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La única población estable de huillines en agua dulce conocida de Argentina se encuentra en el Parque Nacional Nahuel Huapi. Se recorrieron 14 sitios lineales (50–600 m) costeros aguas abajo de la confluencia de los ríos Limay y Traful para evaluar la situación del huillín en el embalse Alicurá. Se detectó la especie en un sector que se encuentra bajo influencia de la represa Alicurá y con presencia de pisciculturas. Queda en evidencia la necesidad de profundizar el estudio sobre el efecto de estas potenciales nuevas amenazas para la recolonización de la cuenca y de consensuar acciones entre las jurisdicciones involucradas.

Alloparental behavior includes a wide range of situations, from occasional fostering to adoption. It is usually the result of brood parasitism, brood adoption or brood mixing, but also due to nest switching. Interspecific alloparental behaviors are less widespread, but there are no key differences in mechanism of underlying behaviors. Some South American grebes are found sympatrically, and some of them usually reproduce on mixed colonies. Here we describe different conspecific and interspecific alloparental behaviors involving Silvery Grebe (Podiceps occipitalis), White-tufted Grebe (Rollandia rolland) and the critically endangered Hooded Grebe (Podiceps gallardoi). We discuss the implications of temporary adoption and potentially ‘true’ adoption, in particular for Hooded Grebes. Our observations show that alloparental behavior is possibly widespread among Neotropical grebes, and in the case of the Hooded Grebe we hypothesize that alloparental intraspecific feeding of non-related juveniles prior to migration could help to increase juvenile survival.

Se registró por primera vez el comportamiento de homing en Chaetophractus villosus. Se capturaron 33 individuos de C. villosus y se liberaron a diferentes distancias en Península Valdés, Chubut, Argentina. Del total de individuos, el 30 % regresó al punto captura dentro de los 12 días desde la liberación. El tiempo de recaptura aumentó de manera no linear respecto a la distancia, por lo que los puntos de liberación podrían estar fuera de su área de acción. El regreso al sitio de captura posiblemente se debe a que los peludos reconozcan a este sitio como fuente de recursos alimenticios.

Upland Goose Chloephaga picta, Ashy-headed Goose Chloephaga poliocephala and Ruddy-headed Goose Chloephaga rubidiceps are endemic goose-like threatened birds of southern South America. This work aimed to study how sheldgeese are distributed both temporally and spatially and characterize their habitat use in part of their breeding range in Southern Argentina, a little-explored subpolar region. We conducted nine surveys between spring 2013 and summer 2016 across a maximum of 235 km in Santa Cruz and 698 km in Tierra del Fuego per survey. We recorded the presence of non-breeding sheldgoose groups and Upland Goose pairs. We collected data at site-scale (~ 0.8 km2) and extracted data from geographic information systems for landscape-scale (5 km2) analyses. We recorded 2396 non-breeding groups containing one, two or the three species, 788 Upland Goose pairs and 102 solitary individuals. The Upland Goose was present in almost all groups and was the most abundant sheldgoose, followed by the Ashy-headed Goose. The Ruddy-headed Goose was observed only in 15 locations. Poa grasslands, meadows and Festuca grasslands were the habitats in which we detected most individuals. Sheldgoose density was higher in Tierra del Fuego than in Santa Cruz, and increased from spring to autumn and decreased in winter. The largest sheldgoose groups were concentrated in meadows and waterbodies. Sheldgeese selected sites with greater habitat diversity, habitat richness and number of habitats patches. Our results provide information to understand which environmental conditions favour sheldgeese and to aid in the selection of important areas for the conservation of these species.

Made available in DSpace on 2022-04-28T19:45:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Consejo Nacional de Investigaciones Científicas y Técnicas Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Natural Environment Research Council Formulating effective management plans for addressing the impacts of invasive non-native species (INNS) requires the definition of clear priorities and tangible targets, and the recognition of the plurality of societal values assigned to these species. These tasks require a multi-disciplinary approach and the involvement of stakeholders. Here, we describe procedures to integrate multiple sources of information to formulate management priorities, targets, and high-level actions for the management of INNS. We follow five good-practice criteria: justified, evidence-informed, actionable, quantifiable, and flexible. We used expert knowledge methods to compile 17 lists of ecological, social, and economic impacts of lodgepole pines (Pinus contorta) and American mink (Neovison vison) in Chile and Argentina, the privet (Ligustrum lucidum) in Argentina, the yellow-jacket wasp (Vespula germanica) in Chile, and grasses (Urochloa brizantha and Urochloa decumbens) in Brazil. INNS plants caused a greater number of impacts than INNS animals, although more socio-economic impacts were listed for INNS animals than for plants. These impacts were ranked according to their magnitude and level of confidence on the information used for the ranking to prioritise impacts and assign them one of four high-level actions—do nothing, monitor, research, and immediate active management. We showed that it is possible to formulate management priorities, targets, and high-level actions for a variety of INNS and with variable levels of available information. This is vital in a world where the problems caused by INNS continue to increase, and there is a parallel growth in the implementation of management plans to deal with them. School of Biological Sciences University of Aberdeen Instituto de Investigaciones Marinas y Costeras (IIMyC) FCEyN-Universidad Nacional de Mar del Plata-CONICET CC 1260 Instituto de Geología de Costas y del Cuaternario (IGCyC) FCEyN-Universidad Nacional de Mar del Plata-CIC Funes 3350 Instituto de Ecología Regional (IER UNT CONICET) and Facultad de Ciencias Naturales e IMl UNT Residencia Universitaria de Horco Molle, Yerba Buena Business School University of Aberdeen Business School University of Stellenbosch, PO Box 610 Laboratorio de Estudios del Antropoceno (LEA) Facultad de Ciencias Forestales Universidad de Concepción Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Dirección Regional Patagonia Norte de la Administración de Parques Nacionales, O’Connor 1188, 8400-San Carlos de Bariloche Laboratorio de Invasiones Biológicas (LIB) Facultad de Ciencias Forestales Universidad de Concepción Institute of Ecology and Biodiversity (IEB) Servicio Agrícola y Ganadero Gobierno de Chile Lab of Vegetation Ecology Instituto de Biociências Universidade Estadual Paulista (UNESP), Av. 24A Centro de Humedales Río Cruces (CEHUM) Universidad Austral de Chile Grupo de Ecología de Invasiones INIBIOMA CONICET Universidad Nacional del Comahue, Quintral 1250 Department of Biology and Biochemistry University of Houston Programa Patagonia Departamento de Conservación de Aves Argentinas/Asociación Ornitológica del Plata Departamento de Análisis de Sistemas Complejos Fundación Bariloche CONICET, Av. Bustillo 9400 EDGE of Existence-Zoological Society of London Lab of Vegetation Ecology Instituto de Biociências Universidade Estadual Paulista (UNESP), Av. 24A Consejo Nacional de Investigaciones Científicas y Técnicas: -2019-74-APN-DIR#CONICET FAPESP: 2018/14995-8 Natural Environment Research Council: NE/S011641/1

