Presencia y abundancia de aves acuáticas en la Meseta Strobel, Patagonia, Argentina

La meseta Strobel, ubicada en la estepa patagónica, alberga más de 1500 lagunas que son utilizadas regularmente por aves acuáticas, incluyendo una de las principales poblaciones reproductivas del Macá Tobiano (Podiceps gallardoi), una especie endémica de la Patagonia austral. Se registró la presencia y abundancia de aves acuáticas en 41 lagunas, cubriendo el amplio espectro de la variabilidad ambiental de la región. Se llevaron a cabo seis campañas de campo desde fines de primavera a principios de otoño en el período 2004–2006. Se registraron un total de 18 especies de aves acuáticas correspondientes a cinco familias. La familia Anatidae fue la más representada con 12 especies, constituyendo el 85% de las aves acuáticas observadas. La distribución de las aves entre las lagunas fue variable, desde un 2.4% de lagunas ocupadas por el Falaropo Común (Steganopus tricolor) y el Pato Zambullidor Grande (Oxyura jamaicensis) hasta un 80% ocupadas por el Cisne Cuello Negro (Cygnus melanocorypha), y la abundancia varió mucho entre especies y estaciones. El Macá Tobiano, en particular, fue observado en 14 lagunas (1–81 individuos). Seis especies fueron detectadas reproduciéndose en la meseta: el Macá Tobiano, el Macá Plateado (Podiceps occipitalis), el Quetro Volador (Tachyeres patachonicus), el Pato Crestón (Anas specularioides), el Cauquén Común (Chloephaga picta) y la Gallareta Chica (Fulica leucoptera). El Macá Tobiano nidificó en cuatro lagunas, tres de las cuales no habían sido reportadas previamente como sitio de reproducción. Los resultados evidencian la necesidad de generar estudios futuros basados en la dinámica de uso de las lagunas para determinar adecuadamente la importancia de la meseta Strobel como hábitat para la avifauna acuática.The Strobel Plateau is a conspicuous and representative basaltic plateau (“meseta”) in the Patagonian steppe, Argentina. This plateau is dotted with more than 1500 shallow lakes, which are regularly used by waterbirds and support one of the main breeding populations of the near threatened Hooded Grebe (Podiceps gallardoi). We collected data on bird presence and abundance in 41 shallow lakes, covering a wide spectrum of the wetland environmental variability found in the area. We conducted six surveys from spring to fall between 2004 and 2006. We recorded a total of 18 waterbird species, which represent 5 different families. Anatidae was the family most represented with 12 species, accounting for 85% of the observed waterbirds. Waterbird distribution among lakes was variable, from 2.4% occupied lakes for Wilson’s Phalarope (Steganopus tricolor) and Andean Ruddy-Duck (Oxyura jamaicensis) to 80% for Black-necked Swan (Cygnus melanocorypha), and abundance varied greatly both between species and seasons. The Hooded Grebe, in particular, was recorded in 14 lakes (1–81 individuals). Six species were detected breeding in the area: Hooded Grebe, Silvery Grebe (Podiceps occipitalis), Flying Steamer-Duck (Tachyeres patachonicus), Crested Duck (Anas specularioides), Upland Goose (Chloephaga picta), and White-winged Coot (Fulica leucoptera). The Hooded Grebe nested at four lakes, three of them not previously known to hold breeding birds. Results point to the need of further studies on the dynamic nature of waterbird lake use to adequately assess the importance of the Strobel Plateau as waterbird habitat.Fil: Lancelotti, Julio Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Marquez, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados UnidosFil: Pascual, Miguel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentin

Population regulation in Magellanic penguins: what determines changes in colony size?

