Foraging in a changing environment: habitat shifts of an oceanic predator over the last half century

Spatial modelling studies stress the importance of predicting future species distribution in changing environments, but it is also important to establish historical distribution ranges of species to provide baseline conditions for understanding distribution shifts. We focused on pelagic ecosystems, the largest ecosystem on Earth. Based on boosting algorithms, we reconstructed the foraging patterns of an oceanic predator, wandering albatross Diomedea exulans, in the highly dynamic Southern Ocean over the last half century. To access the unobserved past oceanographic conditions, we used simulations of the OPA‐PISCES oceanic model for the 1958–2001 period. Firstly, we validated the simulated oceanographic variables (sea surface temperature and height, wind speed and chlorophyll a) for the 1998–2001 period with remotely sensed oceanographic data, which were highly correlated, except chlorophyll a. Secondly, we developed two habitat models (based on simulated and observed oceanographic variables) describing the foraging probability of albatrosses. We detected no statistically significant differences between the two models and predictions of both models matched the observed distribution patterns reasonably. Finally, we projected the most likely historical key pelagic habitats of albatross for the 1958 to 2001 period and characterised recurrent, occasional and unfavourable foraging areas in a decadal basis based on average predictions and their standard deviations. Our findings 1) provided a historical baseline (1958–1968) of recurrent, occasional and unfavourable foraging habitats, 2) evidenced a progressive habitat shift the following decades driven by a propagation of sea surface height from SE South Africa towards Antarctica from 1958 to 2001 and 3) measured habitat change rates of wandering albatross over the last half century. To our knowledge, our study provides the first quantitative long‐term assessment of the spatial response of a marine top predator to changing pelagic habitats of the Southern Ocean and highlighted the oceanographic mechanisms involved, offering new insights on future effects of climate change on the pelagic realm.     

Piecing together the global population puzzle of wandering albatrosses: genetic analysis of the Amsterdam albatross Diomedea amsterdamensis

Wandering albatrosses have been subjected to numerous taxonomic revisions due to discoveries of new species, analyses of morphological data and, more recently, the inclusion of genetic data. The small population of albatrosses (170 individuals including 26 pairs breeding annually) on Amsterdam Island in the Indian Ocean, Diomedea amsterdamensis, has been given species status based on plumage and morphometrics, but genetic data published to date provide weak support and its specific status remains controversial for some authors. We used mitochondrial control region sequence data to elucidate the relationship of the Amsterdam albatross within the wandering albatross complex (Diomedea amsterdamensis, D. antipodensis, D. dabbenena and D. exulans). Three novel haplotypes were present in 35 individuals from Amsterdam Island, and were highly divergent (3.6–7.3%) from haplotypes found in the other three members of the wandering albatross complex. Low levels of genetic variation in Amsterdam albatross likely resulted, at least in part, from a population bottleneck. Geographic isolation in the wandering albatross complex is maintained by high natal philopatry. As Amsterdam Island is the only breeding ground for this critically endangered species, we strongly urge conservation efforts in the area, especially in relation to long line fisheries and other threats such as disease and introduced predators, and it be listed as a distinct species.     

Mercury and cadmium concentrations in the tissues of three species of southern albatrosses

Cadmium and mercury concentrations were measured in the tissues of 64 individual albatrosses [23 wandering albatrosses (Diomedea exulans), 9 royal albatrosses (Diomedea epomophora) and 32 shy albatrosses (Thalassarche cauta)] which were killed as by-catch in longline fishing activities between 1991 and 1994. Mercury concentrations were also determined for 33 shy albatross eggs (excluding shells). The birds were all sexed and assigned to one of two age classes (immature and adult). The three species exhibited differences both in overall concentrations of cadmium and mercury, and also in the pattern of accumulation of metals with age and sex. Wandering albatrosses exhibited the highest mercury concentrations with a mean concentration in adult liver samples of 920.0 ± 794.1 μg g⁻¹ dry weight. Shy albatrosses had the lowest mercury concentrations with mean concentrations in adult livers of 36.3 ± 21.4 mg g⁻¹ dry weight. The highest mercury concentration was 1800 μg g⁻¹ for an adult female wandering albatross. Cadmium concentrations were less variable, with adult royal albatrosses having the highest average concentrations (180.0 ± 165.0 in adult kidneys) and adult shy albatrosses the lowest (40.1 ± 20.0 in adult kidney). The highest individual cadmium concentration was 287 μg g⁻¹ for a juvenile wandering albatross. There was no evidence of increased accumulation of cadmium with age in any of the species, but wandering albatrosses showed higher mercury concentrations in adults than juveniles. Female wandering albatrosses also had significantly higher mercury concentrations than males. The mercury contents of the shy albatross eggs were very low, with a maximum concentration of 5.4 μg g⁻¹. The results of this study are consistent with the findings of previous work on albatrosses and support the notion that the life-history strategy of these species (i.e. long-lived with low reproductive output) may be an important determinant in the concentrations of some metals found in their tissues. Accepted: 15 February 1999     

