Hayden Panettiere in dolphin protest, stranding in Iran, tool use seen again in wild dolphins
Hayden Panettiere , who stars as the indestructible cheerleader Cliare Bennet on the hit TV series Heroes , was involved in a dolphin protest in Japan this week . In association with the anti-whaling group Sea Shepherd , Hayden and a group of surfers paddled into a small bay in Taiji Japan, where Japanese fisherman were preparing to slaughter a group of dolphins as part of their annual dolphin drive hunt. After a dramatic confrontation with the fisherman, an emotional Hayden returned to shore unable to prevent the hunt from taking place, and gave a brief interview with Sky News (AUDIO CLIP) . In a statement released last Friday, Hayden discussed her reasons for joining the protest: She stated: "Because I am in the public eye I feel the need to be a voice of worthy and important causes whose efforts impact the lives of every person on Earth. These animals are being brutally and unnecessarily slaughtered – and who are we to say to they have less of a right to exist than we do." You can find links to video footage of the incident on The Dolphin Pod website .
A mass stranding of striped dolphins in Iran has environmentalists concerned . Over 150 striped dolphins have been found stranded near the southern port of Jask in Iran as part of a mass stranding that began in the end of September. Local Iranian scientists are guessing that the dolphins drowned after becoming entangled in fishing nets. Other possible explanations for the strandings include acute poisoning due to a toxin in the dolphins’ habitat, infectious disease, and exposure to low frequency active sonar used by military organizations. Iranian officials stated that the cause of the strandings remains a mystery.
Scientists form Australia are reporting a sighting of tool use by a wild Indo-Pacific humpback dolphin . An adult Indo-Pacific humpback dolphin was observed by researchers in Hinchinbrook Channel , in northeast Queensland, Australia, carrying a sponge on its rostrum. Researchers suggest that the dolphin was somehow using the sponge as a tool during foraging. This is the second species of dolphin to be observed using tools in the wild – researchers had initially observed Indo-pacific Bottlenose dolphins using sponges in a similar fashion.
What is spyhopping?
What is spyhopping? In this week’s Dolphin Pod News, we heard a short audio clip wherein Hayden Panettiere mentions a cetacean behavior known as spy hopping . Describing her encounter with Japanese hunters and a group of pilot whales trapped in the cove, Hayden said: “There was one point when they were literally spy-hopping, which is when they jump out of the water and stick their heads up out of the water and they can look around”. What exactly is spyhopping and why do whales and dolphins do it? Well for once, the answer to this question is as obvious as it seems it should be. Whales and dolphins hold their heads out of the water in order to visually inspect the environment above the water line. Many species of whales and dolphins are known to engage in spy hopping. Perhaps the most prolific spy-hoppers are orca and humpback whales; two species who receive quite a bit of attention from the tourist industry. Spy hopping behavior consist of the cetacean holding itself vertically in the water and kicking with its tail fluke in order to hold its head above the water line. Some individuals are able to keep this up for minutes at a time. It is quite similar to treading water for a human, although likely somewhat more difficult for cetaceans because they are less buoyant in water than we are.
You may recall from an earlier episode of The Dolphin Pod that dolphins and whales have eyeballs that are specially designed for underwater vision. Whales and dolphins evolved from land animals many millions of years ago, and their eyeballs had to evolve in order to adjust to permanent underwater living. But the changes in their eyeballs were remarkable in that, despite their ability to see quite well underwater, both dolphins and whales have retained excellent vision in air. Although perhaps ‘retained’ is not the correct term; in order for a dolphin’s eyeball to have evolved the ability to see equally as well in water as in air, new anatomical structures were required.
These include a rounded fish-eye like form to the eyeball together with a highly mobile lens that is capable of dramatically changing position. The end result of all this fancy evolution is that, when a dolphin or whale engages in spy hopping behavior, it is able to see almost as well as you or I can at the surface.
