Abstract
Evolutionary explanations for mammalian sociality typically center on inclusive-fitness benefits of associating and cooperating with close kin, or close maternal kin as in some whale ...societies, including killer and sperm whales. Their matrilineal structure has strongly influenced the thinking about social structure in less well-studied cetaceans, including beluga whales. In a cross-sectional study of group structure and kinship we found that belugas formed a limited number of distinct group types, consistently observed across populations and habitats. Certain behaviours were associated with group type, but group membership was often dynamic. MtDNA-microsatellite profiling combined with relatedness and network analysis revealed, contrary to predictions, that most social groupings were not predominantly organized around close maternal relatives. They comprised both kin and non-kin, many group members were paternal rather than maternal relatives, and unrelated adult males often traveled together. The evolutionary mechanisms that shape beluga societies are likely complex; fitness benefits may be achieved through reciprocity, mutualism and kin selection. At the largest scales these societies are communities comprising all ages and both sexes where multiple social learning pathways involving kin and non-kin can foster the emergence of cultures. We explore the implications of these findings for species management and the evolution of menopause.
Although predators influence behavior of prey, analyses of electronic tracking data in marine environments rarely consider how predators affect the behavior of tracked animals. We collected an ...unprecedented dataset by synchronously tracking predator (killer whales, N = 1; representing a family group) and prey (narwhal, N = 7) via satellite telemetry in Admiralty Inlet, a large fjord in the Eastern Canadian Arctic. Analyzing the movement data with a switching-state space model and a series of mixed effects models, we show that the presence of killer whales strongly alters the behavior and distribution of narwhal. When killer whales were present (within about 100 km), narwhal moved closer to shore, where they were presumably less vulnerable. Under predation threat, narwhal movement patterns were more likely to be transiting, whereas in the absence of threat, more likely resident. Effects extended beyond discrete predatory events and persisted steadily for 10 d, the duration that killer whales remained in Admiralty Inlet. Our findings have two key consequences. First, given current reductions in sea ice and increases in Arctic killer whale sightings, killer whales have the potential to reshape Arctic marine mammal distributions and behavior. Second and of more general importance, predators have the potential to strongly affect movement behavior of tracked marine animals. Understanding predator effects may be as or more important than relating movement behavior to resource distribution or bottom-up drivers traditionally included in analyses of marine animal tracking data.
The deep-sea is increasingly viewed as a lucrative environment for the growth of resource extraction industries. To date, our ability to study deep-sea species lags behind that of those inhabiting ...the photic zone limiting scientific data available for management. In particular, knowledge of horizontal movements is restricted to two locations; capture and recapture, with no temporal information on absolute animal locations between endpoints. To elucidate the horizontal movements of a large deep-sea fish, a novel tagging approach was adopted using the smallest available prototype satellite tag – the mark-report pop-up archival tag (mrPAT). Five Greenland sharks (Somniosus microcephalus) were equipped with multiple mrPATs as well as a standard archival satellite tag (miniPAT) that were programmed to release in sequence at 8–10 day intervals. The performance of the mrPATs was quantified. The tagging approach provided multiple locations per individual and revealed a previously unknown directed migration of Greenland sharks from the Canadian high Arctic to Northwest Greenland. All tags reported locations, however, the accuracy and time from expected release were variable among tags (average time to an accurate location from expected release = 30.8 h, range: 4.9–227.6 h). Average mrPAT drift rate estimated from best quality messages (LQ1,2,3) was 0.37 ± 0.09 m/s indicating tags were on average 41.1 ± 63.4 km (range: 6.5–303.1 km) from the location of the animal when they transmitted. mrPATs provided daily temperature values that were highly correlated among tags and with the miniPAT (70.8% of tag pairs were significant). In contrast, daily tilt sensor data were variable among tags on the same animal (12.5% of tag pairs were significant). Tracking large-scale movements of deep-sea fish has historically been limited by the remote environment they inhabit. The current study provides a new approach to document reliable coarse scale horizontal movements to understand migrations, stock structure and habitat use of large species. Opportunities to apply mrPATs to understand the movements of medium size fish, marine mammals and to validate retrospective movement modeling approaches based on archival data are presented.
