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Robert W Furness - One of the best experts on this subject based on the ideXlab platform.
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predator avoidance behaviour in a nocturnal Petrel exposed to a novel predator
Ibis, 2013Co-Authors: Will T S Miles, Matt Parsons, A Close, Richard Luxmoore, Robert W FurnessAbstract:Many species of bird recognize acoustic and visual cues given by their predators and have complex defence adaptations to reduce predation risk. Recognition of threats posed by specific predators and specialized anti-predation behaviours are common. In this study we investigated predator recognition and anti-predation behaviours in a pelagic seabird, Leach's Storm-Petrel Oceanodroma leucorhoa, at a site where predation risk from Great Skuas Stercorarius skua is exceptionally high. Leach's Storm-Petrels breed in burrows and come on land only at night. Counter-predator adaptations were investigated correlatively in relation to changing natural light levels at night, and experimentally in relation to nocturnal visual and acoustic signals from Great Skuas. Colony attendance by Leach's Storm-Petrels was attuned to changes in light conditions at night and was highest when nights were darkest. This behaviour is likely to reduce predation risk on land; however, specific recognition of Great Skuas and specialized defence behaviours were not found. Leach's Storm-Petrels, in particular apparently non-breeding individuals, were entirely naive to the threat posed by Great Skuas and were captured easily in a variety of different ways, on the ground and in the air. Lack of specialized behavioural adaptations in Leach's Storm-Petrels against Great Skuas may be because spatial overlap of breeding distributions of these species appears to be a rare and recent phenomenon.
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Marine habitat use of wintering spectacled Petrels Procellaria conspicillata, and overlap with longline fishery
Marine Ecology Progress Series, 2009Co-Authors: Leandro Bugoni, Liliana D'alba, Robert W FurnessAbstract:Satellite transmitters were used to determine the marine habitat utilization and fishery overlap of wintering spectacled Petrels Procellaria conspicillata in the southwestern Atlantic Ocean in 2006 and 2007. Kernel density analysis of tracked birds demonstrated intense use of waters in the Brazilian Exclusive Economic Zone, from 26 to 31° S, mainly over the continental shelf break and off- shore waters (mean depth in the < 20% kernel density areas = 1043 ± 794 m), over warm tropical and subtropical waters (mean SST = 22°C and 21°C in 2006 and 2007, respectively) and mesotrophic/ oligotrophic waters (chlorophyll a density = 0.301 and 0.281 mg m -3 in 2006 and 2007, respectively). These habitats used by spectacled Petrels are remarkably different from those used by their sister species, the white-chinned Petrel P. aequinoctialis, which occurs mainly over the continental shelf on sub-Antarctic and productive waters. A close association between spectacled Petrels and the pelagic longline fishery was demonstrated through comparison of the main kernel areas used by spectacled Petrels and the areas used by the pelagic longline fleet determined by fishing effort at resolution of 1 × 1° quadrants. Travel speeds and distances during night and daytime periods did not differ. The present study demonstrates the importance of high resolution fishing effort data to address relation- ships between bird marine habitat use and specific fishing fleets, and to determine marine habitats and investigate at sea segregation between closely related species.
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monteiro s storm Petrel oceanodroma monteiroi a new species from the azores
Ibis, 2008Co-Authors: Joël Bried, Mark Bolton, Andrea L Smith, Elena Gomezdiaz, Vicki L Friesen, Renata Medeiros, Jose L Roscales, Robert W FurnessAbstract:The existence of two seasonally distinct breeding populations of Oceanodroma storm-Petrels in the Azores islands was first documented in 1996. The discovery of morphological differences between the populations led to the suggestion that they may represent cryptic sibling species. Recent mtDNA and microsatellite analysis from storm-Petrel populations has considerably advanced our understanding of their taxonomic relationships. Here we present new information on the timing of breeding and moult of the two Azores populations, the extent of exchange of individuals between seasons, and diet from feather isotopes. We conclude that the hot-season Azores population should be considered a new species for which we propose the name Oceanodroma monteiroi, Monteiro's Storm-Petrel. The species is both genetically distinct and genetically isolated from the sympatric cool-season population of Madeiran Storm-Petrel Oceanodroma castro, and from all other populations of Oceanodroma castro in the Atlantic and Pacific Oceans examined to date. Differences in the vocalizations permit species recognition, and the extent of primary feather wear and stage of moult aids separation of the two species in the Azores, which is especially valuable during August when both attend the breeding colonies in large numbers. Feather carbon and nitrogen isotopes reveal that the diet of Monteiro's Storm-Petrel differs from that of the sympatric Madeiran Storm-Petrel during both breeding and non-breeding seasons, and unlike the Madeiran Storm-Petrel, Monteiro's Storm-Petrel appears to maintain the same foraging environment during the summer and winter months, though it shows a dietary shift to higher trophic levels during the non-breeding season. Monteiro's Storm-Petrel is thought to be confined to the Azores archipelago, where it is currently known to nest on just two small neighbouring islets. The total population size was estimated at 250–300 pairs in 1999.
