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Continental islands are often sites of low diversity and endemism, as well as important areas for the protection of bird populations, especially seabirds. On Isla Observatorio and the Año Nuevo Islands, in the Southwestern Atlantic, the latest assessment of avifauna dates from more than 20 years ago. In this study, we use a combination of methods to update the status of the main seabird colonies and the most abundant avian terrestrial predator at Observatorio and Goffré Islands during the breeding season. In only 4.5 km2, the islands would harbour ~ 90,000 breeding seabirds. Seabird colonies occupied different areas of the islands and varied in their population status, with Imperial Shags (Leucocarbo atriceps) showing an increase and Southern Giant Petrels (Macronectes giganteus) a decrease according to the last surveys. Magellanic Penguin (Spheniscus magellanicus) population estimations also suggest a decrease but the last survey was based on total, and not on occupied nest sites. We recorded and assessed one new breeding species: The globally near-threatened Striated Caracara (Phalcoboenus australis), which has an important breeding population of around 15 territorial pairs at Observatorio Island. These islands appear to be an important regional bird site and future studies would determine their trends and threats, especially those related with invasive species., SI

Marine top predators living in sympatry tend to use their environment differentially, thereby reducing niche overlap. Magellanic penguins (Spheniscus magellanicus) and gentoo penguins (Pygoscelis papua) coexist at Martillo Is., Argentina. During the 2014, 2015 and 2017 breeding seasons a total of thirty-one Magellanic and eleven gentoo penguins were equipped with GPS-TDR loggers to record foraging trips. Both species dove to similar maximum depths with analogous effort (dives per hour). Magellanics, however, undertook longer trips and travelled further away from the colony (25 h and 43 km vs. 10 h and 20 km on average, respectively). Gentoos on the other hand, performed longer dives, had a higher percentage of “U” shaped dives and spent more time during the bottom phase of the dive. Gentoos foraged exclusively within an area close to the colony and in waters not deeper than 80 m. Magellanics had more variability in their behaviors and were not associated to a specific depth or distance from the colony. The ecological circumstances of both species (targeted prey and surrounding environment) suffice to explain the particular behaviors of both species independently from the presence of the other. Gentoos seem to focus on benthic prey which remains stable in this environment throughout the year, and Magellanics behave more opportunistically searching for pelagic prey during early chick rearing. Competition may not be always shaping coexistence of species of similar trophic positions and behaviors. Particularly, if resources are not limited, both species can behave in ways they find optimal without factoring the coexistence of the other species.

Durante las últimas décadas, las poblaciones de cauquenes (Chloephaga sp.) en Argentina han disminuido drásticamente. En Bahía Franklin, Isla de los Estados, se registraron y estudiaron 21 nidos de Cauquén Común (Chloephaga picta) y 4 de Cauquén Real (Chloephaga poliocephala). Todos los nidos estaban ubicados en el suelo en sectores de pendiente muy baja. La distancia entre nidos fue de 216.6 y 973 m, su densidad de 0.10 y 0.02 nidos/ha y el tamaño promedio de puesta de 5.4 y 4.7 huevos para el Cauquén Común y el Cauquén Real, respectivamente. Los nidos estaban ubicados principalmente en el turbal graminoideo, seguido por el pastizal y el arbustal. Las plantas predominantes en las inmediaciones del nido fueron Marsippospermum grandiflorum, Poa flabellata, Empetrum rubrum y Chiliotrichum diffusum, con una altura promedio de la vegetación de 72 cm en los nidos del Cauquén Común y 97 cm en los del Cauquén Real, y una baja cobertura. Se observó una asociación espacial interespecífica, posiblemente de tipo “nidificación protectora”, entre ambos cauquenes con el Pingüino Penacho Amarillo (Eudyptes chrysocome) y el Pingüino Patagónico (Spheniscus magellanicus). En el sur de la Patagonia, los perros (Canis lupus familiaris) y el visón americano (Neovison vison), entre otras especies nativas y exóticas, están provocando consecuencias negativas para la nidificación de los cauquenes. La Isla de los Estados aún no ha sido colonizada por estos predadores, lo que la hace un sitio de importancia para la reproducción y conservación de estas aves amenazadas. During the last decades wild geese (Chloephaga sp.) populations in Argentina have decreased dramatically. We recorded and studied 21 nests from the Upland Goose (Chloephaga picta) and 4 from the Ashy-headed Goose (Chloephaga poliocephala) in Bahía Franklin, Staten Island. All the nests were located on the ground in low slope areas. Distances between nests were 216.6 and 973 m, nest densities were 0.10 and 0.02 nests/ha, and clutch size was 5.4 and 4.7 eggs for the Upland Goose and the Ashyheaded Goose, respectively. Nests were located mainly on the graminoid bog, followed by grasslands and shrubby areas. Predominant plants near the nest were Marsippospermum grandiflorum, Poa flabellata, Empetrum rubrum and Chiliotrichum diffusum, with an average vegetation height of 72 cm for nests of the Upland Goose and 97 cm for nests of the Ashy-headed Goose, and low cover. We observed an interspecific spatial association between both species and the Rockhopper Penguin (Eudyptes chrysocome) and the Magellanic Penguin (Spheniscus magellanicus), possibly from the type “protective nesting”. In southern Patagonia dogs (Canis lupus familiaris) and the American mink (Neovison vison), among other native and exotic predators, have negative consequences for the nesting geese. Staten Island has not been yet colonized by these predators, thus highlighting the relevance of this site for the reproduction and conservation of these endangered species.