El visón americano es un carnívoro semiacuático de América del Norte. Fue introducido en Argentina y Chile (década 1930) en criaderos peleteros, a partir de los cuales se originaron poblaciones silvestres. Actualmente se distribuye en casi toda Patagonia, ocupando todos los biotopos acuáticos. Es un predador generalista que representa una de las mayores amenazas para vertebrados acuáticos. Sus depredadores en el rango invadido se conocen de manera anecdótica. En esta nota documentamos una interacción depredador-presa previamente registrada en el rango natural del visón americano, pero mediada por una subespecie del depredador no mencionada previamente en la literatura. Finalmente, alentamos los estudios de dieta del tucúquere y otras rapaces para determinar la importancia de la depredación como factor de mortalidad para el visón. The American mink is an amphibious carnivore native to North America. It was introduced in Argentina and Chile (1930s) in fur farms where wild populations originated later. It is now widely present in Patagonia and has colonized all types of aquatic habitats. Mink predators have only been reported anecdotally. We confirm the occurrence of a predator-prey interaction previously described for the natural range of the American mink, but mediated by a subspecies of the predator not mentioned in literature to date. Finally, we encourage more studies on raptor diets to determine the importance of predation as a mortality factor for mink in Patagonia. Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Administración de Parques Nacionales; Argentina. Asociación Ornitológica del Plata; Argentina Fil: Formoso, Anahí Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Cabanas, Diego. Asociación Argentina de Fotógrafos de Naturaleza; Argentina Fil: Podestá, Darío Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina. Asociación Argentina de Fotógrafos de Naturaleza; Argentina Fil: Roesler, Carlos Ignacio. Asociación Ornitológica del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Zoological Society of London; Reino Unido

Three migratory species of sheldgeese (Chloephaga spp.) make seasonal movements across a large portion of the Argentine territory. All three of these species have been affected by anthropogenic actions which have caused dramatic population drops, especially for the Ruddy-headed Goose (Chloephaga rubidiceps). Although telemetry techniques have rapidly advanced, knowledge of the migratory routes of many Neotropical birds is still incipient. The study of migration routes should be a top priority, especially when conservation and management actions are necessary along the main migratory routes. The goal of this work is to present new evidence of important stopover sites and concentration areas of migratory sheldgeese in eastern Patagonia. We conducted fieldwork during the fall, winter and spring of 2017, all of 2018 and the summer of 2019 in Chubut province, Argentina. We identified one stopover area for sheldgeese within a recently created protected area, the Parque Interjurisdiccional Marino Costero Patagonia Austral (PIMCPA), that could be a key site for the protection of the three species, in particular for the Ruddy-headed Goose. Results will provide input for decision-making processes during the design of future infrastructure projects already planned in eastern Patagonia along the migratory route of several species.

The large hairy armadillo (Chaetophractus villosus) was introduced to the Isla Grande of Tierra del Fuego almost 35 years ago. Previous studies described the armadillo’s distribution relative to heated oil pipelines. The present study updates this distribution, and evaluates associations with additional environmental variables to better explain the dispersion process and to propose areas for the control/eradication of this invasive species. We conducted 52 random transects looking for indirect evidence of the presence of C. villosus such as burrows and “foraging pits”. We looked for associations between the presence/habitat use of armadillos with local environmental characteristics and landscape features. We also gathered information about the invasion process through interviews with rural settlers. The species’ distribution was calculated with the Minimum Convex Polygon method, and a linear invasion rate was calculated. Finally, a map with priority areas for eradication was developed. Armadillos occur in areas with tall and medium-height vegetation and avoid low and floodable terrains. Signs of armadillo presence were more abundant in areas with humic soils but were not associated with any landscape features. The distribution of C. villosus increased by 4735.92 km2 in 12 years with an average linear expansion rate of 10.91 km/year. Humans seem to have facilitated the spread of armadillos towards the south. Implementation of any control measures should be focused on two areas of the island: namely those with high terrains, medium/high vegetation height and humic soils. This invasion represents a socio-ecological problem that needs full and urgent attention while eradication is still feasible.

