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Body-mounted accelerometers provide a new prospect for estimating power use in flying birds, as the signal varies with the two major kinematic determinants of aerodynamic power: wingbeat frequency and amplitude. Yet wingbeat frequency is sometimes used as a proxy for power output in isolation. There is, therefore, a need to understand which kinematic parameter birds vary and whether this is predicted by flight mode (e.g. accelerating, ascending/descending flight), speed or morphology. We investigate this using high-frequency acceleration data from (i) 14 species flying in the wild, (ii) two species flying in controlled conditions in a wind tunnel and (iii) a review of experimental and field studies. While wingbeat frequency and amplitude were positively correlated, R 2 values were generally low, supporting the idea that parameters can vary independently. Indeed, birds were more likely to modulate wingbeat amplitude for more energy-demanding flight modes, including climbing and take-off. Nonetheless, the striking variability, even within species and flight types, highlights the complexity of describing the kinematic relationships, which appear sensitive to both the biological and physical context. Notwithstanding this, acceleration metrics that incorporate both kinematic parameters should be more robust proxies for power than wingbeat frequency alone.

Understanding how animals move in dense environments where vision is compromised is a major challenge. We used GPS and dead-reckoning to examine the movement of Magellanic penguins commuting through vegetation that precluded long-distance vision. Birds leaving the nest followed the shortest, quickest route to the sea (the ‘ideal path’, or ' I-path ') but return tracks depended where the birds left the water. Penguins arriving at the beach departure spot mirrored the departure. Most of those landing at a distance from the departure spot travelled slowly, obliquely to the coast at a more acute angle than a beeline trajectory to the nest. On crossing their I-path , these birds then followed this route quickly to their nests. This movement strategy saves birds distance, time and energy compared to a route along the beach and the into the colony on the I-track and saves time and energy compared to a beeline trajectory which necessitates slow travel in unfamiliar areas. This suggests that some animals adopt tactics that take them to an area where their navigational capacities are enhanced for efficient travel in challenging environments.

Background Understanding what animals do in time and space is important for a range of ecological questions, however accurate estimates of how animals use space is challenging. Within the use of animal-attached tags, radio telemetry (including the Global Positioning System, ‘GPS’) is typically used to verify an animal’s location periodically. Straight lines are typically drawn between these ‘Verified Positions’ (‘VPs’) so the interpolation of space-use is limited by the temporal and spatial resolution of the system’s measurement. As such, parameters such as route-taken and distance travelled can be poorly represented when using VP systems alone. Dead-reckoning has been suggested as a technique to improve the accuracy and resolution of reconstructed movement paths, whilst maximising battery life of VP systems. This typically involves deriving travel vectors from motion sensor systems and periodically correcting path dimensions for drift with simultaneously deployed VP systems. How often paths should be corrected for drift, however, has remained unclear. Methods and results Here, we review the utility of dead-reckoning across four contrasting model species using different forms of locomotion (the African lion Panthera leo, the red-tailed tropicbird Phaethon rubricauda, the Magellanic penguin Spheniscus magellanicus, and the imperial cormorant Leucocarbo atriceps). Simulations were performed to examine the extent of dead-reckoning error, relative to VPs, as a function of Verified Position correction (VP correction) rate and the effect of this on estimates of distance moved. Dead-reckoning error was greatest for animals travelling within air and water. We demonstrate how sources of measurement error can arise within VP-corrected dead-reckoned tracks and propose advancements to this procedure to maximise dead-reckoning accuracy. Conclusions We review the utility of VP-corrected dead-reckoning according to movement type and consider a range of ecological questions that would benefit from dead-reckoning, primarily concerning animal–barrier interactions and foraging strategies.

The identification of when, how and where animals feed is essential to estimate the amount of energy they obtain and to study the processes associated with prey search and consumption. We combined the use of animal-borne video cameras and accelerometers to characterise the body and head movements associated to four types of prey capture behaviours in the Magellanic Penguin (Spheniscus magellanicus). In addition, we evaluated how the K-Nearest Neighbour (K-NN) algorithm recognized these behaviours from acceleration data. Finally, we compared the total capture and the capture per unit time (CPUT) derived by identifying prey capture events using the K-NN algorithm to that derived by counting undulations in the dive profile (“wiggles”). During captures, body and head movements were highly variable in the tridimensional space. Energy expenditure (i.e., VeDBA values) during diving periods with prey captures was from three to four times higher than during controls diving periods (i.e., with no capture events). The K-NN classification resulted effective and showed accuracy scores above 90% when considering both head and body related features. In addition, when captures were estimated using the K-NN method, the CPUT was similar or higher to that estimated by counting wiggles. Our study contributes to the knowledge of the trophic ecology of this species and provides an alternative method for estimating prey consumption in the Magellanic Penguin and other diving seabirds.

Background Fine-scale data on animal position are increasingly enabling us to understand the details of animal movement ecology and dead-reckoning, a technique integrating motion sensor-derived information on heading and speed, can be used to reconstruct fine-scale movement paths at sub-second resolution, irrespective of the environment. On its own however, the dead-reckoning process is prone to cumulative errors, so that position estimates quickly become uncoupled from true location. Periodic ground-truthing with aligned location data (e.g., from global positioning technology) can correct for this drift between Verified Positions (VPs). We present step-by-step instructions for implementing Verified Position Correction (VPC) dead-reckoning in R using the tilt-compensated compass method, accompanied by the mathematical protocols underlying the code and improvements and extensions of this technique to reduce the trade-off between VPC rate and dead-reckoning accuracy. These protocols are all built into a user-friendly, fully annotated VPC dead-reckoning R function; Gundog.Tracks, with multi-functionality to reconstruct animal movement paths across terrestrial, aquatic, and aerial systems, provided within the Additional file 4 as well as online (GitHub). Results The Gundog.Tracks function is demonstrated on three contrasting model species (the African lion Panthera leo, the Magellanic penguin Spheniscus magellanicus, and the Imperial cormorant Leucocarbo atriceps) moving on land, in water and in air. We show the effect of uncorrected errors in speed estimations, heading inaccuracies and infrequent VPC rate and demonstrate how these issues can be addressed. Conclusions The function provided will allow anyone familiar with R to dead-reckon animal tracks readily and accurately, as the key complex issues are dealt with by Gundog.Tracks. This will help the community to consider and implement a valuable, but often overlooked method of reconstructing high-resolution animal movement paths across diverse species and systems without requiring a bespoke application.

