertebrate animal extinctions on islands, particularly those that lack native mammalian carnivores. In 2001, the American mink (Mustela vison) was recorded for the first time on Navarino Island, in the Cape Horn Biosphere Reserve (55° S) in Chile, representing the southernmost population of mink worldwide. In order to assess its potential impact on native fauna, we studied its diet on Navarino Island, as part of an integrative management program on invasive species. Over a three-year period (2005-2007) we collected 512 scats in semi-aquatic habitats: marine coasts, riparian and lake shores. Overall, the main prey was mammals (37 % biomass), and birds (36 %), followed by fish (24 %). Over the spring and summer, mink consumed significantly more birds, whereas mammals constituted the main prey over the autumn and winter when migratory birds had left the area. Among birds, the mink preyed mainly on adult Passeriformes, followed by Anseriformes and Pelecaniformes, caught as chicks. Among mammals, the exotic muskrat (Ondatra zibethicus) was the most important prey, and together with the native rodent Abrothrix xanthorhinus it accounted for 78 % of the biomass intake. For an integrated management of invasive exotic mammal species on Navarino Island and in the Cape Horn Biosphere Reserve it is important to further research interactions established here among the various introduced mammals, and to initiate immediate control of the mink population in its initial stage of invasion.Las especies exóticas de mamíferos carnívoros invasores constituyen una de las principales causas de extinciones de vertebrados en islas, particularmente en aquellas que carecen de predadores mamíferos nativos. En 2001, el visón norteamericano (Mustela vison) fue registrado por primera vez en Isla Navarino en la Reserva de Biosfera Cabo de Hornos (55° S) en Chile, representando la población de visones más austral del mundo. Para estudiar su impacto potencial sobre la fauna nativa, estimamos su dieta en Isla Navarino como parte de un programa de control de especies invasoras. Durante tres años (2005-2007) colectamos 512 fecas en diversos habitats semiacuáticos: costa marina, riberas de ríos y lagos. La dieta consistió principalmente en mamíferos (37 % biomasa), aves (36 %) y peces (24 %). Durante la primavera y el verano el visón consumió significativamente más aves, sin embargo los mamíferos constituyeron la presa principal durante el otoño y el invierno, cuando las aves migratorias han abandonado la region. La depredación sobre aves afectó principalmente a Passeriformes adultos, seguidos por Anseriformes y Pelecaniformes que fueron capturados como polluelos. Respecto a los mamíferos, un roedor exótico, la rata almizclera (Ondatra zibethicus), fue la presa principal y junto al roedor nativo Abrothrix xanthorhinus constituyó el 78 % de la biomasa de presas de mamíferos. Para un manejo integral de especies de mamíferos exóticos invasores en Isla Navarino y la Reserva de Biosfera Cabo de Hornos es importante desarrollar investigación sobre las interacciones entre los mamíferos introducidos e iniciar un control inmediato de la población de visones en su estado inicial de invasión.