Surviving with low genetic diversity: the case of albatrosses

Low genetic diversity is predicted to negatively impact species viability and has been a central concern for conservation. In contrast, the possibility that some species may thrive in spite of a relatively poor diversity has received little attention. The wandering and Amsterdam albatrosses (Diomedea exulans and Diomedea amsterdamensis) are long-lived seabirds standing at an extreme along the gradient of life strategies, having traits that may favour inbreeding and low genetic diversity. Divergence time of the two species is estimated at 0.84 Myr ago from cytochrome b data. We tested the hypothesis that both albatrosses inherited poor genetic diversity from their common ancestor. Within the wandering albatross, per cent polymorphic loci and expected heterozygosity at amplified fragment length polymorphisms were approximately one-third of the minimal values reported in other vertebrates. Genetic diversity in the Amsterdam albatross, which is recovering from a severe bottleneck, was about twice as low as in the wandering albatross. Simulations supported the hypothesis that genetic diversity in albatrosses was already depleted prior to their divergence. Given the generally high breeding success of these species, it is likely that they are not suffering much from their impoverished diversity. Whether albatrosses are unique in this regard is unknown, but they appear to challenge the classical view about the negative consequences of genetic depletion on species survival.     

Early‐life foraging: Behavioral responses of newly fledged albatrosses to environmental conditions

In order to survive and later recruit into a population, juvenile animals need to acquire resources through the use of innate and/or learnt behaviors in an environment new to them. For far‐ranging marine species, such as the wandering albatross Diomedea exulans, this is particularly challenging as individuals need to be able to rapidly adapt and optimize their movement strategies in response to the highly dynamic and heterogeneous nature of their open‐ocean pelagic habitats. Critical to this is the development and flexibility of dispersal and exploratory behaviors. Here, we examine the movements of eight juvenile wandering albatrosses, tracked using GPS/Argos satellite transmitters for eight months following fledging, and compare these to the trajectories of 17 adults to assess differences and similarities in behavioral strategies through time. Behavioral clustering algorithms (Expectation Maximization binary Clustering) were combined with multinomial regression analyses to investigate changes in behavioral mode probabilities over time, and how these may be influenced by variations in day duration and in biophysical oceanographic conditions. We found that juveniles appeared to quickly acquire the same large‐scale behavioral strategies as those employed by adults, although generally more time was spent resting at night. Moreover, individuals were able to detect and exploit specific oceanographic features in a manner similar to that observed in adults. Together, the results of this study suggest that while shortly after fledging juvenile wandering albatrosses are able to employ similar foraging strategies to those observed in adults, additional skills need to be acquired during the immature period before the efficiency of these behaviors matches that of adults.     

Regulation of foraging trips and incubation routine in male and female wandering albatrosses

The resolution of the conflict between eggcare and foraging was studied in male and female wandering albatrosses. The foraging zone and range, duration of incubation shifts and foraging trips, and associated changes in body mass were studied. Costs during incubation, expressed as the time spent incubating and the proportional loss of body mass, were similar for both sexes. The mass gained at sea was related to the duration of foraging trips, but the relationship was much less significant in males, where foraging ranges, though similar on average to those of females, were very variable. Males foraged in more southerly waters than females, and gained mass more rapidly. Only females appeared to regulate the duration of foraging trips, and this compensated for the mass lost during the incubation fast. Previous breeding experience had no influence on foraging efficiency. Egg desertion because of depletion of body reserves was very rare because birds have a wide safety margin, i.e. the difference between the average body mass when relieved and that at nest desertion. This safety margin enables the birds to compensate for the high variability in the duration of foraging trips, and is probably a reason for the high breeding success of wandering albatrosses. Decisions to return from the sea to the nest or to desert the nest are probably related to the status of body reserves, and have been selected in the large wandering albatross so that both present and future reproductive success are maximised.     

