Search

International audience; The expansion of human activities in offshore maritime regions has outpaced the development of scientific knowledge and cooperative governance across these areas beyond national jurisdiction (ABNJ). In this context, current negotiations by the United Nations aim for an international legally-binding instrument to improve governance and sustainable use of biodiversity in ABNJ. Penguins are among the most threatened seabird groups today, notably at sea from fisheries and oiling. Here, we examine the available information on penguins’ movements and evaluate their use of ABNJ across species and life-cycle stages. We highlight that in most of the 18 extant penguin species, the birds may undertake spectacular migrations, seasonally or throughout life-cycle stages. Long-range movements were reported in 16 species, with trans-jurisdictional distribution in 14 species, including 13 in ABNJ. Species richness in ABNJ varied extensively according to oceanic region, and also varied according to season. Transboundary movements, notably to ABNJ, are thus remarkably prevalent among penguin species. Consequently, provisions of the treaty under negotiation may crucially benefit penguin conservation, notably by creating a uniform legal framework to designate protected areas in ABNJ, and by promoting the precautionary approach to extraction activities. However, the seasonally-dynamic utilisation of ABNJ by penguins supports the pertinence of adding innovative protection tools, such as mobile Marine Protected Areas, to the negotiations for a more adequate protection of marine biodiversity. Underlining penguins’ remarkable connectivity to the high seas can thus further strengthen this instrument aiming to protect a global ocean commons heritage of mankind.

Each winter, the North Atlantic Ocean is the stage for numerous cyclones, the most severe ones leading to seabird mass-mortality events called ‘‘winter wrecks.’’ During these, thousands of emaciated seabird carcasses are washed ashore along European and North American coasts. Winter cyclones can therefore shape seabird population dynamics by affecting survival rates as well as the body condition of surviving individuals and thus their future reproduction. However, most often the geographic origins of impacted seabirds and the causes of their deaths remain unclear. We performed the first ocean-basin scale assessment of cyclone exposure in a seabird community by coupling winter tracking ∼ 1,500 individuals of five key North Atlantic seabird species (Alle alle, Fratercula arctica, Uria aalge, Uria lomvia, and Rissa tridactyla) and cyclone locations. We then explored the energetic consequences of different cyclonic conditions using a mechanistic bioenergetics model and tested the hypothesis that cyclones dramatically increase seabird energy requirements. We demonstrated that cyclones of high intensity impacted birds from all studied species and breeding colonies during winter but especially those aggregating in the Labrador Sea, the Davis Strait, the surroundings of Iceland, and the Barents Sea. Our broad-scale analyses suggested that cyclonic conditions do not increase seabird energy requirements, implying that they die because of the unavailability of their prey and/or their inability to feed during cyclones. Our study provides essential information on seabird cyclone exposure in a context of marked cyclone regime changes due to global warming. at-sea distributioncyclonesenergy expenditureGLS trackingseabird migrationseascape ecology North Atlantic winter cyclones starve seabirds

Este artículo contiene 21 páginas, 6 figuras, 5 tablas., Seabirds inhabiting vast water masses provide numerous examples where opposing phenomena, such as natal and breeding philopatry vs. vagility have dug cryptic taxonomic boundaries among closely related taxa. The taxonomy of little shearwaters of the North Atlantic Ocean (Little–Audubon’s shearwater complex, Puffinus assimilis–lherminieri) still remains unclear, and complementary information on non-breeding distributions and at-sea behaviour becomes essential to unravel divergent local adaptations to specific habitats. Using miniaturized light-level geolocators from seven study areas in the North Atlantic, we evaluate the spatial and habitat segregation, estimate the timing of their key life-cycle events and describe the at-sea behaviour of three taxa of these little shearwaters year-round to distinguish ecological patterns and specializations that could ultimately unravel potential lineage divergences. We also assess morphometric data from birds that were breeding at each study area to further discuss potential adaptations to specific habitats. Our results show that, while birds from different taxa segregated in space and habitats, they share ecological plasticity, similar annual phenology and diel foraging behaviour. These ecological inconsistencies, while defining the evolutionary stressors faced by these taxa, do not suggest the existence of three Evolutionary Significant Units. However, they confirm the recent evolutionary divergence among the three little shearwaters of the North Atlantic., We acknowledge the Ministerio de Economía y Competitividad (MINECO), the Fondos FEDER (CGL2009-11278/BOS, CGL2013-42585-P), the EU LIFE Programme (LIFE09 NAT/PT/000041) and the British Ornithologists’ Union for funding.RR was supported by postdoctoral contracts of the Juan de la Cierva (JCI-2012–11848) and PLEAMAR (2017/2349) programs from the Spanish MINECO and the European Maritime and Fisheries Fund (EMFF), respectively, VHP by a postdoctoral fellowship of Fundação para a Ciência e a Tecnologia (FCT; SFRH/BPD/85024/2012) and ZZ by a PhD grant (APIF-2012) from Universitat de Barcelona (Spain).

