Seabirds

Birds encounter climate at the scale of microclimates that can vary rapidly in time and space and so understanding potential vulnerability and adaptations to those microclimates requires fine‐scale measurements that accurately track thermal exposures. However, few options exist for recording the microclimates actually experienced by birds (realized microclimates). We constructed and tested a simple, low‐cost, temperature logger for recording the realized microclimates of ground‐nesting birds. We developed attachment protocols for band‐mounting Thermochron iButtons on Ring‐billed Gull (Larus delawarensis) chicks. We tested these mounted, temperature‐logging devices on 20 chicks weighing > 200 g (device weight was 4 g), attaching devices for 48 h and observing behavior before and after attachment and removal. Devices recorded temperature immediately surrounding the leg at 2‐min intervals. Recorded temperatures were strong predictors of observed thermoregulatory behaviors (panting and sitting), outperforming predictions based on air temperatures measured by basic, static approaches. Through comparison with matched controls (chicks with just a band), we detected no adverse physiological effects of devices, no effects on social or feeding behavior, and only a short‐term decrease in inactivity immediately after device attachment (likely due to increased preening). By attaching iButtons to the legs of birds, we quantified realized thermal exposure, integrating air temperature, modes of environmental heat transfer, and bird behavior at microclimatic scales. Although not yet validated for broader use, our approach (including possible miniaturization) should be suitable to measure thermal exposure of adults, not just chicks, allowing collection of data concerning thermal exposures during flight under field conditions. At ~ $25 USD per device, our approach facilitates experimental protocols with robust sample sizes, even for relatively modest budgets.

There is now abundant evidence that contemporary climatic change has indirectly affected a wide-range of species by changing trophic interactions, competition, epidemiology and habitat. However, direct physiological impacts of changing climates are rarely reported for endothermic species, despite being commonly reported for ectotherms. We review the evidence for changing physiological constraints on endothermic vertebrates at high temperatures, integrating theoretical and empirical perspectives on the morphology, physiology and behavior of marine birds. Potential for increasing heat stress exposure depends on changes in multiple environmental variables, not just air temperature, as well as organism-specific morphology, physiology and behavior. Endotherms breeding at high latitudes are vulnerable to the forecast, extensive temperature changes because of the adaptations they possess to minimize heat loss. Low-latitude species will also be challenged as they currently live close to their thermal limits and will likely suffer future water shortages. Small, highly-active species, particularly aerial foragers, are acutely vulnerable as they are least able to dissipate heat at high temperatures. Overall, direct physiological impacts of climatic change appear underrepresented in the published literature, but available data suggest they have much potential to shape behavior, morphology and distribution of endothermic species. Coincidence between future heat stress events and other energetic constraints on endotherms remains largely unexplored but will be key in determining the physiological impacts of climatic change. Multi-scale, biophysical modeling, informed by experiments that quantify thermoregulatory responses of endotherms to heat stress, is an essential precursor to urgently-needed analyses at the population or species level.

Global forage-fish landings are increasing, with potentially grave consequences for marine ecosystems. Predators of forage fish may be influenced by this harvest, but the nature of these effects is contentious. Experimental fishery manipulations offer the best solution to quantify population-level impacts, but are rare. We used Bayesian inference to examine changes in chick survival, body condition and population growth rate of endangered African penguins Spheniscus demersus in response to 8 years of alternating time–area closures around two pairs of colonies. Our results demonstrate that fishing closures improved chick survival and condition, after controlling for changing prey availability. However, this effect was inconsistent across sites and years, highlighting the difficultly of assessing management interventions in marine ecosystems. Nevertheless, modelled increases in population growth rates exceeded 1% at one colony; i.e. the threshold considered biologically meaningful by fisheries management in South Africa. Fishing closures evidently can improve the population trend of a forage fish- dependent predator—we therefore recommend they continue in South Africa and support their application elsewhere. However, detecting demographic gains for mobile marine predators from small no-take zones requires experimental time frames and scales that will often exceed those desired by decision makers.

A large patch of anomalously warm water (nicknamed “the Blob”) appeared off the coast of Alaska in the winter of 2013–2014 and subsequently stretched south to Baja California. This northeastern Pacific warm-water anomaly persisted through the end of 2015. Scientists and the public alike noted widespread changes in the biological structure and composition of both open ocean and coastal ecosystems. Changes included geographical shifts of species such as tropical copepods, pelagic red crabs, and tuna; closures of commercially important fisheries; and mass strandings of marine mammals and seabirds. The
ecological responses to these physical changes have been sparsely quantified and are largely unknown. Here, we provide a bottom-up summary of some of the biological changes observed in and around the areas affected by the Blob.