Predator–prey interactions: why do larger albatrosses eat bigger squid?

The relationship between predator sizes and prey sizes is well documented for terrestrial but rarely for marine ecosystems. We show that wandering albatrosses, the biggest albatross species, feed on larger cephalopod prey than those consumed by smaller albatrosses (grey-headed and black-browed albatrosses). This reflects differences in timing of breeding, foraging ecology and their feeding methods. Wandering albatrosses breed later in the year, during the austral winter, than smaller albatrosses (therefore catching older squid) and forage most of the year in Antarctic open waters, sub-Antarctic, subtropical and tropical waters, overlapping minimally with the smaller albatrosses' foraging range while breeding. Also, wandering albatrosses mostly scavenge whereas smaller albatrosses feed more on live prey. Prey ecology may also play a key role because many squid species might experience post-spawning mortality during the austral winter, becoming easily available to wandering albatrosses. Spawning in winter can be linked to predator avoidance (i.e. reduction in mortality in winter by avoiding pelagic predators) and would allow squid larvae to develop and take advantage of the high productivity (i.e. Antarctic phytoplankton bloom) in spring and at the beginning of summer. Thus, aspects of prey and predator ecology may combine to generate observed differences in prey size.     

Postnatal dispersal of wandering albatrosses Diomedea exulans: implications for the conservation of the species

Many large marine vertebrates are today threatened by human activities and it is therefore crucial to obtain information on their distribution and behaviour at sea. In particular little is known about the time necessary for juveniles to acquire the foraging skills of adults. We tracked 13 juvenile wandering albatrosses Diomedea exulans by satellite telemetry during their first year at sea. They covered an average distance of 184,000 km during the first year and restricted their dispersal to the unproductive waters of the subtropical Indian Ocean and Tasman Sea. This region of low wind velocities does not overlap with the foraging areas used by adults. After an innate phase of rapid dispersal with a fixed flight direction, young birds progressively increased their daily flight distances and attained adult flight efficiency within their first six months at sea. The complete overlap of the juveniles’ foraging ranges with major long‐line fisheries in the subtropical waters constitutes a major threat that could jeopardize the long term recovery ability of populations of the endangered wandering albatross in the Indian Ocean.     

A comprehensive isotopic investigation of habitat preferences in nonbreeding albatrosses from the Southern Ocean

Albatrosses are among the world's most endangered seabirds. Threats during the nonbreeding period have major impacts on their population dynamics, but for most species, detailed information on distribution and ecology remains essentially unknown. We used stable isotope values (δ¹³C and δ¹⁵N) in feathers to infer and compare the moulting (nonbreeding) habitats of 35 populations that include all the 20 species and subspecies (444 individuals) of albatrosses breeding within the Southern Ocean and in fringing subtropical waters. Isotopic values together with a review of available information show that the 20 albatrosses can be categorized into three groups depending on their favoured moulting grounds: 12 (60%) taxa forage primarily in warm neritic waters, six (30%) in northern oceanic waters and two (10%) in oceanic waters of the Southern Ocean. Stable isotopes indicate that habitat preferences during the nonbreeding period vary much less among different breeding populations in some species (wandering, Salvin's, grey‐headed and light‐mantled sooty albatrosses), than others (black‐browed, Indian yellow‐nosed and sooty albatrosses). The major finding of our isotopic investigation is that the great majority of albatrosses spend the nonbreeding period outside the Southern Ocean, with only three species (and in the sooty albatross, just one of the breeding populations) favouring oceanic subantarctic waters at that time. Hence, the study highlights the overwhelming importance of subtropical waters for albatrosses, where the birds are known to interact with human activities and are more likely to be negatively affected by the diverse range of fisheries operating in both neritic and oceanic waters.     

