Telecoupling analysis of the Patagonian Shelf: a new approach to study global seabird-fisheries interactions to achieve sustainability

The Southwest Atlantic Ocean, particularly the extended Patagonian Shelf, constitutes a complex, globally-relevant ecosystem. It is a highly productive area, and it maintains a high diversity and abundance of seabird species. At the same time, the Patagonian Shelf experiences pressues, such as fisheries that have been identified as a main stressor for marine ecosystems worldwide, including being a principal cause of seabird population declines. Using the telecoupling framework - which incorporates natural and socioeconomic interactions over large distances - we present here a holistic look at the dynamics of threatened seabird- fisheries interactions for the Patagonian Shelf over space and time. Based on the best-available public data for seabird presence, we used machine learning and geographic information systems to model-predict the at-sea distribution of seabirds. Then, maps were overlaid with fisheries distributions to show spatial correlation and hotspots for co-occurrence between seabirds and fisheries. We found that even this remote corner of the Atlantic Ocean is globally connected to XXX nations and XXX other outside-stakeholders through fisheries. By identifying and characterizing the systems, flows, agents, causes and effects involved in this telecoupling process, we highlighted specific complexities, bottlenecks and sensitivities that must still be addressed to achieve both biodiversity conservation and management as well as fisheries sustainability not only in this study area, but worldwide.Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; ArgentinaFil: Huettmann, Falk. University of Alaska; Estados Unido

Even at the uttermost ends of the Earth: how seabirds telecouple the Beagle Channel with regional and global processes that affect environmental conservation and socio-ecological sustainability

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; ArgentinaFil: Pizarro Pinochet, Jose Cristobal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad de Concepción; ChileFil: 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; ArgentinaFil: Huettmann, Falk. University Of Alaska; Estados Unido

Seasonally persistent foraging niche segregation between sympatric Southern Rockhopper and Magellanic penguins breeding at Isla de los Estados, Argentina

Variation in the foraging strategies used among species is a key factor in determining the trophic structure of ecological communities. Moreover, foraging niche differentiation could be driven by inter-specific competition and/or variation within species due to seasonal, age, sex and/or individual factors. Using stable isotope analysis, we assessed inter- and intra-specific differences in the foraging niches of female Southern Rockhopper penguin (Eudyptes chrysocome; SRP) and male and female Magellanic penguins (Spheniscus magellanicus; MP) at Isla de los Estados, Argentina. We sampled whole blood and feathers from breeding adults, representing the breeding and pre-moult periods over two consecutive years (2012 and 2013). We also compared stable isotope values between tissue to test for consistency in individuals foraging niches and the potential for foraging niche specialisation and segregation within breeding pairs. We observed clear foraging niche segregation between species that persisted during both breeding and pre-moult periods. SRP foraged in more oceanic/pelagic waters (lower δ13C values) while MP used coastal/benthic foraging habitats (higher δ13C values). In addition, SRP fed on lower trophic level prey (low δ15N values) relative to MP during both time periods. The isotopic foraging niches of MP highly overlapped between sexes at the population level and there was little to no evidence of niche segregation within breeding pairs or individual consistency in the seasonal foraging niche of both species. The results suggest that inter-specific foraging niche segregation is likely a more important factor influencing the trophic ecology and foraging behaviours of these species, relative to intra-specific factors. Even so, the persistence of inter-specific foraging niche segregation outside the breeding season suggests that either the potential for competition for food resource or foraging habitats remain high during this time or that the ultimate factors responsible for foraging niche segregation among these two species may be unrelated to these proximate factors.Fil: Rosciano, Natalia Gimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Polito, Michael J. Lousiana State University; Estados UnidosFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; Argentin

Factors affecting reproductive success and clutch quality of Magellanic Penguin (Spheniscus Magellanicus) in the Beagle Channel, 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.Fil: Scioscia, Gabriela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Favero, Marco. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Schiavini, Adrian Carlos Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Wildlife Conservation Society; Estados Unido

Where’s the best supermarket deal? Female Southern Rockhopper Penguins (Eudyptes chrysocome) show variable foraging areas during the guard stage at Isla de los Estados, Argentina