The marine birds, resident and migratories species, of the coast of S„o Paulo State. From August 1997 to December 2003, studies
allowed 20 main islands to be identified along the coast of São Paulo that constitute breeding colonies of six species of resident seabirds (Fregata magnificens, Sula leucogaster, Larus dominicanus, Sterna maxima, S. eurygnatha and S. hirundinacea). In all colonies estimations were made of the effective population size (suggesting a total of 24.000 individuals in Sao Paulo), banding and reprodutive cycle observations. The peak of the breeding season for all the six species begins in autumm and ends in spring. Biological samples were taken for genetic analyses and environmental characterizations were carried
out of the areas used for breeding. It was found that S. maxima is the most endangered species, with a effective population size of only 754 individuals, and in Brazil there are colonies of this species only in the coast of Sao Paulo. The results obtained, besides contributing to the related projects, also allow guidelines that aim for the preservation of
those island and points of rest during migration (Santos-Cubat„o Mangrove, Tanigu·,Iguape and CananÈia) that have been exposed to high levels of human interaction, mainly at The Alcatrazes Archipelago that has the biggest frigate bird colony of south Brazil and it is
a center of endemic terrestrial animals besides being 5 islands considered very important to seabird breeding (ItaÁuce, Apara, Laje da ConceiÁ„o, Queimada Grande and Guararitama).

This paper presents a review of the current knowledge on seabird diversity in Brazil. The term 'seabird' is applied ro members of the Orders Sphenisciforrnes (penguins). Procellariiformes (albatrosses. petrels, shearwaters and allies), some Pelecaniformcs (boobies, gannets, pelicans and frigatebirds) and some marine Charadriiforrnes (skuas, gulls. terns and skimmers). A total or 91 species of 14 families have been confirmed in the country. Of these, 25 breed in the country and the remaining 65 are divided into the following categories: 'Migrants from Southern South America. sub-Antarctic or Antarctic regions· (28 spp.), 'Migrants from Nonhern Hemisphere' (13 ssp.). and 'Vagrants (26 ssp.). Some species have two status categories because in Brazil migrant birds overlap with resident ones. Fifty species breed on Brazilian oceanic islands. while six have been nesting and breeding on small coastal islands
in south-east and south Brazil. Seven species breed on the continental coast or further inland. Migrant birds include coastal (gulls and terns) and pelagic (penguins. albatrosses, petrels and skuas) species. Coastal migrants are mainly from the Northern Hemisphere. while pelagic ones originate from the Southern Ocean. Brazil harbours a significant diversity of seabirds and has great responsibility in the conservation of many species. However. there are still few conservation programmes involving seabirds. Many islands where eabirds breed (e.g. Fernando de Noronha Archipelago) are not adequately managed and important coastal habitats have suffered from everal hundred years of degradation from human impacts.

This document contains a summary of information and research on aquatic environment issues relevant to the management of New Zealand fisheries. It is designed to complement the Ministry’s annual Reports from Fisheries Assessment Plenaries (e.g., the November Plenary, MPI 2015b, and the May plenary, MPI 2015a) and emulate those documents’ dual role in providing an authoritative summary of current understanding and an assessment of status relative to any overall targets and limits. However, whereas the Reports from Fisheries Assessment Plenaries have a focus on individual fishstocks, this report has a focus on aquatic environment fisheries management issues and biodiversity responsibilities that often cut across many fishstocks, fisheries, or activities, and sometimes across the responsibilities of multiple agencies.
This update has been developed by the Science Team within the Fisheries Management Directorate of the Regulation and Assurance branch, Ministry for Primary Industries (MPI). It does not cover all issues but, as anticipated, includes more chapters than previous editions. As with the Reports from Fisheries Assessment Plenaries, it is expected to change and grow as new information becomes available, more issues are considered, and as feedback and ideas are received. This synopsis has a broad, national focus on each issue and the general approach has been to avoid too much detail at a local, fishery, or fishstock level. For instance, the benthic (seabed) effects of mobile bottom‐fishing methods are dealt with at the level of all bottom trawl and dredge fisheries combined rather than at the level of a target fishery that, although it might be locally important, might contribute only a small proportion of the total impact. The details of benthic impacts by individual fisheries will be documented in the respective chapters in the May or November Report from the Fisheries Assessment Plenary, and linked there to the fine detail and analysis in Aquatic Environment and Biodiversity Reports (AEBRs), Fisheries Assessment Reports (FARs), and Final Research Reports (FRRs). Such sections have already been developed for several species in the Fishery Assessment Plenary Reports, and others will follow.
The first part of this document describes the legislative and broad policy context for aquatic environment and biodiversity research commissioned by MPI, and the science processes used to generate and review that research. The second, and main, part of the document contains chapters focused on various aquatic environment issues for fisheries management. Those chapters are divided into five broad themes: protected species; non‐ QMS (mostly fish) bycatch; benthic effects; ecosystem issues (including New Zealand’s oceanic setting); and marine biodiversity. A third part of the review includes a number of appendices for reference. This review is not yet comprehensive in its coverage of all issues or of all research within each issue, but attempts to summarise the best available information on the issues covered. Each chapter has been considered by the appropriate working group at least once.

