Recent studies have revealed intriguing details about the hunting tactics of southern elephant seals, showcasing their remarkable adaptations for deep-sea hunting. These findings provide insight into the complex behaviours and sensory mechanisms that enable these massive predators to thrive in their challenging underwater environment.
New research from the Woods Hole Oceanographic Institution (WHOI) and partners reveals that Weddell seals that inhabit the icy waters of Erebus Bay, Antarctica, employ a careful hunting strategy when it comes to diving, timing their dives to balance energy use and foraging efficiency.
The study, published in Communications Biology, shows that the seals perform their longest and deepest dives early in the day, and not during midday when sunlight is at its peak.
The ozone layer is back on our radar. Although its condition has improved after the Montreal Protocol was implemented, the hole reappears every spring over the Antarctic.
In recent years, it is no longer just a winter phenomenon anymore; it Is stretching into the early summer, coinciding with crucial times in the life cycles of local wildlife and emerging vegetation, exposing them to the sun's ultraviolet rays. As our planet changes, the timing of this exposure could have profound effects on the delicate ecosystems of the Antarctic.
A recent study in the Biophysical Journal reveals that Arctic seals are able to efficiently retain heat and moisture during respiration as a result of the elaborate structures in their nasal cavity.
Elephant seals were recently the focus of a groundbreaking study that explored their sleep patterns during dives. The research, partly funded by the U.S. National Science Foundation and published in the journal Science, provides a unique insight into the world of these marine mammals.”
A new study involving elephant seals fitted with caps similar to those worn by humans in sleep clinics to measure electroencephalographic activity, or brain waves, has revealed the seals take short naps during deep dives. Unlike other marine mammals, they enter rapid eye movement, or REM, sleep, with accompanying paralysis, but do so at depths below those occupied by their predators.
DNA research has shown that Mycobacterium pinnipedii, which today causes tuberculosis (TB) primarily in pinnipeds, infected human populations living in the coastal areas of Peru prior to European colonisation
The earliest cases are found in Peru and northern Chile and are dated to ~700 CE, with possible cases occurring as early as 290 CE.
The researchers also discovered TB in the skeletons of people who lived nowhere near the coast some 400 to 1,000 years ago — a scenario incompatible with TB transmission directly from infected pinnipeds or their tissues.
Every year, many marine animals migrate between foraging areas and breeding sites, often managing their movements with precision.
For pregnant female elephant seals, they travel more than 10,000 kilometres across the Eastern North Pacific Ocean annually, before returning to their breeding beaches where they will give birth within five days of their arrival.
How do they achieve such precise timing, without any GPS or navigation software?
Most of these sounds were measured at more than 21 kHz, which is beyond the range of human hearing of 20 to 20,000 hertz. A particular high-pitched whistle came in at 49.8 kHz. When the seals harmonised multiple tones, the resultant sound may exceed 200 kHz, which is beyond what even cats and dogs can hear).
The discovery was the subject of a paper published online in the journal The Journal of the Acoustical Society of America.
The discovery of the extinct monk seal species came about after an international team of biologists examined seven fossil specimens (including a complete skull) found on south Taranaki beaches in New Zealand between 2009 and 2016.
Named Eomonachus belegaerensis, the new species was about 2.5m long and weighed around 200 to 250kg. It is believed to have lived in the waters around New Zealand three million years ago.
