Hello Kitty! Please Don’t Kill Me!

Cats kill billions of birds and mammals every year, new study says.

Katia Andreassi

for National Geographic News

Published January 29, 2013

Maybe the butler didn’t do it. But the cat probably did.

A new study, published January 29 in Nature Communications , estimates that cats are responsible for killing billions of birds and mammals in the continental U.S. every year. The estimate: 1.4 billion to 3.7 billion bird victims and 6.9 billion to 20.7 billion mammals. Peter Marra, the senior author of the study, called the results “stunning.” (Watch: A house cat’s point of view. )

“For the last 20, 30, 40 years,” he said, “the number that has been batted around as a max was about 500 million.”

And there are a lot of potential feline killers. Over 80 million pet cats reside in American homes and as many as 80 million more stray and feral cats survive outside.

The authors found that the stray and feral cats are responsible for most of the kills. But pets aren’t exactly innocent: They are blamed for about a third of the bird action. The study also discovered that the cats mainly kill native species like chipmunks and house wrens, not invasive pests like the Norway rat (Rattus norvegicus). (Video: Secret lives of cats. )

The study is part of a larger effort to quantify the threats to birds, said Marra, an ecologist with the Migratory Bird Center at the Smithsonian Conservation Biology Institute in Washington, D.C. Cats happened to be the first threat they considered. Plans are to look at other threats related to human activity: wind turbines, buildings, automobiles, and pesticides. The research is important, Marra said, because “a lot of these causes of mortality may be reversible.” He hopes the study will aid policymakers and help cat owners realize “cats are having a larger impact than we thought.”

So what can be done about all these wild killer cats?

Current efforts to rein in America’s feral cats are insufficient. While a feral cat management technique called Trap-Neuter-Return (TNR) stops some cats from reproducing, it doesn’t stop those cats from preying on wildlife. The Humane Society of the United States supports TNR as part of the solution, but acknowledges that it will not noticeably reduce the cat population. John Hadidian, a senior scientist with the society, notes that TNR only reaches about two million cats, and it can be “cumbersome and expensive.” He hopes that the attention from papers like this will encourage novel approaches like oral contraceptives for cats.

To some cat observers, the study news was no surprise. Economist Gareth Morgan made headlines around the world last week when he launched a proposal to rid New Zealand of cats. Morgan, whose website features a cartoon kitten announcing “I love to kill,” believes that pet cats are endangering New Zealand’s birds. While his website advocates a New Zealand without cats, and he would like people to make their current cat their last, he says he really wants cats to be regulated the way dogs are. He points to laws enacted in Western Australia as an example: Cats must be registered, neutered, and microchipped. The microchip, a small identifying device embedded under the skin, can be detected by vets or authorities so they can reunite lost pets with their owners and differentiate between pets and strays. “I’m not saying they should kill their cats,” Morgan said. “If they are really into cats, that’s fine, but you must control them.”

Morgan admits this is “an emotional issue” in a country where nearly half of the households have at least one feline. “It’s not that cat owners don’t care,” Morgan said, “it’s that they haven’t thought about it.”

Meanwhile, people in the U.S. aren’t likely to turn on cats either. Cat ownership has increased from about 56 million pet cats in the mid-1990s to the current count of 80 million. Though cats are viewed as both a conservation threat and a human companion, the Humane Society’s Hadidian thinks common ground can be reached. “Both the bird people and the cat people want the same thing,” he said, “fewer cats outdoors.”


Mysteries of spider silk strength unraveled

Female Nephila clavipes on her web. The web was characterized using Brillouin spectroscopy to directly and non-invasively determine the mechanical properties. (Credit: Jeffery Yarger)

Jan. 27, 2013 — Scientists at ASU are celebrating their recent success on the path to understanding what makes the fiber that spiders spin — weight for weight — at least five times as strong as piano wire. They have found a way to obtain a wide variety of elastic properties of the silk of several intact spiders’ webs using a sophisticated but non-invasive laser light scattering technique.

“Spider silk has a unique combination of mechanical strength and elasticity that make it one of the toughest materials we know,” said Professor Jeffery Yarger of ASU’s Department of Chemistry and Biochemistry, and lead researcher of the study. “This work represents the most complete understanding we have of the underlying mechanical properties of spider silks.”

Spider silk is an exceptional biological polymer, related to collagen (the stuff of skin and bones) but much more complex in its structure. The ASU team of chemists is studying its molecular structure in an effort to produce materials ranging from bulletproof vests to artificial tendons.

The extensive array of elastic and mechanical properties of spider silks in situ, obtained by the ASU team, is the first of its kind and will greatly facilitate future modeling efforts aimed at understanding the interplay of the mechanical properties and the molecular structure of silk used to produce spider webs.

The team published their results in a recent issue of Nature materials and their paper is titled “Non-invasive determination of the complete elastic moduli of spider silks.”