This article presents results from a large-scale investigation of bird use in the Scottish Islands. Although avian archaeology has sometimes been overlooked, it has become increasingly clear that birds were a small but often important component of past diets. This is particularly relevant when it is considered that a diverse range of birds, and particularly aquatic birds, thrive in coastal and island locations. Large colonies of gregariously breeding seabirds provided a concentrated resource which could be targeted intensely for both meat and eggs. The use of aquatic birds in the Scottish Islands is therefore integral to holistically understanding diet and resource use in these settings. Aquatic birds would have offered a wide variety of dietary resources to prehistoric populations including meat and eggs, but also oil and fat. The exploitation of seabirds endured throughout Scottish Island prehistoric living from the Mesolithic to the Late Iron Age (and much further beyond), within a picture of resource use that shows both continuity and flexibility in the exploitation of aquatic birds. The acquisition of these resources required the development of several species and habitat-specific fowling techniques that demonstrate in-depth understanding of the avian resources being exploited. Local hunting and targeted fowling trips to more distant locations in the landscape and seascape are indicated by the zooarchaeological data. Exploitation of aquatic birds displays a summer focus but as part of a year-round fowling calendar, whilst preservation for later consumption may provide information on another element of the dietary picture.

Keywords
Birds; Seabirds; Fowling; Scottish Islands; Avian archaeology; Zooarchaeology

This book has six chapters presenting a wide variety of global seabird related issues, from India to Svalbard, Norway. It also has a detailed history of the use and chemical content of guano and advanced certification schemes in fisheries for seabird conservation.

Marine debris such as plastic fragments and fishing gears are accumulating in the ocean at alarming rates. This study assesses the incidence of debris in the gastrointestinal tracts of seabirds feeding at different depths and found stranded along the Brazilian coast in the period 2010-2013. More than half (55%) of the species analysed, corresponding to 16% of the total number of individuals, presented plastic particles in their gastrointestinal tracts. The incidence of debris was higher in birds feeding predominantly at intermediate (3-6 m) and deep (20-100 m) waters than those feeding at surface (< 2 m). These results suggest that studying the presence of debris in organisms mainly feeding at the ocean surface provides a limited view about the risks that this form of pollution has on marine life and highlight the ubiquitous and three-dimensional distribution of plastic in the oceans.

This article considers what is probably the most influential of all transformations to the medieval mind: the arduous heaven-bound journey of all Christians that played out in numerous forms in medieval thought and practice – as pilgrimage, as life-long psychological preparation, as spiritual ascension on death, as psychosomatic experience at Judgement. The Seafarer, one of numerous overtly and didactically religious poems in the ten-century Exeter manuscript, engages this popular theme through a narrative that is at once metaphorical and literal; it involves an ascetic peregrination of the yearning spirit, but also the tactile and physical endurance of a solitary, desolate voice navigating the atol yþa gewealc ‘terrible tossing of waves’ (6a). Into this maritime portrayal of pious transcendence comes an equally abiding image – that of the soaring bird. The key envy of birds which makes them dynamic movers between elements and between spheres enables these creatures to occupy an in-betweenness that has, of course, made them commonplace figures of the fleeing or liberated human soul across cultures and centuries, including Anglo-Saxon England. Whilst the six named species in lines 19b-25a of the poem, and the anfloga ‘lone-flier’ flight imagery at lines 58-64a have by no means lacked critical attention separately, I attempt a reading that brings these two passages together: vividly real, wandering, noisy seabirds and a pelagic bird-soul image. Far from appearing as mere background incidentals, the poet’s treatment of the seabirds we first encounter resonates with contemporary ornithological knowledge, and suggests that they feature specifically as species that best convey the trials and endeavours of a sea-going speaker who observes, listens to, and names seabirds. Speculating and conducting the journey to heaven, that is, involves a human-to-avian transformation, in which the pilgrim must inhabit and traverse the seabirds’ territory. Moreover, the curious essence of seabirds as winged creatures that are always at home on the seas and journeying to a home elsewhere establishes them as what I term ‘native foreigners’, a paradox that highlights the seafarer’s conflicting yearnings and, more widely, reflects the difficult dynamic between the earthly and celestial in the poem’s perceptions of the soul’s journey. As metaphoric relations dissolve into ambiguity even whilst they are established, this very paradox suggests birds as ideal correlatives: birds’ mysteries are aligned with uncertain adventures towards God beyond far horizons, towards a destination which is never reached in the poem.