The paradigm-changing opportunities of biologging sensors for ecological research, especially movement ecology, are vast, but the crucial questions of how best to match the most appropriate sensors and sensor combinations to specific biological questions and how to analyse complex biologging data, are mostly ignored. Here, we fill this gap by reviewing how to optimize the use of biologging techniques to answer questions in movement ecology and synthesize this into an Integrated Biologging Framework (IBF). We highlight that multisensor approaches are a new frontier in biologging, while identifying current limitations and avenues for future development in sensor technology. We focus on the importance of efficient data exploration, and more advanced multidimensional visualization methods, combined with appropriate archiving and sharing approaches, to tackle the big data issues presented by biologging. We also discuss the challenges and opportunities in matching the peculiarities of specific sensor data to the statistical models used, highlighting at the same time the large advances which will be required in the latter to properly analyse biologging data. Taking advantage of the biologging revolution will require a large improvement in the theoretical and mathematical foundations of movement ecology, to include the rich set of high-frequency multivariate data, which greatly expand the fundamentally limited and coarse data that could be collected using location-only technology such as GPS. Equally important will be the establishment of multidisciplinary collaborations to catalyse the opportunities offered by current and future biologging technology. If this is achieved, clear potential exists for developing a vastly improved mechanistic understanding of animal movements and their roles in ecological processes and for building realistic predictive models. Fil: Williams, Hannah J.. Swansea University; Reino Unido Fil: Taylor, Lucy. University of Oxford; Reino Unido. Save The Elephants; Kenia Fil: Benhamou, Simon. Centre National de la Recherche Scientifique; Francia Fil: Bijleveld, Allert. Utrecht University; Países Bajos Fil: Clay, Thomas. University of Liverpool; Reino Unido Fil: de Grissac, Sophie. Swansea University; Reino Unido Fil: Demsar, Urska. University of St. Andrews; Reino Unido Fil: English, Holly M.. Swansea University; Reino Unido Fil: Franconi, Novella. Swansea University; Reino Unido Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Griffiths, Rachael. Swansea University; Reino Unido Fil: Kay, William P.. Swansea University; Reino Unido Fil: Morales, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Potts, Jonathan. University of Sheffield; Reino Unido Fil: Rogerson, Katharine F.. University of East Anglia; Reino Unido Fil: Rutz, Christian. University of St. Andrews; Reino Unido Fil: Spelt, Anouk. University of Bristol; Reino Unido Fil: Trevail, Alice. University of Liverpool; Reino Unido Fil: Wilson, Rory P.. Swansea University; Reino Unido Fil: Börger, Luca. Swansea University; Reino Unido

It is fundamentally important for many animal ecologists to quantify the costs of animal activities, although it is not straightforward to do so. The recording of triaxial acceleration by animal-attached devices has been proposed as a way forward for this, with the specific suggestion that dynamic body acceleration (DBA) be used as a proxy for movement-based power. Dynamic body acceleration has now been validated frequently, both in the laboratory and in the field, although the literature still shows that some aspects of DBA theory and practice are misunderstood. Here, we examine the theory behind DBA and employ modelling approaches to assess factors that affect the link between DBA and energy expenditure, from the deployment of the tag, through to the calibration of DBA with energy use in laboratory and field settings. Using data from a range of species and movement modes, we illustrate that vectorial and additive DBA metrics are proportional to each other. Either can be used as a proxy for energy and summed to estimate total energy expended over a given period, or divided by time to give a proxy for movement-related metabolic power. Nonetheless, we highlight how the ability of DBA to predict metabolic rate declines as the contribution of non-movement-related factors, such as heat production, increases. Overall, DBA seems to be a substantive proxy for movement-based power but consideration of other movement-related metrics, such as the static body acceleration and the rate of change of body pitch and roll, may enable researchers to refine movement-based metabolic costs, particularly in animals where movement is not characterized by marked changes in body acceleration. Fil: Wilson, Rory P.. Swansea University; Reino Unido Fil: Börger, Luca. Swansea University; Reino Unido Fil: Holton, Mark. Swansea University; Reino Unido Fil: Scantlebury, D. Michael. The Queens University of Belfast; Irlanda Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Rosell, Frank. University of South‐Eastern Norway; Noruega Fil: Graf, Patricia M.. Universitat Fur Bodenkultur Wien; Austria. University of Ljubljana; Eslovenia Fil: Williams, Hannah. Swansea University; Reino Unido Fil: Gunner, Richard. Swansea University; Reino Unido Fil: Hopkins, Lloyd. Swansea University; Reino Unido Fil: Marks, Nikki. The Queens University of Belfast; Irlanda Fil: Geraldi, Nathan R.. King Abdullah University of Science and Technology; Arabia Saudita Fil: Duarte, Carlos M.. King Abdullah University of Science and Technology; Arabia Saudita Fil: Scott, Rebecca. Geomar-Helmholtz Centre for Ocean Research Kiel; Alemania Fil: Strano, Michael S.. Massachusetts Institute of Technology; Estados Unidos Fil: Robotka, Hermina. Max Planck Institute für Ornithologie; Alemania Fil: Eizaguirre, Christophe. , Queen Mary University of London; Reino Unido Fil: Fahlman, Andreas. undación Oceanogràfic de la Comunidad Valenciana; España Fil: Shepard, Emily L. C.. Swansea University; Reino Unido. Max Planck Institute für Ornithologie; Alemania