Individual foraging site fidelity in lactating New Zealand fur seals: Continental shelf vs. oceanic habitats

Wide‐ranging marine central place foragers often exhibit foraging site fidelity to oceanographic features over differing spatial scales (i.e., localized coastal upwellings and oceanic fronts). Few studies have tested how the degree of site fidelity to foraging areas varies in relation to the type of ocean features used. In order to determine how foraging site fidelity varied between continental shelf and oceanic foraging habitats, 31 lactating New Zealand fur seals (Arctocephalus australis forsteri 1 ) were satellite tracked over consecutive foraging trips (14–108 d). Thirty‐seven foraging trips were recorded from 11 females that foraged on the continental shelf, in a region associated with a coastal upwelling, while 65 foraging trips were recorded from 20 females that foraged in oceanic waters. There were no significant differences in the mean bearings (to maximum distance) of individual's consecutive foraging trips, suggesting individual fidelity to foraging areas. However, overlap in area and time spent in area varied considerably between continental shelf and oceanic foragers. Females that foraged on the continental shelf had significantly greater overlap in consecutive foraging trips when compared to females that foraged in oceanic waters (overlap in 5 × 5 km grid cells visited on consecutive trips 55.9%± 20.4% and 13.4%± 7.6%, respectively). Females that foraged on the continental shelf also spent significantly more time within the same grid cell than females that foraged in oceanic waters (maximum time spent in 5 × 5 km grid cells: 14%± 5% and 4%± 2%, respectively). This comparatively high foraging site fidelity may reflect the concentration of productivity associated with a coastal upwelling system, the Bonney Upwelling. Lower foraging site fidelity recorded by seals that foraged in oceanic waters implies a lower density/larger scale habitat, where prey are more dispersed or less predictable at fine scales, when compared to the continental shelf region.     

Giant petrels as predators of albatross chicks

Giant petrels Macronectes spp. are not thought to be important predators of albatross chicks, although they are known to kill pre-fledging Thalassarche and Phoebetria albatrosses. We report the first records of predation of healthy great albatross Diomedea spp. chicks, killing wandering albatrosses D. exulans at night on sub-Antarctic Marion Island. Breeding success of this species has decreased markedly in the area where attacks occurred, suggesting that giant petrel predation events are a recent phenomenon. Mouse attacks on wandering albatross chicks may have contributed to the development of this hunting technique. We also report the first observations of giant petrel predation on pre-fledging grey-headed albatross T. chrysostoma chicks as well as additional records of sooty albatross P. fusca chicks being targeted. Only adult northern giant petrels M. halli have been confirmed to kill albatross chicks on Marion Island. Given the threatened status of wandering albatrosses, and the importance of Marion Island for this species, monitoring of their breeding success is necessary to assess whether the predation of chicks by giant petrels spreads around the island.     

Notes on New Zealand mammals 8. Predation on nesting southern royal albatrosses Diomedea epomophora by a New Zealand sea lion Phocarctos hookeri

Abstract

This note documents unusual predation of southern royal albatrosses Diomedea epomophora on land by an individual New Zealand sea lion Phocarctos hookeri. During a survey of albatross nests on Campbell Island in the New Zealand sub‐antarctic in January 2005, 128 corpses of adult albatrosses were found at or near nests within a 230 ha area. Flattened vegetation and flipper prints near the nests suggested sea lion predation, and subsequently a male sea lion was found near a line of freshly killed birds. The predation rate was estimated to be at least seven birds per day over a number of weeks; similar skeletal remains from the previous year were observed in a neighbouring area. The impact of one threatened species on another can be a dilemma for conservation managers. In this case, apparently only one male sea lion was involved and, because of the ongoing impact to the albatross population, permission was obtained to cull that individual on 17 January 2005. No further incidents were observed over the following three seasons (2006–08).     