El visón americano (Neovison vison) es el carnívoro exótico invasor de mayor distribución en Patagonia. Basados en relevamientos de campo y archivos históricos se presenta información detallada sobre su actual distribución en 180 km del Río Negro. Este foco representa la distribución más noreste, un nuevo ambiente invadido (Monte Oriental) y una nueva provincia con poblaciones silvestres (Buenos Aires). Documentamos la existencia de un criadero en las ciudades de Carmen de Patagones y Viedma (1965-1974), que podría ser el origen de este foco. Recomendamos diseñar e implementar planes de monitoreo y control de manera urgente. American mink (Neovison vison) is the most widespread invasive carnivore in Patagonia. Based on eld surveys and historical records, we present novel and detailed information of the American Mink present distribution along 180km of the Río Negro. This invasion nucleus represents the most northeastern area recorded for the species, a new invaded ecoregion (Monte Oriental) and a new province with wild populations (Buenos Aires). We document the existence of a fur farm located in Carmen de Patagones and Viedma cities (1965-1974) that may have originated this focus. We recommend the prompt design and implementation of a control plan. Fil: Failla, Mauricio. Proyecto Patagonia Noreste; Argentina Fil: Fasola, Laura. Administración de Parques Nacionales. Delegación Regional Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina

SummarySince its rediscovery in 1998, two major threats have been mentioned for the enigmatic Austral RailRallus antarcticus: cattle management by burning grass and rushes and predation by American minkNeovison vison. Added to the lack of a protocol to monitor this secretive bird, ever-growing threats make it necessary to study its global situation in depth to take accurate and urgent management decisions. We firstly studied how threats to the Austral Rail currently impact their occupancy and relative density (RD) at a wetland scale and habitat features associated with its presence at survey site scale inside wetlands in Santa Cruz province, Argentina. We additionally developed a monitoring protocol to detect the rail effectively and promptly by studying responses to playback with two different vocalisations at different times of the day and season. Both threats evaluated were negatively related to occupancy and RD of the Austral Rail, especially mink presence appearing to have an additive effect. We propose American mink control as crucial for Austral Rail conservation, while it would also be necessary to conserve a portion of wetlands exempt from burning and cattle presence. At survey sites, its presence was positively related with c.1–1.5 m tall rushes, whilst rails avoided low- density rush areas that resulted after management of rushes with fire to create pasture. To detect rails, both vocalisations can be confidently used at any time of the day and season. The poor knowledge about species ecology, mismanagement of vegetation in wetlands, expansion of American mink in Patagonia, construction on two dams in the Santa Cruz river basin, added to the already modified humidity conditions due to global climate change, force us to suggest that the Austral Rail should be considered as globally ‘Endangered’ (EN), to ensure the consideration of the species in management decisions.

Effective long-term management is needed to address the impacts of invasive alien species (IAS) that cannot be eradicated. We describe the fundamental characteristics of long-term management policies for IAS, diagnose a major shortcoming, and outline how to produce effective IAS management. Key international and transnational management policies conflate addressing IAS impacts with controlling IAS populations. This serious purpose–implementation gap can preclude the development of broader portfolios of interventions to tackle IAS impacts. We posit that IAS management strategies should directly address impacts via impact-based interventions, and we propose six criteria to inform the choice of these interventions. We review examples of interventions focused on tackling IAS impacts, including IAS control, which reveal the range of interventions available and their varying effectiveness in counteracting IAS impacts. As the impacts caused by IAS increase globally, stakeholders need to have access to a broader and more effective set of tools to respond. Fil: García Díaz, Pablo. University of Aberdeen; Reino Unido Fil: Cassey, Philip. University of Adelaide; Australia Fil: Norbury, Grant. Crown Research Institutes. Landcare Research; Nueva Zelanda Fil: Lambin, Xavier. University of Aberdeen; Reino Unido Fil: Montti, Lia Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Pizarro, J. Cristóbal. Universidad de Concepción; Chile Fil: Powell, Priscila Ana. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina Fil: Burslem, David F. R. P.. University of Aberdeen; Reino Unido Fil: Cava, Mário. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Damasceno, Gabriella. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Asociación Ornitológica del Plata; Argentina Fil: Fidelis, Alessandra. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Huerta, Magdalena F.. Universidad Austral de Chile; Chile. Universidad de Concepción; Chile Fil: Langdon, Bárbara. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma | Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma.; Argentina Fil: Linardaki, Eirini. University of Aberdeen; Reino Unido Fil: Moyano, Jaime. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma | Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma.; Argentina Fil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma | Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma.; Argentina Fil: Pauchard, Aníbal. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma | Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede San Martín de Los Andes-inibioma.; Argentina Fil: Phimister, Euan. University of Aberdeen; Reino Unido Fil: Raffo, Eduardo. Gobierno de Chile. Servicio Agrícola y Ganadero; Chile Fil: Roesler, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Rodríguez Jorquera, Ignacio. Universidad Austral de Chile; Chile. Universidad de Concepción; Chile Fil: Tomasevic, Jorge A.. Universidad Austral de Chile; Chile. Universidad de Concepción; Chile

As in other parts of the globe, the American mink has invaded the southern cone of Latin America successfully. Nowadays it is one of the most widespread and feared invasive vertebrates in southern Argentina and Chile. Unfortunately, these are only 2 countries of a list of over 30 where it has invaded in Europe and Asia (Macdonald and Harrington 2003; Bonesi and Palazon 2007). The wide distribution that it has reached in occupied territories and the difficulties to trap mustelid efficiently discourage the idea of investing on eradication programs (King et al. 2009). However, recent control programs focused on clear conservation or economic objectives have evidenced that they can deliver auspicious results when immigration is controlled.

