Tag Archives: orca

Killer Whale

Several species of Killer Whale, scientist say

A study in the journal Genome Research suggests there are several species of killer whale.

It has long been thought that there are at least three types of killer whales: residents who eat fish; transients who eat mammals; and offshores about who little is known. The new research gives the strongest evidence yet supporting the theory there are several species of killer whales throughout the world’s oceans.

One of the whales suggested as a new species is the “pack ice killer whale” from the Antarctic. This has a large eye-patch and two-tone gray color pattern. This type specialises in hunting seals, which are often on the ice and need to be knocked off the ice by the whales before they can be caught.

The “Ross Sea killer whale”, also, from the Antarctic is another considered a distinct species. This has a narrow angled eye patch. It is the smallest of 3 Antarctic types and eats fish that are found under the ice pack, following them deep into the ice as it breaks up in the summer months.

A third recommended for separate species listing is the Pacific Transient killer whale. This looks similar to an Antactic open water type with the typical black and white color pattern and eye-patch, but is genetically distinct. The Transients are known to feed on all types of marine mammals, including other whales, dolphins, and seals and sea lions.

Further Reading:
Killer Whales
Genomic Analysis Indicates Mulitples Species of Killer Whale
Complete mitochondrial genome phylogeographic analysis of killer whales (Orcinus orca) indicates multiple species

Albatrosses feed with Killer Whales

Scientists have recorded the first observations of how albatrosses feed alongside marine mammals at sea.

A miniature digital camera was attached to the backs of four black-browed albatrosses (Thalassarche melanophrys). Results are published online this week in the open-access journal PLoS ONE.

Albatrosses fly many hundreds of kilometers across the open ocean to find and feed upon their prey. Despite the growing number of studies concerning their foraging behaviour, relatively little is known about how albatrosses actually locate their prey. The still images recorded from the cameras showed that some albatrosses actively followed a killer whale (Orcinus orca), possibly to feed on food scraps left by this diving predator. The camera images together with the depth profiles showed that the birds dived only occasionally, but that they actively dived when other birds or the killer whale were present. This association with diving predators or other birds may partially explain how albatrosses find their prey more efficiently in the apparently ‘featureless’ ocean, with a minimal requirement for energetically costly diving or landing activities.

The camera, developed by the National Institute for Polar Research in Tokyo, is removed when the albatross returns to its breeding ground after foraging trips. It is small and weighs 82g. Although the camera slightly changes the aerodynamic shape of the albatross, it didn’t affect the breeding success of the study birds.

Dr Richard Phillips from British Antarctic Survey (BAS) says, “These images are really interesting. They show us that albatrosses associate with marine mammals in the same way as tropical seabirds often do with tuna. In both cases the prey (usually fish) are directed to the surface and then it’s easy hunting for the birds.”

The study took place at the breeding colony of black-browed albatrosses at Bird Island, South Georgia in January 2009, as part of a UK-Japan International Polar Year 2007-9 project.

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Killer Whales Die without Chinook Salmon

When you mention killer whales, the image of one ambushing a terrified seal often springs to mind. But there are populations of killer whales who live exclusively on fish. And not on just any fish: they are very specialised in which fish they will eat.

According to research published in Biology Letters, two populations studied in the northeastern Pacific Ocean prefer to eat Chinook salmon (Oncorhynchus tshawytscha). So much so that if the numbers of Chinook salmon drop this directly affects the numbers of killer whales. The whales seem unable to adopt a new food, become weak and have a higher mortality.

The authors conclude that other killer whale populations may be similarly constrained to one or two prey species, because the young whales will have learnt their fishing strategies from the rest of the group. They too will be limited in their ability to switch to new food if necessary.

Journal Reference:
John K. B. Ford, Graeme M. Ellis, Peter F. Olesiuk, and Kenneth C. Balcomb
Linking killer whale survival and prey abundance: food limitation in the oceans’ apex predator?
Biol Lett 2009 : rsbl.2009.0468v1-rsbl20090468.

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New IMAX Film: DOLPHINS AND WHALES

Filmmakers and environmentalists Francois and Jean-Jacques Mantello and ocean explorer Jean-Michel Cousteau are pleased to announce they have joined forces on the new 3D documentary film DOLPHINS AND WHALES 3D: Tribes of the Ocean, which will be released at IMAX (R) Theatres beginning on February 15th, 2008. This latest installment in 3D Entertainment’s unique ocean themed film series will deliver a strong and compelling conservation message while bringing audiences on a close encounter, for the very first time in 3D, with small and giant cetaceans such as humpback and sperm whales, orcas and dolphins.

“I am delighted to be associated with this new, unforgettable underwater voyage where viewers will don their 3D glasses much in the same way we put on our diving masks and will be immersed in the rarely seen world of these fascinating but vulnerable creatures,” says Jean-Michel Cousteau. “DOLPHINS AND WHALES 3D: Tribes of the Ocean is an ideal means of reaching a vast audience and helping individuals around the world to understand that we need to act responsibly in order to ensure the preservation of the world’s oceans and its inhabitants because, in the end, the most crucial partners whales and dolphins have are YOU and me.”

“DOLPHINS AND WHALES 3D: Tribes of the Ocean will show a large variety of cetacean species, filmed exclusively in the wild, as they really are in their daily lives: interacting socially, playing, communicating through their highly complex system of sound, feeding, breeding, migrating and perpetually fighting for their survival,” explains the film’s director, Jean-Jacques Mantello.

“Although each encounter with these wild creatures was truly magical and highly emotional, this marks one of the most challenging and epic productions I have ever taken on.”

Principal photography began in June 2004 in Polynesia. An extensive three years were required to capture the footage during the course of 12 international expeditions and over 600 hours underwater at some of the remotest locations on Earth, including off the Pacific Ocean atolls of Moorea and Rurutu, Vava’u island of the Kingdom of Tonga, Pico Island in the Azores archipelago, the Valdez Peninsula in Argentina, Sapphire Coast of Australia, Bay of Islands in New Zealand and Canada’s Hudson Bay. Unlike other IMAX-type documentaries, the film consists solely of underwater footage, with none of the usual “dive preparation” sequences.

The film trailer can been seen at http://www.DOLPHINSandWHALES3D.com
High-resolution photos from the film are available at http://www.3DEpublicity.com.

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