Annual energy budget and food requirements of breeding wandering albatrosses (<Emphasis Type="Italic">Diomedea exulans</Emphasis>)

Energy budgets form an integral part of our understanding of animal energetics, particularly when presented in the context of reproduction. In this paper, I created a time-energy budget for a breeding pair of wandering albatrosses (Diomedea exulans) to estimate the annual breeding costs and food requirements of the population at Possession Island, Crozet Archipelago. For a breeding cycle that lasts 356 days on average, a pair uses 2,733 MJ to raise a single chick to fledging. This estimate is 1.21 times higher than previously calculated for wandering albatrosses breeding at Marion Island. Unlike the current analysis, the previous study assumed that foraging costs were constant across all stages of the breeding cycle. Recent evidence shows that foraging costs vary during breeding for wandering albatrosses at Crozet and this is probably true for all populations. Incubation costs have also been shown to be substantially lower than previously determined. Therefore, if a wandering albatross pair at Crozet uses a total of 2,733 MJ to breed, they would need to consume at least 1.7 kg bird^–1 day^–1 of fresh food, on average, to balance their own energy requirements and to provision a single chick for approximately 278 days. At this rate of food consumption, the breeding population at Crozet would consume approximately 340 tonnes of fresh food per breeding season.     

Cryptic speciation and population differentiation in the yellow-nosed albatross species complex

The two species of yellow-nosed albatross, Atlantic (Thalassarche chlororhynchos) and Indian (T. carteri), are morphologically similar, but they differ in breeding behaviour and distribution. Both species are listed as endangered by the IUCN due to the limited number of breeding sites, threats from introduced predators and diseases, and impact of commercial fishing. We quantified genetic variation between and within the two species. Using nuclear (microsatellites and two nuclear sequences) and mitochondrial (control region) markers, we analysed 354 samples from four breeding islands (Atlantic: Nightingale, Inaccessible, and Gough; Indian: Amsterdam) and bycatch samples from South Africa and New Zealand. In addition to all markers separating the two species, nuclear markers showed Atlantic yellow-nosed albatrosses from Gough Island are genetically distinct from those breeding at Nightingale and Inaccessible Islands in the Tristan da Cunha archipelago. Nuclear markers confirmed that all bycatch samples were Indian yellow-nosed albatrosses, however, the bycatch birds from South Africa and New Zealand were distinct from each other and from birds breeding on Amsterdam Island, suggesting colony specific dispersal at sea. Our study supports the current recognition of two yellow-nosed albatross species and recognises genetically distinct groups of both Atlantic and Indian yellow-nosed albatross breeding on different islands, which is important for their conservation and management.

     

Wind,Waves, and Wing Loading: Morphological Specialization May Limit Range Expansion of Endangered Albatrosses

Among the varied adaptations for avian flight, the morphological traits allowing large-bodied albatrosses to capitalize on wind and wave energy for efficient long-distance flight are unparalleled. Consequently, the biogeographic distribution of most albatrosses is limited to the windiest oceanic regions on earth; however, exceptions exist. Species breeding in the North and Central Pacific Ocean (Phoebastria spp.) inhabit regions of lower wind speed and wave height than southern hemisphere genera, and have large intrageneric variation in body size and aerodynamic performance. Here, we test the hypothesis that regional wind and wave regimes explain observed differences in Phoebastria albatross morphology and we compare their aerodynamic performance to representatives from the other three genera of this globally distributed avian family. In the North and Central Pacific, two species (short-tailed P. albatrus and waved P. irrorata) are markedly larger, yet have the smallest breeding ranges near highly productive coastal upwelling systems. Short-tailed albatrosses, however, have 60% higher wing loading (weight per area of lift) compared to waved albatrosses. Indeed, calculated aerodynamic performance of waved albatrosses, the only tropical albatross species, is more similar to those of their smaller congeners (black-footed P. nigripes and Laysan P. immutabilis), which have relatively low wing loading and much larger foraging ranges that include central oceanic gyres of relatively low productivity. Globally, the aerodynamic performance of short-tailed and waved albatrosses are most anomalous for their body sizes, yet consistent with wind regimes within their breeding season foraging ranges. Our results are the first to integrate global wind and wave patterns with albatross aerodynamics, thereby identifying morphological specialization that may explain limited breeding ranges of two endangered albatross species. These results are further relevant to understanding past and potentially predicting future distributional limits of albatrosses globally, particularly with respect to climate change effects on basin-scale and regional wind fields.     