Understanding the spatial distribution of seabirds contributes to comprehending their ecological requirements and dispersion patterns. We studied the at-sea distribution of female Southern Rockhopper Penguins (Eudyptes chrysocome (J.R. Forster, 1781)) at Isla de los Estados colony during the early chick-rearing period. We used a clustering analysis approach to identify different groups according to the foraging trip (tracking and diving data from GPS and temperature and depth data loggers) and diet (d15N composition on blood samples) characteristics. Foraging trips differed in duration, location, and dive depths explored. Females in clusters 1 and 3 traveled longer distances and in opposite directions (36.3 6 21.3 and 40.3 6 14.0 km, respectively). Females in cluster 2 fed closer to the colony (16.8 6 7.8 km). Dives occurred in pelagic habitats. Higher d15N values suggested a greater proportion of fish (e.g., the Fuegian sprat, Sprattus fuegensis (Jenyns, 1842)) consumption in the northern foraging areas (cluster 1). The variability observed in the spatial distribution suggests flexibility in the foraging behavior of Southern Rockhopper Penguins and availability of adequate foraging areas within the colony range during the early chick-rearing period, both important features for Southern Rockhopper Penguin population. These results contribute to understanding the use of the Southern Ocean by marine mesopredators and top predators and to the marine spatial planning in the area.Fil: Rosciano, Natalia Gimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Pütz, Klemens. Antarctic Research Trust; AlemaniaFil: Polito, Michael J.. State University of Louisiana; Estados UnidosFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; Argentina. Wildlife Conservation Society; Estados Unido

Colony attendance patterns of Magellanic Penguin (Spheniscus magellanicus) at Isla Martillo, Beagle Channel, Tierra del Fuego: guidelines to minimize human disturbance

En este trabajo se analizó el patrón de actividad de la colonia de Pingüino de Magallanes (Spheniscus magellanicus) en Isla Martillo, Tierra del Fuego, Argentina. Se determinó la variación temporal en el patrón general de ingresos y egresos de animales a la colonia durante las distintas etapas del ciclo reproductivo y se estimó el porcentaje de individuos en el mar. La distribución de frecuencias de individuos ingresando y egresando de la colonia difirió entre los distintos momentos del día, tanto entre las etapas del ciclo reproductivo como en cada una de ellas. Esta variación indicaría un patrón horario dinámico del flujo de animales. No obstante, se encontró un horario en el cual la actividad es mínima en la colonia. Asimismo, se observaron diferencias con otras colonias en los horarios de mayor actividad. A partir de estos resultados, se recomienda que el manejo turístico deba ser sitio-específico, y que los avistajes sin desembarco y las visitas guiadas se realicen entre las 10:00 y las 17:00 h a fin de minimizar los disturbios en horarios de mayor actividad para los pingüinos en la Isla Martillo. en el patrón general de ingresos y egresos de animales a la colonia durante las distintas etapas del ciclo reproductivo y se estimó el porcentaje de individuos en el mar. La distribución de frecuencias de individuos ingresando y egresando de la colonia difirió entre los distintos momentos del día, tanto entre las etapas del ciclo reproductivo como en cada una de ellas. Esta variación indicaría un patrón horario dinámico del flujo de animales. No obstante, se encontró un horario en el cual la actividad es mínima en la colonia. Asimismo, se observaron diferencias con otras colonias en los horarios de mayor actividad. A partir de estos resultados, se recomienda que el manejo turístico deba ser sitio-específico, y que los avistajes sin desembarco y las visitas guiadas se realicen entre las 10:00 y las 17:00 h a fin de minimizar los disturbios en horarios de mayor actividad para los pingüinos en la Isla Martillo.The aim of this study was to analyze the daily activity pattern in Magellanic Penguins (Spheniscus magellanicus) at Isla Martillo, Tierra del Fuego, Argentina. Departure and arrival times were evaluated throughout the breeding cycle and the frequency distribution of penguins at sea estimated. The frequency distribution of arrival and departure times between the three different stages and within each stage varied throughout the day. This variation indicated a dynamic pattern for both activities. Nevertheless, a range time with lower activity was found for the colony. Furthermore, differences on peak activities with other colonies were noted. Given these results we suggest that tourist management should be site-specific, and recommend that bird-watching and guided visits take place from 10:00 to 17:00 h in order to minimize disturbance during the peak activities of penguins at Martillo Island.Fil: Scioscia, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Favero, Marco. 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; ArgentinaFil: Schiavini, Adrian Carlos Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Wildlife Conservation Society; Estados Unido

Inter-annual variation in the trophic niche of Magellanic penguins Spheniscus magellanicus during the pre-molt period in the Beagle Channel

