The hunting strategy of white sharks ( Carcharodon carcharias ) near a seal colony

Klimley, A. Peter; Bœuf, Burney J. Le; Cantara, Kelly M.; Richert, John E.; Davis, Scott F.; Sommeran, Sean Van; Kelly, John

doi:10.1007/s002270000489

Cited by 131 publications

(101 citation statements)

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“…Species of shark that attack dolphins, such as tiger (Galeocerdo cuvier) and white (Carcharodin carcharias), use a stealth foraging tactic where they stalk and attack unwary prey (Heithaus et al, 2002). The burst speed for white sharks is 6-7ms -1 (Kimley et al, 2001), which is likely to be used in an attack. Thus, once a group of dolphins becomes aware of an eminent shark attack and attempts to flee, the near-term pregnant dolphins will be vulnerable to the predatory event because their maximum swim speed (3.54ms ) is half that of the sharks' attack speed.…”

Section: Discussionmentioning

confidence: 99%

Pregnancy is a drag: hydrodynamics, kinematics and performance in pre- and post-parturition bottlenose dolphins (Tursiops truncatus)

Noren

Redfern

Edwards

2011

Journal of Experimental Biology

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SUMMARY Constraints on locomotion could be an important component of the cost of reproduction as carrying an increased load associated with eggs or developing fetuses may contribute to decreased locomotor performance for females across taxa and environments. Diminished performance could increase susceptibility to predation, yet the mechanism(s) by which gravidity and pregnancy affect locomotion remains largely unexplored. Here we demonstrate that morphology, hydrodynamics and kinematics were altered during pregnancy, providing a mechanism for diminished locomotor performance in two near-term pregnant (10 days pre-parturition) bottlenose dolphins (Tursiops truncatus). Near-term pregnancy resulted in a 51±14% increase in frontal surface area, coinciding with dramatic increases in drag forces while gliding. For example, pregnant females encountered 80 N of drag at 1.7 m s–1 whereas that magnitude of drag was not encountered until speed doubled for females 18 months post-parturition. Indeed, drag coefficients based on frontal surface area were significantly greater during pregnancy (Cd,F=0.22±0.04) than at 18 months post-parturition (Cd,F=0.09±0.01). Pregnancy also induced a gait change as stroke amplitude and distance per stroke were reduced by 13 and 14%, respectively, compared with non-pregnant periods (1–24 months post-parturition). This was concomitant with a 62 and 44% reduction in mean and maximum swim speeds, respectively, during the pregnancy period. Interestingly, attack speeds of known predators of dolphins surpass maximum speeds for the pregnant dolphins in this study. Thus, pregnant dolphins may be more susceptible to predation. This study demonstrates unequivocally that changes in morphology, hydrodynamics and kinematics are associated with diminished performance during pregnancy in dolphins.

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Section: Discussionmentioning

confidence: 99%

Pregnancy is a drag: hydrodynamics, kinematics and performance in pre- and post-parturition bottlenose dolphins (Tursiops truncatus)

Noren

Redfern

Edwards

2011

Journal of Experimental Biology

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“…Recent advances in our understanding of adult white shark movements and habitat utilization have come through the use of electronic tag technologies. Shortterm acoustic tracks off North America have revealed that sharks prefer shallower depths (0 to 50 m) on the continental shelf (Carey et al 1982, Goldman et al 1996, Goldman 1997, Klimley et al 2001. Longer satellite tracks revealed that adult white sharks made large-scale pelagic movements from the coastal waters of California into the eastern and central Pacific as far west as Hawaii (Boustany et al 2002).…”

Section: Introductionmentioning

confidence: 99%

Movements, behavior and habitat preferences of juvenile white sharks Carcharodon carcharias in the eastern Pacific

Weng¹,

O’Sullivan²,

Lowe³

et al. 2007

Mar. Ecol. Prog. Ser.