Migratory sheldgeese (continental Upland Goose Chloephaga picta, Ashy-headed Goose C. poliocephala, and continental Ruddy-headed Goose C. rubidiceps) are endemic birds of southern South America. They are currently threatened by illegal hunting, overgrazing, and invasive predators. Because their breeding area is intensely grazed by sheep and cows, we studied the interaction of sheldgeese flocks and breeding pairs with livestock in the Tierra del Fuego and Santa Cruz provinces in Patagonia, Argentina. We conducted road-based surveys of sheldgeese flocks and breeding pairs from spring 2013 to summer 2016 to explore sheldgeese behavior. In addition, we monitored Upland Goose nests using camera traps and estimated nest daily survival rates in nests unprotected and protected from livestock with an electric fence. Sheldgeese flocks and breeding pairs were more frequently sighted alone than associated with livestock. Also, when sheldgeese foraged alongside livestock, there were fewer individuals resting and these allocated more time to forage than in the absence of livestock. We did not observe lower individual vigilance in sheldgeese flocks sharing foraging patches with livestock. Nests protected by electric fences had higher daily survival rates than unprotected ones. Our results indicate that one important conservation action should be to identify areas that concentrate a great number of breeding pairs of sheldgeese, and protect them from livestock, mainly during the peak of the reproductive season.

Incluye contenido parcial de los autores Biological invasion is one of the main threats to native biodiversity. For a speciesto become invasive, it must be voluntarily or involuntarily introduced by humans into a nonna-tive habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this dataset, we make available occurrence and abundance data on mammal species that (1) transposeda geographical barrier and (2) were voluntarily or involuntarily introduced by humans into theNeotropics. Our data set is composed of 73,738 historical and current georeferenced recordson alien mammal species of which around 96% correspond to occurrence data on 77 speciesbelonging to eight orders and 26 families. Data cover 26 continental countries in the Neotrop-ics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Floridain the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 coun-tries of Caribbean islands. Our data set also includes neotropical species (e.g.,Callithrixsp.,Myocastor coypus,Nasua nasua)considered alien in particular areas of Neotropics. The mostnumerous species in terms of records are fromBossp. (n=37,782),Sus scrofa(n=6,730), andCanis familiaris(n=10,084); 17 species were represented by only one record (e.g., Syncerus caf-fer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of spe-cies in the data set (n=20 species), partly because of uncertainties regarding taxonomicidentification of the generaCallithrix,which includes the speciesCallithrix aurita, Callithrixflaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, andtheir hybrids. This unique data set will be a valuable source of information on invasion riskassessments, biodiversity redistribution and conservation-related research. There are no copy-right restrictions. Please cite this data paper when using the data in publications. We alsorequest that researchers and teachers inform us on how they are using the data

Invasive American mink is a severe threat to endangered waterbird populations. In Europe and South America, control efforts have been increasing in the last decades. Mink has a proven acute impact on the Hooded Grebe, a critically endangered specialist of highland plateau lakes in Patagonia where a single mink attack can deplete up to 4% of the global population. We aimed to examine mink ecology in Austral Patagonia to inform ongoing control programs in the region and contribute to efforts elsewhere to counteract mink impact. We evaluated mink distribution at a regional scale and found that its distribution extends across the steppe-arid environment, often assumed to be an obstacle for mink colonization. Consequently, its current distribution fully overlaps with the Hooded Grebe breeding grounds. At a finer scale, we used 3 techniques to detect American mink at different times of the year and found a temporal sex-biased occupation-dispersion pattern: permanent presence of both sexes in areas around the plateaus used by grebes and upstream male biased dispersion in late summer (which leads young mink to the grebes’ lakes). Therefore, plateau perimeters function as an invasion front that resets yearly. Lastly, from scat content analysis we detected a shift in mink diet from a generalist type in lowland rivers to a diet specialized on birds in highland lakes, where attacks are exclusively directed towards Hooded Grebes and where waterbird presence might be a determinant of mink presence (regardless of other prey). All of these findings have profound relevance for control schedules and priorities. Fil: Fasola, Laura. Proyecto Macá Tobiano; Argentina. Administración de Parques Nacionales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Roesler, Carlos Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. The Zoological Society Of London; Reino Unido. Proyecto Macá Tobiano; Argentina

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Las especies invasoras constituyen una amenaza para la biodiversidad nativa. El éxito de las especies invasoras pese a su baja variabilidad genética se conoce como “paradoja genética”. El visón americano (Neovison vison) fue introducido en varias regiones del planeta como Europa, Asia y América del Sur con fines peleteros. En Argentina fue introducido en la década de 1930 y, como resultado de la liberación de individuos en la na-turaleza, lograron establecerse poblaciones silvestres en la región Patagónica. El objetivo del presente trabajo es estudiar la diversidad genética de una población asilvestrada de la provincia de Santa Cruz y compararla con la de una población en cautiverio. Analizamos un fragmento de 359 pb de la región control de ADN mitocondrial y encontramos índices de variabilidad similares entre la población silvestre y la población cautiva. Al igual que en poblaciones asilvestradas de otras regiones del planeta, no se observa una reducción en la variabilidad genética en la población silvestre de Santa Cruz, probablemente como consecuencia de liberaciones y escapes recurrentes desde diversas fuentes de cautiverio. Alien species represent a threat to native biodiversity. The suc-cess of invasive species despite their reduced genetic diversity is known as “the genetic paradox”. The American mink (Neovison vison) was introduced in several regions of the world, like Europe, Asia and South America. In Argentina, they were introduced in the 1930’s by the fur industry and wild populations were established in Patagonia due to liberations and escapes. In this study, we analyzed the genetic diversity of a wild American mink population of northern Santa Cruz province and compared it with a captive population. We sequenced a 359-bp fragment of the mtDNA control region and found that genetic variability was similar between both groups. Like in other wild invasive populations, genetic variability was not reduced in the population of Santa Cruz, probably as a consequence of frequent releases and escapes from different sources of captive minks. Fil: Malerba, Martina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Roesler, Carlos Ignacio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina Fil: Pereda, Maria Inés. Aves Argentinas; Argentina Fil: de Miguel, Andrés. Aves Argentinas; Argentina Fil: Martina, Florencia Lucia. Aves Argentinas; Argentina Fil: Mahler, Bettina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina