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Nocturnal foraging by great skuas Stercorarius skua: implications for conservation of storm-Petrel populations
Journal of Ornithology, 2006Co-Authors: Stephen C Votier, Richard A Phillips, Stuart Bearhop, Jonathan E. Crane, Ana León, Claire A. Mcsorley, Eduardo Mínguez, Ian P. Mitchell, Matthew Parsons, Robert W FurnessAbstract:At St Kilda, Outer Hebrides, a large colony of great skuas Stercorarius skua feed extensively on one of the largest colonies of Leach’s storm-Petrels Oceanodroma leucorhoa in Europe, but little is known about the dynamics of this predator–prey system. Recently published population estimates of storm-Petrels make it possible to estimate the impact of skua predation for the first time. Although skuas in the southern hemisphere catch Petrels attending breeding colonies at night, it is not known whether congeners in the northern hemisphere also forage during the hours of darkness. We found (using radio-transmitters) that skuas regularly forage at night and (using light intensifying equipment) observed them catching storm-Petrels at night. However, skuas also foraged during daylight hours, and it is unknown whether they might also catch storm-Petrels at sea. Data on diet composition reveals that the proportion of storm-Petrels in skua diet declined between 1996 and 1997, but remained constant thereafter. Although a large proportion of the storm-Petrel prey is likely to consist of non-breeders, numbers consumed suggest that breeders and an unknown quantity of transients may also been eaten. The numbers of storm-Petrels eaten are not sustainable and may result in substantial long-term population declines. Under current conditions, maintenance of large populations of both Leach’s storm-Petrels and great skuas at St Kilda appears to be mutually exclusive.
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status and distribution of fea s Petrel bulwer s Petrel manx shearwater little shearwater and band rumped storm Petrel in the azores archipelago
Waterbirds: The International Journal of Waterbird Biology, 1999Co-Authors: Luis R Monteiro, Robert W Furness, David R. Thompson, Jaime A Ramos, J C Pereira, P R Monteiro, R S Feio, Stuart Bearhop, M Laranjo, Geoff M HiltonAbstract:-This paper reports the first comprehensive surveys of Fea's Petrel (Pterodromafeae), Bulwer's Petrel (Bulweria bulwerii), Manx Shearwater (Puffinus puffinus), Little Shearwater (Puffinus assimilis baroli) and two temporally-segregated forms of Band-rumped Storm-Petrel (Oceanodroma castro) in the whole Azores archipelago, conducted from 1996 to 1998. Listening to nocturnal vocalizations was the main survey method. Breeding of Fea's Petrel was not confirmed and new sites of Bulwer's Petrel were not found (previous status: one site, 50 pairs), but previously undocumented colonies were identified for the remaining species. Manx Shearwater occurred in four colonies with 115-235 pairs (previous status: probable breeder), Little Shearwater occurred in 28 colonies with 840-1,530 pairs (previously: four locations, >150 pairs), hot-season Band-rumped Storm-Petrels occurred in 5 colonies with 250-300 pairs (previously: two locations, 200 pairs) and cool-season Band-rumped Storm-Petrels were found in eight locations with 665-740 pairs (previously: three locations, 600 pairs). Most colonies were confined to precipitous cliffs and islets, which may be a result of predation threats by introduced mammals. Although these surveys provided a valuable revision of the status and distribution for these species of conservation concern, further survey work is warranted and target areas are indicated. We discuss the potential and limitations of listening for nocturnal vocalizations as a method to survey and monitor shearwater and Petrel populations in inaccessible habitats. Received 24 May 1999, accepted 8 July 1999.
Flavio Quintana - One of the best experts on this subject based on the ideXlab platform.
