Stories tagged dolphins

...and, let's face it, who doesn't? You, too, can master the art of echolocation.

May
18
2009

Baby Tucuxi, unaware of impending attack...
Baby Tucuxi, unaware of impending attack...Courtesy Matt Walker

Reading about mutinous mammals is waaaay better than writing the final paper of my undergrad career! Agreed? Yes, well to the point. Now I've heard that dolphins will bite ya if provoked, but that even that is extremely rare.

It is not uncommon for mammals to practice infanticide. It is practiced for a variety of reasons. Males may attack young of their own species so the mother is more receptive to further reproduction from that male. It is also practiced when resources are low and a groups well-being is in danger from lack of food. Both males and females of a species will practice infanticide.

Among their scientific class Cetaceans, a class including dolphins, whales, and porpoises violent behavior including infanticide is very rare and largely undocumented...until now!

Tucuxi Dolphins, native to the Amazon basin were observed practicing infanticide in Brazil by Mariana Nery, of the Southern University of Chile in Valdivia, and Sheila Simao, of the Federal Rural University of Rio de Janeiro, Brazil. Adult male Tucuxi are known to be aggressive but they rarely exhibit this behavior towards younger individuals. Nery and Simao observed six adult Tucuxi separate a newborn Tucuxi calf from its mother. They proceeded to ram into it, hold it under water, and toss it into the air. When the mother attempted to intervene four of the males herded her away. While the adult males attacked the calf the mother floated on her back. This behavior indicates either passiveness, or more likely a signal that she is receptive to sexual behavior. I believe she did this to distract the adult males from injuring or killing the calf, and to let them know she could reproduce again. To no avail. Sadly, the mother was seen days later without her calf.

Sometimes, there isn't safety in numbers. And most of the time, I think, it's probably a bummer to be a sardine. But it's really tough to be one of these sardines!

More cool video and an explanation of how all that was caught on film here.

Hey! Why did I now know about this until now? Whose idea was this? And... can I have this when it dies? I could stuff it and hang it above my bathtub.

An Austrailian film crew has captured footage of the newest classified species of the dolphin family. It's the snub fin dolphin and it's been nicknamed "the ugliest dolphin." Check out this video to rate its appearance for yourself.

Nov
09
2007

Bring 'em on: Come on you nasty sharks...I'll take you all on. (Flickr photo by Cayusa)
Bring 'em on: Come on you nasty sharks...I'll take you all on. (Flickr photo by Cayusa)
The Miami Dolphins on the NFL football field maybe struggling through a winless season so far, but their namesakes off the coast of California chalked up a big win a few months ago.

When surfer Todd Endris was surfing near Monterey on Aug. 28, a 12- to 15-foot great white shark attacked him. It’s not uncommon for surfers to be the targets of sharks, who look up through the water to see what they think is a tasty seal.

Three shark bites peeled skin off his back and had ripped his right leg down to the bone. Then to the rescue came a pod of dolphins.

The formed a protective ring around him, allowing Endris to get his wits about him, paddle to shore and get first aid attention on shore from a friend.

I heard Endris share his tale on the Today Show earlier this week. You can get the full report by clicking here. But my biggest question was left unanswered. Why did the dolphins intervene?

Science doesn’t have the answer yet, but cases of dolphins rescuing people go back to tales from ancient Greece.

Just last year, four lifeguards in New Zealand were saved from sharks by the similar action of a pod of dolphins.

One more interesting twist to the story, within six weeks Endris was back on his surfboard riding the waters off on Monterey again.

So what do you think is at play with dolphins coming to the rescue? Do you think they do this for other species as well, or just humans? Share your thoughts here with Science Buzz readers.

Aug
08
2007

Enjoy the picture
Enjoy the pictureCourtesy Alessio Marrucci
After an “intensive survey of its natural habitat,” the Yangtze River dolphin has been officially declared extinct. So if, as a person, you ever wanted to see one alive, you’re out of luck. And if, as a Yangtze River dolphin, you ever wanted to be alive, also, you’re out of luck.

From a population of thousands in the 1950s, human activity reduced the Yangtze River, or Baiji, dolphin to just a handful of individuals by the turn of the century. Industrialization of the Yangtze River, unsustainable fishing practices, and mass shipping, rather than direct human persecution, placed the Baiji dolphins under extreme pressure, and now they’re all dead, forever. An article in The Guardian states that this is “the fourth time an entire evolutionary line of mammals has vanished from the face of the Earth since the year 1500.” Quite an achievement.

Cross it off your list.

Jan
17
2007

A pod of dolphins is trapped on Long Island: Photo NOAA.
A pod of dolphins is trapped on Long Island: Photo NOAA.

Some two dozen dolphins are stranded in a Long Island creek. Experts think the unusually warm weather through mid-January confused the creatures, which usually head out to deeper water in winter. This recalls some stories from last year, when bad weather stranded whales on Cape Cod, and a confused dolphin swam up the Thames River in England.

Dec
14
2005

Whales and dolphins occasionally run aground on beaches around the world. In Cape Cod, near Boston, animal rescue workers deal with some 200 incidents a year.

But something unusual happened on Friday, December 9. A powerful storm, combined with low tides, trapped large numbers of whales and dolphins. Altogether, 39 animals died.

Mass strandings occur when groups of these social creatures get caught in shallow areas when the tide is heading out. The December event was unusual not only for the large number of animals involved, but that two different species were beached in two different locations.