![]() The latter is achieved through the interplay of cardiovascular responses, thermoregulation, body size, hydrodynamics, and cost-efficient swimming ( Kooyman and Ponganis, 1998 Davis, 2014 Williams and Davis, 2021). Such dive performance is dependent on increased oxygen (O 2) storage, hypoxemic tolerance, pressure tolerance, and the regulation of metabolism ( Ponganis, 2015). Maximum reported dive durations are even more impressive: 3.7 h in Cuvier’s beaked whale, 2 h in elephant seals, and 32 min in emperor penguins ( Hindell et al., 1991 Stewart and DeLong, 1995 Goetz et al., 2018 Quick et al., 2020). ![]() Routine durations and depths of deep dives of exceptional divers are remarkable: 60–70 min and 1,400 m in Cuvier’s beaked whale ( Ziphius cavirostris), 20–30 min and 400–600 m in elephant seals ( Mirounga sp.), and 8–12 min and 400–500 m in emperor penguins ( Aptenodytes forsteri) ( Le Boeuf et al., 1986 Hindell et al., 1991 Kooyman and Kooyman, 1995 Tyack et al., 2006 Sato et al., 2011 Robinson et al., 2012 Schorr et al., 2014 Shearer et al., 2019 Kooyman et al., 2020). “These are opening the door to a much greater understanding of how these animals are able to perform some quite amazing feats of diving and exercise,” she says.The diving prowess of marine mammals and seabirds has long fascinated biologists as well as the lay public. ![]() Recent technological advances have enabled these kinds of readings to be collected from free-living whales, says Hooker. These results demonstrate “the quite extraordinary level of flexibility and control that these diving mammals have over their heart rate and blood flow”, says Sascha Hooker at the University of St Andrews, UK. Whales then recover upon resurfacing by dramatically increasing their breathing and heart rate, he says. The reduction in heart rate during dives enables whales to temporarily redistribute oxygenated blood from the heart to other muscles needed for lunging, says Goldbogen. The whale’s heart rate was at its lowest when it was diving for food and shot up after it resurfaced, reaching a peak of 37 beats per minute. The whale dived for as long as 16.5 minutes at a time, reaching a maximum depth of 184 metres, and stayed at the surface for intervals ranging from 1 to 4 minutes. Read more: Humpback whales use their flippers to swat salmon into their mouths They detected heart rates of just 2 to 8 beats per minute hundreds of times. The researchers were then able to monitor the whale’s heart rate for almost 9 hours. The monitors were held in place with suction cups. During lunge feeding, a blue whale engulfs a volume of prey-filled water that can be larger than its own body.įrom a large inflatable boat in Monterey Bay, California, Goldbogen and his team used a 6-metre pole to attach heart rate monitors to a single blue whale. The finding is particularly extraordinary given that whales have an energetically demanding feeding method, says Jeremy Goldbogen at Stanford University, California. Previous predictions were that the whales would have a resting heart rate of 15 beats per minute. This is well below the rates the large animals were calculated to have. When blue whales dive for food they can reduce their heart rates to as low as 2 beats per minute. We have checked the pulse of a wild-living blue whale for the first time, and discovered something remarkable. Image courtesy of the Duke Marine Robotics and Remote Sensing Lab The blue whale heart beats slowly when the animals feeds
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