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oceanographic and biological landscapes used by the southern giant Petrel during the breeding season at the patagonian shelf
Marine Biology, 2011Co-Authors: Sofia Copello, Flavio Quintana, Ana I Dogliotti, Domingo A GagliardiniAbstract:The study of how and why marine animals distribute themselves at sea has important conservation and management implications of the species and their habitats. We characterize the oceanographic and biological landscapes of the marine areas used by breeding Southern Giant Petrels (Macronectes giganteus) at Patagonian colonies and explore inter-sexual and inter-colony differences. The at-sea movements of 16 adults (7 males and 9 females) were studied by means of satellite telemetry techniques during 1999, 2000, 2002, and 2004 breeding seasons. Southern Giant Petrels utilized an oceanographic scenario characterized by high productivity, warm sea surface temperature, and shallow waters. The biological landscape was characterized by a high availability of squid and carrion nearby colonies. Females spent more time in the shelf break and exploited deeper waters than males. In contrast, males spent more time in coastal areas and they showed a higher spatial overlap with areas of high squid density than females. Such a prosperous foraging scenario for both sexes may play a key role in the growth of the breeding population of Southern Giant Petrel Patagonian colonies.
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Speciation and phylogeography of giant Petrels Macronectes
Molecular Phylogenetics and Evolution, 2009Co-Authors: N.m.s.m. Techow, Richard A Phillips, Colleen O'ryan, Rosemary Gales, Manuel Marin, D. Patterson-fraser, Flavio Quintana, Markus S. Ritz, David R. Thompson, Ross M. WanlessAbstract:We examine global phylogeography of the two forms of giant Petrel Macronectes spp. Although previously considered to be a single taxon, and despite debate over the status of some populations and the existence of minimal genetic data (one mitochondrial cytochrome b sequence per form), the current consensus based on morphology is that there are two species, Northern Giant Petrel M. halli and Southern Giant Petrel M. giganteus. This study examined genetic variation at cytochrome b as well as six microsatellite loci in giant Petrels from 22 islands, representing most island groups at which the two species breed. Both markers support separate species status, although sequence divergence in cytochrome b was only 0.42% (corrected). Divergence was estimated to have occurred approximately 0.2 mya, but with some colonies apparently separated for longer (up to 0.5 my). Three clades were found within giant Petrels, which separated approximately 0.7 mya, with the Southern Giant Petrel paraphyletic to a monophyletic Northern Giant Petrel. There was evidence of past fragmentation during the Pleistocene, with subsequent secondary contact within Southern Giant Petrels. The analysis also suggested a period of past population expansion that corresponded roughly to the timing of speciation and the separation of an ancestral giant Petrel population from the fulmar Fulmarus clade.
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diet of the southern giant Petrel in patagonia fishery related items and natural prey
Endangered Species Research, 2008Co-Authors: Sofia Copello, Flavio Quintana, Fabian PerezAbstract:There is an increasing interest in dietary composition of threatened seabirds as an impor- tant key to understanding their feeding ecology, population dynamics and interaction with fisheries. Several seabird species exploit discards from fisheries as their main food. The southern giant Petrel Macronectes giganteus is a wide-ranging procellariform. It is considered a near-threatened species under International Union for Conservation of Nature (IUCN) criteria and has been included as a threatened species in the Appendix 2 of the Convention on the Conservation of Migratory Species of Wild Animals. The diet of Patagonian colonies of this species remains unknown, even though under- standing the relationship between southern giant Petrels and fisheries may be crucial to the conserva- tion of this species in the Southwestern Atlantic. We describe the diet of the southern giant Petrel from north Patagonian colonies using chick regurgitations and evaluate its relationships with the fisheries. Carrion occurred in the diets of 90.8% of birds sampled, while cephalopods occurred in the diets of 65.1%. Crustaceans were present in 43.7% of samples and fishes in 19.4%. Anthropogenic items were found in 72.7% of the samples. The presence in the Petrel's diet of target and discarded species from fishery vessels, and the high incidence of marine debris, suggests an extensive use of discard over the Patagonian Shelf. The population of southern giant Petrels in northern Patagonia has reached higher, stable levels. Such a population trend could be linked, at least partially, to the use of fisheries discards.
Frédérique Olivier - One of the best experts on this subject based on the ideXlab platform.