A partir de 1840 las costas del Pacífico Sur fueron testigo de un espectacular cicloproductivo orientado a la extracción de guano fósil para fertilizar las agotadas tierraseuropeas. Hoy en día este crucial período de la historia latinoamericana está ausenteen la bibliografía chilena, fomentándose el olvido del pasado peruano de las regionesanexadas a Chile con la Guerra del Pacífico (1879-1883). Proponemos analizar loscambios en el patrón de asentamiento durante este ciclo productivo, durante el cualse fundaron poblados y puertos que articularon la explotación del fertilizante a lo largode la costa del Desierto de Atacama en la región de Tarapacá, Norte de Chile,sacando a la luz procesos históricos que se mantienen bajo un velo de olvido.

Little terns have been nesting at the Boyne estuary mouth for decades, possibly millennia given the suitability of the habitat.
• The site can produce up to 100 nesting pairs with circa 200 fledglings in optimal conditions (e.g. 2013).
• The 2017 season was the worst breeding season seen at the Baltray site since the inception of the organised wardening and protection scheme in 2007 marked by the almost complete absence of courtship/display.
• An exhaustive analysis of the possible causes of this eliminated factors such as weather, disturbance, predation etc and suggests that an increased dredging regimen both in time and in volume in end 2016 and through the breeding season in 2017 is a likely cause.
• This finding requires further investigation as well as appropriate management of dredging operations so as not to adversely impact the favourability of the site for breeding little terns in compliance with the EU Birds and Habitat Directive and their transposition into national law.
• The Appropriate Assessment (AA) undertaken in support of the dredging conditions fails to assess the impact on little terns and contains several important factual errors.
• The level of dredging exceeded the level assessed in the AA.

Understanding the mechanisms that link prey availability to predator behaviour and population change is central to projecting how a species may respond to future environmental pressures. We documented the behavioural responses and breeding investment of macaroni penguins Eudyptes chrysolophus across five breeding seasons where local prey density changed by five-fold; from very low to highly abundant. When prey availability was low, foraging trips were significantly longer and extended overnight. Birds also foraged farther from the colony, potentially in order to reach more distant foraging grounds and allow for increased search times. These extended foraging trips were also linked to a marked decrease in fledgling weights, most likely associated with reduced rates of provisioning. Furthermore , by comparing our results with previous work on this population, it appears that lowered first-year survival rates associated, at least partially, with fledging masses were also evident for this cohort. This study integrates a unique set of prey density, predator behaviour and predator breeding investment data to highlight a possible behavioural mechanism linking perturbations in prey availability to population demography.

1. Nonlinear, parametric curve-fitting provides a framework for understanding diverse ecological and evolutionary trends (e.g. growth patterns and seasonal cycles). Currently, parametric curve-fitting requires a priori assumptions of curve trajectories, restricting their use for exploratory analyses. Furthermore, use of analytical techniques [nonlinear least-squares (NLS) and nonlinear mixed-effects models] for complex parametric curves requires efficient choice of starting parameters.


2. We illustrate the new R package FlexParamCurve that automates curve selection and provides tools to analyse nonmonotonic curve data in NLS and nonlinear mixed-effects models. Examples include empirical and simulated data sets for the growth of seabird chicks.


3. By automating curve selection and parameterization during curve-fitting, FlexParamCurve extends current possibilities for parametric analysis in ecological and evolutionary studies.

