How Diving Mammals Stay Underwater for So Long

http://animalzoon.blogspot.in/

Imagine holding your breath while chasing down a giant squid (Architeuthis dux)—multi-tentacled monsters wielding suckers lined with tiny teeth—in freezing cold water, all in the dark. That would take a lot out of anybody, yet sperm whales (Physeter macrocephalus) do this day in and day out.

The ability to dive underwater for extended periods is a specialized feat marine and aquatic mammals have evolved over millions of years. Diving mammals will slow their heart rate, stop their breathing, and shunt blood flow from their extremities to the brain, heart, and muscles when starting a dive. (Related: "Can Diving Mammals Avoid the Bends?")

But champion divers, such as elephant seals, can hold their breath for about two hours. "It was known that they rely on internal oxygen stores when they're down there," said Michael Berenbrink, a zoologist at the University of Liverpool, England, who specializes in how animals function.

But there was something else going on in the bodies of these animals that researchers were missing, until now.

So what's new? A study published June 13 in the journal Science reports that diving mammals—including whales, seals, otters, and even beavers and muskrats—have positively charged oxygen-binding proteins, called myoglobin, in their muscles.

This positive characteristic allows the animals to pack much more myoglobin into their bodies than other mammals, such as humans—and enables diving mammals to keep a larger store of oxygen on which to draw while underwater.

Why is it important? Packing too many proteins together can be problematic, explained Berenbrink, a study co-author, because they clump when they get too close to each other.

"This [can cause] serious diseases," he added. In humans, ailments like diabetes and Alzheimer's can result.

But myoglobin is ten times more concentrated in the muscles of diving mammals than it is in human muscles, Berenbrink said.

Since like charges repel each other—think of trying to push together the sides of two magnets with the same charge—having positively charged myoglobin keeps the proteins from sticking to each other.

Penguins support gorillas as biscuit makers respond to palm oil threat

http://animalzoon.blogspot.in/

Penguins are coming to the aid of gorillas, according to a survey which reveals that the UK's leading biscuit manufacturers are responding to the environmental threats of palm oil production.

Many of the biggest names in biscuits including Marks & Spencer, Sainsbury's and United Biscuits – which makes some of the UK's most popular biscuits including McVitie's Digestive and Penguin – have pledged to reduce the amount of palm oil in their products.

The Rainforest Foundation UK (RFUK) and Ethical Consumer magazine together surveyed over 50 of the UK's biggest biscuit manufacturers about their use of palm oil or its derivatives.

The top scoring companies were the Co-op, M&S, Sainsbury's, Waitrose and United Biscuits. Those at the bottom of the ranking were mostly American-based companies including Asda/Walmart, PepsiCo and Kraft, makers of Ritz and Oreo biscuits.

The project was carried out in response to the increasing threat that palm oil production is posing to the world's rainforest and to the people that rely on these forests for their livelihoods. Palm oil is a core ingredient in many food products but companies are not required by EU law to label products containing it until December 2014.

Having destroyed vast areas of forest in countries including Indonesia, which is home to orangutans, the RFUK says palm oil companies are now planning to expand into the rainforests of the Congo basin in Africa, home to lowland gorillas and other threatened primates. Palm oil companies are also partly responsible for the recent devastating forest fires in Sumatra, which caused pollution episodes in Malaysia and Singapore.

Simon Counsell, executive director of The Rainforest Foundation, UK said: "UK biscuit manufacturers and retailers are showing that it is possible to outright reduce the use of palm oil, which is going to have to occur globally if large areas of Africa's rainforests are to be saved from conversion to palm plantations."

Leonie Nimmo, researcher at Ethical Consumer, added: "This survey clearly shows that environmental campaigning is having a positive impact on the palm oil policies of many companies which is something we wholeheartedly support. Consumers now have a choice in buying biscuits which are reducing the risks to both people and wildlife."

North American Birds Declining as Threats Mount

http://animalzoon.blogspot.com/

Throughout the year, birders look forward to changing seasons and avian scenes as they explore woods, grasslands, and wetlands: the spectacle of spring migration, the songs of breeding birds, the autumn southward flight of wintering species from northern nesting grounds.

Increasingly, though, both casual bird-watchers and ornithologists note a steady decline in numbers—not just of endangered species, but also of common birds not usually considered to be at risk. Study after study, survey after survey show a worrisome downward trend in populations.

A National Audubon Society report called "Common Birds in Decline," for instance, shows that some widespread species generally thought to be secure have decreased in number as much as 80 percent since 1967, and the 19 others in the report have lost half their populations. The figures reflect an array of threats faced by birds throughout North America. (Read about the decline of European songbirds in National Geographic magazine.)

Migrants return from Central America to find that the brushy field where they nested the previous year is now a strip mall.

Millions of songbirds annually suffer bloody death in the claws of domestic cats. Millions more collide with city skyscrapers or communications towers, or fly into the glass windows of suburban houses.

And climate change could degrade or even eliminate habitats in ways that scientists have only recently begun to study and try to forecast.

Threats to songbirds occasionally make splashy headlines, as when Smithsonian scientists released a report in January indicating that free-ranging domestic cats kill far more birds than previously believed: between 1.4 and 3.7 billion birds annually in the lower 48 states.

Rare Breed of Killer Whale May Be New Species

http://animalzoon.blogspot.in/

The rarely-seen "type D" orcas—which live in the Southern Ocean—are one of four varieties of killer whale. Researchers recently sequenced type D's genome using material collected from a museum skeleton from 1955. (Watch: "Killer Whales 'Gang Up' to Capture Seal.")

Scientists first spotted type D killer whales in 1955, when a pod of them washed ashore on a New Zealand beach. The stranding stood out as unusual because of the whales' strange appearance. While typical killer whales—types A, B, and C—have streamlined bodies and large, white eye-patches, type D whales have tiny eye markings and large, bulbous heads. (Watch: "Killer Whales vs. Minke Whale.")

The type D pod's stranding resulted in a handful of photos and the collection of one skeleton by the Museum of New Zealand Te Papa Tongarewa in Wellington (map).

According to Robert Pitman, a marine biologist at the U.S. National Marine Fisheries Service, and a co-author of the new study, for many years researchers thought the whales were the result of genetic mutations because there were no other known sightings.

But some 50 years after the New Zealand stranding, a group of researchers, including Pitman, took a closer look at the documentation of the event. They unearthed other accounts of the weird whales, and found that the New Zealand pod was not the only sighting in history.

"We started seeing photos of this type of animal from various places, all around the Antarctic waters," Pitman said. "The weather is bad down there all the time," he said. "That's why the whale escaped notice from scientists for so many years."