•Currently complex to track horizontal movements of deep water species.•Prototype mrPATs, the smallest available satellite tag, were tested to address this question.•Horizontal tracks were derived through sequential releases of multiple mrPATs per shark.•The experimental design revealed a timed migration of sharks from Canada to northwest Greenland.•mrPATs can be used to understand the movements of large/medium size fish and marine mammals.•mrPATs can validate retrospective movement models using archival depth/temperature data.
To understand beluga whale (Delphinapterus leucas) estuarine use in the Nelson River estuary, southwest Hudson Bay, we recorded and examined beluga movements and habitat associations for the July ...through August period in 2002-2005. We compared locations of belugas fitted with satellite transmitters ("tags") (2002-2005) and aerial-surveyed (2003 and 2005) belugas for years of differing freshwater flow from the Nelson River which is influenced by hydroelectric activity. Using the beluga telemetry location data, we estimated an early August behavioral shift in beluga distribution patterns from local estuarine use to a progressively more migratory behavior away from the estuary. The timing of this shift in behavior was also apparent in results of beluga aerial surveys from the 1940s-1960s, despite environmental changes including later freeze-up and warming ocean temperatures. Overall, during the higher than average discharge ("wet") year of 2005, the three tagged belugas ranged farther from the Nelson River but not farther from the nearest shore along southwestern Hudson Bay, compared to the 10 tagged belugas tracked during the "dry" years of 2002-2004 with below average discharges. Aerial survey data for 2003 and 2005 display a similar dry vs. wet year shift in spatial patterns, with no significant change in overall density of belugas within the study area. In the Nelson estuary, proximity to the fresh-salt water mixing area may be more important than the shallow waters of the upper estuary. Killer whales (Orcinus orca) were observed in the Churchill area (200 km northwest) during each year of study, 2002-05, and belugas may benefit from the proximity to shallow estuary waters that provide protection from the larger-bodied predator. Study results contribute to an understanding of the influence of environmental variation on how and why belugas use estuaries although considerable uncertainties exist and additional research is required.
We collated available satellite telemetry data for six species of ice-associated marine mammals in the Pacific Arctic: ringed seals (Pusa hispida; n = 118), bearded seals (Erignathus barbatus, ...n = 51), spotted seals (Phoca largha, n = 72), Pacific walruses (Odobenus rosmarus divergens, n = 389); bowhead whales (Balaena mysticetus, n = 46), and five Arctic and sub-arctic stocks of beluga whales (Delphinapterus leucas, n = 103). We also included one seasonal resident, eastern North Pacific gray whales (Eschrichtius robustus, n = 12). This review summarized the distribution of daily locations from satellite-linked transmitters during two analysis periods, summer (May–November) and winter (December–April), and then examined the overlap among species. Six multi-species core use areas were identified during the summer period: 1) Chukotka/Bering Strait; 2) Norton Sound; 3) Kotzebue Sound; 4) the northeastern Chukchi Sea; 5) Mackenzie River Delta/Amundsen Gulf; and 6) Viscount Melville Sound. During the winter period, we identified four multi-species core use areas: 1) Anadyr Gulf/Strait; 2) central Bering Sea; 3) Nunivak Island; and 4) Bristol Bay. During the summer period, four of the six areas were centered on the greater Bering Strait region and the northwestern coast of Alaska and included most of the species we examined. The two remaining summer areas were in the western Canadian Arctic and were largely defined by the seasonal presence of Bering-Chukchi-Beaufort stock bowhead whales and Eastern Beaufort Sea stock beluga whales, whose distribution overlapped during both summer and winter periods. During the winter period, the main multi-species core use area was located near the Gulf of Anadyr and extended northwards through Anadyr and Bering Straits. This area is contained within the Bering Sea “green belt”, an area of enhanced primary and secondary productivity in the Bering Sea. We also described available telemetry data and where they can be found as of 2017. These data are important for understanding ice-associated marine mammal movements and habitat use in the Pacific Arctic and should be archived, with appropriate metadata, to ensure they are available for future retrospective analyses.
Sensory ability in the narwhal tooth organ system Nweeia, Martin T.; Eichmiller, Frederick C.; Hauschka, Peter V. ...
Anatomical record (Hoboken, N.J. : 2007),
April 2014, Volume:
297, Issue:
4
Journal Article
Sensory ability in the narwhal tooth organ system Nweeia, Martin T.; Eichmiller, Frederick C.; Hauschka, Peter V. ...