The Ruddy-headed Goose Chloephaga rubidiceps has two separate and genetically distinct populations, one sedentary that inhabits the Malvinas/Falklands Islands and another migratory, which inhabits continental southern South America. New information suggests that these populations should be considered as different evolutionarily significant units. The latter population breeds in Austral Patagonia (Argentina and Chile) and overwinters in Central Argentina. It was a very common species in Austral Magellanic steppe grasslands before 1931, when it was declared an agricultural pest by the Argentinian government, together with other sheldgeese species. Since then, the continental Ruddy-headed Goose population has declined becoming one of the scarcest species in Austral Magellanic steppe. Nowadays, its population is categorised as critically endangered in Argentina and endangered in Chile. We present data from six road censuses conducted in the breeding areas of Santa Cruz and Tierra del Fuego provinces, Argentina, during 2013-2014 and 2014-2015 (>4600 km, 70 days) and review population trends of the Ruddy-headed Goose since the early 1900s. We counted a maximum of 19 individuals in Santa Cruz and 49 in Tierra del Fuego throughout the breeding season. A literature review indicates that during the last 40 years the size of continental population of Ruddy-headed Goose has been < 800 individuals, approximately 10% of the estimated population in the 1900s. This decline matches the period following the application of control techniques and the introduction of exotic predator species in the breeding grounds of Tierra del Fuego. We review and discuss formerly proposed conservation actions that may have a positive and rapid effect on sheldgoose numbers recovery. We suggest that the continental population of Ruddy-headed Goose should on a precautionary basis be treated as a critically endangered population until genetic studies determine whether we are in the presence of a new 'Critically Endangered' species. Fil: Cossa, Natalia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Roesler, Carlos Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Reboreda, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina

In 2011, the invasive American mink Neovison vison became the most acute threat to the globally critically endangered Hooded Grebe Podiceps gallardoi (global population

El visón es una especie de carnívoro invasor con una amplia distribución en Patagonia y por su comportamiento de forrajeo es el carnívoro invasor con el mayor potencial para afectar a la biodiversidad en la región. La información disponible acerca de la presencia/ausencia del visón en la región y de estimaciones poblacionales es muy escasa aun cuando esto es vital para la planificación de acciones de manejo. En este trabajo integramos la información disponible acerca de la presencia del visón hasta la fecha y evaluamos su presencia en sitios donde hay vacíos de información, basándonos en la ubicación de los puntos de liberación de individuos, distribución confirmada y estimaciones de la capacidad de dispersión. Proponemos una Herramienta de Priorización de Áreas (HPA) para definir sitios prioritarios para el manejo, superponiendo mapas de distribución de la especie, de hábitat adecuado y áreas de importancia para la conservación de la biodiversidad. Entre las áreas prioritarias, seleccionamos tres y sugerimos un Protocolo de Tareas de Erradicación (PTE) como estrategia de manejo del visón americano, basado en experiencias de erradicación Europeas exitosas. Finalmente, estimamos costos relativos asociados a la implementación de tal PTE en cada una de las áreas seleccionadas. Presentamos este trabajo como una herramienta aplicada, enfocada en mostrar una forma simplificada para afrontar el problema de las especies invasoras en Patagonia y su manejo.

A combination of infrared cameras and plasticine eggs were used to identify potential nest predators of Flightless Steamer-Ducks (Tachyeres pteneres) and Flying Steamer-Ducks (T. patachonicus) and to evaluate the relative efficacy of these methods for identifying predators. Cameras were set up at 31 artificial nests with plasticine eggs and at four Flightless and two Flying steamer-duck nests. Two avian predators, Chimango Caracara (Milvago chimango) and Southern Crested Caracara (Caracara plancus), and two mammalian predators, Fuegian Culpeo fox (Pseudalopex culpaeus lycoides) and American mink (Neovison vison), were identified as depredating artificial nests from photos. Active Flightless and Flying steamer-duck nests were found only on islets, and from the photos the Chimango and Southern Crested caracaras were identified as nest predators. Mammalian predators were not photographed on islets (neither on artificial nor natural nests). Though the potential predator community at Lapataia Bay was small, there were considerable similarities in physical evidence and marks left at nests, especially within avian predators. Also, depredated nests were sometimes revisited by other predators and these multi-predator visits sometimes caused changes to the appearance of the depredated nest following departure of the initial predator. The cameras provided an objective method for definitive identification of nest predators. Fil: Liljesthrom, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Valenzuela, Alejandro Eduardo Jorge. Administración de Parques Nacionales. Delegación Regional Patagonia; Argentina Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Schiavini, Adrian Carlos Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