Noninvasive, safe, quick marking of individual animals using distinctive colors that are highly visible and persistent is a valuable methodology, but practical techniques and permanent safe dyes are lacking. Here we describe a novel, remotely controlled dye machine to rapidly mark stationary animals in predictable locations, such as birds sitting on nests on the ground or mammals at a den or burrow site. From the month of June when birds were on eggs, using the machine, we spot-dyed 77 California least terns (Sternula antillarum browni) at a colony in California, USA, in 4 days without handling them. Concomitantly, we developed a suite of permanent (until molt or shedding), mainly phthalocyanine dyes that are incorporated chemically into feathers or fur of animals and cannot be preened or rubbed off, which have never been used before to dye animals. We found no toxicity of the dyes during in vivo testing over 1 month. This method of remote marking with permanent dyes should prove to be a useful method in animal ecology for distinguishing among individuals with minimal disturbance. (c) 2017 The Wildlife Society.

Mendonca VM, Raffaelli DG, Boyle PR. 2007. Interactions between shorebirds and benthic invertebrates at Culbin Sands lagoon, NE Scotland: Effects of avian predation on their prey community density and structure. Sci Mar 71(3):579-591.

ABSTRACT: In the North Sea, during autumn-winter, intertidal flats often receive a massive influx of migratory shorebirds (wildfowl, waders and seabirds), which utilise the high prey densities that are available. The present study was conducted at Culbin Sands lagoon, NE Scotland, in 1994-1996, to investigate benthic invertebrate standing stock, and the energy flow from benthic invertebrates to shorebirds. Benthic invertebrate standing stock was estimated to be 500 kJ m-2 yr-1, and shorebird consumption efficiency to be 18% of the available standing stock. A series of manipulative field experiments were then conducted to test the effects of shorebirds on benthic invertebrate densities and community structure. Birds were excluded from caged areas (exclosures), and benthic invertebrate densities (total and by class size) in caged and uncaged areas were compared for each season separately. During autumn-winter, especially the gastropod Hydrobia ulvae and larger-sized (>15 mm) clams Macoma balthica were observed to be the most impacted species, being significantly more abundant in birdexclosures than in bird-accessed areas.

Man-made habitats provide suitable nesting, resting
and feeding habitats for many birds at coastal sites. Despite
intensive study outside Europe, very few data are available
to date on the bird communities that exploit artificial
intertidal sites along the European coasts. Between July 2009
and December 2010, 32 ornithological surveys were performed
at six artificial intertidal sites in the lagoon of Venice
(Italy). Overall, 101 species (with 23,399 birds) were observed,
about a third of those occurring in the lagoon of Venice;
58 of these species were of conservation concern. Ten
species comprised about 80 % of the total; bird abundance
was the highest during the post-breeding migration and wintering
period. Multivariate analysis identified similarity
among sites, seasons and observed behaviours. Dredge islands
were mostly used by waders as foraging sites, when surrounding
tidal flats were still flooded. In winter the six dredged
islands supported about 2 % of the dunlins Calidris alpina
occurring in the whole lagoon of Venice and about 10 % of
the grey plovers Pluvialis squatarola. Since the study sites
comprised just the 6%of the total dredge island area available
in 2009–2010, the results indicate as large fractions of these
shorebird populations might exploit the dredge island habitats
for foraging. Among the newly created habitats, intertidal
ponds and inner tidal flats were the most heavily used by
birds, followed by dykes and mounds with ruderal vegetation.
Maintenance of the habitat mosaic is a need for a
conservation- based management of the dredge islands.

The most common invasive mammals—mice, rats, and cats—have been introduced to islands around the world, where they continue to negatively affect native biodiversity. The eradication of those invasive mammals has had positive effects on many species of seabirds. However, the removal of one invasive mammal species may result in abundance changes of other species due to trophic and competitive interactions among species. Understanding the overall impact of several invasive species is a key challenge when evaluating the possible effects of eradication programmes. Here we assess the influence of the three most common invasive mammals on nest survival of Cory’s shearwater (Calonectris diomedea). We monitored six breeding colonies over 3 years and measured the activity of mice, rats and cats to examine the influence of invasive mammals on nest survival. We found that nest survival showed a similar temporal trend in all years, with lowest weekly survival probabilities shortly after chicks hatched. Cats were identified as major predators of chicks, but no measure of colony-specific cat activity was able to adequately explain variation in shearwater nest survival. Nest survival was on average 0.38 (95 % confidence interval 0.20–0.53) and varied among colonies as well as over time. We found a small positive influence of rats on nest survival, which may indicate that the presence of small rodents as alternative prey may reduce cat predation of chicks. Our findings suggest that the eradication of rodents alone may exacerbate the adverse effects of cats on shearwater nest survival.