Between 25–30 November 2013, 2014 and 2015, miniaturized video cameras were attached to Magellanic Penguins (Spheniscus magellanicus; n = 14) in Punta Norte/San Lorenzo, Peninsula Valdes, Chubut, Argentina. The objective was to examine prey selection, consumption of untraceable prey, and inter- and intraspecific interactions. During 56.3 hr of video footage, 1,621 dives from 14 individuals were recorded. Magellanic Penguins swam through shoals of lobster krill (Munida gregaria morph subrugosa), selectively consuming the fish, primarily anchovies (Engraulis anchoita), that were dispersed along the shoal, but did not consume the lobster krill. Magellanic Penguins captured fish on dives of less than 2 m in depth. The tagged individuals foraged with conspecifics in 2% (n = 33) of the total recorded dives. In addition, a multispecies feeding association was also documented (n = 1). Results were constrained to the upper 40 m of the water column; below this depth light level was too low for detections by video. The development of cameras with a light source and wider-angle lens are crucial to improve our understanding of Magellanic Penguin foraging behavior.

Postnatal growth is an important life-history trait that varies widely across avian species, and several equations with a sigmoidal shape have been used to model it. Classical three-parameter models have an inflection point fixed at a percentage of the upper asymptote which could be an unrealistic assumption generating biased fits. The Richards model emerged as an interesting alternative because it includes an extra parameter that determines the location of the inflection point which can move freely along the growth curve. Recently, nonlinear mixed models (NLMM) have been used in modeling avian growth because these models can deal with a lack of independence among data as typically occurs with multiple measurements on the same individual or on groups of related individuals. Here, we evaluated the useful- ness of von Bertalanffy, Gompertz, logistic, U4 and Richards?s equations modeling chick growth in the imperial shag Phalacrocorax atriceps. We modelled growth in commonly used morphological traits, including body mass, bill length, head length and tarsus length, and compared the performance of models by using NLMM. Estimated adult size, age at maximum growth and maximum growth rates markedly differed across models. Overall, the most consistent performance in estimated adult size was obtained by the Richards model that showed deviations from mean adult size within 5%. Based on AICc values, the Richards equation was the best model for all traits analyzed. For tarsus length, both Richards and U4 models provided indis- tinguishable fits because the relative inflection value estimated from the Richards model was very close to that assumed by the U4 model. Our results highlight the bias incurred by three-parameter models when the assumed inflection placement deviates from that derived from data. Thus, the application of the Richards equation using the NLMM framework represents a flexible and powerful tool for the analysis of avian growth. Fil: Svagelj, Walter S.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Gomez Laich, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina

Previous studies on vertical transmission of lice on terrestrial birds have shown that the intensity of parasitism can vary within broods in relation to the hatching order of chicks. In species where the hatching order has an important effect on chick survival, lice would benefit from living on the host with the highest survival prospects. In the present work, we test this hypothesis using as model lice from the Imperial Shag, an obligate brood reducer. Our specific aims were to investigate how infestation of Eidmanniella pellucida varies in relation to the age, the order of birth and the hatching date of chicks. We observed that chicks were infested by their parents during their first days of life, mainly by lice in nymphal stage. The first chick to hatch was the most infested. Infestation was also affected by hatching date, increasing as the season progressed, reaching a maximum at the peak of the breeding season and decreasing gradually after that. The age of the chick was unrelated to the intensity of infestation. Our results suggest that lice would prefer the chick that is more likely to survive and highlights the adaptive strategies of lice according to the ecology of their hosts. Fil: Leonardi, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Svagelj, Walter Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina

Jellyfish and other pelagic gelatinous organisms (“gelata”) are increasingly perceived as an important component of marine food webs but remain poorly understood. Their importance as prey in the oceans is extremely difficult to quantify due in part to methodological challenges in verifying predation on gelatinous structures. Miniaturized animal-borne video data loggers now enable feeding events to be monitored from a predator's perspective. We gathered a substantial video dataset (over 350 hours of exploitable footage) from 106 individuals spanning four species of non-gelatinous-specialist predators (penguins), across regions of the southern oceans (areas south of 30°S). We documented nearly 200 cases of targeted attacks on carnivorous gelata by all four species, at all seven studied localities. Our findings emphasize that gelatinous organisms actually represent a widespread but currently under-represented trophic link across the southern oceans, even for endothermic predators, which have high energetic demands. The use of modern technological tools, such as animal-borne video data loggers, will help to correctly identify the ecological niche of gelata. Fil: Thiebot, Jean-Baptiste. National Institute of Polar Research; Japón Fil: Arnould, John PY. Deakin University; Australia Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Ito, Kentaro. SOKENDAI Graduate University for Advanced Studies; Japón Fil: Kato, Akiko. Université de La Rochelle; Francia Fil: Mattern, Thomas. University of Otago; Nueva Zelanda Fil: Mitamura, Hiromichi. Kyoto University; Japón Fil: Noda, Takuji. Kyoto University; Japón Fil: Poupart, Timothée. Deakin University; Australia Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Raclot, Thierry. Université de Strasbourg; Francia Fil: Ropert-Coudert, Yan. Université de La Rochelle; Francia Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Seddon, Philip J.. University of Otago; Nueva Zelanda Fil: Sutton, Grace J.. Deakin University; Australia Fil: Yoda, Ken. Nagoya University; Japón Fil: Takahashi, Akinori. SOKENDAI Graduate University for Advanced Studies; Japón

