Quid's pro quo...

rhamphotheca:

The Hourglass Dolphin (Lagenorhynchus cruciger) is a small rarely encountered dolphin that occurs in the oceanic waters of  Antarctica and the Sub-Antarctic. It was identified as a new species by Qouy and Galmard in 1824 from a drawing made in the South Pacific in 1820. It is the only cetacean to have been widely accepted as a species solely on witness accounts. Hourglass dolphins tend to move in groups of about 5 to 10. They are believed to eat mostly small fish and squid…

(read more: Wikipedia)      (photos: T - Ocean Defender; B - Lomvi2)


rhamphotheca:

Sperm Whales Adopt Deformed Dolphin

by Chelsea Wald

Sperm whales are fierce squid hunters, but they also have a softer side. In a serendipitous sighting in the North Atlantic, researchers have discovered a group of the cetaceans that seem to have taken in an adult bottlenose dolphin with a spinal malformation, at least temporarily. It may be that both species simply liked the social contact. Creatures form “friendly” connections with members of other species throughout the animal kingdom. These often short-lived relationships can offer increased protection from predators and more effective foraging.

behavioral ecologists Alexander Wilson and Jens Krause of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin did not expect to find a mixed-species group when they set out to observe sperm whales (Physeter macrocephalus) some 15 to 20 kilometers off the island of Pico in the Azores in 2011. But when they got there, they found not only a group that included several whale calves, but also an adult male bottlenose dolphin ( Tursiops truncatus). Over the next 8 days, they observed the dolphin six more times while it nuzzled and rubbed members of the group...

(read more: Science NOW)          

(photos: Alexander D. M. Wilson/Aquatic Mammals)

Aww.  Sperm whales are such good mommas.  They babysit each others’ calves while taking turns diving to feed.  Hanging with a dolphin does not seem so out of the question. 


rhamphotheca:

Ancient ‘Killer Walrus’ Not So Deadly After All

by Megan Gannon

A “killer walrus” thought to have terrorized the North Pacific 15 million years ago may not have been such a savvy slayer after all, researchers say.

A new analysis of fossil evidence of the prehistoric beast shows it was more of a fish-eater than an apex predator with a bone-crushing bite.

Traces of the middle Miocene walrus, named Pelagiarctos thomasi, were first found in the 1980s in the Sharktooth Hill bone bed of California. A chunk of a robust jawbone and sharp pointed teeth, which resembled those of the bone-cracking hyena, led researchers to believe the walrus ripped apart birds and other marine mammals in addition to the fish that modern walruses eat today.

But a more complete lower jaw and teeth from the long-gone species were recently discovered in the Topanga Canyon Formation near Los Angeles. Researchers say the shape of the teeth from this new specimen suggest the walrus was unlikely adapted to regularly feed on large prey. Instead, they think it was a generalist predator, feasting on fish, invertebrates and the occasional warm-blooded snack…

(read more: Live Science)           

(images: Robert Boessenecker, PLOS ONE, doi:10.1371/journal.pone.005431)


rhamphotheca:

The Mystery of the Beaked Whales
by Virginia Morrell
With their distinctive snouts and massive bodies, beaked whales such as the Blainville’s (bottom), are the kind of marine mammal people notice. Although there are 21 species in the beaked whale family (Ziphiidae, including the Cuvier’s beaked whale, top), they’re rarely seen and remain one of the most mysterious and least studied of whales. That’s largely because they live far out at sea and spend much of their time diving and feeding at depths exceeding 1000 meters.
Now, scientists from the National Oceanic and Atmospheric Association Southwest Fisheries Science Center in San Diego, California, have analyzed data from six surveys completed off the Pacific coast from Canada to Mexico over an 18-year period from 1991 to 2008. Their study, reported today in PLOS ONE, provides the first abundance trend estimates for beaked whales—and reveals a disturbing population decline for this group. Neither hunting nor being entangled in fishing nets is causing the drop, the team reports…
(read more: Science NOW)                 
(images: Bahamas Marine Mammal Research Organisation)
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rhamphotheca:

The Mystery of the Beaked Whales

by Virginia Morrell

With their distinctive snouts and massive bodies, beaked whales such as the Blainville’s (bottom), are the kind of marine mammal people notice. Although there are 21 species in the beaked whale family (Ziphiidae, including the Cuvier’s beaked whale, top), they’re rarely seen and remain one of the most mysterious and least studied of whales. That’s largely because they live far out at sea and spend much of their time diving and feeding at depths exceeding 1000 meters.

Now, scientists from the National Oceanic and Atmospheric Association Southwest Fisheries Science Center in San Diego, California, have analyzed data from six surveys completed off the Pacific coast from Canada to Mexico over an 18-year period from 1991 to 2008. Their study, reported today in PLOS ONE, provides the first abundance trend estimates for beaked whales—and reveals a disturbing population decline for this group. Neither hunting nor being entangled in fishing nets is causing the drop, the team reports…

(read more: Science NOW)                 

(images: Bahamas Marine Mammal Research Organisation)


tommypom:

Some days I just want to be pet.. regardless of what you were planning to do on the computer.


News: Deal struck to protect whales from wind turbines

seacetaceans:

Groups developing offshore wind farms from New Jersey to Virginia have agreed to try to protect North Atlantic right whales.

The deal was announced Wednesday by several environmental groups and the developers. They say the voluntary measures are the first of their kind.

The developers are pledging to reduce or avoid loud noises that could affect the whales by avoiding building towers and doing other activities at the peak of whales’ migratory season.

The companies also agree to watch for whales and to use tools and technologies to keep the work as quiet as possible.