Knowledge about the spatial distribution of seabirds at sea is important for conservation. During marine conservation planning, logistical constraints preclude seabird surveys covering the complete area of interest and spatial distribution of seabirds is frequently inferred from predictive statistical models. Increasingly complex models are available to relate the distribution and abundance of pelagic seabirds to environmental variables, but a comparison of their usefulness for delineating protected areas for seabirds is lacking. Here we compare the performance of five modelling techniques (generalised linear models, generalised additive models, Random Forest, boosted regression trees, and maximum entropy) to predict the distribution of Balearic Shearwaters (Puffinus mauretanicus) along the coast of the western Iberian Peninsula. We used ship transect data from 2004 to 2009 and 13 environmental variables to predict occurrence and density, and evaluated predictive performance of all models using spatially segregated test data. Predicted distribution varied among the different models, although predictive performance varied little. An ensemble prediction that combined results from all five techniques was robust and confirmed the existence of marine important bird areas for Balearic Shearwaters in Portugal and Spain. Our predictions suggested additional areas that would be of high priority for conservation and could be proposed as protected areas. Abundance data were extremely difficult to predict, and none of five modelling techniques provided a reliable prediction of spatial patterns. We advocate the use of ensemble modelling that combines the output of several methods to predict the spatial distribution of seabirds, and use these predictions to target separate surveys assessing the abundance of seabirds in areas of regular use.

Animal movement is a fundamental eco-evolutionary process yet the behaviour of juvenile animals is largely unknown for many species, especially for soaring seabirds which can range widely over the oceans at low cost. We present an unprecedented dataset of 98 juvenile albatrosses and petrels (nine species), tracked for the first three months after independence. There was a startling diversity within and among species in the type and scale of post-natal movement strategies, ranging from area-restricted to nomadic patterns. Spatial scales were clustered in three groups that ranged from <3000 km to >6000 km from the natal nest. In seven of the nine species, the orientation of flight paths and other movement statistics showed strong similarities between juveniles and adults, providing evidence for innate orientation abilities. Our results have implications for understanding the development of foraging behaviour in naïve individuals and the evolution of life history traits such as survival, lifespan and breeding strategy. Juvenile and immature individuals play a key role in the dynamics of animal populations 1 , particularly in long-lived species for which they can represent up to 50% of the total population 2. It is therefore essential to account for the specific traits and strategy of juveniles when modelling the fate of populations 3. However, for most species, the behaviour and fate of juveniles remain almost unknown. In animals with parental care, the critical stage for juveniles is when they start to move and forage independently. At this stage, juveniles generally suffer high mortality, which is likely a result of low foraging efficiency or non-optimal morphology compared to that of adults 4,5. How such naïve individuals navigate in their environment, especially for large scale dispersive movements such as migration or exploration, has been identified as a priority for research 6. The concept of dispersal, or natal dispersal, is often used to describe the movement of a juvenile leaving its natal grounds to breed elsewhere 7. This therefore excludes the post-fledging movements of highly philopatric species , which return to breed at their natal colonies. However, as pointed out in recent studies 8 , dispersal includes the " movement of new fledglings in all directions with no inherent directional preferences ". These movements may, in time, lead to 'true' dispersal, in the most commonly used sense 7 , or to the birds' return to their colony of origin. Substantial individual variability has been documented in the dispersal behaviour of terrestrial animals 7,9. Individuals move in heterogeneous environments, making their displacement landscape-dependant. Indeed, non-flying terrestrial animals are severely constrained by movement costs related to energy landscapes 10,11. While birds are far less constrained, terrestrial birds still generally follow topographic features and landmasses during their migration or dispersal, and use specific sites for stopovers 8 .The case of seabirds is very different, as adults have capacities for large scale movements over open, comparatively featureless oceans 12,13. This is particularly true for procellariiform species (albatrosses and petrels), which can undertake extremely long migratory movements 14,15. When juvenile petrels and albatrosses leave their nests for the first time, they have 'the world as their oyster' , in that they can potentially fly at low metabolic costs, using winds to move in a vast, apparently homogenous , environment. These naive birds face no topographic constraints on where and when to move. Whilst the oceanic realm is certainly not a featureless environment for seabirds that are known to be sensitive to oceanographic features such as bathymetry, currents, wind zonation, eddies, or odours such as dimethyl sulphide 16 , the