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nest selection by snow Petrels pagodroma nivea in east antarctica validating predictive habitat selection models at the continental scale
Ecological Modelling, 2008Co-Authors: Frédérique Olivier, Simon WotherspoonAbstract:Abstract Little is known on the factors controlling distribution and abundance of snow Petrels in Antarctica. Studying habitat selection through modeling may provide useful information on the relationships between this species and its environment, especially relevant in a climate change context, where habitat availability may change. Validating the predictive capability of habitat selection models with independent data is a vital step in assessing the performance of such models and their potential for predicting species’ distribution in poorly documented areas. From the results of ground surveys conducted in the Casey region (2002–2003, Wilkes Land, East Antarctica), habitat selection models based on a dataset of 4000 nests were created to predict the nesting distribution of snow Petrels as a function of topography and substrate. In this study, the Casey models were tested at Mawson, 3800 km away from Casey. The location and characteristics of approximately 7700 snow Petrel nests were collected during ground surveys (Summer 2004–2005). Using GIS, predictive maps of nest distribution were produced for the Mawson region with the models derived from the Casey datasets and predictions were compared to the observed data. Models performance was assessed using classification matrixes and Receiver operating characteristic (ROC) curves. Overall correct classification rates for the Casey models varied from 57% to 90%. However, two geomorphologically different sub-regions (coastal islands and inland mountains) were clearly distinguished in terms of habitat selection by Casey model predictions but also by the specific variations in coefficients of terms in new models, derived from the Mawson data sets. Observed variations in the snow Petrel aggregations were found to be related to local habitat availability. We discuss the applicability of various types of models (GLM, CT) and investigate the effect of scale on the prediction of snow Petrel habitats. While the Casey models created with data collected at the nest scale did not perform well at Mawson due to regional variations in nest micro-characteristics, the predictive performance of models created with data compiled at a coarser scale (habitat units) was satisfactory. Substrate type was the most robust predictor of nest presence between Casey and Mawson. This study demonstrate that it is possible to predict at the large scale the presence of snow Petrel nests based on simple predictors such as topography and substrate, which can be obtained from aerial photography. Such methodologies have valuable applications in the management and conservation of this top predator and associated resources and may be applied to other Antarctic, Sub-Antarctic and lower latitudes species and in a variety of habitats.
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Distribution and abundance of Wilson’s storm Petrels Oceanites oceanicus at two locations in East Antarctica: testing habitat selection models
Polar Biology, 2006Co-Authors: Frédérique Olivier, Simon J. WotherspoonAbstract:Over the last decades, Antarctic seabird populations have been studied as bioindicators of the variability in the Southern Ocean marine ecosystem. Little information is available on the distribution and abundance of Wilson’s storm Petrel ( Oceanites oceanicus ) in East Antarctica although the bioindicator value of this species has been investigated. Regional surveys were conducted at two coastal locations, Casey (66°S, 110°E) and Mawson (67°S, 62°E), to locate Wilson’s storm Petrel nests using systematic searches in sites selected with a balanced random sampling design. Conducted in ice-free areas of similar size, searches located 553 Wilson’s storm Petrel nests at Mawson and 630 at Casey. Comparable densities were observed between locations but regional estimates suggest that Wilson’s storm Petrels are more abundant at Casey. Habitat preferences of Wilson’s storm Petrels were investigated using resource selection functions based on Generalized Additive and Linear Models (GAMs and GLMs), which allow their ecological niche to be graphically and quantitatively described. The orientation of nests in relation to the prevailing winds was identified as a determinant of nest distribution at both locations. However, selected rock substrate types differed between Mawson and Casey. Snow was confirmed to constrain the spatial distribution of nests, especially at Casey where snow precipitations and accumulation are more common in summer, confirming the results of previous temporal surveys focusing on breeding success. At the southern edge of its geographic distribution, the Wilson’s storm Petrel may be subject to more obvious climate related habitat changes in East Antarctica. Such models may provide valuable information to detect the potential effect of climate variations on this species and others, in the context of a broad Antarctic ecosystem monitoring.