We describe nest-site characteristics and studied breeding habitat use of Kelp geese (Chloephaga hybrida) and Flightless Steamer ducks (Tachyeres pteneres) along 137km of coastline on the northern shore of the Beagle Channel, Argentina, and 87 km of island coastline. Also, we examined the importance of vegetation cover, predation and tourism on the distribution of nests among islands. We found all nests only on islands and islets. Nesting sites for both species were strongly associated with higher proportions of high vegetation cover (shrubs), and for Kelp geese they were also associated to the absence of terrestrial predators. Tourist presence on islands was not associated to the presence of nest for neither species. The northern coasts of the Beagle Channel and the islands and islets along the channel have similar habitat types. However, the islands and islets are relatively inaccessible to mammalian terrestrial predators compared to the coast of the channel were terrestrial predators are frequently recorded. Therefore, islands and islets seem to provide a relatively safe nesting habitat for Kelp geese and Flightless Steamer ducks by offering refuge mainly from ground predators. Additionally, habitat changes caused by increased human disturbance along the northern shore of the Beagle Channel may also explain the presence of nests only on islands and islets, though further studies are needed to assess these effects. This study provides new information on the breeding habitat and nesting sites of Flightless Steamer ducks and Kelp geese in the Beagle Channel, which in the future may contribute to the identification of priority breeding sites, and habitats and habitat features to protect. Also, it highlights the importance of islands and islets of the Beagle Channel as a safe breeding refuge for these two ground nesting seabirds. Fil: Liljesthrom, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Schiavini, Adrian Carlos Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Saenz Samaniego, Ricardo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

The American mink (Neovison vison) is a semi-aquatic, generalist carnivore released onto Tierra del Fuego (TDF) Island in the 1940s, subsequently spreading to adjacent islands in the archipelago with potential effects on native prey populations. Knowledge of this new predator's trophic ecology is essential to identify threats, plan control strategies and conserve native fauna. We studied seasonal mink diet in TDF in different habitats. We identified undigested remains from 493 scats collected between May 2005 and March 2009 along marine coasts and freshwater shores (rivers and lakes). Small mammals and fish were the main mink prey in TDF (over 65% of diet items). Seasonal variations were not detected, but diet did vary significantly between marine and freshwater habitats, where more terrestrial items were consumed. Among mammals, mink consumed more small native rodents than exotic species. Native fish consumption was also important with greater representation of species from the families Nototheniidae and Galaxiidae in marine and freshwater habitats respectively. Birds were the third item in importance, but did not constitute a particularly large part of the mink's diet on TDF. Overall, differences found in mink diet between habitats reflected their generalist/opportunistic feeding behaviour and did not differ greatly from observations in its native range or in other areas where it has been introduced. Our results establish the interactions between this novel predator and its prey and also illustrate the need to continue research on native prey populations to quantify mink impact on them and understand the ecological context of this biotic assemblage. Fil: Valenzuela, Alejandro Eduardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Saenz Samaniego, Ricardo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Schiavini, Adrian Carlos Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

Knowledge about interactions between endangered native southern river otters (Lontra provocax) and introduced American mink (Neovison vison) is essential for effective management of both species. We evaluated competition for spatial and trophic niches between otter and mink in overlapping and non-overlapping areas, comparing distribution, habitat preference, diet and mink marking behavior. We surveyed otter and mink signs along 250 km of Beagle Channel coastline. Habitat suitability models were constructed based on species presence/absence and habitat characteristics, using generalized linear models. Feces were collected for diet analyses. Otters used forested coasts with 12°–32° shoreline slope and without human influence, and our evidence suggests they were not affected by mink presence. Mink preferred forested and shrubland coasts with 10°–28° shoreline slope. Neither human influence nor otter presence affected mink habitat occupation, but in the presence of otters, mink left fewer signs. Otters consumed more aquatic prey than mink, and mink modified their diet in the presence of otters, consuming more exotic small terrestrial mammals and less fish as well as shifting to smaller and shallower fish species that are less consumed by otters. Mink showed more plastic, generalist behavior than otters, being more tolerant of human presence, using more habitat types and having greater diet breadth. At the same time, otters apparently affect mink adversely and could help limit their invasion in sympatric areas. Conservation and recovery of otters, therefore, may produce a secondary benefit of simultaneously reducing the effect of mink, thereby providing an additional way to control this exotic predator’s population.

Aquatic foraging is a fundamental component of the behavior of a number of small mammals, yet comprehensive observations of diving are often difficult to obtain under natural circumstances. Semiaquatic mammals, having evolved to exploit prey in both aquatic and terrestrial environments, are generally not as well adapted for diving (or for life in the water) as are fully aquatic species. Because dive ability also tends to increase with body size, small, semiaquatic mammals are presumed to have fairly limited dive ability. Nevertheless, diving plays an important role in food acquisition for many such species. We used time–depth recorders (TDRs) to measure and describe the dive performance of 9 female and 5 male free-living American mink (Neovison vison; body mass approximately 1 kg) on lowland rivers in the southern United Kingdom. We recorded dives up to 2.96 m deep (maximum depth X 5 1.82 m) and up to 57.9 s in duration (maximum duration X ¯ 5 37.2 s). Dive duration was approximately 40% of that predicted by allometry for all air-breathing diving vertebrates (as might be expected for a small, semiaquatic animal) but was twice as long as previously measured for mink in captivity. Mink performed up to 189 dives per day (X ¯ 5 35.7 dives/day), mostly during daylight, and spent a maximum of 38.4 minutes diving per day (X ¯ 5 7.6 min/day). Some individuals maintained particularly high diving rates over the coldest months, suggesting that the benefits of aquatic foraging in winter outweigh the costs of heat loss. We observed a number of very shallow dives (depth approximately 0.3 m) of particularly long duration (up to 30 s). The function of these dives is currently unknown, but possibilities include searching for prey, travelling, or avoidance of threats. There is only 1 other study of which we are aware that presents detailed measurements of dive performance in a small, shallow-diving, semiaquatic mammal.