Energy management during the breeding season is crucial for central place foragers since parents need to feed themselves and their offspring while being spatially and temporally constrained. In this work, we used overall dynamic body acceleration as a measure of activity and also to allude to the foraging energy expenditure of breeding Imperial cormorants Phalacrocorax atriceps. We also analyzed how changes in the time or energy allocated to different activities affected the foraging trip energy expenditure and estimated the daily food requirements of the species. Birds spent 42 % of the total energy flying to and from the feeding areas and 16 % floating at sea. The level of activity underwater was almost 1.5 times higher for females than for males. The most expensive diving phase in terms of rate of energy expenditure was descending though the water column. The total foraging trip energy expenditure was particularly sensitive to variation in the amount of time spent flying. During the breeding season, adult cormorants breeding along the Patagonian coast would consume approximately 10,000 tons of food. Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Wilson, Rory P.. University of Wales. Institute of Environmental Sustainability. Biological Sciences; Reino Unido Fil: Shepard, Emily L. C.. University of Wales. Institute of Environmental Sustainability. Biological Sciences; Reino Unido Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina

Intersexual differences in the foraging behaviour have been examined in several seabird species, especially those exhibiting sexual size dimorphism. We studied intersex behavioural differences in the Imperial Cormorant (Phalacrocorax atriceps), a size dimorphic seabird. Twenty adults (11 females and 9 males), breeding at Punta León (43°04′S; 64°2′W), Chubut, Argentina, were equipped with loggers to measure tri-axial acceleration and depth, to calculate the foraging trip time/activity budgets and diving behaviour. Both sexes had similar foraging trip durations, spending a similar proportion of the foraging time flying and floating on the sea surface. However, females spent more time underwater, executing more and shallower dives. Females also recovered more quickly than males from dives performed to depths of less than 30 m and spent more time foraging along the bottom at any depth than males. We conclude that if allometric effects affect the foraging behaviour of Imperial Cormorants, they only do so during diving because no differences were observed in the total amount of time sexes spent flying or foraging. Geschlechtsunterschiede bei der Nahrungsaufnahme wurden bereits für mehrere Seevögel beschrieben, besonders für solche mit geschlechtsabhängiger Körpergröße. Wir untersuchten geschlechtsspezifische Verhaltensunterschiede bei der Blauaugenscharbe, einem Seevogel mit geschlechtsbedingt unterschiedlicher Körpergröße. Achtundzwanzig adulte Tiere (11 Weibchen, 9 Männchen), die bei Punta León (43°04′S; 64°2′W), Chubut, Argentinien, brüteten, wurden mit Datenloggern zur Aufzeichnung ihrer drei-achsigen Beschleunigung und Tauchtiefe versehen, um ihre Zeit- und Aktivitäts-Budgets und ihr Tauchverhalten zu messen. Beide Geschlechter verbrachten etwa gleich viel Zeit bei ihren Ausflügen zur Nahrungssuche, mit in etwa auch gleich großen Zeit-Anteilen für Fliegen und Treiben auf dem Wasser. Aber die Weibchen verbrachten mehr Zeit unter Wasser bei häufigeren Tauchgängen in flacherem Wasser. Sie erholten sich auch rascher als die Männchen von Tauchgängen in Tiefen bis zu 30 Meter und verbrachten in jeder Tiefe mehr Zeit als die Männchen bei der Nahrungsaufnahme am Grund. Wir schließen hieraus, dass, wenn allometrische Effekte das Nahrungsaufnahme-Verhalten von Blauaugenscharben überhaupt beeinflussen, diese Einflüsse nur beim Tauchen auftreten, da in der Zeit, die fliegend oder für die Nahrungsaufnahme verbracht wurde, kein Geschlechtsunterschied festgestellt werden konnten. Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Quintana, Flavio Roberto. Wildlife Conservation Society; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Shepard, E. L. C.. University of Wales; Reino Unido Fil: Wilson, R. P.. University of Wales; Reino Unido

Animal behaviour is largely defined in terms of movement or lack of it, so precise quan- tification of animal movement is a potentially powerful way of identifying several animal behaviours. Animal-attached tags that record acceleration lend themselves particularly to this. In this work we show how tri-axial acceleration can be used to identify some of the behaviours of imperial cormorants Phalacrocorax atriceps. Based on the assessment of tri-axial acceleration signals, the following behaviours were identified in free-living birds: standing, sitting, floating on water, flying, walking and diving. During diving, the descent, bottom and ascent phases could be distinguished. We consid- ered the factors which coded for the different behaviours and this allowed us to design a key that will allow researchers assessing tri-axial accelerometry data to identify some of the behaviours that imperial cormorants perform.

We studied the exploitation of crab-beds and fishing grounds by Olrog's Gulls Larus atlanticus in non-breeding areas along the coast of Buenos Aires province, Argentina. During 2004 and 2005, censuses were performed in different areas of Mar Chiquita coastal lagoon and Mar del Plata harbour. Additionally, from April to August 2005 the movements of five non-breeding individuals were studied by means of radio-telemetry. At both study sites the highest numbers of Olrog's Gulls were observed between June and August. A total of 278 radio-tracked locations (from 407 samples) were registered. All the tracked individuals showed strong site fidelity, with 96% of the radio signals registered in the vicinity of the lagoon's mouth, associated with both crab-beds and areas where sport-fishing activities took place. Conservation issues in non-breeding areas should be tackled in the near future, given the conservation status of this species (Vulnerable) and the fact that each year several Olrog's Gulls are being killed because of their interaction with sport-fishing activities.ResumoSe estudió la utilización de cangrejales y áreas de pesca por la Gaviota de Olrog durante el periodo no reproductivo. Durante los aãos 2004 y 2005 se realizaron censos en diferentes áreas de la Laguna Costera Mar Chiquita y el Puerto Mar del Plata, Provincia de Buenos Aires, Argentina. En ambos sitios de estudio el mayor número de individuos se observó entre los meses de junio y agosto. Adicionalmente entre los meses de abril y agosto de 2005 se estudiaron los movimientos de cinco individuos no reproductores mediante el uso de radio-transmisores. De un total de 407 muestras se obtuvieron 278 localizaciones. Todos los individuos instrumentados mostraron una alta fidelidad al sitio. El 96% de las localizaciones se registraron en cercanías de la desembocadura de la laguna, asociadas a cangrejales y areas de pesca deportiva. Considerando el estatus de conservación de la Gaviota de Olrog (‘Vulnerable’) y los efectos negativos de su interacción con la pesca deportiva, programas de conservación en áreas no reproductivas deben ser implementados.

Colonial pinnipeds may be subject to substantial consumptive competition because they are large, slow-moving central place foragers. We examined possible mechanisms for reducing this competition by examining the diving behaviour of harbour seals (Phoca vitulina) after equipping 34 seals (11 females, 23 males) foraging from three locations; Rømø, Denmark and Lorenzenplate and Helgoland, Germany, in the Wadden Sea area with time-depth recorders. Analysis of 319,021 dives revealed little between-colony variation but appreciable inter-sex differences, with males diving deeper than females, but for shorter periods. Males also had higher vertical descent rates. This result suggests that males may have higher overall swim speeds, which would increase higher oxygen consumption, and may explain the shorter dive durations compared to females. Intersex variation in swim speed alone is predicted to lead to fundamental differences in the time use of three-dimensional space, which may help reduce consumptive competition in harbour seals and other colonial pinnipeds. Fil: Wilson, Rory P.. Swansea University; Reino Unido. GEOMAR Helmholtz Centre for Ocean Research; Alemania Fil: Liebsch, Nikloai. Customized Animal Tracking Solutions; Australia Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Kay, William P.. Swansea University; Reino Unido Fil: Bone, Andrew. Swansea University; Reino Unido Fil: Hobson, Victoria J.. Swansea University; Reino Unido Fil: Siebert, Ursula. University of Veterinary Medicine Hannover. Institute for Terrestrial and Aquatic Wildlife Research; Argentina

The Magellanic penguin Spheniscus magellanicus has recently colonized two new coastal sites (Islote Lobos and El Pedral), increasing the number of colonies in northern Patagonia, Argentina. Assuming foraging parameters during the breeding season to be valid short-term indicators of population health, we studied several foraging parameters of penguins from the two new established sites and from an older and well-established colony (Punta Norte) also localized in the north of Patagonia. Penguins from the recently formed colonies performed shorter foraging trips and visited waters closer to their colony than birds from Punta Norte, with penguins from Punta Norte spending almost twice the time at sea spent by penguins from El Pedral. Penguins from Punta Norte also spent more time underwater, spent a higher proportion of the complete diving cycle searching for prey, performed more wiggles (indicative of prey capture) and had fewer estimated prey captures per unit time underwater than penguins from Islote Lobos and El Pedral. This information suggests that, given no limitations on nest-site availability and no prevalence of predators, the good foraging conditions around El Pedral and Islote Lobos may be implicated in the increase in these two relatively new colonies. Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Wilson, Rory P.. Swansea University. College Of Sciences; Reino Unido Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Luzenti, Elvio Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos

The energetic costs of animal movement change with body condition, although the consequences of this for foraging efficiency are rarely considered. We deployed externally attached devices to Magellanic penguins (Spheniscus magellanicus), known to increase the costs of swimming via increased drag in a consistent manner, and noted, however, that foraging behaviour and efficiency varied dramatically between years. We used our results to construct an energetics-based model and found that small increases in drag due to the attachment of externally attached tags predicted accelerating harm as prey availability decreased, which accorded with our observations. This explains earlier observations of differential breeding success in tagged versus untagged penguins in particular years, highlights the importance of understanding how animal body condition may affect population processes in general and advocates caution in interpretations of tag-derived data over variable environmental conditions. Fil: Wilson, R. P.. Swansea University. College Of Sciences; Reino Unido Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Ciancio Blanc, Javier Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos

The effects of different environmental and operational factors on the incidental capture of Black-browed Albatross (Thalassarche melanophris) in long-line fishing operations were analysed. This is the most commonly captured seabird by Argentine long-line fishing vessels, and significant decreases in its populations have been mainly attributed to long-line fishing practices. The estimated mean rate ± s.d. of by-catch for the analysed period (1999–2003) was 0.03 ± 0.39 birds per 1000 hooks. Black-browed Albatrosses were mainly caught during day settings. Higher capture rates were observed during autumn and winter. The effect of the length of long-lines on the incidental capture of Black-browed Albatrosses was also analysed, showing that higher capture rates occurred when short long-lines were deployed. Seasonal differences in the distribution of captures were observed, being widely distributed to the north of the shelf-break during autumn–winter (i.e. non-breeding season) and mostly concentrated in southernmost latitudes, closer to the presumed breeding area in the Malvinas (Falkland) Islands during spring–summer. Mortalities during winter were mainly associated with the Patagonian Toothfish (Dissostrichus eleginoides) fishery, while those observed during summer were associated with long-liners targeting Kingklip (Genypterus blacodes) on the Patagonian Shelf.