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nesting habitat preferences of snow Petrels pagodroma nivea and wilson s storm Petrels oceanites oceanicus in east antarctica a modelling approach to predict species distribution
2006Co-Authors: Frédérique OlivierAbstract:Although snow Petrels are ubiquitous around the Antarctic, population estimates of this “not so charismatic” top predator are generally limited. Such information is highly valuable for the monitoring and management of Antarctic and Southern Ocean ecosystems, especially in a climate change context. There is a need to complement long–term temporal demographic information obtained at a limited number of monitoring sites with spatial distribution data. Systematic surveys of snow Petrels and Wilson’s storm Petrels were undertaken at Casey (2002-2003) and Mawson (2004-2005) in order to provide better regional population estimates and test the performance of predictive distribution models based on topographic and substrate variables for refining such estimates. As habitat selection modelling is rarely used in Antarctic regions, methodological developments focus on dealing with the peculiarities of a semi-colonial hollow-nesting species, testing habitat selection modelling approaches and comparing the output of four types of models (Generalized Linear and Generalized Additive Models, Classification Trees and Ecological Niche Factor Analysis) across a range of scales. Snow Petrel nest distribution was directly related to the nature of the rock substrate and to major topographic/geomorphological parameters such as hill slope and the direction of the prevailing winds. Model performance varied with the scale at which models were implemented, suggesting that nest selection processes happen predominantly at the habitat unit and individual nest scales. Further study at the nest scale highlighted that the influence of biotic related parameters such as conspecific attraction (modelled as autocorrelation due to coloniality) may be of lesser influence than selection based on individual nest quality. An alternative modelling method, ENFA, which creates environmental envelopes for the niche of the species with presence data only was identified as valuable for Antarctic data sets, which often lack comprehensive records of species absence. The validation of the models created at Casey with nest data collected in the Mawson region returned satisfactory prediction rates in two different habitat types, coastal islands and inland mountains, suggesting that it may be possible to predict snow Petrel distribution across East Antarctica using remotely sensed information on topography and geomorphology, for example high-resolution aerial photography to guide in the design of and complement ground surveys. Similar modelling procedures applied to Wilson’s storm Petrels produced more mitigated results and selection for this species appeared to be based principally on nest microhabitat characteristics. However, modelling provided useful information on the large-scale habitat preferences and ecological requirements of both species.
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gis based application of resource selection functions to the prediction of snow Petrel distribution and abundance in east antarctica comparing models at multiple scales
Ecological Modelling, 2005Co-Authors: Frédérique Olivier, Simon WotherspoonAbstract:Abstract Snow Petrel numbers must be of the order of several millions. However, accurate population estimates are sparse although such information is necessary to monitor potential changes in the Antarctic ecosystem. A census of snow Petrel nests was conducted at Casey (East Antarctica) during summer 2002–2003. Twenty percent of the ice-free areas (available nesting habitat for snow Petrels) was surveyed using a “random block design”. During this survey, approximately 5000 nests were located. Generalized additive and linear modelling techniques and classification trees (GAM, GLM and CT) were used to fit resource selection functions, which modelled snow Petrel abundance or presence–absence in relation to a set of environmental predictors (elevation, slope, aspect, curvature and substrate types estimated in percentage cover). The effect of spatial scale on the processes that influence habitat selection was investigated using GIS as a tool to create and test models at a hierarchical range of scales—from 200 m grid-sites level to 20 m quadrats. The strong predictive value of aspect, slope and percent cover in boulder and SCREE were identified at all scales. However, the significance of environmental predictors varied with scale, indicating that spatial scale matters in detecting habitat selection processes. In general, models were improved with the addition of spatial dependence terms representing the effect of conspecific attraction (coloniality), but these models were less applicable for predictive purposes. By predicting abundance from environmental characteristics (acquired for example, using aerial photography), resource selection functions may be a useful tool to refine population estimates of several Petrel species in Antarctica without requiring intensive ground surveys.
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Variations of snow Petrel breeding success in relation to sea-ice extent: detecting local response to large-scale processes?
Polar Biology, 2005Co-Authors: Frédérique Olivier, Jan A. Van Franeker, Jeroen C. S. Creuwels, Eric J. WoehlerAbstract:Demographic parameters were estimated for snow Petrels Pagodroma nivea nesting at the study colony of Reeve Hill near Casey station, Antarctica between 1984 and 2003. Average breeding success for the colony varied from 18.2% to 76.5%. Breeding effort, hatching and fledging success were subject to a high interannual variability. We examined the influence of regional sea-ice extent on the breeding performance of snow Petrels at Reeve Hill. Fewer birds were breeding when sea-ice had been extensive during April–May. Overall breeding success and fledging success were improved during years with extensive sea-ice cover in winter. Successful breeding effort and breeding success were depressed when there was extensive sea-ice cover during January–February. Sea surface temperatures also correlated to snow Petrel breeding performance parameters. Previous work showed that large-scale climatic events (ENSO, Antarctic circumpolar wave) and the related sea-ice cover around the Antarctic might affect the lower trophic levels of the marine environment and consequently food availability for snow Petrels. A comparison with the long-term study conducted at Ile des Pétrels (Terre Adélie) suggests that despite similarities in the underlying biological processes that control snow Petrel breeding performance, the nature of the correlation of large-scale environmental factors with breeding performance differs substantially between the two colonies, probably because of the confounding effects of other environmental factors acting at a local scale (local weather, nest quality), which also affect bird body condition.
