Thursday, August 14, 2014

14/08/2014: Whales and dolphins squeal with delight while another faces extinction

Whales and dolphins squeal with delight

Beluga whales and bottlenose dolphins express their pleasure by squealing like children, a new study suggests for the first time.
A bottlenose dolphin calls.
Photograph by Frans Lanting, National Geographic Creative

The squeaky sounds, which are different from the echolocation buzzes some whales and dolphins use to home in on prey, suggest there’s yet another aspect of behavior that people share with marine mammals, among the smartest groups of the animal kingdom.

For decades, scientists and marine mammal trainers have noticed these “extra” vocalizations when they rewarded captive animals with food. They have also observed it in wild animals.

Some have brushed it off as an inadvertent artifact of the training process, or figured it was a part of the food calls some whales and dolphins make. (See “Dolphins Have ‘Names,’ Respond When Called.”)

This new work, published August 13 in the Journal of Experimental Biology, suggests that belugas and bottlenose dolphins make the noises to express their delight.

A bottlenose dolphin calls. Photograph by Frans Lanting, National Geographic Creative

Read more HERE

The vaquita porpoise is rapidly going extinct 
The vaquita, a small porpoise found only in the Gulf of California, is rapidly going extinct, an international team of scientists reported earlier this month.
Only 97 vaquita porpoises remain in the wild. Their steep decline is blamed largely on illegal gill-net fishing in the Gulf of California.
Photograph by Flip Nicklin, Minden Pictures/Corbis

The researchers say that the marine mammals—whose name means "little cow" in Spanish—are accidentally drowning in the gill nets local fishers deploy for fish and shrimp. A mere 97 vaquitas remain.

Vaquitas are shy creatures, and rarely seen, except when they're pulled to the surface—dead—in nets. They've been known to science only since 1958, when three skulls were found on a beach.

At the time, it was thought that they numbered in the low thousands. Scientists and fishers alike say the animals, with their pretty facial markings ("they look like they're wearing lipstick and mascara," one scientist said) and sleek bodies, are endearing.

There's danger now that the porpoises will become the second cetacean (the first was the baiji, or Chinese river dolphin) to succumb to human pressures, most likely disappearing forever by 2018.

"It's a complete disappointment for everybody, because we've all been working hard to turn this around, and the [Mexican] government has addressed this from the highest level possible," said Lorenzo Rojas-Bracho, a cetacean conservation specialist at Mexico's Commission of Natural Protected Areas and a member of the team.

Indeed, the Mexican government established a presidential commission on vaquita conservation in 2012, when scientists estimated the porpoise's population at 200.

Read more HERE

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