2009/10/28 by Yoko Mitani, Russel D. Andrews, Katsufumi Sato +3 · 1 citation
Earth and Planetary Sciences · Engineering · Environmental Science · #Aerospace Engineering and Energy Systems #Arctic and Antarctic ice dynamics #Biology #Descent (aeronautics) #Ecology #Falling (accident) #Geography #Geology #Juvenile #Marine animal studies overview #Meteorology #Oceanography #Predation #Rest (music)
paper · doi:10.1098/rsbl.2009.0719
openalex publication_date 2009/10/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
During their long migrations through the Pacific, northern elephant seals, Mirounga angustirostris, never haul out on land and they rarely spend more than a few minutes at a time at the surface. They are almost constantly making repetitive, deep dives, raising the question of when do they rest? One type of dive, the drift dive, characterized by a time-depth profile with a phase of lower than average descent speed is believed to be a resting dive. To examine the behaviour of seals during drift dives, we measured body position and three-dimensional diving paths of six juvenile seals. We found that seals rolled over and sank on their backs during the drift phase, wobbling periodically so that they resembled a falling leaf. This enabled seals to drastically slow their descent rate, possibly so that negatively buoyant seals can rest without ending up in the abyss. This reduces the work required to return to the surface to breath, and allows them time to rest, process food or possibly sleep during the descent phase of these dives where they are probably less susceptible to predation.