Pierre Jouventin - One of the best experts on this subject based on the ideXlab platform.
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Wilson’s Storm Petrels Oceanites oceanicus Recognise the Olfactory Signature of Their Mate
Ethology, 2007Co-Authors: Pierre Jouventin, Vincent Mouret, Francesco BonadonnaAbstract:Chemical signals in birds have rarely been considered as recognition cues. Nevertheless, recent experiments showed that several Petrel species are able to recognize their nest by smell, and in at least one species even their mate. But the use of smell may be different across the Petrel species and olfactory nest recognition appears to be dependent on species’ breeding biology. To increase our knowledge of individual olfactory recognition in Petrels and the relationships between breeding biology and use of smell, we tested Wilson’s storm Petrels Oceanites oceanicus in Antarctica. In previous experiments, these birds failed to home if rendered anosmic, but the method employed to obtain anosmia (potentially stressing birds) and the fact that they breed in 24-h daylight suggest that they might use visual, rather than olfactory, cues to recognize their nest. Our birds were tested in T-maze experiments where nest odours or partner odours were presented. Wilson’s storm Petrels preferred odours of their own nest and mate. Results on olfactory nest recognition confirm and complete previous results, viz. anosmic Wilson’s storm Petrels do not home. Storm Petrels olfactory mate recognition suggests that this ability may be widespread in burrowing Petrels and implements olfactory nest recognition.
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evidence for nest odour recognition in two species of diving Petrel
The Journal of Experimental Biology, 2003Co-Authors: Francesco Bonadonna, Pierre Jouventin, Gregory B Cunningham, Florence Hesters, Gabrielle A NevittAbstract:SUMMARY In nearly every procellariiform species, the sense of smell appears to be highly adapted for foraging at sea, but the sense of smell among the diving Petrels is enigmatic. These birds forage at considerable depth and are not attracted to odour cues at sea. However, several procellariiform species have recently been shown to relocate their nesting burrows by scent, suggesting that these birds use an olfactory signature to identify the home burrow. We wanted to know whether diving Petrels use smell in this way. We tested the common diving Petrel Pelecanoides urinatrix and the South-Georgian diving Petrel Pelecanoides georgicus to determine whether diving Petrels were able to recognise their burrow by scent alone. To verify the efficacy of the method, we also tested a bird that is known to use olfaction for foraging and nest recognition, the thin-billed prion Pachyptila belcheri . In two-choice T-maze trials, we found that, for all species, individuals significantly preferred the odour of their own nest material to that of a conspecific. Our findings strongly suggest that an individual-specific odour provides an olfactory signature that allows burrowing Petrels to recognize their own burrow. Since this ability seems to be well developed in diving Petrels, our data further implicate a novel adaptation for olfaction in these two species that have been presumed to lack a well-developed sense of smell.
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Importance of the large copepod Paraeuchaeta antarctica (Giesbrecht, 1902) in coastal waters and the diet of seabirds at Kerguelen, Southern Ocean
Journal of Plankton Research, 2002Co-Authors: Pierrick Bocher, Yves Cherel, F. Alonzo, Suzanne Razouls, J.p. Labat, Patrick Mayzaud, Pierre JouventinAbstract:The importance of the euchaetid copepod Paraeuchaeta antarctica in the subantarctic pelagic ecosystem was quantified in the coastal waters of the Golfe du Morbihan at Kerguelen Islands by comparing food samples from two diving seabirds with concurrent net samples taken within the predator foraging area. Paraeuchaeta antarctica occurred in very high densities (up to 30 individuals m–3 and 96 mg dry weight m–3) in the water column, being more abundant in the deepest part of the gulf than in shallow waters or at the more offshore shelf stations. The common diving Petrel feeds almost exclusively on crustaceans, its diet being dominated by the amphipod Themisto gaudichaudii (52% by number and 84% by reconstituted mass) and P. antarctica (33% and 16%, respectively). Rockhopper penguins preyed upon crustaceans and fish, with four taxa being important, namely T. gaudichaudii (37% and 23%, respectively), Euphausia vallentini (24% and 41%), postlarval fish (10% and 24%), and P. antarctica (13% and 3%). Paraeuchaeta antarctica dominated numerically in 21% of the diving-Petrel food samples and in 12% of penguin samples. The two bird species segregated by preying upon different developmental stages of P. antarctica, diving Petrels fed equally on CV of both sexes and CVI, while penguins fed on CVI only. Comparison of P. antarctica found in net and food samples indicated no prey selection by common diving Petrels that caught the different copepod stages in proportion to their availability in the water column. On the other hand, the diving performance of penguins, which is better than that of the Petrels (mean maximum dive depths 69 m for penguins versus 32 m in Petrels), allows them to catch CVI in deeper waters, probably near the bottom. Our study shows that P. antarctica is a major component of the coastal macrozooplankton community and a significant prey for two species of diving seabirds inhabiting Kerguelen. This is also the first record of a copepod species as a prey for penguin, and the first to highlight P. antarctica in the food of austral seabirds.