Seabirds are often studied at individual colonies, but the confounding effects of emigration and mortality processes in open populations may lead to inappropriate conclusions on the mechanisms underlying population changes. Magellanic penguin (Spheniscus magellanicus) colonies of variable population sizes are distributed along the Argentine coastline. In recent decades, several population and distributional changes have occurred, with some colonies declining and others newly established or increasing. We integrated data of eight colonies scattered along ~600 km in Northern Patagonia (from 41°26´S, 65°01´W to 45°11´S, 66°30´W, Rio Negro and Chubut provinces) and conducted analysis in terms of their growth rates, production of young and of the dependence of those vital rates on colony age, size, and location. We contrasted population trends estimated from abundance data with those derived from population modeling to understand if observed growth rates were attainable under closed population scenarios. Population trends were inversely related to colony size, suggesting a density dependent growth pattern. All colonies located in the north — which were established during the last decades — increased at high rates, with the smallest, recently established colonies growing at the fastest rate. In central-southern Chubut, where colonies are the oldest, the largest breeding aggregations declined, but smaller colonies remained relatively stable. Results provided strong evidence that dispersal played a major role in driving local trends. Breeding success was higher in northern colonies, likely mediated by favorable oceanographic conditions. However, mean foraging distance and body condition of chicks at fledging were influenced by colony size. Recruitment of penguins in the northern area may have been triggered by a combination of density dependence, likely exacerbated by less favorable oceanographic conditions in the southern sector. Our results reaffirm the idea that individual colony trends do not provide confident indicators of population health, highlighting the need to redefine the scale for the study of population changes.Fil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Garcia Borboroglu, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Global Penguin Society. Washington; Estados Unidos. University of Washington; Estados UnidosFil: Boersma, P. Dee. Global Penguin Society. Washington; Estados Unidos. University of Washington; Estados UnidosFil: Pascual, Miguel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia; Argentin

Fishless shallow lakes of Southern Patagonia as habitat for waterbirds at the onset of trout aquaculture

1. The Strobel Meseta, a basaltic plateau of Patagonia (Santa Cruz Province, Argentina), holds thousands of shallow fishless lakes that are prime habitat for many species of waterbirds, including some considered 'near threatened'. In recent years, several lakes have been stocked with trout which has created uncertainty about the potential effects on the recipient ecosystem. 2. Limnological and topographical analyses were performed in a group of 32 lakes of the Strobel Meseta in order to characterize and classify individual lakes of the meseta based on their limnological and topographic features, analyze the association between lake type and use by aquatic birds in general and by the endemic hooded grebe (Podiceps gallardoi) in particular, and evaluate the overlap between trout aquaculture and critical habitat for waterbirds. 3. The lakes were classified by multivariate analyses into four characteristic types: Turbid, high conductivity lakes (T), small vegetated lakes (SV) and larger lakes which were subdivided into either vegetated (LV) or unvegetated (LU). In general, macrophyte cover was the main classificatory variable, whereas conductivity, pH, surface, and depth contributed moderately. Large vegetated lakes were generally found to be important for waterbirds and provided critical habitat for the hooded grebe, whereas trout farmers largely favoured largeunvegetated lakes. However, since some large vegetated lakes have already been stocked, there is some level of geographical overlap between waterbird habitat and trout farming. 4. The existence of some level of spatial segregation between production and critical waterbird habitat affords opportunities for designing a spatially-based management system for trout aquaculture.Fil: Lancelotti, Julio Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; ArgentinaFil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados UnidosFil: Dieguez, Maria del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Pascual, Miguel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentin

Nest site selection of the Kelp gull (Larus dominicanus) in the Beagle Channel, Tierra del Fuego, Argentina

Nest site selection of Kelp gulls Larus dominicanus breeding in Conejo and Bridges islands, Tierra del Fuego, Argentina, was assessed between 14 and 30 December 2005 to describe variability in nest site features and determine variables affecting nest choice. Fourteen microhabitat variables were quantified at 40 nest sites and at 40 random points in each island during the late incubation stage. Nests at the two colonies were placed on different kinds of substrates across areas with varying degrees of cover provided either by rocks or vegetation. Despite the variability observed in nest site features, rock cover and rocky substrates were the main factors determining nest site selection. At Conejo Island, nest sites presented more rock cover, less percentage of vegetation cover and of vegetation debris substrate, and were placed further from the nearest vegetation in comparison to random points. Similarly, gulls at Bridges Island selected nest sites with more rock cover which were placed mainly on rocky and vegetation substrates. This contrasts with results previously obtained in Argentina, which indicated that vegetation is a key factor influencing Kelp gull nest site selection. Over 80% of the nests at both study colonies were placed on the northern slopes of the islands, relatively more protected from the strong prevailing southwest winds, and nests at both colonies tended to be more protected on their southern side either by rocks or vegetation. Results obtained at Tierra del Fuego confirm the plasticity of microhabitat use by Kelp gulls, and their ability to take advantage of nesting sites according to availability and local environmental factors.Fil: Suarez, Nicolas Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Yorio, Pablo Martin. Wildlife Conservation Society; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Breeding range expansion and population distribution shifts of Magellanic Penguins in northern Patagonia, Argentina