Scientists have observed that spyhopping occurs frequently when dolphins or whales interact with tourist boats. It is simply a case of that they wish to see what all the fuss is about at the surface, and the best way to do this is to hold your head out of the water. Echolocation is entirely ineffective in air. The difference in density between air and water means that any echolocation directed at the surface will be completely useless – all of the sound waves will bounce off of the surface, making it impossible for a whale or dolphin to tell what is going on without sneaking a peak. Spyhopping is seen frequently around Vancouver Island in British Columbia – where groups of tourist in whale watching vessels flock to see the largest dolphin of all: the orca. The vast majority of objects and phenomena that a dolphin or whale needs to know about can be found under the water. But humans, in our strange surface-skimming boats, present a curious new object to whales and dolphins; an object that must be inspected both above and below the water’s surface to be fully appreciated.
But spyhopping is only one of the many cetacean behaviors that take place ‘at the surface’. Aside from breaking the surface to breath and spyhop, whales and dolphins are known to lunge out of the water, and to porpoise – a behavior where they arc out of the water but remain mostly horizontal while travelling at speed; presumably to reduce drag when in a hurry. They also engage in a variety of behaviors that fall under the umbrella of ‘breaching ’. Breaching can take many forms, from shallow side-flops, to high jumps many meters above the water’s surface. In the case of spinner dolphins or dusky dolphins, these breaches and jumps can be accompanied by crazy spins or other twists and turns, forming complex aerial displays. Scientist are still puzzled as to the meaning of the various forms of breaching. Different forms of breaching and jumping may be used as visual communicative signals, as means of orientation, as social signals associated with play, fighting or courtship, as a means of stunning fish, in order to create a loud sounds used in communication, or as a way to remove parasites. Spyhopping on the other hands appears to be a very simple behavior with an obvious goal; to see what’s going on .
Surf’s up dude! Humans aren’t the only animal that likes to catch a wave every now and then. Even though they don’t use surf boards, dolphins love to go surfing! Just like human body surfers, dolphins have been known to ride the crests of big waves as they roll into shore. Just before the wave will crash into shore, the dolphins will turn around and rush back into open water. They can even be seen leaping clear out of the water from the top of a wave. The waves and the currents that they create help to push the dolphins along in the water, allowing them to attain fast swimming speeds with minimal effort. This is similar to the way that newborn dolphin calves stick close to their mother’s side in order to help them swim. As a mother dolphin swims quickly through the water, she forms something called a ‘slipstream’ next to her body as the water rushes past her. If the baby dolphin is inside this slipstream, he or she will be carried along with mom. To watch video of dolphins riding the waves, visit The Dolphin Pod.com
Do dolphins float or sink?
The winner of last week’s quiz is Brianna Bowman, who correctly stated that the Median Notch is the indentation between the two flukes of a dolphin’s tail.
Now for this week’s quiz: if a dolphin stops swimming g and remains motionless, will it float or sink?
Think you know the answer? Surf on over to thedolphnipod.com and click on Dolphin Quiz – leave your answer in the comments section. Winners will randomly be chosen from the correct answers, and will be announced on next week’s show.
The Biennial Conference on the Biology of Marine Mammals is a gathering of marine mammalogists and other scientists from around the world. This year the 17th Biennial conference will be held in Cape Town, South Africa, from November 29 - December 3, 2007. The conference is put on by the Society for Marine Mammalogy , and may just be the largest gathering of marine mammal scientist in the world. What follows is my interview with Dr. Kathleen Dudzinski about the conference.
That’s it for this week’s edition of The Dolphin Pod – thanks for tuning in. If you would like more information about the stories from this week’s episode, check out thedolphinpod.com. If you’ve got questions or comments about this week’s podcast episode, please contact us through the website. Why not consider signing up for the Dolphin Communication Project’s online community? You’ get access to a forum where you can discuss the The Dolphin Pod with other listeners. The DCP website offers a chance to adopt one of our dolphins from the Bahamas, as well as learn more about volunteer, internship and ecotour opportunities.
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