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effect of sea ice extent on adult survival of an antarctic top predator the snow Petrel pagodroma nivea
Oecologia, 2000Co-Authors: Christophe Barbraud, Henri Weimerskirch, Christophe Guinet, Pierre JouventinAbstract:The snow Petrel Pagodroma nivea is an obligate associate of sea-ice and one of the most abundant seabird species of the Southern Ocean. Time- and sex-specific annual variation in adult survival was estimated using capture-mark-recapture of Petrels nesting at Petrels Island, Terre Adelie, 1981–1997. On the basis of a regression analysis, 44% of the variation was linked inversely to the latitudinal extent of sea-ice during winter (June) in the region offshore of the study colony, where this population is likely to spend the non-breeding season. Monthly sea-surface temperature anomalies tended to influence adult survival but the relationship was not statistically significant. Why sea-ice extent should have such a critical effect on this species is yet to be explained, but the relationship, in the context of environmental warming and the consequent potential loss of Antarctic sea-ice, is an important one for this species.
Christophe Barbraud - One of the best experts on this subject based on the ideXlab platform.
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Do repeated captures and handling affect phenotype and survival of growing Snow Petrel (Pagodroma nivea)?
Polar Biology, 2020Co-Authors: Sophie M. Dupont, Karine Delord, Charline Parenteau, Cécile Ribout, Christophe Barbraud, Olivier Chastel, Frederic AngelierAbstract:In vertebrates, developmental conditions can affect not only fledging success but also the phenotype of the offspring, with potential long-term consequences on adult performance. However, surprisingly the potential impact of anthropogenic disturbance on developing chicks is rarely investigated, notably in Antarctic wildlife. In this study, we specifically investigated the effects of repeated nest visits, capture, and handling on offspring survival and several complementary offspring phenotypic traits in the Snow Petrel ( Pagodroma nivea ) chicks after thermal emancipation. We did not find any significant effect of our disturbance protocol on the morphology (body size, body mass, body condition), the physiology (breath rate, stress-induced corticosterone levels) and the behaviour (defense behaviour) of developing Snow Petrels. This specific disturbance protocol did not have any significant effect on chick survival, but there was a non-significant trend towards a lower survival for the disturbed group ( p = 0.1006), which showed an especially high mortality during a period of repeated snow storms. To conclude, investigator disturbance seems to have little effect on Snow Petrel chicks after thermal emancipation, but to remain cautious, we recommend to avoid capture and handling of Snow Petrel chicks during or soon after inclement weather.
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Species‐specific foraging strategies and segregation mechanisms of sympatric Antarctic fulmarine Petrels throughout the annual cycle
Ibis, 2016Co-Authors: Karine Delord, Sophie De Grissac, David Pinaud, Christophe Barbraud, Patrick Pinet, Yves Cherel, Agnes Lewden, Henri WeimerskirchAbstract:International audienceDetermining the year-round distribution and behaviour of birds is necessary for a betterunderstanding of their ecology and foraging strategies. Petrels form an important componentof the high-latitude seabird assemblages in terms of species and individuals. The distributionand foraging ecology of three sympatric fulmarine Petrels (Southern FulmarFulmarus glacialoides, Cape Petrel Daption capense and Snow Petrel Pagodroma nivea)were studied at Adelie Land, East Antarctica, by combining information from miniaturizedsaltwater immersion geolocators and stable isotopes from feathers. During thebreeding season at a large spatial scale (c. 200 km), the three species overlapped in theirforaging areas located in the vicinity of the colonies but were segregated by their dietand trophic level, as indicated by the different chick d15N values that increased in theorder Cape Petrel < Southern Fulmar < Snow Petrel. During the non-breeding season,the three fulmarines showed species-specific migration strategies along a wide latitudinalgradient. Snow Petrels largely remained in ice-associated Antarctic waters, Southern Fulmarstargeted primarily the sub-Antarctic zone and Cape Petrels migrated further north.Overall, birds spent less time in flight during the non-breeding period than during thebreeding season, with the highest percentage of time spent sitting on the water occurringduring the breeding season and at the beginning of the non-breeding period beforemigration. This activity pattern, together with the d13C values of most feathers, stronglysuggests that moult of the three fulmarine Petrels occurred at that time in the very productivehigh Antarctic waters, where birds fed on a combination of crustaceans and fish.The study highlights different segregating mechanisms that allow the coexistence of closelyrelated species, specifically, prey partitioning during the breeding season and spatialsegregation at sea during the non-breeding season
