Elephant seals recognize each other by the rhythm of their calls

Date: July 20, 2017

Source: Cell Press

Summary: Every day, humans pick up on idiosyncrasies such as slow drawls, high-pitched squeaks, or hints of accents to put names to voices from afar. This ability may not be as unique as once thought, researchers report. They find that unlike all other non-human mammals, northern elephant seal males consider the spacing and timing of vocal pulses in addition to vocal tones when identifying the calls of their rivals.

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Climate changes put the freeze on elephant seal births

By Pauline Askin

SYDNEY (Reuters) - More ice means fewer elephant seal pups, according to Australian scientists studying breeding colonies on Macquarie Island near Antarctica and atmospheric changes in the region that have affected the feeding grounds.

"When there's more sea ice the population is likely to go down and in years when there's less sea ice the population is likely to go up," John van den Hoff, a marine biologist at the Australian Antarctic Division, told Reuters.

"When there's extra sea ice the seals can't access the continental shelf as readily as when there's either an average or lesser amount of sea ice."

The causes are due to climate variability linked to a hole in the ozone layer over Antarctica, not climate change, said van den Hoff, a lead researcher on a paper published in the Proceedings of the Royal Society B.

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Thanks To This Seal, A Newlywed Couple Was Stranded On An Island

A newlywed couple who decided to spend their honeymoon on a remote island got a little more than they bargained for when they became stranded -- all thanks to a lazy seal.

The giant elephant seal stole the couple's dinghy and refused to budge for four days. After the large marine mammal took up residence in the inflatable boat, Eddie Stebbings and Bee Bueche were stuck on the United Kingdom's Skomer Island for several days.

The couple, who work as wildlife wardens, decided to spend their first few months of marriage caring for a colony of 180 baby Atlantic gray seals on the tiny British island, Wales Online reports. Stebbings and Bueche used the dinghy to travel the three miles back-and-forth between the mainland and Skomer, which is well known for its wildlife population.

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Tagged seals help find missing piece in global climate puzzle

Researchers pinpoint fourth known source of bottom water, a crucial oceanic heat-sink.

Richard A. Lovett

24 February 2013

MARTIN BIUW

By tracking the voyages of elephant seals off Antarctica, and with the help of satellite imaging and undersea sensors, researchers have discovered a long-elusive source for the deep-ocean streams of cold water that help to regulate the Earth's climate.

Antarctic bottom water (AABW) is cold, highly saline water that forms near the shores of Antarctica. Being denser than typical seawater, it sinks to the depths and then moves north in sluggish currents that spread across the globe.

Continued:  http://www.nature.com/news/tagged-seals-help-find-missing-piece-in-global-climate-puzzle-1.12488

Ocean Warming Causes Elephant Seals to Dive Deeper

ScienceDaily (Feb. 9, 2012) — Global warming is having an effect on the dive behaviour and search for food of southern elephant seals. Researchers from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association cooperating in a joint study with biologists and oceanographers from the Universities of Pretoria and Cape Town have discovered that the seals dive deeper for food when in warmer water. The scientists attribute this behaviour to the migration of prey to greater depths and now wish to check this theory using a new sensor which registers the feeding of the animals below water.


The southern elephant seals from Marion Island, located in the south western part of the Indian Ocean, are extreme divers in the truest sense of the word. The animals spend more than 65 per cent of their lives in depths of over 100 metres, diving far deeper than their fellow species in southern areas. The maximum dive depth of these seals is over 2000 metres. However, the water masses through which the elephant seals from Marion Island swim in search of food are becoming increasingly warmer due to climate change and are forcing the animals to dive deeper. The Southern Ocean is warmed primarily in the water levels up to a depth of 1000 metres and therefore in those areas in which squid and fish ought to be found."This prey is moving down to greater depths presumably due to the increasing water temperatures and this is forcing the seals to follow them," explains Dr. Horst Bornemann from the Alfred Wegener Institute.




Read on:  http://www.sciencedaily.com/releases/2012/02/120209140200.htm

Elephant seal travels 18,000 miles in 11 months

Wide ranging nomadic existence
December 2011. An elephant seal, fitted with a satellite tracking device by Wildlife Conservation Society (WCS), was tracked travelling an astonishing 18,000 miles in 11 months.

WCS tracked the male seal from December, 2010, to November, 2011. The animal - nicknamed Jackson - was tagged on the beach in Admiralty Sound in Tierra del Fuego in southern Chile. WCS conservationists fitted Jackson with a small satellite transmitter that recorded his exact location when he surfaced to breathe.

Nomadic existence
Jackson swam 1,000 miles north, 400 miles west, and 100 miles south from the original tagging location, meandering through fjords and venturing past the continental shelf as he foraged for fish and squid. During this tracking, the WCS team analyzed the data to better understand elephant seal migratory routes.

Elephant seals are potential indicators of the health of marine ecosystems and may show how climate change influences the distribution of prey species that serve as the basis of Patagonia's rich marine ecosystem. To protect this vast region, conservationists need to know how wildlife uses it throughout the year.

Clues to sustainability
"Jackson's travels provide a roadmap of how elephant seals use the Patagonian Coast and its associated seas," said Caleb McClennen, WCS Director for Global Marine Programs. "This information is vital to improving ocean management in the region, helping establish protected areas in the right places, and ensuring fisheries are managed sustainably without harming vulnerable marine species like the southern elephant seal."

The information WCS gathers will serve as a foundation for a new model of private-public, terrestrial-marine conservation of the Admiralty Sound, Karukinka Natural Park (a WCS private protected area), and Alberto de Agostini National Park. It will help build a broader vision for bolstering conservation efforts across the Patagonian Sea and coast.


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