Diving behavior, foraging strategies, and energetics of female Steller sea lions during early lactation

Olivier, Paul A.; Andrews, Russel D.; Burkanov, Vladimir N.; Davis, Randall W.

doi:10.1016/j.jembe.2022.151707

Cited by 6 publications

(6 citation statements)

References 35 publications

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“…This dive behavior, which is indicative of area intensive searching with prey pursuit on the seafloor, is similar to that of benthic‐foraging NZSL in the Auckland Islands and Otago Peninsula based on time‐depth recordings (Augé et al, 2011a; Chilvers & Wilkinson, 2009; Crocker et al, 2001). In addition, this behavior resembles the foraging behavior (based on three‐dimensional dive path with video from animal‐borne data recorders) of female Steller sea lions ( Eumetopias jubatus ) in the Kuril Islands in Russia, which feed predominately on demersal Atka mackerel ( Pleurogrammus monopterygius ; Olivier, 2015; Olivier et al 2022).…”

Section: Discussionmentioning

confidence: 83%

Home ranges and diving behavior of endangered New Zealand sea lions along the Catlins coast of South Island, New Zealand

Reed

Childerhouse²,

Robertson

et al. 2022

Marine Mammal Science

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New Zealand sea lions (NZSL, Phocarctos hookeri) were extirpated from mainland New Zealand during pre-European subsistence hunting. They began reoccupying South Island in 1994, and the newest breeding colony arose in 2006 along the Catlins Coast on southeastern South Island and currently consists of <10 individuals. The goal of this study was to use animal-borne satellite telemeters and miniature data recorders (MDRs) to determine home ranges, three-dimensional movements, and foraging strategy of female NZSL along the Catlins Coast during the austral winter of 2019. Total home ranges were small (97 km 2 ) and primarily restricted to nearshore areas. Dives were shallow (8.9 m), short in duration (1.4 min), and had a mean swimming speed of 1.5 m s À1 . We identified three dive types based primarily on total dive duration, mean maximum depth, total distance swam, and path linearity. The estimated at-sea metabolic rate varied among dive types because of differences in flipper stroke frequency and swim speed. Female NZSL along the Catlins Coast have smaller home ranges and make shorter foraging trips compared with females in the Auckland Islands, and suitable habitat for breeding and prey availability along the southeast coast are encouraging for future population growth.

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Section: Discussionmentioning

confidence: 83%

Home ranges and diving behavior of endangered New Zealand sea lions along the Catlins coast of South Island, New Zealand

Reed

Childerhouse²,

Robertson

et al. 2022

Marine Mammal Science

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“…New sensors facilitate data collection on prey capture (e.g. Tennessen et al, 2019 ; Olivier et al, 2022 ), drift rates (used to infer body condition; e.g. Biuw, 2003 ; Biuw et al, 2007 ) and acceleration, breath rate and heart rate (used to infer FMRs; e.g.…”

Section: Resultsmentioning

confidence: 99%

Key questions in marine mammal bioenergetics

McHuron

Adamczak

Arnould

et al. 2022

Conservation Physiology

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Bioenergetic approaches are increasingly used to understand how marine mammal populations could be affected by a changing and disturbed aquatic environment. There remain considerable gaps in our knowledge of marine mammal bioenergetics, which hinder the application of bioenergetic studies to inform policy decisions. We conducted a priority-setting exercise to identify high-priority unanswered questions in marine mammal bioenergetics, with an emphasis on questions relevant to conservation and management. Electronic communication and a virtual workshop were used to solicit and collate potential research questions from the marine mammal bioenergetic community. From a final list of 39 questions, 11 were identified as ‘key’ questions because they received votes from at least 50% of survey participants. Key questions included those related to energy intake (prey landscapes, exposure to human activities) and expenditure (field metabolic rate, exposure to human activities, lactation, time-activity budgets), energy allocation priorities, metrics of body condition and relationships with survival and reproductive success and extrapolation of data from one species to another. Existing tools to address key questions include labelled water, animal-borne sensors, mark-resight data from long-term research programs, environmental DNA and unmanned vehicles. Further validation of existing approaches and development of new methodologies are needed to comprehensively address some key questions, particularly for cetaceans. The identification of these key questions can provide a guiding framework to set research priorities, which ultimately may yield more accurate information to inform policies and better conserve marine mammal populations.

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“…environmental characteristics, we were able to investigate the influence of prey size on northern fur seal foraging behavior. The incorporation of animal-borne video into marine predator tracking studies has exploded in recent years with videos helping to quantify prey encounter rates (e.g., Watanabe and Takahashi, 2013;Thiebot et al, 2016;Oliver et al, 2022), prey avoidance behavior (Handley et al, 2018;Mattern et al, 2018), location and timing of foraging (e.g., Yoshino et al, 2020;Sutton et al, 2021), and impacts of multispecies foraging groups (Sutton et al, 2020;Michel et al, 2022). Studies examining the foraging success of individuals are critical for understanding how changes to habitat and prey resources could impact overall population dynamics (e.g., Lewis et al, 2001;Pettorelli et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Animal-borne video cameras reveal differences in northern fur seal foraging behavior related to prey size selection

Kuhn

Sterling²,

McCormley³

et al. 2022

Front. Mar. Sci.

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A key aspect of foraging ecology research is understanding how predator foraging behavior and success are influenced by variation in prey resources. For northern fur seals (Callorhinus ursinus), an understanding of predator-prey relationships is critical to help identify potential causes for the unexplained population decline in Alaska. To examine how foraging behavior differs based on prey size selection, we equipped northern fur seals on St. Paul and St. George islands (Alaska, USA) in September (2017, n=6) and August (2018, n=4, and 2019, n=3) with satellite-linked dive recorders and animal-borne video cameras. We categorized prey capture attempts based on relative prey size (small vs. large) and examined differences in capture depth, time of day, water temperature, and depth relative to the mixed-layer. Successful prey captures (n= 2224) primarily occurred at night (89.7 ± 3.1%) and small prey accounted for the majority of captures (70.5 ± 13.2%), but there was significant variation among individuals. Large prey were captured at nearly twice the depth of small prey (42.9 ± 3.7 m and 23.1 ± 1.8 m, respectively) and the proportion of large prey caught during the day was 3 times higher than at night (0.77 ± 0.1 vs. 0.25 ± 0.1). There was no relationship between prey size and water temperature after we accounted for temperature changes with depth. The highest proportion of prey captures occurred below the mixed-layer depth regardless of prey size, but the proportion of small prey captures above mixed-layer depth was double that of large prey. This enhanced understanding of northern fur seal prey capture behavior will be pivotal for better interpretation of decades of historical dive and diet data and can provide insight into how northern fur seals may respond to future variation in prey resources, which is essential to develop ecosystem-based approaches for northern fur seal conservation.

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Diving behavior, foraging strategies, and energetics of female Steller sea lions during early lactation

Cited by 6 publications

References 35 publications

Home ranges and diving behavior of endangered New Zealand sea lions along the Catlins coast of South Island, New Zealand

Home ranges and diving behavior of endangered New Zealand sea lions along the Catlins coast of South Island, New Zealand

Key questions in marine mammal bioenergetics

Animal-borne video cameras reveal differences in northern fur seal foraging behavior related to prey size selection

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