The Upland Goose (Chloephaga picta) is a ground-nesting bird that has suffered a precipitous population decline in the last 60 years. We monitored Upland Goose nests with camera traps in S...

Following the establishment of American mink farms outside North America, the species has successfully invaded Europe and South America, and in some places, their presence demonstrably threatens native biodiversity. We surveyed for mink signs along the Andean Patagonian forest in Argentina from 38°52′ S to 54°52′ S, revealing that their range has now expanded to span 800 km of contiguous occupation on the continent including several types of wetlands and has also colonised Tierra del Fuego Island. Rate of expansion was estimated using two methodologies and varied between 5.53 and 9.00 km/year (linear method, large-scale spread) and 4.86 km/year (within a more restricted area, grid method). Diet throughout the region fitted the generalist pattern described for mink elsewhere. Native small mammals were the most frequently consumed category. Crustaceans (patchily distributed in the region) occurred in the diet in proportion to their availability (r s=0.961, p

The Southern river otter or 'huillin', Lontra provocax, is an endangered species endemic of the Andean Patagonian region of Argentina and Chile. It feeds almost exclusively on the genera of macro-crustacea: Aegla and Sammastacus. The aim of this study was to analyse the role of food availability on the huillin's distribution using a scale-dependent analysis of crustacean and otter distributions. We compared the distributions of otters and macro-crustaceans along a north-south regional gradient, between river basins of northern Patagonia, in an altitudinal gradient within a river basin, and between habitat types within a lake. We investigated the distribution of otters by sign surveys along lake shores, river banks and marine coasts, and of crustaceans using surveys in the water, undigested remains in mink (Mustela vison) scats, presence of external skeletons at the waterside and through interviews with local people. Our results show that there were heterogeneities in the distributions of macro-crustaceans at four scales and these were generally reflected in the distributions of freshwater otters. We conclude that the main factor limiting the distributions of L. provocax in freshwater environments is the availability of macro-crustaceans. This paper shows how scale-dependent type analyses of population distribution serves as a method for identifying key environmental factors for species for which the use of long-term demographies is unfeasible.

American mink Mustela vison, originally bred in fur farms, have become established in areas occupied by native endangered Southern river otter Lontra provocax, in Patagonia. In accordance with European experience, this biological invasion in South America raises questions about the interaction between invasive mink and native otter, from the viewpoints of both community assembly and conservation. We set out (1) to find which aspects of habitat structure were related to the distribution of signs of both this invasive species and Southern river otter Lontra provocax, in Argentinean Patagonia and their most common prey and (2) to test general predictions of niche partitioning between these two species. Based on surveys of 447 of 600 m transects for otter and mink scats/footprints along the waterside of lakes and rivers in the Andean Patagonian region, we compared diet composition (from scat analysis) and micro-habitat preferences (from field signs) of the two species. Otters were more specialist than mink in habitat use and diet. Mink used different habitats in other river basins where otters were absent. Where they occurred together in the basin of the Limay River, the distributions of their signs were similar, and mink diet was more similar to that of otters. There was no detectable difference in otter diet before and after mink arrival in the Limay basin. Contrary to the prediction of niche partitioning, and to the findings of European studies, resource use by mink was more similar to that of otters where the species occurred sympatrically than where they were allopatric.

Understanding processes and impacts of biological invasions is fundamental for ecology and management. Recent reviews summarized the mechanisms by which invasive species alter entire ecosystems, but quantitative assessments of these mechanisms are lacking for actual assemblages to determine their relative importance, frequency and patterns. We updated information on introduced vertebrates in the Tierra del Fuego Archipelago (TDF) via an exhaustive literature review and new data to evaluate ecosystem impact mechanisms and provide management recommendations. To date, 24 exotic vertebrates have naturalized in TDF, outnumbering natives nearly 2:1, with the North American beaver (Castor canadensis) and muskrat (Ondatra zibethica) being the most widely distributed species and also impacting the ecosystem through the greatest number of mechanisms. Introduced vertebrates occupied most parts of the archipelago with human-inhabited islands having greater taxa richness. All exotics potentially altered ecosystems by one or more mechanisms: 100% food webs, 92% invasional meltdown, 42% habitat modification, 38% disease or parasite transmission, 21% soil property and disturbance regime changes. Impact to habitat structure was the main clustering criterion for this assemblage. Within the species that physically alter habitats, we found two sub-groups: 1) large herbivores and 2) ?others? including beavers and muskrats. Species that did not alter habitat were divided further into those with predatory trophic effects (carnivorous mammals and trout, sub-group 4) and the rest with assorted impacts (sub-group 3). By establishing high quality information on archipelago-wide assemblage, distribution, impacts and mechanisms for exotic vertebrates, we recommend, based on ecological criteria, prioritizing the management of sub-group 2. A secondary priority might be given to the carnivores in sub-group 4, while species in sub-groups 1 and 3 are less urgent. As the first systematic survey of introduced fauna on an archipelago-scale, we identified knowledge gaps, such as population abundance and dynamics for specific species, which are needed to orient future work, but the notable progress made to date is highlighted. Fil: Valenzuela, Alejandro Eduardo Jorge. Administración de Parques Nacionales Argentinos; Argentina Fil: Anderson, Christopher Brian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; Argentina. Omora Sub-Antarctic Research Alliance; Estados Unidos Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Cabello, José Luís. Patagonia Wildlife Ltda.; Argentina