Inter-annual variations in the diets of seabirds are often a reflection of resource availability, with population dynamics and community structure implications. We investigated the trophic niche of Magellanic penguins Spheniscus magellanicus during the pre-molt stage in 6 years (2009 and 2013−2017) at Martillo Island, Beagle Channel, Argentina, using carbon and nitrogen stable isotope analysis of feathers. We found higher values in 2009 compared to the other years for both isotopes and estimated different proportions of prey in the diet of Magellanic penguins throughout the years. In 2009, penguins consumed mainly a mixture of benthic and benthopelagic fish, whereas from 2013 to 2017, the proportion of the pelagic form of squat lobster Munida gregaria, considered a key species in the Beagle Channel, increased over time and nearly dominated diets in 2017. Our results confirm that Magellanic penguins act as sentinels, reflecting shifts in the marine community of the Beagle Channel via inter-annual variation in their trophic niche and diet composition.Fil: Dodino, Samanta Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Riccialdelli, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Polito, M.J.. State University of Louisiana; Estados UnidosFil: Pütz, K.. Antartic Research Trust; AlemaniaFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; Argentin

Reproductive aspects and habitat use by Upland Goose (Chloephaga picta) and ashyheaded Goose (Chloephaga poliocephala) in Staten Island, Argentina

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; ArgentinaFil: Saenz Samaniego, Ricardo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; ArgentinaFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; Argentin

The dynamic trophic niche of an island bird of prey

Optimal foraging theory predicts an inverse relationship between the availability of preferred prey and niche width in animals. Moreover, when individuals within a population have identical prey preferences and preferred prey is scarce, a nested pattern of trophic niche is expected if opportunistic and selective individuals can be identified. Here, we examined intraspecific variation in the trophic niche of a resident population of striated caracara (Phalcoboenus australis) on Isla de los Estados (Staten Island), Argentina, using pellet and stable isotope analyses. While this raptor specializes on seabird prey, we assessed this population's potential to forage on terrestrial prey, especially invasive herbivores as carrion, when seabirds are less accessible. We found that the isotopic niche of this species varies with season, age, breeding status, and, to a lesser extent, year. Our results were in general consistent with classic predictions of the optimal foraging theory, but we also explore other possible explanations for the observed pattern. Isotopic niche was broader for groups identified a priori as opportunistic (i.e., nonbreeding adults during the breeding season and the whole population during the nonbreeding season) than it was for individuals identified a priori as selective. Results suggested that terrestrial input was relatively low, and invasive mammals accounted for no more than 5% of the input. The seasonal pulse of rockhopper penguins likely interacts with caracara's reproductive status by constraining the spatial scale on which individuals forage. Niche expansion in spatially flexible individuals did not reflect an increase in terrestrial prey input; rather, it may be driven by a greater variation in the types of marine prey items consumed.Fil: Balza, Ulises. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lois, Nicolás Alejandro. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; 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; ArgentinaFil: Polito, Michael J.. State University of Louisiana; Estados UnidosFil: Pütz, Klemens. Antarctic Research Trust; AlemaniaFil: Salom, Amira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Wildlife Conservation Society; Estados Unidos. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; Argentin

Population Trends of a Mixed-Species Colony of Humboldt and Magellanic Penguins in Southern Chile after Establishing a Protected Area

Worldwide marine protected areas (MPAs) have been designated to protect marine resources, including top predators such as seabirds. There is no conclusive information on whether protected areas can improve population trends of seabirds when these are further exploited as tourist attractions, an activity that has increased in past decades. Humboldt Penguins (Spheniscus humboldti) and Magellanic Penguins (S. magellanicus) breed sympatrically on Puñihuil Islets, two small coastal islands off the west coast of Chiloé Island (41° S) in southern Chile that are subject to exploitation for tourism. Our goal was to compare the population size of the mixed colony of Humboldt and Magellanic Penguins before and after protection from unregulated tourism and freely roaming goats in 1997. For this purpose, two censuses were conducted in 2004 and 2008, and the numbers compared with those obtained in 1997 by other authors. The proportion of occupied, unoccupied, and collapsed/flooded burrows changed between years; there were 68% and 34% fewer collapsed burrows in 2004 and 2008, respectively, than in 1997. For the total number of burrows of both species, we counted 48% and 63% more burrows in 2004 and 2008, respectively, than in 1997. We counted 13% more burrows of Humboldt Penguins in 2008 than in 1997, and for Magellanic Penguins, we estimated a 64% increase in burrows in 2008. Presumably, this was as a result of habitat improvement attributable to the exclusion of tourists and the removal of goats from the islets. Although tourist visits to the islets are prohibited, tourism activities around the colonies are prevalent and need to be taken into account to promote appropriate management