Studies of the at-sea distribution and trophic ecology of penguins are essential to understand their role in the broader marine food web. Magellanic Penguins Spheniscus magellanicus have a wide distribution and their foraging behaviour varies across breeding sites and between sexes, among others. In this study, we characterized the at-sea areas, the diving strategies and the relative trophic level of Magellanic Penguins breeding at Isla de los Estados, Argentina, during the early chick-rearing period. In addition, we quantified the interannual, sexual and individual variability in those parameters during three breeding seasons (2011–2013) using devices recording position and dive depth, and obtained blood samples for stable isotope analysis. During the early chick-rearing period, Magellanic Penguins showed small differences between the sexes in their foraging behaviour and large overlap in the at-sea areas used, suggesting no intraspecific variation between sexes. Although there was interannual variability in the foraging behaviour and the trophic level of the penguins, most of the studied nests managed successfully to raise both chicks during the first stage of the breeding cycle (guard stage). The foraging ecology of Magellanic Penguins from this colony was comparable with results of past studies at other breeding colonies. This study contributes to the identification of important at-sea areas for Magellanic Penguins at the southern edge of their distribution and also to the identification of possible threats in the study area such as interaction with fisheries. Fil: Rosciano, Natalia Gimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Pütz, Klemens. Antarctic Research Trust; Alemania Fil: Polito, Michael J.. State University of Louisiana; Estados Unidos Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

Seabird distributions are determined by physical and biological factors operating at variable scales and levels of ecological organization. Accordingly, changes in the composition of the marine avifauna often correspond to large-scale (macro-mega) shifts in water mass properties. Yet, few studies have addressed biogeographical patterns across multiple current systems, spanning from highly-productive to oligotrophic waters. In this study, we characterize the at-sea assemblages of nesting seabirds across the Eastern South Pacific Ocean (ESPO), a vast region spanning from the Humboldt Current to the South Pacific Gyre. Employing multivariate techniques, we first identify four distinct species assemblages and then relate their distributions to the underlying environmental conditions. Our results show that Julian day, depth, sea surface temperature, sea surface salinity, and chlorophyll-α concentration are the most important factors explaining the distribution patterns of these assemblages. Moreover, environmental conditions also explain overall seabird abundance and species richness, two community-level characteristics indicative of ocean productivity. Seabird abundance was best explained by four variables, associated with onshore-offshore gradients (distance to the coast, ocean depth), and the influence of coastal upwelling (mean mixed layer depth, sea surface salinity). Richness was best explained by seasonality (Julian day) and by the presence of water mass boundaries (sea surface temperature coefficient of variation). Our findings underscore the importance of environmental factors structuring the distribution and biogeography of seabirds across gradients of ocean productivity and water mass properties. Understanding the environmental drivers of seabird abundance and richness in the ESPO will inform the prioritization and design of effective marine conservation measures in this poorly studied region.

We describe the migration routes and non-breeding areas of Common Terns (Sterna hirundo) from the Azores Archipelago, based on ringing (banding) recoveries and tracking of three birds using geolocators. Over 20 years, there have been 55 transatlantic recoveries of Common Terns from the Azores population: six from Argentina and 49 from Brazil. The three tracked birds migrated south in different months (August, September, November), but the northern migration was more synchronous, with all leaving in April. The birds were tracked to three areas of the South American coast: the male spent November—April on the northern Brazilian coast (13°N–2°S), whereas the two females first spent some time off central-eastern Brazil (4–16°S; one for 1 week, the other for 3 months) and then moved south to the coast of south-eastern Brazil, Uruguay and northern Argentina (24–39°S). Although caution is needed given the small sample size and errors associated with geolocation, the three tracked terns potentially travelled a total of ∼23 200 km to and returning from their non-breeding areas, representing an average movement of ∼500 km day−1. With the exception of Belém, in northern Brazil, and Lagoa do Peixe, in southern Brazil, the coastal areas used by the tracked birds were also those with concentrations of ringing recoveries, confirming their importance as non-breeding areas for birds from the Azores. info:eu-repo/semantics/publishedVersion

This is the first study using geolocators (global location sensing, GLS) to track the movements of a pelagic tropical seabird. We used GLS to describe at-sea distribution and activity patterns of wedge-tailed shearwaters Puffinus pacificus breeding on Aride Island, Seychelles, in the late chick-rearing, non-breeding and pre-breeding periods. During late chick-rearing and pre-breeding periods, shearwaters foraged relatively close to the colony. In the non-breeding period, shearwaters; were found on a west-east gradient along the equator, between 5 degrees N and 10 degrees S. Some of the tracked individuals showed little dispersion, staying as close as 1000 km to Aride Island, while others travelled 3500 km to the Central Indian Ocean Basin. Individual core areas of activity showed little overlap. Overall, wedge-tailed shearwaters showed short-distance movements and exploited relatively unproductive oceanic waters. At-sea distribution largely matched that of yellowfin and skipjack tunas, emphasising the importance of the association with subsurface predators rather than associations with physical oceanographic features that enhance primary productivity. During the non-breeding period, the feeding activity of, shearwaters was mainly concentrated in the daylight period, when tunas also forage. A different behaviour, characterised by a much lower proportion of the night sitting on the sea surface, was recorded in the pre-laying exodus of 1 female to more productive waters, suggesting a different feeding strategy and/or targeting of different prey. Knowledge of the at-sea distribution of wedge-tailed shearwaters allows quantification of the overlap with industrial fisheries, which will be crucial to devise fisheries policies for the Indian Ocean with important implications for the conservation of this species.