Use and exploitation of channel waters by the black-browed albatross

Black-browed albatrosses are the most abundant albatross species of the southern hemisphere, breeding on sub-Antarctic and Antarctic oceanic islands around the globe. Their foraging habitat during the breeding season is reasonably well known along its distributional range, indicating a preferred use of waters <500 m deep. The discovery of a colony inserted within the Admiralty Sound, Tierra del Fuego, poses an interesting challenge to the known precepts on foraging behavior for the species. In this study, we present the first record on the foraging distribution of the only known inner-channel colony of albatrosses in the world, using high-resolution GPS loggers. Black-browed albatrosses breeding at the Albatross Islet used exclusively inner-channel waters, at least during the chick-guard stage. Our results indicate a significant smaller foraging range during chick-guard compared with conspecifics from Diego Ramirez and Falklands/Malvinas Islands. Implications for the conservation of this colony are discussed.     

Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico

For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state‐space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998–2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their “final” foraging sites. We identified new foraging “hotspots” where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13‐year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at‐sea foraging habitats for this imperiled species.     

Postnatal dispersal of wandering albatrosses Diomedea exulans: implications for the conservation of the species

Many large marine vertebrates are today threatened by human activities and it is therefore crucial to obtain information on their distribution and behaviour at sea. In particular little is known about the time necessary for juveniles to acquire the foraging skills of adults. We tracked 13 juvenile wandering albatrosses Diomedea exulans by satellite telemetry during their first year at sea. They covered an average distance of 184,000 km during the first year and restricted their dispersal to the unproductive waters of the subtropical Indian Ocean and Tasman Sea. This region of low wind velocities does not overlap with the foraging areas used by adults. After an innate phase of rapid dispersal with a fixed flight direction, young birds progressively increased their daily flight distances and attained adult flight efficiency within their first six months at sea. The complete overlap of the juveniles' foraging ranges with major long-line fisheries in the subtropical waters constitutes a major threat that could jeopardize the long term recovery ability of populations of the endangered wandering albatross in the Indian Ocean.     

Molecular provenance analysis for shy and white-capped albatrosses killed by fisheries interactions in Australia, New Zealand, and South Africa

Shy and white-capped albatrosses, Thalassarche cauta and T. steadi, respectively, are phenotypically similar and are known to suffer fisheries-related bycatch mortality across their foraging range. Assessments of the extent or scale of impact of bycatch mortality on these species have previously been precluded by difficulties identifying bycatch carcasses to species level. In this study, a fast and simple molecular test based on a single nucleotide polymorphism in mtDNA of shy and white-capped albatrosses was used to determine the species composition of fisheries bycatch carcasses recovered from Australian, New Zealand, and South African waters. The only area where bycatch mortality of both species co-occurred was in Tasmanian waters; in all other zones the bycatch was exclusively comprised of white-capped albatrosses. Genotypic provenance assignment tests of shy albatrosses, a species with significant genetic structure between island colonies, correctly assigned 72% to their island of origin. These data are the first to provide insight into the relative vulnerability of shy and white-capped albatrosses to bycatch mortality across their foraging range, and to establish the vast differences in the at-sea distributions of these two species.     

Satellite tracking of light-mantled sooty albatrosses

Five light-mantled sooty albatrosses (Phoebetria palpebrata) breeding at Macquarie Island were tracked with miniaturised satellite transmitters during foraging trips of the incubation period. Birds moved rapidly to specific sectors of the Southern Ocean, where they spent several days foraging before returning to their nests. These specific sectors were at an average distance of 1516 km from Macquarie Island and located in pelagic Antarctic waters, mostly along the Antarctic continent. The maximum foraging range was in average 1721 km and the total distance covered by two birds for which there were complete tracks was 6463 and 6975 km. This study confirms previous suggestions that light-mantled sooty albatrosses are able to forage in the waters of the high Antarctic while breeding in the sub-Antarctic. The implications of the extreme separation of feeding zones from nesting grounds, in terms of conservation and life-history strategies, are discussed.