Anatomical record (Hoboken, N.J. : 2007),
April 2014, 2014-04-00, 20140401, Volume:
297, Issue:
4
Journal Article
Cumberland Sound, an inlet on Baffin Island, Nunavut, Canada, is undergoing changes in sea ice cover, which is affecting the marine food web. A small population of beluga whales Delphinapterus leucas ...inhabits Cumberland Sound year round and this population is currently listed as threatened. Relatively little is known about the foraging behaviour of these belugas, but we expected that food web changes, primarily an increased abundance of capelin in the region, would have an impact on their diet and dive behaviour. We evaluated fatty acids in blubber samples collected from subsistence-hunted belugas in Cumberland Sound from the 1980s to 2010, and analyzed satellite tag information from 7 belugas tagged in 2006 to 2008 to gain a better understanding of their foraging behaviour. There was a change in the fatty acid profile of beluga blubber from the 1980s compared to the 1990s and 2000s. Specific fatty acids indicative of capelin and Arctic cod increased and decreased over time respectively, suggesting an increased consumption of capelin with a reduction in Arctic cod in summer in more recent years. Dive behaviour suggested different foraging tactics across seasons. Shallow short dives occurred in summer, which may indicate foraging on capelin, while deeper longer dives were made in autumn and winter, possibly indicating foraging on deeper prey such as Arctic cod and Greenland halibut. Potentially, autumn and winter are important foraging seasons for belugas, amassing energy reserves as blubber and creating a possible competitive conflict for resource use between belugas and expanding commercial fisheries.
For many decades, humans have captured white whales (Delphinapterus leucas) for food, research, and public display, using a variety of techniques. The recent use of satellite-linked telemetry and ...pectoral flipper band tags to determine the movements and diving behaviour of these animals has required the live capture of a considerable number of belugas. Three principal techniques have been developed; their use depends on the clarity and depth of the water, tidal action, and bottom topography in the capture area. When the water is clear enough so that the whales can be seen swimming under the water and herded into shallow sandy areas, a hoop net is placed over the whale's head from an inflatable boat. When the water is murky and the belugas cannot easily be seen under the water, but can be herded into relatively shallow sandy areas, a seine net is deployed from a fast-moving boat to encircle them. If the whales are in deep water and cannot be herded into shallow water, a stationary net is set from shore to entangle them. Once captured, the whales have to be restrained in a way that allows them to breathe easily, have the tags attached, and be released as quickly as possible. The methods have proved to be safe, judging from the whales' rapid return to apparently normal behavioural patterns. /// Durant de nombreuses décennies, l'homme s'est livré à la capture des baleines blanches (Delphinapterus leucas) à l'aide de diverses techniques, dans le but de se nourrir, de faire de la recherche et d'exposer publiquement ces animaux. L'utilisation récente de la télémesure en liaison avec un satellite et des rubans-sondes fixés sur les nageoires pectorales pour déterminer les déplacements et le comportement en plongée de ces animaux a nécessité la capture vivante d'un grand nombre de bélougas. On a recouru à trois techniques principales, dont l'utilisation dépend de la clarté et de la profondeur de l'eau, de l'action des marées et de la topographie du fond dans la zone de capture. Quand l'eau est assez claire pour qu'on voie les baleines nager sous la surface et qu'on puisse les rabattre dans des zones sableuses peu profondes, on place un verveux sur la tête de la baleine depuis un canot pneumatique. Quand l'eau est trouble et qu'on ne distingue pas bien les bélougas sous la surface tout en pouvant les rabattre vers des zones sableuses de profondeur relativement faible, on déploie une senne depuis un bateau qui se déplace à grande vitesse pour les encercler. Si les baleines sont en eau profonde et qu'on ne peut les rabattre dans de l'eau peu profonde, on installe un filet fixe depuis le rivage pour qu'elles s'y prennent. Une fois capturées, les baleines doivent être maîtrisées de telle façon que leur respiration n'est pas entravée; il faut ensuite fixer les sondes sur les animaux, qu'on doit relâcher le plus rapidement possible. Si l'on en juge par le retour rapide des baleines à des schémas de comportement normal, ces méthodes se révèlent sécuritaires.
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