Human-wildlife dynamics exhibit novel characteristics in the Anthropocene, given the unprecedented degree of globalization that has increased the linkages between habitats and people across space and time. This is largely caused by transnational mobility and migration, international labor, resource markets, and trade. Understanding the relationship between humans and wildlife, and their associated telecoupling processes, helps to promote better management practices and governance for reconciling socioeconomic and conservation interests. Even remote places on the globe exhibit these features. For example, in southern Patagonia’s coastal and marine ecosystems, seabirds are not only very abundant and charismatic members of the wildlife community, nowadays, their colonies are a main tourism attraction of global significance, and in the past they were used for consumptive and scientific purposes that also linked the “uttermost ends of the Earth” with distant places. Thus, in this study, we review human-seabird interactions in the iconic Beagle Channel (BC) in the Argentine portion of the Tierra del Fuego Archipelago. We adapted and employed the coupled human and natural systems (CHANS) approach and telecoupling framework to integrate disparate social and biological information and obtain a more holistic understanding of current human-seabird dynamics and trends in the BC. Although our assessment includes the temporal scale of human-seabird relationships, we centered the CHANS and telecoupling analysis on the modern seabird-tourism interaction, focused on the channel’s Argentine sector, in which tourism is most intensively developed. Our synthesis of the BC’s telecoupled CHANS allowed us to recognize the strong historical local-to-global interactions between both human and natural subsystems and the sharp increase in distance telecoupling during the 20th century. Despite this globalizing trend in seabirds connecting the BC’s local ecosystems to distant places, ironically we found few linkages between Argentina and Chile, despite both countries sharing political sovereignty over this single biogeographical unit. Recognizing and studying the telecouplings identified in this study would help multilateral efforts to incorporate the spillover systems (especially with Chile) and sending systems (i.e., transnational tourists’ countries of origin) into extant regional policies (e.g., state protected areas) and global initiatives (e.g., the United Nations’ sustainable development goals). It would also enable more informed decisions regarding specific proposals based on market-based incentives (e.g., payment for ecosystem services), certification schemes (e.g., Distintivo Onashaga) and participatory approaches (e.g., comanagement of natural resources with local communities). Integrating these scales into the management of the BC would help ensure that humans continue to enjoy meaningful relationships with this unique and charismatic wildlife and at the same time reinforce responsible tourism as a local-global strategy for sustainable development and global conservation. Fil: Raya Rey, Andrea Nélida. Universidad Nacional de Tierra del Fuego, Argentina. Instituto de Ciencias Polares, Ambiente y Recursos Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Pizarro Pinochet, Jose Cristobal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad de Concepción; Chile Fil: Anderson, Christopher Brian. Universidad Nacional de Tierra del Fuego, Argentina. Instituto de Ciencias Polares, Ambiente y Recursos Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Huettmann, Falk. University Of Alaska; Estados Unidos