Understanding changes in seabird distribution and abundance is fundamental to effectively direct conservation and management strategies. Magellanic penguins (Spheniscus magellanicus) have 66 breeding colonies distributed along 4000 km of coastline in Patagonia, Argentina, with a global population of 1.2-1.6 million pairs. We updated the distribution pattern and estimated colony size and trends at the stronghold of the global population, located along the northernmost Atlantic breeding range. In this 1,000 km sector, we censused 28 colonies that total 628,000 pairs, representing 42% of the extant colonies and 57% of the global population. Colony sizes were highly variable, from 31 breeding pairs in Isla Vernaci Sudoeste (45°S) to 199,140 in Estancia San Lorenzo (42°S). Mean and maximum density (active nests/100m2) were variable among colonies, but the highest values were found in northern Chubut (Estancia San Lorenzo, dmax = 83) and the lowest in golfo San Jorge, southern Chubut (Isla Tovita, dmax = 7). Colony growth rates were variable, but virtually all colonies located in the northernmost area (Rio Negro and northern Chubut) continued showing consistently high rates, while in central and southern Chubut colonies declined or remained relatively stable. Estancia San Lorenzo became the largest colony known for the species, exceeding Punta Tombo (42°) by approximately 60,000 pairs. Recently, new colonies expanded the species breeding distribution range; Punta Pozos (41°S) in 2014 and Bahía San Antonio (40°S) in 2018.The northward redistribution of the metapopulation is generating new conservation and management challenges, particularly related to tourism development.Fil: Garcia Borboroglu, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Global Penguin Society; Estados Unidos. University of Washington; Estados UnidosFil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Wildlife Conservation Society; Estados Unidos10th International Penguin ConferenceDunedinNueva ZelandaUniversity of OtagoGlobal Penguin Societ

Population trends of Imperial Cormorants (Leucocarbo atriceps) in northern coastal Argentine Patagonia over 26 years

Monitoring programmes are essential for detecting population changes, but data series are difficult to sustain over time. Additionally, wide-scale monitoring is needed to adequately interpret demographic behaviour given the metapopulation dynamics characteristics ofmost seabird species and to understand the underlying factors, such as anthropogenic pressures and climate change. Many cormorant species are largely dependent on coastal marine environments, which are subject to increasing pressures from human activities. Here, we update information on the distribution and size of Imperial Cormorant (Leucocarbo atriceps) colonies along 1,000 km of coastline in Argentina, and review published information to assess population trends at different spatial scales over 26 years (1990-2016). During 2016, the number of nests per colony ranged between 2 and 5,617 (median: 441 nests; n = 26). Total number of breeding pairs was estimated at 21,482. During the study period, two new locations were colonised, whilst another two were abandoned. Significant growth rates ranged from 1.022 to 1.117 (median: 1.036; n = 6) for increasing colonies and from 0.580 to 0.977 (median: 0.962; n = 8) for declining colonies, but the overall breeding population remained stable between 1990 and 2016 (λ = 1.000, C.I. 95% = 0.991-1.008). Our study provides one of the longest time series on seabird breeding numbers along a wide coastal sector in South America. Given the high yearly variability in nest numbers at individual Imperial Cormorant colonies, as well as the observed establishment and extinction of colonies, large scale and long term monitoring is necessary for a comprehensive understanding of overall changes in the population distribution patterns.Fil: Yorio, Pablo Martin. Wildlife Conservation Society Argentina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Pozzi, Luciana Melina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Herrera, Gonzalo. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Punta, Gabriel. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Secretaría de Pesca de la Provincia del Chubut; ArgentinaFil: Svagelj, Walter Sergio. Universidad Nacional de Mar del Plata; ArgentinaFil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentin

Population distribution shifts of Magellanic Penguins in northern Patagonia, Argentina: Implications for conservation and management strategies