139

116

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Understanding of juvenile life stages of large pelagic predators such as the white shark Carcharodon carcharias remains limited. We tracked 6 juvenile white sharks (147 to 250 cm total length) in the eastern Pacific using pop-up satellite archival tags for a total of 534 d, demonstrating that the nursery region of white sharks includes waters of southern California, USA, and Baja California, Mexico. Young-of-the-year sharks remained south of Point Conception whereas one 3 yr old shark moved north to Point Reyes. All juvenile white sharks displayed a diel change in behavior, with deeper mean positions during dawn, day and dusk (26 ± 15 m) than during night (6 ± 3 m). Sharks occasionally displayed deeper nocturnal movements during full moon nights. On average, vertical excursions were deeper and cooler for 3 yr olds (226 ± 81 m; 9.2 ± 0.9°C) than young-of-the-year animals (100 ± 59 m; 11.2 ± 1.4°C). Juvenile white sharks are captured as bycatch in both US and Mexican waters, suggesting that management of fishing mortality should be of increased concern.KEY WORDS: Juvenile white shark · Carcharodon carcharias · Habitat · Diel behavior · Satellite tag · BycatchResale or republication not permitted without written consent of the publisher

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“…To examine at-sea feeding behavior, technology to measure stomach temperature has been used with a variety of marine predators, such as seabirds (Catry et al, 2004;Grémillet and Plös, 1994;Weimerskirch et al, 2005;Weimerskirch and Wilson, 1992;Wilson et al, 1992), sharks (Klimley et al, 2001;Sepulveda et al, 2004), turtles (Tanaka et al, 1995), and marine mammals (Andrews, 1998;Austin et al, 2006;Hedd et al, 1995;Lesage et al, 1999). This technology is based on the assumption that ectothermic prey of marine endotherms is colder than the predators' core body temperature.…”

Section: Introductionmentioning

confidence: 99%

Identifying and quantifying prey consumption using stomach temperature change in pinnipeds

Kuhn

Costa

2006

Journal of Experimental Biology

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SUMMARY For many marine predators knowledge of foraging behavior is limited to inferences based on changes in diving or movement patterns at sea. This results in an incomplete and potentially inaccurate view of the foraging ecology of a species. This study examined the use of stomach temperature telemetry to identify and quantify prey consumed in both a phocid (northern elephant seal Mirounga angustirostris) and an otariid (California sea lion Zalophus californianus) species. In addition, we used opportunistic water consumption by northern elephant seals to test a method to distinguish between prey and water ingestion. Over 96% of feedings could be identified based on a decline in stomach temperature, even when meals were separated by as little as 70 min. Water consumption was distinguishable from prey consumption, as the rate of recovery in stomach temperature was significantly faster for water (F1,142=79.2, P<0.01). However, using this method, the overlap in recovery rates between prey and water resulted in 30.6% of water ingestion events being misclassified as prey ingestion. For both species, the integral calculated from the decline in stomach temperature over time (area above the curve) could be used to estimate mass consumed, when adjusted for the temperature difference between the prey and core body temperature. For California sea lions, there was a significant effect of individual on the ability to quantify prey consumed, which was not related to their mass or sex. Although many factors may influence the ability to use stomach temperature change to identify and quantify prey consumed, this study has shown measures of stomach temperature can accurately identify prey consumption and provide an estimate of meal mass, allowing for a greater understanding of the feeding behavior of marine mammals.

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The hunting strategy of white sharks ( Carcharodon carcharias ) near a seal colony

Cited by 131 publications

References 0 publications

Pregnancy is a drag: hydrodynamics, kinematics and performance in pre- and post-parturition bottlenose dolphins (Tursiops truncatus)

Pregnancy is a drag: hydrodynamics, kinematics and performance in pre- and post-parturition bottlenose dolphins (Tursiops truncatus)

Movements, behavior and habitat preferences of juvenile white sharks Carcharodon carcharias in the eastern Pacific

Identifying and quantifying prey consumption using stomach temperature change in pinnipeds

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