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effect of sea ice extent on adult survival of an antarctic top predator the snow Petrel pagodroma nivea
Oecologia, 2000Co-Authors: Christophe Barbraud, Henri Weimerskirch, Christophe Guinet, Pierre JouventinAbstract:The snow Petrel Pagodroma nivea is an obligate associate of sea-ice and one of the most abundant seabird species of the Southern Ocean. Time- and sex-specific annual variation in adult survival was estimated using capture-mark-recapture of Petrels nesting at Petrels Island, Terre Adelie, 1981–1997. On the basis of a regression analysis, 44% of the variation was linked inversely to the latitudinal extent of sea-ice during winter (June) in the region offshore of the study colony, where this population is likely to spend the non-breeding season. Monthly sea-surface temperature anomalies tended to influence adult survival but the relationship was not statistically significant. Why sea-ice extent should have such a critical effect on this species is yet to be explained, but the relationship, in the context of environmental warming and the consequent potential loss of Antarctic sea-ice, is an important one for this species.
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Subspecies-selective predation of snow Petrels by skuas
Oikos, 1999Co-Authors: Christophe BarbraudAbstract:Snow Petrel (Pagodroma nivea) populations in Antarctica are highly variable in body size (coefficient of variation of 5%, 7%, 8%, 9% for wing, tarsus, and bill lengths, and bill depth, respectively). Two subspecies have been recognised, a large one P. n. major and a small one P. n. minor. At few locations both subspecies breed sympatrically in varying proportions. Snow Petrels' main predator on breeding grounds is the south polar skua (Catharacta maccormicki). To understand the evolutionary processes shaping body size in the snow Petrel, I evaluated selective predation of snow Petrels by south polar skuas on an island near Antarctica. Food remains (n = 43) collected in 16 skua territories indicated no significant subspecies-selective predation on adult snow Petrel. In both subspecies nest characteristics (open, intermediate and concealed; n = 110) and predation on eggs and chicks were studied. Egg predation did neither differ significantly between the larger (15.8%) and smaller subspecies (12.5%) of snow Petrel, nor within each subspecies relative to body size of the pairs. More chicks issued from pairs of the larger subspecies (37.5%) than chicks issued from pairs of the smaller one (0%) disappeared during the breeding season because of predation by skuas. No size-selective predation on chicks was found within the large subspecies, Birds of the large subspecies occupied more open nest sites than birds of the small subspecies (P < 0.001), and open nests were preyed upon more often than concealed nests (P = 0.041). As body size seems to be heritable in the snow Petrel according to subspecies (h 2 = 0.61 ± 0.14) and within subspecies (smaller: h 2 = 0.92 ± 0.31: larger: h 2 = 0.87 ± 0.37). predation by south polar skuas may pose a selection against the larger subspecies.
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Fulmarine Petrels and South Polar Skua Catharacta maccormickii populations on Ardery Island, Windmill Islands, Antarctica.
Emu, 1998Co-Authors: Christophe Barbraud, Susan C BakerAbstract:The Ardery and Odbert Islands, Antarctica (66°22′S, 110°27′E) have been declared a Specially Protected Area (SPA) because of their breeding populations of species of fulmarine Petrels. Published information on the bird life in this SPA was summarised by Bonner & Lewis-Smith (1985) and van Franeker et al. (1990). During the summer 1995/96, a survey of the distribution and numbers of fulmarine Petrels and South Polar Skuas Catharacta maccormicki on Ardery Island was undertaken for comparison with previous surveys. Population counts on the island were made from 20–31 December 1995, during early incubation for most species. We counted the number of ‘apparently occupied nest sites’ (van Franeker et al. 1990) of Southern Fulmar Fulmarus glacialoides, Antarctic Petrel Thalassoica antarctica, and Cape Petrel Daption capense breeding in the open. In a couple of locations populations were estimated. For Snow Petrel Pagodroma nivea, the breeding population was considered to equal number of pairs sitting on rocks at dusk, a period when they often sit at nest entrances (Marchant & Higgins 1990).