Wildlife populations are dynamic and changes in their spatial distribution and/or abundance at different locations may potentially change the scenarios under which conservation efforts should be allocated. To maximize success in management and/or conservation actions, regular monitoring and dynamic frameworks to re-adapt strategies are needed. Fluctuations in the size of penguin populations and shifts in the distribution pattern may reflect the combination of natural and anthropogenic alterations in their marine and coastal habitats where they forage and breed, respectively. This study updates information on the breeding distribution of Magellanic penguin (Spheniscus magellanicus) and their abundance along 1,200 km of coastline along its northernmost Atlantic breeding range, allowing to assess population trends at the colony level and to compare the status of the overall population at the regional scale. A total population of 643,070 pairs was estimated at 30 colonies, most of which were located on islands (70%). Colony size was highly variable, from 3 to 204,416 breeding pairs. Results show a clear northward redistribution with new recent settlements expanding the breeding range by 1° latitude. The overall breeding population in this coastal sector increased by about 19.7% (CI 10.7%–29.72%) from the mid-1990s to the 2015–2017 period. Growth rates varied among coastal sectors, but most colonies in the northernmost area (Rio Negro and northern Chubut) had consistently high rates of increase, while colonies in central and southern Chubut declined or remained relatively stable. Our results reflect the status of Magellanic penguins for over half of their global population and show considerable changes in their breeding distribution in a relatively short time. This dynamic scenario generates new conservation challenges, highlighting the importance of long-term monitoring and the need for coordination between resource managers of the different jurisdictions where Magellanic penguins breed.Fil: Garcia Borboroglu, Jorge Pablo. University of Washington; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Pozzi, Luciana Melina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Parma, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Dell'arciprete, Olga Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentin

Pinguino de Magallanes (Spheniscus magellanicus)

El magallánico es un pingüino de tamaño mediano. La longitud corporal, desde la punta del pico a la uña del dedo medio extendido, es de 48 centímetros (± 0,5 cm, n = 59); dependiendo de la temporada, la masa corporal varía entre un mínimo de 1,8 kilogramos cerca de la inanición, y unos 6 kilogramos al inicio de la muda. El mayor peso registrado fue de 8,6 kilogramos (n = 28.493) (Boersma, datos no publ.). Los machos son generalmente más grandes, con picos más anchos y cloacas más pequeñas que las hembras (Scolaro et al. 1983; Boersma y Davies 1987; Gandini et al. 1992). Para más detalles.Fil: Boersma Dee, P.. University of Washington; Estados UnidosFil: Garcia Borboroglu, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Frere, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; ArgentinaFil: Kane, Olivia. University of Washington; Estados UnidosFil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Putz, Klemens. Antarctic Research Trust; AlemaniaFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Rebstock, Ginger A.. University of Washington; Estados UnidosFil: Simeone, Alejandro. University of Washington; Estados UnidosFil: Smith, Jeffrey. University of Washington; Estados UnidosFil: Van Buren, Amy. University of Washington; Estados UnidosFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentin

Magellanic Penguin (Spheniscus magellanicus)

This Penguin Book represents the state of the art of all penguin species´ statuses, distributions, abundances and population trends, written by the leading experts for each penguin species. The publication will be the most updated source of information of highest credibility about penguins and after the book is published a website will be used to keep the information current and the conservation needs assessable. Academics, conservation groups, NGOs and decision makers need a trustable source of information and recommendations. The information contained in this book is needed to support the status recommendations of penguins in the IUCN Red List. Status decisions help catalyze research and determine conservation actions for each penguin species. The book highlights the plight of the penguins, identifying emerging conservation issues and opportunities. An overview of the distribution, abundance and breeding biology of each species is provided in a similar format so comparisons among species may be made. The book will increase understanding of common threats to penguins and will be used to educate governments and help local research and conservation groups put the plight of penguins into perspective.Fil: Boersma, P. Dee. University of Washington; Estados UnidosFil: Frere, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kane, Olivia. University of Washington; Estados UnidosFil: Pozzi, Luciana Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Pütz, Klemens. No especifíca;Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Rebstock, Ginger A.. University of Washington; Estados UnidosFil: Simeone, Alejandro. Universidad Andrés Bello; ChileFil: Smith, Jeffrey. University of Washington; Estados UnidosFil: Van Buren, Amy. University of Washington; Estados UnidosFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Garcia Borboroglu, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin