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Stanley, Falkland Islands

Dwyer J.F.,EDM International Inc. | Cockwell S.G.,Falklands Conservation
Journal of Raptor Research | Year: 2011

On the Falkland Islands (Malvinas), raptors historically were perceived as a threat to livestock, and consequently were widely persecuted through the mid-twentieth century. Conservation measures now minimize persecution and have facilitated increases in raptor populations, but the ecology of raptors on the Falkland Islands (Malvinas) remains poorly understood. We investigated social hierarchies within an assemblage of nonmigratory raptorial scavengers: Variable Hawk (Buteo polyosoma), Striated Caracara (Phalcoboenus australis), Southern Caracara (Caracara plancus), and Turkey Vulture (Cathartes aura jota). During thirty observation sessions of 30 min each, we recorded 1386 aggressive interactions involving one or more of these species. We found that Variable Hawks were aggressors in 98% (95% CI = 96-100%) of interactions with Striated Caracaras, 82% (69-95%) of interactions with Turkey Vultures, and 80% (72-88%) of interactions with Southern Caracaras. Southern Caracaras were aggressors in 100% of interactions with Striated Caracaras, and 90% (80-100%) of interactions with Turkey Vultures. Turkey Vultures were aggressors in 71% (61-82%) of interactions with Striated Caracaras. Within species, we found adult Southern Caracaras were aggressors in 78% (72-84%) of interactions with conspecific juveniles and 76% (68-85%) of interactions with conspecfic subadults. Adult Striated Caracaras were aggessors in 100% of interactions with conspecific juveniles and 97% (91-100%) of interactions with conspecfic subadults. Predicted patterns of size-based dominance typical of complex African and South American avian scavenger assemblages were not observed in the relatively simple assemblage of the Falkland Islands (Malvinas), but we did observe single-species groups of up to 83 Southern Caracaras and 42 Striated Caracaras. © 2011 The Raptor Research Foundation, Inc. Source

Wakefield E.D.,Natural Environment Research Council | Phillips R.A.,Natural Environment Research Council | Trathan P.N.,Natural Environment Research Council | Arata J.,Instituto Antartico Chileno | And 6 more authors.
Ecological Monographs | Year: 2011

Telemetry methods and remote sensing now make it possible to record the spatial usage of wide-ranging marine animals and the biophysical characteristics of their pelagic habitats. Furthermore, recent statistical advances mean that such data can be used to test ecological hypotheses and estimate species' distributions. Black-browed Albatrosses Thalassarche melanophrys are highly mobile marine predators with a circumpolar breeding and foraging distribution in the Southern Hemisphere. Although they remain relatively abundant, increased fisheries bycatch has led to their listing as endangered by conservation bodies. We satellite-tracked 163 breeding Black-browed Albatrosses and eight closely related Campbell Albatrosses T. impavida from nine colonies. We then quantified habitat usage, and modeled population-level spatial distribution at spatiotemporal scales >50 km and 1 month, as a function of habitat accessibility, habitat preference, and intraspecific competition, using mixed-effects generalized additive models (GAMM). During incubation, birds foraged over a wider area than in the post-brood chick-rearing period, when they are more time constrained. Throughout breeding, the order of habitat preference of Black-browed Albatrosses was for neritic (0-500 m), shelf-break and upper shelf-slope (500-1000 m), and then oceanic (>1000 m) waters. Black-browed Albatrosses also preferred areas with steeper (>3°) bathymetric relief and, in addition, during incubation, warmer sea surface temperatures (peak preference ∼16°C). Although this suggests specialization in neritic habitats, incubation-stage Blackbrowed Albatrosses from South Georgia also foraged extensively in oceanic waters, preferring areas with high eddy kinetic energy (>250 cm2/s2), especially the Brazil-Malvinas Confluence, a region of intense mesoscale turbulence. During chick-rearing, this species had a more southerly distribution, and following the seasonal retreat of sea ice, birds from some populations utilized neritic polar waters. Campbell Albatrosses showed similar bathymetric preferences but also preferred positive sea level anomalies. Black-browed Albatross foraging areas were partially spatially segregated with respect to colony and region, with birds preferring locations distant from neighboring colonies, presumably in order to reduce competition between parapatric conspecifics. At the global scale, the greatest concentrations of breeding Black-browed Albatrosses are in southern South American neritic, shelf-break, and shelf-slope waters. These regions also hold large fisheries and should therefore be a priority for introduction of bycatch mitigation measures. © 2011 by the Ecological Society of America. Source