Understanding the demography of an invasive species is crucial to better guide managers seeking to slow the spread of the invader. Habitat differences can affect demographic rates, which may in turn impact the speed of the invasion, but this has been rarely addressed. We studied the demography of invasive North American beavers ( Castor canadensis ) in 2 contrasting habitat types of the island, forest and steppe, on Tierra del Fuego in southern Patagonia. We used repeated observations, mark-resight methods, telemetry, and camera traps to estimate colony size and demographic rates of beavers in the 2 habitats. Colony size and the number of offspring (“kits”) produced per colony per year were higher in the steppe, contrary to the belief that forest is better habitat. This may be the result of the longer time since invasion in the forests of Tierra del Fuego and that the forest subpopulation is showing density-dependent regulation. Survival of beavers was high in all age classes and was higher than survival rates recorded in North America. Our work shows that plasticity of habitat use and predator release have likely facilitated beaver invasion in Patagonia. The higher productivity and detectability of beavers in the steppe call for active management in a habitat previously assumed to be subprime. Entender la demografia de las especies invasoras es crucial para guiar a los gestores que intentan frenar la expansion de los invasores. Las diferencias en el tipo de habitat pueden afectar las tasas demograficas, lo que a su vez puede impactar en la velocidad de la invasion, pero esto ha sido raramente investigado. Estudiamos la demografia de castores norteamericanos invasores ( Castor canadensis ) en dos habitats contrastantes, bosque y estepa, en la isla de Tierra del Fuego en el sur de Patagonia. Utilizamos observaciones repetidas, metodos de marcado-reavistaje, telemetria y camaras trampa para estimar el tamano de colonia y las tasas demograficas de castores en los dos tipos de habitat. El tamano de colonia y el numero de crias producido por colonia por ano fue mayor en la estepa, contrario a la creencia de que el bosque es un mejor habitat. Creemos que este puede ser el resultado de un mayor tiempo de invasion en los bosques de Tierra del Fuego y que la subpoblacion del bosque esta mostrando regulacion denso-dependiente. La supervivencia de castores fue alta en todas las clases de edad y fue mas alta que las tasas de supervivencia registradas en Norteamerica. Nuestro trabajo muestra que la plasticidad en el uso de habitat y la ausencia de depredadores han probablemente facilitado la invasion de castores en Patagonia. La alta productividad y detectabilidad de castores en la estepa llaman a un control activo en un habitat que antes habia sido considerado suboptimo.

The Southern river otter or huillín Lontra provocax has been classified as 'endangered', with the loss of riparian forest identified as the main threat to its survival. We used new information on distribution from Argentina to define their status. There are no data on the huillin's population structure and dynamics, and no estimate of its abundance or population trends at a relevant scale. Our survey teams covered 435 locations in lakes, rivers and coastal sites using a standard and repeatable methodology of 600 m survey transects as adopted for otter surveys across Europe. We found that its present geographic range in Argentina is slightly larger than is characteristic of a species at risk of extinction at the national level, although its contemporary distribution is still radically contracted in comparison to its historical distribution. Fil: Cassini, Marcelo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Grupo de Estudios en Ecología de Mamíferos; Argentina Fil: Fasola, Laura. University of Oxford; Reino Unido Fil: Chehébar, Claudio. Administración de Parques Nacionales. Delegación Regional Patagonia; Argentina Fil: Macdonald, David W.. University of Oxford; Reino Unido

Lontra provocax is an endemic species from Patagonia that has been categorized as "endangered" by the International Union for Conservation of Nature. In this study, noninvasive molecular methods were used to investigate the genetic diversity and haplotype distribution of L. provocax in Argentinean Patagonia. We analyzed 150 scat samples collected from 1995 to 2006 and obtained 13 sequences of control region with 1 haplotype and 34 sequences of cytochrome b with 4 haplotypes. The population of the south of Patagonia (Tierra del Fuego and De los Estados Island) showed a relatively high haplotype diversity (h = 0.71) and was statistically different to the population of the north (analysis of molecular variance, F(ST) = 0.15, P = 0.018). We concluded that there are 2 different subpopulations of L. provocax that deserve conservation attention and that the southern population appears not to have suffered a human-induced population bottleneck of the sort typically experienced by various otter species around the world.

The impact of alien American mink on the native fauna of oceanic islands has been demonstrated in a number of locations. In the sub-Antarctic Cape Horn Biosphere Reserve of southern Chile the species is currently expanding in an area where the native fauna evolved in the absence of terrestrial predators. To evaluate any emerging problems we therefore investigated seasonal variation in prey use by mink on Navarino Island within the Reserve. We identified undigested remains in 414 scats collected from the shores of 27 ponds over JanuaryNovember 2006. Diet consisted mainly of mammals and birds. Mammals, including both native and exotic rodents, were the predominant prey in all seasons but birds were of equal importance during the summer (when birds breed and their abundance and diversity increases on the island). Exotic rodents were the only identifiable mammalian prey item during winter. Native wetland birds constituted a substantial proportion of mink diet, and greater than that reported in other areas. Many birds breeding on Navarino Island are ground-nesting, a strategy that evolved in the absence of native mammalian predators. Considering the international importance of this region, our results emphasize the need for an assessment of the impact of mink predation on the populations of native prey. Fil: Ibarra, Jose Tomas. Pontificia Universidad Católica de Chile; Chile Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. University of Oxford; Reino Unido Fil: Macdonald, David W.. University of Oxford; Reino Unido Fil: Ricardo, Rozzi. Universidad de Magallanes; Chile Fil: Cristián, Bonacic. Pontificia Universidad Católica de Chile; Chile