Nav: Home

Southern elephant seals may adjust their diving behavior to stay in prey patches

December 14, 2016

When southern elephant seals find dense patches of prey, they dive and return to the surface at steeper angles, and are more sinuous at the bottom of a dive, according to a study published December 14, 2016 in the open-access journal PLOS ONE by Yves Le Bras from Centre d'Etude Biologiques de Chizé, and colleagues.

Female southern elephant seals (Mirounga leonina) spend most of the year -- 10 months -- at sea, foraging for myctophids (lanternfish) and cephalopods. Unlike some predators, these seals need to return to the ocean's surface to breathe between dives for their prey, so efficient diving behavior is key to successful foraging. To see if the seals adjust their diving behavior with prey density, Le Bras and colleagues fitted nine female southern elephant seals in the Indian Ocean with loggers that recorded data including location, depth, acceleration, and horizontal speed.

The researchers found that diving seals made two major adjustments when encountering prey at high rates. First, the seals dove at steeper angles, reducing the transit phases of the dives, thus making them more efficient. Second, the seals were more sinuous at the bottom phase of dives, reducing the horizontal travel distance at the surface. This may counteract horizontal displacement from water currents, helping the seals stay in favorable prey patches.

While only nine seals were included in the study, the researchers suggest that their findings may apply to other air-breathing divers that also eat small prey such as fishes or crustaceans. In contrast, air-breathing divers that favor large prey such as Antarctic toothfish may return to the surface to feed. This work may also help predict how changes in prey distribution might affect predator populations.
-end-
In your coverage please use this URL to provide access to the freely available paper: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0167226

Citation: Le Bras Y, Jouma'a J, Picard B, Guinet C (2016) How Elephant Seals (Mirounga leonina) Adjust Their Fine Scale Horizontal Movement and Diving Behaviour in Relation to Prey Encounter Rate. PLoS ONE 11(12): e0167226. doi:10.1371/journal.pone.0167226

Funding: This work was supported by: http://www.poitou-charentes.fr/accueil.html;http://www.deux-sevres.com/deux-sevres/default.aspx;http://www.agence-nationale-recherche.fr/?Project=ANR-11-BSV7-0022;http://www.agence-nationale-recherche.fr/?Projet=ANR-07-VULN-0005;http://www.fondation.total.com/;https://cnes.fr/fr.

Competing Interests: The authors have declared that no competing interests exist.

PLOS

Related Seals Articles:

Tooth be told: Earless seals existed in ancient Australia
A fossilised seal tooth, dating back approximately three million years, found on a Victorian beach proves earless seals existed in Australia in prehistoric times.
Neanderthals ate mussels, fish, and seals too
Over 80,000 years ago, Neanderthals fed themselves on mussels, fish and other marine life.
Scientists listen to whales, walruses, & seals in a changing arctic seascape
A year-round acoustic study of marine mammals in the northern Bering Sea is providing scientists with a valuable snapshot of an Arctic world already under drastic pressure from climate change, according to WCS (Wildlife Conservation Society), Columbia University, Southall Environmental Associates, and the University of Washington.
Grey seals discovered clapping underwater to communicate
An international study, led by Australia's Monash University, has discovered wild grey seals can clap their flippers underwater during breeding season.
TV crews capture first evidence of leopard seals sharing food
Previously unseen footage captured during filming for the Netflix series Our Planet -- narrated by Sir David Attenborough -- reports up to 36 seals seen feeding at the same king penguin colony in South Georgia.
Mapping Oregon coast harbor seal movements using wearable devices
Wearable devices fitted to harbor seals reveal their movements around the Oregon coast, for a population that has been increasing following the implementation of marine reserves and protection acts.
Wearable device reveals how seals prepare for diving
A wearable noninvasive device based on near-infrared spectroscopy (NIRS) can be used to investigate blood volume and oxygenation patterns in freely diving marine mammals, according to a study publishing June 18 in the open-access journal PLOS Biology by J.
Antarctic biodiversity hotspots exist wherever penguins and seals poop
Scientists have found that on the desolate Antarctic peninsula, nitrogen-rich poop from colonies of penguins and seals enriches the soil so well that it helps create biodiversity hotspots throughout the region.
Chemical records in teeth confirm elusive Alaska lake seals are one of a kind
Lifelong chemical records stored in the canine teeth of an elusive group of seals show that the seals remain in freshwater their entire lives and are likely a distinct population from their relatives in the ocean.
Plastic in Britain's seals, dolphins and whales
Microplastics have been found in the guts of every marine mammal examined in a new study of animals washed up on Britain's shores.
More Seals News and Seals Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.