Baylis A.M.M.,Falklands Conservation | Zuur A.F.,Highland Statistics Ltd. | Zuur A.F.,University of Aberdeen | Brickle P.,Falkland Islands Government | Pistorius P.A.,Nelson Mandela Metropolitan University
Ibis | Year: 2012

Detecting and predicting how populations respond to environmental variability are eminent challenges in conservation research and management. This is particularly true for wildlife populations at high latitudes, many of which demonstrate changes in population dynamics associated with global warming. The Falkland Islands (Southwest Atlantic) hold one of the largest Gentoo Penguin Pygoscelis papua populations in the world, representing c. 34% of the global population. The numbers of breeding Gentoo Penguins at the Falkland Islands have shown a high degree of inter-annual variability since monitoring commenced in 1990. However, proximate causes of annual variability in breeding numbers have not been explored. Here we examine 21years of Gentoo Penguin breeding surveys from the Falkland Islands and assess whether inter-annual variability in the number of breeding pairs were correlated with proxies of environmental variability. There was a positive correlation between the number of breeding pairs and a broad-scale climatic variation index, the Southern Oscillation Index (SOI). In turn, the SOI was significantly correlated with spring sea surface temperature anomalies, indicating a more immediate atmospherically forced response to El Niño Southern Oscillation variability in the Southwest Atlantic than previously reported. However, we also describe a non-linear response to environmental variability that may highlight foraging plasticity and/or the complexity of regional ecosystem interactions that operate across a range of different scales. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union. Source

Ochyra R.,Polish Academy of Sciences | Crabtree D.,Falklands Conservation | Tangney R.,National Museum of Wales
Cryptogamie, Bryologie | Year: 2015

Bucklandiella didyma (Mont.) Bednarek-Ochyra et Ochyra and Codriophorus laevigatus (Mitt.) Bednarek-Ochyra et Ochyra are recorded for the first time from the Falkland Islands. Bucklandiella heterostichoides (Cardot) Bednarek-Ochyra et Ochyra, B. membranacea (Mitt.) Bednarek-Ochyra et Ochyra and B. ptychophylla (Mitt.) Bednarek-Ochyra et Ochyra are newly reported from East Falkland and B. sudetica (Funck) Bednarek-Ochyra et Ochyra is a new addition to the bryoflora of We st Falkland. In total, seven species of Bucklandiella Roiv. are currently known from the Falkland Islands and they are briefly characterised, their geographical range is surveyed and global distribution of selected species is mapped. The status of five species of Bucklandiella which are excluded from the bryoflora of the archipelago is briefly considered. A key to determination of species of taxa of the Racomitrioideae in the Falkland Islands is presented. © 2015 Adac. Tous droits réservés. Source

Baylis A.M.M.,Deakin University | Wolfaardt A.C.,Joint Nature Conservation Committee | Crofts S.,Falklands Conservation | Pistorius P.A.,Nelson Mandela Metropolitan University | Ratcliffe N.,British Antarctic Survey
Polar Biology | Year: 2013

The Falkland Islands currently supports one of the largest Southern Rockhopper Penguin (Eudyptes c. chrysocome) populations. Archipelago-wide censuses conducted in 2000 and 2005 revealed that the number of breeding pairs had declined by 30 % during this period. To establish whether the breeding population continued to decline, an archipelago-wide census was conducted in 2010. We report a conservative estimate of 319,163 ±SD 24,820 pairs breeding at the Falkland Islands in 2010. This represents a 51 % increase when compared with the number counted in 2005. A simple stochastic population model was developed to investigate the extent to which changes in demographic parameters between 2005 and 2010 could account for the increase in breeding pairs. The population model predicted a 38 % increase in the number of breeding pairs over a 5-year period (289,431 ±SD 24,615). The increase in the number of breeding pairs was therefore probably attributed to improved vital rates in the period between the 2005 and 2010 archipelago-wide censuses in combination with other factors such as a reduction in the proportion of adult birds that abstained from breeding. Based on the 2010 Falkland Islands estimate, the global population of the subspecies E. c. chrysocome is now closer to 870,000 breeding pairs of which the Falkland Islands accounts for approximately 36 %, the second largest proportion after Chile. We conclude that despite fluctuations, the number of Southern Rockhopper Penguins breeding at the Falkland Islands has increased over the last 15 years and suggest that the 'Vulnerable' conservation status of the species be re-assessed. © 2013 Springer-Verlag Berlin Heidelberg. Source

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