Highly specialized diving birds display substantial dichotomy in neck length with, for example, cormorants and anhingas having extreme necks, while penguins and auks have minimized necks. We attached acceleration loggers to Imperial cormorants Phalacrocorax atriceps and Magellanic penguins Spheniscus magellanicus, both foraging in waters over the Patagonian Shelf, to examine the difference in movement between their respective heads and bodies in an attempt to explain this dichotomy. The penguins had head and body attitudes and movements that broadly concurred throughout all phases of their dives. By contrast, although the cormorants followed this pattern during the descent and ascent phases of dives, during the bottom (foraging) phase of the dive, the head angle differed widely from that of the body and its dynamism (measured using vectorial dynamic acceleration) was over four times greater. A simple model indicated that having the head on an extended neck would allow these cormorants to half the energy expenditure that they would expend if their body moved in the way their heads did. This apparently energy-saving solution is likely to lead to greater heat loss though and would seem tenable in slow-swimming species because the loss of streamlining that it engenders would make it detrimental for fast-swimming taxa such as penguins. Fil: Wilson, Rory P.. Swansea University; Reino Unido Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Dell´Omo, Giacomo. Ornis Italica; Italia Fil: Holton, Mark. Swansea University; Reino Unido Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina

The Cape Gannet Morus capensis (Lichtenstein, 1823) is a seabird endemic to southern Africa, breeding at only six localities, three in Namibia and three in South Africa. The population is currently estimated to be 151 000 pairs (Crawford et al. 2007). After the breeding season, some Cape Gannets disperse north, along the west coast of Africa, while many follow sardine Sardinops sagax schools eastward. The species is usually restricted to the continental shelf of Africa and rarely seen more than a few hundred kilometres offshore (Crawford 2005). In spite of this relatively restricted distribution, vagrants of this species have been reported in Australia, New Zealand, Amsterdam Island (Indian Ocean), Spain, Argentina, Brazil and Perú (Berteaux 1991, Ramírez Llorens 1996, García-Godos 2002, Vooren 2004, Crawford 2005). Fil: Rebstock, Ginger A.. Wildlife Conservation Society; Estados Unidos. University of Washington; Estados Unidos Fil: Agüero, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Boersma, P. Dee. University of Washington; Estados Unidos Fil: Ebert, Luis Augusto. Wildlife Conservation Society; Estados Unidos Fil: Gómez Laich, Agustina Marta. Centro Universitário Leonardo da Vinci; Brasil Fil: Lisnizer, Nora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Svagelj, Walter Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Trivellini, Maria Magdalena. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina

Numerous methods are currently available to track animal movements. However, only one of these, dead-reckoning, has the capacity to provide continuous data for animal movements over fine scales. Dead-reckoning has been applied almost exclusively in the study of marine species, in part due to the difficulty of accurately measuring the speed of terrestrial species. In the present study we evaluate the use of accelerometers and a metric known as overall dynamic body acceleration (ODBA) as a proxy for the measurement of speed for use in dead-reckoning. Data were collated from previous studies, for 10 species locomoting on a treadmill and their ODBA measured by an attached data logger. All species except one showed a highly significant linear relationship between speed and ODBA; however, there was appreciable inter- and intra-specific variance in this relationship. ODBA was then used to estimate speed in a simple trial run of a dead-reckoning track. Estimating distance travelled using speed derived from prior calibration for ODBA resulted in appreciable errors. We describe a method by which these errors can be minimised, by periodic ground-truthing (e.g., by GPS or VHF telemetry) of the dead-reckoned track and adjusting the relationship between speed and ODBA until actual known positions and dead-reckoned positions accord. Fil: Bidder, Owen R.. Swansea University; Reino Unido Fil: Soresina, Marion. Swansea University; Reino Unido Fil: Shepard, Emily L. C.. Swansea University; Reino Unido Fil: Halsey, Lewis G.. Roehampton University; Reino Unido Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Wildlife Conservation Society; Estados Unidos Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Wilson, Rory P. Swansea University; Reino Unido

Colonial seabirds are central place foragers and likely to be subject to substantial competition for resources. Mechanisms proposed for reducing intra-specific competition include differential inter-sex area use mediated by adult choice. We used GPS loggers and dive recorders to study area use and dive depth in a total of 27 male and 26 female imperial cormorants Phalacrocorax atriceps breeding at a colony of some 6500 birds at Punta Leon, Chubut, Argentina during 2004 and 2005. Although time spent travelling and distances between the colony and foraging sites were similar for both sexes, males and females travelled away from their colony using routes virtually perpendicular to each other so that their foraging areas were distinctly different; females hunted close to the coast while males foraged offshore in deeper water. Consideration of foraging efficiency underwater, defined as the duration spent on the bottom divided by the dive cycle duration, showed that females were more efficient at depths < 40 m while males more efficient at depths > 40 m. We suggest that the substantial sexual dimorphism in this species may be responsible for the different depth-linked foraging efficiencies and that selection for appropriate depths could lead to differential habitat use and putative differences in prey selection. Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos Fil: Wilson, Rory P.. Swansea University; Reino Unido Fil: Dell'arciprete, Olga Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Shepard, Emily. Swansea University; Reino Unido Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina

In air-breathing animals, the time and energy costs of each dive are primarily determined by depth-related upthrust, swim speed and temperature. While studies have previously investigated how animals should optimise their behaviour in relation to either upthrust or speed they have rarely been examined in tandem. We took overall dynamic body acceleration (ODBA) as a proxy for the mechanical power used during the bottom phases of dives of imperial shags Phalacrocorax atriceps, as these birds forage benthically, in order to define: (1) the minimum power required for swimming at depth and (2) how the use of power above this threshold varied with dive depth. Results showed that ODBA declined with increasing dive depth in a manner correlated with the reduction in upthrust, and that the use of power above that required for prey searching increased with increasing dive depth. This may constitute a response to depth-related patterns in prey availability. We present a model to investigate an alternative hypothesis that the ability of birds to produce burst speeds is also inversely related to the power required to counter buoyancy. Under the model assumptions, achievable burst speeds vary up to 0.7 m s–1 across dive depths from 5 to 60 m. Ultimately, prey preferences cannot be separated from prey fields, but we suggest that this model may provide insight into the ability of air-breathing divers to pursue various prey types according to dive depth. Fil: Shepard, Emily L. C.. Swansea University; Reino Unido Fil: Wilson, Rory P.. Swansea University; Reino Unido Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos

Depth-dependent buoyancy resulting from the compression of body-associated air is a major force modulating energy expenditure in diving seabirds, yet quantification of its effects in free- living animals is problematic. Between November 2006 and December 2008, we used multiple chan- nel loggers (daily diaries (DDs)); recording triaxial acceleration, depth and speed, during foraging of 34 Magellanic penguins Spheniscus magellanicus from 3 colonies in Argentina to derive a new proxy for energy expenditure, overall dynamic body acceleration (ODBA). Assuming ODBA to be linearly related to power, energy expenditure was highest during dive descent, nearer the surface and in those dives terminating at greater depths due to steeper descent angles. Swim speed during descent was invariant of maximum dive depth. Calculated energy expenditure during the bottom phase of the dive was invariant of depth, but energy expenditure of birds returning to the surface was lowest at any given depth for birds that had engaged in deeper dives due to the effects of buoyancy. Four birds, equipped with beak angle-measuring sensors as part of the DDs, captured 89% of their prey (nor- mally pelagic school fish) during fast passive ascents using buoyancy to aid in capture. Details from one of these birds showed that this passive ascent occurred at a mean velocity of 1.94 m s -1 for a mean of 2.02 s; ascent angles during such rushes were steeper when the bird was deeper, which was pre- sumed to reflect a response to the diminished buoyant force at greater pressures. Passive ascents during prey capture appear to be an important mechanism for Magellanic penguins to capture fast- moving prey with minimal energy expenditure.

Eutrophication increases the biomass of opportunistic green macroalgae that covers intertidal zones, and macroalgal blooms may affect the intertidal invertebrate community and predation of invertebrates by shorebirds. In San Antonio Bay, Argentina, eutrophication from the discharge of wastewater from a coastal town produces periodic macroalgal blooms. Our aim was to assess if macroalgal blooms affect the foraging behaviour and diet of the American Oystercatcher (Haematopus palliatus). A macroalgal transplant experiment was performed in order to evaluate how epifaunal species respond to a macroalgal canopy. The availability of prey for Oystercatchers, and their foraging behaviour and diet, were analysed in two paired channels with different nutrient loadings. Oystercatchers generally ate the most profitable prey and avoided prey with a profitability value lower than the mean rate of energy intake. During the macroalgal blooms, Oystercatchers avoided two prey species with high profitability values, shifting their foraging strategy and feeding onto a suboptimal prey but with a high encounter rate. Our results suggest that nutrient loadings and the macroalgal blooms that they generate have effects on the diet and foraging behaviour of Oystercatchers, which results in an increase of the average rate of energy intake of Oystercatchers foraging along the channel subject to a macroalgal bloom. Fil: García, Germán Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Isacch, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Albano, Mariano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Favero, Marco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Cardoni, Daniel Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Luppi, Tomas Atilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Iribarne, Oscar Osvaldo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Animals may forage using different currencies depending on whether time minimization or energy maximization is more pertinent at the time. Assessment of net energy acquisition requires detailed information on instantaneous activity-specific power use, which varies according to animal performance, being influenced, for example, by speed and prey loading, and which has not been measured before in wild animals. We used a new proxy for instantaneous energy expenditure (overall dynamic body acceleration), to quantify foraging effort in a model species, the imperial shag Phalacrocorax atriceps, during diving. Power costs varied nonlinearly with depth exploited owing to depth-related buoyancy. Consequently, solutions for maximizing the gross rate of gain and energetic efficiency differed for dives to any given depth. Dive effort in free-ranging imperial shags measured during the breeding season was consistent with a strategy to maximize the gross rate of energy gain. We suggest that the divergence of time and energy costs with dive depth has implications for the measurement of dive efficiency across diverse diving taxa. Fil: Shepard, Emily L. C.. Swansea University; Reino Unido Fil: Wilson, Rory P.. Swansea University; Reino Unido Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Forman, Dan W.. Swansea University; Reino Unido

Speed is a key determinant of energy expenditure in free-living animals, and particularly in marine vertebrates, where power requirements for swimming increase as a cubed function of the speed. However, current devices used to measure swim speed in free-living animals have limitations, including excessive drag, low resolution, high stall speed. (ca. 0.3 m s-1), cost, biofouling and susceptibility to damage. We present a speed sensor system that utilises the reflectance of infrared light against a flexible paddle that bends in relation to the flow of water over the study animal. In labaratory trials, this performed well across a range of speeds (0.1 to 1.75 m s-1), and had a stall speed of 0.1 m s-1. The advantages of this present paddle system are that, it is impervious to the presence of matter in the water column, is inexpensive and easily replaceable. Furthermope, the system is able to record speed data at an unparalleled resolution, limited solely by sampling frequency. Data from deployments of devices on free-living imperial cormorants Phalacrocorax atriceps identified changes in speed within and between swim strokes, and also showed that greater speed was generated per kick as the buoyancy decreased with depth. As such, the flexible paddle system holds promise for the measurement of speed in free-living, aquatic animals. Fil: Shepard, Emily L. C.. University of Wales; Reino Unido Fil: Wilson, Rory P. University of Wales; Reino Unido Fil: Liebsch, Nikolai. University of Wales; Reino Unido Fil: Quintana, Flavio Roberto. Wildlife Conservation Society; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Lucke, Klaus. Forschungs und Technologiezentrum Westküste; Alemania