Durante las últimas décadas, las poblaciones de cauquenes (Chloephaga sp.) en Argentina han disminuido drásticamente. En Bahía Franklin, Isla de los Estados, se registraron y estudiaron 21 nidos de Cauquén Común (Chloephaga picta) y 4 de Cauquén Real (Chloephaga poliocephala). Todos los nidos estaban ubicados en el suelo en sectores de pendiente muy baja. La distancia entre nidos fue de 216.6 y 973 m, su densidad de 0.10 y 0.02 nidos/ha y el tamaño promedio de puesta de 5.4 y 4.7 huevos para el Cauquén Común y el Cauquén Real, respectivamente. Los nidos estaban ubicados principalmente en el turbal graminoideo, seguido por el pastizal y el arbustal. Las plantas predominantes en las inmediaciones del nido fueron Marsippospermum grandiflorum, Poa flabellata, Empetrum rubrum y Chiliotrichum diffusum, con una altura promedio de la vegetación de 72 cm en los nidos del Cauquén Común y 97 cm en los del Cauquén Real, y una baja cobertura. Se observó una asociación espacial interespecífica, posiblemente de tipo “nidificación protectora”, entre ambos cauquenes con el Pingüino Penacho Amarillo (Eudyptes chrysocome) y el Pingüino Patagónico (Spheniscus magellanicus). En el sur de la Patagonia, los perros (Canis lupus familiaris) y el visón americano (Neovison vison), entre otras especies nativas y exóticas, están provocando consecuencias negativas para la nidificación de los cauquenes. La Isla de los Estados aún no ha sido colonizada por estos predadores, lo que la hace un sitio de importancia para la reproducción y conservación de estas aves amenazadas. During the last decades wild geese (Chloephaga sp.) populations in Argentina have decreased dramatically. We recorded and studied 21 nests from the Upland Goose (Chloephaga picta) and 4 from the Ashy-headed Goose (Chloephaga poliocephala) in Bahía Franklin, Staten Island. All the nests were located on the ground in low slope areas. Distances between nests were 216.6 and 973 m, nest densities were 0.10 and 0.02 nests/ha, and clutch size was 5.4 and 4.7 eggs for the Upland Goose and the Ashyheaded Goose, respectively. Nests were located mainly on the graminoid bog, followed by grasslands and shrubby areas. Predominant plants near the nest were Marsippospermum grandiflorum, Poa flabellata, Empetrum rubrum and Chiliotrichum diffusum, with an average vegetation height of 72 cm for nests of the Upland Goose and 97 cm for nests of the Ashy-headed Goose, and low cover. We observed an interspecific spatial association between both species and the Rockhopper Penguin (Eudyptes chrysocome) and the Magellanic Penguin (Spheniscus magellanicus), possibly from the type “protective nesting”. In southern Patagonia dogs (Canis lupus familiaris) and the American mink (Neovison vison), among other native and exotic predators, have negative consequences for the nesting geese. Staten Island has not been yet colonized by these predators, thus highlighting the relevance of this site for the reproduction and conservation of these endangered species. Fil: Petracci, Pablo. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina Fil: Saenz Samaniego, Ricardo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; Argentina Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; Argentina

En este estudio se estimó la duración de los viajes de alimentación y el tamaño corporal de machos y hembras del Pingüino Patagónico durante el período reproductivo en una colonia del Canal Beagle, Tierra del Fuego, y se determinaron las implicancias de estos parámetros sobre el éxito reproductivo y la calidad de la nidada. La duración de los viajes difirió significativamente entre sexos y entre las distintas etapas reproductivas. Las hembras realizaron viajes más extensos que los machos durante la etapa de incubación. Esto podría deberse a diferencias en las reservas corporales y en capacidades de alimentación relacionadas con su condición corporal. En ambos sexos, los viajes realizados durante la etapa de incubación fueron más prolongados, mientras que los realizados durante el cuidado temprano de pichones fueron más cortos. Los viajes de alimentación tuvieron menor duración cuando los pichones eran más pequeños y necesitaban de un mayor cuidado parental. Se registró un alto valor de éxito reproductivo (1.51 pichones por nido) comparado con el de colonias de las Islas Malvinas y Punta Tombo. Estos resultados podrían explicarse por diferencias en la disponibilidad de alimento en aguas cercanas a la colonia. El tamaño corporal de los padres no se relacionó con el éxito reproductivo. No obstante, las hembras con mayor tamaño corporal produjeron pichones de mayor tamaño al comienzo de la muda y nidadas de mayor calidad. La correlación positiva entre el tamaño de la hembra y el tamaño de los pichones al comienzo de la muda sugiere un aporte importante de las hembras en el desarrollo del pichón. The aim of this work was to study foraging trip duration and body size of male and female Magellanic Penguins during the breeding season and to determine the association of these parameters with both reproductive success and clutch quality in a colony located in the Beagle Channel, Tierra del Fuego. Trip duration differed significantly between sexes and between breeding stages. Females performed longer trips than males during incubation. We suggest that this could be due to differences in body reserves and foraging capabilities related with their body condition. In both sexes, foraging trips during incubation were longer than in the other stages, while the shortest trips were observed during early chick rearing. Trips were shorter when chicks were smaller and required greater parental care. A high value of reproductive success (1.51 chicks per nest) was recorded in comparison to that observed in colonies from the Malvinas Islands and Punta Tombo. These results could be related to differences in food availability in nearby waters. Body size of parents was not associated with reproductive success. Notwithstanding, larger females produced larger chicks at early moult and clutches of higher quality. The correlation between female body size and chick size at early moult suggests an important contribution of females on chick’s development.