Diving behavior and swimming style of nursing bearded seal pups

Watanabe, Yuki; Lydersen, Christian; Sato, Katsufumi; Naito, Yoshiro; Miyazaki, Nobuyuki; Kovacs, Kit M.

doi:10.3354/meps07806

Cited by 13 publications

(12 citation statements)

References 28 publications

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“…In the early days after bearded seal pupping in May, pups spend most of their time hauled out of the water (Watanabe et al. ), accessible to polar bears. The later pupping relative to ringed seals could, in part, explain why bearded seal consumption is better reflected in summer–fall diet estimates of SB bears.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, we tentatively suggest a previously unreported seasonal importance of bearded seal to the nutritional needs of SB polar bears of all sex/age classes. In the early days after bearded seal pupping in May, pups spend most of their time hauled out of the water (Watanabe et al 2009), accessible to polar bears. The later pupping relative to ringed seals could, in part, explain why bearded seal consumption is better reflected in summer-fall diet estimates of SB bears.…”

Section: Seasonal Variation In Dietsmentioning

confidence: 99%

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Temporal complexity of southernBeaufortSea polar bear diets during a period of increasing land use

et al. 2017

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Abstract. From 2000 to 2013, use of land as a seasonal habitat by polar bears (Ursus maritimus) of the southern Beaufort Sea (SB) subpopulation substantially increased. This onshore use has been linked to reduced spatial and temporal availability of sea ice, as well as to the availability of subsistence-harvested bowhead whale (Balaena mysticetus) bone piles. Here, we evaluated the role of climate conditions on consumption of traditional ice-associated prey relative to onshore bowhead whale bone piles. We determined seasonal and interannual trends in the diets of SB polar bears using fatty acid-based analysis during this period of increasing land use. Diet estimates of 569 SB polar bears from 2004 to 2012 showed high seasonal fluctuations in the proportions of prey consumed. Higher proportions of bowhead whale, as well as ringed seal (Pusa hispida) and beluga whale (Delphinapterus leucas), were estimated to occur in the winter-spring diet, while higher proportions of bearded seal (Erignathus barbatus) were estimated for summer-fall diets. Trends in the annual mean proportions of individual prey items were not found in either period, except for significant declines in the proportion of beluga in spring-sampled bears. Nonetheless, in years following a high winter Arctic oscillation index, proportions of ice-associated ringed seal were lower in the winterspring diets of adult females and juveniles. Proportions of bowhead increased in the winter-spring diets of adult males with the number of ice-free days over the continental shelf. In one or both seasons, polar bears that were in better condition were estimated to have consumed less ringed seal and/or more bowhead whale than those in worse condition. Therefore, climate variation over this recent period appeared to influence the extent of onshore vs. on-ice food use, which in turn, appeared to be linked to fluctuating condition of SB polar bears.

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Section: Discussionmentioning

confidence: 99%

Section: Seasonal Variation In Dietsmentioning

confidence: 99%

Temporal complexity of southernBeaufortSea polar bear diets during a period of increasing land use

et al. 2017

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“…1). In contrast, the bearded seal pupping season does not begin until early May (Smith 1981;Watanabe et al 2009) making it unlikely that polar bear tissues sampled for this study would contain significant amounts of assimilated nutrients from bearded seal pups.…”

Section: Discussionmentioning

confidence: 99%

Quantifying dietary pathways of proteins and lipids to tissues of a marine predator

Cherry

Derocher

Hobson

et al. 2010

Journal of Applied Ecology

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Abstract1. Using measurements of naturally occurring stable isotopes in animal tissues is useful for monitoring diets of wide-ranging species that would otherwise be logistically difficult to evaluate. However, differential metabolic routing of macromolecules within a consumer can be problematic when using stable isotope analysis of bulk tissues to trace dietary input. 2. We used stable isotope (d 13 C, d 15 N) analysis to examine polar bear Ursus maritimus diet, which includes both lipid-rich blubber and the proteinaceous tissues of their marine mammal prey. Because the proportion of proteins and lipids consumed may depend on prey type and size, it was necessary to consider metabolic routing of these macromolecules separately in isotope mixing models. 3. Bayesian mixing models (MixSIR, version 1.04) were used to separately estimate protein (d C) dietary inputs. We used existing knowledge of the relative lipid and protein intake for polar bears and isotopic information from both macromolecules to estimate overall diet composition. 4. The results for both male and female polar bears indicated that smaller prey (e.g. ringed seal Pusa hispida) contributed the largest proportion to the protein-metabolic pathway. In contrast, the largest proportion of the lipid-metabolic pathway for both sexes tended to consist of larger prey (e.g. bearded seal Erignathus barbatus). 5. The diet composition of male polar bears consisted of more large than small prey. Diet estimates for females overlapped to some degree with males but tended to consist of less large prey. 6. Synthesis and applications. Monitoring polar bear diet may help determine the effects of climateinduced environmental changes in Arctic marine ecosystems including shifts in prey composition. Additionally, tracing origins of anthropogenic pollutants is currently a priority for wildlife managers concerned with the health of marine mammals. However, our results indicate using stable isotopes to infer dietary inputs when proportions of macromolecules fluctuate amongst food sources requires the sampling and analysis of multiple tissues representing distinct macromolecular metabolic pathways. In such cases, utilizing only proteinaceous tissues for analysis will result in erroneous dietary source estimates and inaccuracies when examining trophic-level transfer of contaminants, especially those that are lipophylic.

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“…In some species, such as pinnipeds, young animals can be instrumented and their behavior documented relatively easily (e.g. Raum-Suryan & Rehberg 2004, Pitcher et al 2005, Rehberg & Burns 2008, Watanabe et al 2009). Unfortunately, pelagic cetaceans are more difficult to access, and data are lacking on young calf behavior in many species.…”

Section: Introductionmentioning

confidence: 99%

Tagging young humpback whale calves: methodology and diving behavior

Stimpert¹,

Mattila²,

Nosal³

et al. 2012

Endang. Species. Res.

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Despite the importance of young animals to the proliferation of a species, logistic hurdles often prevent the study of individuals' behavior and habitat requirements. This is particularly an issue in the case of cetaceans, which spend a large proportion of their time at depth. We conducted a study to describe the dive behavior of young humpback whale Megaptera novaeangliae calves on their breeding grounds in Hawaii, USA. We first implemented and evaluated strategies for approaching whale groups and deploying suction-cup tags (DTAGs), resulting in 3 successful attachments of DTAGs in the winter of 2011. The approach technique that was most successful while minimizing reactions from the whale groups was a passive drift approach. Tagged calves exhibited consistent dives to shallow depths when their groups were stationary, and some deeper dives that approached the ocean bottom, up to 78 m in one case. Mean dive durations ranged from 2.2 to 3.5 min, with calves spending 40% of their time within 3 m of the surface. This is the first study to collect tag data from baleen whale calves less than 6 mo in age and provides habitat use data important for management of this endangered species. KEY WORDS: Humpback whale · Calf · Tagging · Diving behavior · Hawaii Resale or republication not permitted without written consent of the publisherEndang Species Res 19: 11-17, 2012 proven to be low-impact, scientists and managers refrained from deploying them on young calves. Tagging of adults with suction-cup tags has been reported to elicit mild and short-term reactions in most large species (Hooker et al. 2001, Johnson et al. 2009), although some smaller species have reacted more strongly and for a longer duration (Schneider et al. 1998). Biopsy sampling of large whales, which also involves close boat approaches, has also resulted in only mild behavioral reactions (Weinrich et al. 1992, Clapham & Mattila 1993, Brown et al. 1994. Given this precedent, we believed that, if conducted mindfully and conservatively, tagging of calves has the potential to yield valuable information on young animal behavior with minimal distress to the ap proached and tagged individuals.Our goals with this manuscript are 2-fold. First we document our field procedures for tagging humpback whale calves on their breeding grounds, comparing 2 approach tactics and making recommendations on strategy for future experiments tagging young baleen whale calves. We then present a basic description of the diving behavior of the tagged animals, the first such description for this life stage of a baleen whale. MATERIALS AND METHODS Study locationThis research was conducted between February 21 and March 4, 2011 in the leeward waters of Maui, Hawaii, USA. The research vessels included the RV 'Hihimanu' (hereafter 'big boat') and a 17 ft inflatable. The big boat was an 11 m safe boat style vessel with twin 250 hp Mercury 4-stroke outboard engines. The inflatable had a 25 hp Mercury 2-stroke outboard engine and could also be propelled by 2 people paddling with...

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Diving behavior and swimming style of nursing bearded seal pups

Cited by 13 publications

References 28 publications

Temporal complexity of southernBeaufortSea polar bear diets during a period of increasing land use

Temporal complexity of southernBeaufortSea polar bear diets during a period of increasing land use

Quantifying dietary pathways of proteins and lipids to tissues of a marine predator

Tagging young humpback whale calves: methodology and diving behavior

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