The White-chinned Petrel Procellaria aequinoctialis is the second most commonly captured species by Argentinean longliners. The severe declines that this species has experienced in some of its populations (e.g. South Georgia Islands) have been principally attributed to incidental mortality associated with longliners. In this study we analyse the spatio-temporal variability in the mortality rates of White-chinned Petrels on the Patagonian Shelf and the effects that environmental and operational variability have on such mortality. The average capture rate (¡ 1 SD) for the period 1999–2003 was 0.014 ¡ 0.090 White-chinned Petrels for every 1,000 hooks deployed. Higher capture rates were observed when short longlines were deployed. Capture rates were not affected by the wind speed or by the time to the full moon. The distribution of the captures differed throughout the year. During autumn–winter most captures took place in the north of the Patagonian Shelf, whereas during spring–summer incidental captures occurred principally to the south between 45uS and 50uS. El Petrel Barba Blanca Procellaria aequinoctialis constituye la segunda especie ma´s frecuentemente capturada por la flota palangrera Argentina. Los importantes decrecimientos poblacionales observados en algunas poblaciones de esta especie (e.g. Islas Georgias del Sur) han sido principalmente atribuidos a la mortalidad incidental asociada a embarcaciones palangreras. En este trabajo se analizo´ la variacio´n espacio- temporal en las tasas de captura incidental del Petrel Barba Blanca a lo largo de la Plataforma Continental Argentina y se estudio´ el efecto que diferentes variables ambientales y operacionales tienen sobre la mortalidad incidental de esta especie. La tasa de captura promedio (¡ d.s) durante el periodo 1999–2003 fue de 0.014 ¡ 0.090 Petreles Barba Blanca cada 1.000 anzuelos. Mayores tasas de captura fueron registradas al utilizar palangres cortos. No se observo´ un efecto de la intensidad del viento ni de la distancia a la luna llena sobre las tasas de captura. La distribucio´n de las capturas difirio´ a lo largo del an˜ o. Durante el oton˜ o-invierno la mayorı´a de las capturas estuvieron localizadas al norte de la Plataforma Continental Argentina, mientras que durante los meses de primavera-verano las capturas estuvieron localizadas principalmente entre los 45uS y 50uS. Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Favero, Marco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina

Researchers hoping to elucidate the behaviour of species that aren’t readily observed are able to do so using biotelemetry methods. Accelerometers in particular are proving particularly effective and have been used on terrestrial, aquatic and volant species with success. In the past, behavioural modes were detected in accelerometer data through manual inspection, but with developments in technology, modern accelerometers now record at frequencies that make this impractical. In light of this, some researchers have suggested the use of various machine learning approaches as a means to classify accelerometer data automatically. We feel uptake of this approach by the scientific community is inhibited for two reasons; 1) Most machine learning algorithms require selection of summary statistics which obscure the decision mechanisms by which classifications are arrived, and 2) they are difficult to implement without appreciable computational skill. We present a method which allows researchers to classify accelerometer data into behavioural classes automatically using a primitive machine learning algorithm, k-nearest neighbour (KNN). Raw acceleration data may be used in KNN without selection of summary statistics, and it is easily implemented using the freeware program R. The method is evaluated by detecting 5 behavioural modes in 8 species, with examples of quadrupedal, bipedal and volant species. Accuracy and Precision were found to be comparable with other, more complex methods. In order to assist in the application of this method, the script required to run KNN analysis in R is provided. We envisage that the KNN method may be coupled with methods for investigating animal position, such as GPS telemetry or dead-reckoning, in order to implement an integrated approach to movement ecology research. Fil: Bidder, Owen R.. Swansea University; Reino Unido Fil: Campbell, Hamish A.. The University Of Queensland; Australia Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Urgé, Patricia. Swansea University; Reino Unido Fil: Walker, James. Swansea University; Reino Unido Fil: Cai, Yuzhi. Swansea University; Reino Unido Fil: Gao, Lianli. The University Of Queensland; Australia Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Wilson, Rory P.. Swansea University; Reino Unido

Animal movement, as measured by the overall dynamic body acceleration (ODBA), has recently been shown to correlate well with energy expenditure. However, accelerometers measure a summed acceleration derived from 2 components: static (due to gravity) and dynamic (due to motion). Since only the dynamic component is necessary for the calculation of ODBA, there is a need to establish a robust method for determining dynamic acceleration, currently done by substracting static values from the total acceleration. This study investigated the variability in ODBA arising from deriving static acceleration by smoothing total acceleration over different durations. ODBA was calculated for 3 different modes of locomotion within 1 species (the imperial shag) and for swimming in 4 species of marine vertebrates that varied considerably in body size. ODBA was found to vary significantly with the length of the running mean. Furthermore, the variability of ODBA across running means appeared to be related to the stroke period and hence body size. The results suggest that the running mean should be taken over a minimum period of 3 s for species with a dominant stroke period of up to this value. For species with a dominant stroke period above 3 s, it is suggested that static acceleration be derived over a period of no less than 1 stroke cycle.