“This information should help provide a blueprint for structural engineering of an abundant array of bio-inspired materials, such as precise materials engineering of synthetic fibers to create stronger, stretchier, and more elastic materials,” explained Yarger.

Other members of Yarger’s team, in ASU’s College of Liberal Arts and Sciences, included Kristie Koski, at the time a postdoctoral researcher and currently a postdoctoral fellow at Stanford University, and ASU undergraduate students Paul Akhenblit and Keri McKiernan.

The Brillouin light scattering technique used an extremely low power laser, less than 3.5 milliwatts, which is significantly less than the average laser pointer. Recording what happened to this laser beam as it passed through the intact spider webs enabled the researchers to spatially map the elastic stiffnesses of each web without deforming or disrupting it. This non-invasive, non-contact measurement produced findings showing variations among discrete fibers, junctions and glue spots.

Four different types of spider’s webs were studied. They included Nephila clavipes (pictured), A. aurantia (“gilded silver face”-common to the contiguous United States), L. Hesperus the western black widow and P. viridans the green lynx spider, the only spider included that does not build a web for catching prey but has major silk elastic properties similar to those of the other species studied.

The group also investigated one of the most studied aspects of orb-weaving dragline spider silk, namely supercontraction, a property unique to silk. Spider silk takes up water when exposed to high humidity. Absorbed water leads to shrinkage in an unrestrained fiber up to 50 percent shrinkage with 100 percent humidity in N. clavipes silk.

Their results are consistent with the hypothesis that supercontraction helps the spider tailor the properties of the silk during spinning. This type of behavior, specifically adjusting mechanical properties by simply adjusting water content, is inspirational from a bio-inspired mechanical structure perspective.

“This study is unique in that we can extract all the elastic properties of spider silk that cannot and have not been measured with conventional testing,” concluded Yarger.

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Top Ten New Species of 2010

Darwin’s Bark Spider

Photograph courtesy Matjaz Kuntner

Created by the Darwin’s bark spider—called one of the top ten new species of 2010—a river-spanning web dwarfs a park ranger in Madagascar in 2008.

Each May the International Institute for Species Exploration at Arizona State University (ASU), along with an international committee of taxonomists, announces their choices for the top ten species that were formally recognized during roughly the previous year. Participants draw up their own criteria, and selections can be made based on anything from unique attributes to odd names.

The announcement is timed to celebrate the May 23 birthday of Carolus Linnaeus, who developed the scientific system of plant and animal names more than 250 years ago.

Darwin’s bark makes the world’s largest webs of any single spider—as wide as 82 feet (25 meters), or about as long as two city buses.

(See related pictures: “World’s Biggest, Strongest Spider Webs Found.”)

The annual list draws attention to how little we know about Earth’s species, said Quentin Wheeler, director of the ASU institute. (See pictures of the top ten new species of 2009.)

So far, scientists have documented about two million species, but another ten million may still be unknown.

“For us to sit back and think we understand evolutionary history—how life arose and why it’s as diverse as it is—is a joke when we’re missing 80 percent of the evidence,” Wheeler said.

“In reality we’ve just scratched the surface of that fascinating story.”

(Related: “Ten Weirdest New Animals of 2010: Editors’ Picks.”)

—Christine Dell’Amore

Published May 24, 2011

New Mongoose-Like Carnivorous Mammal Discovered in Madagascar

Durrell””s vontsira (Salanoia durrelli) — the first new carnivorous mammal to be discovered for 24 years. It was discovered on the Island of Madagascar by a team from Durrell Wildlife Conservation Trust (DWCT), the Natural History Museum, London, Nature Heritage, and Conservation International (CI). (Credit: © Durrell Wildlife Conservation Trust)

A new species of small carnivore, known as Durrell””s vontsira (Salanoia durrelli) has been identified by researchers from the Durrell Wildlife Conservation Trust, the Natural History Museum, London, Nature Heritage, Jersey, and Conservation International (CI). The small, cat-sized, speckled brown carnivore from the marshes of the Lac Alaotra wetlands in central eastern Madagascar weighs just over half a kilogramme and belongs to a family of carnivores only known from Madagascar. It is likely to be one of the most threatened carnivores in the world.

The findings are outlined in the latest issue of the taxonomic journal Systematics and Biodiversity.

The carnivore was first seen swimming in a lake by researchers from the Durrell Wildlife Conservation Trust on a field trip surveying bamboo lemurs (Hapalemur griseus alaotrensis) in 2004. After briefly examining the animal, the team suspected they had witnessed a new species and so took photographs. By examining brown-tailed vontsira (Salanoia concolor) specimens in the Natural History Museum””s collections, Museum zoologists confirmed the animal was a new species. The brown-tailed vontsira is the closest relative of the new species, which zoologists named in honour of the conservationist and writer Gerald Durrell, who died 15 years ago.

Fidimalala Bruno Ralainasolo, a conservation biologist working for Durrell Wildlife Conservation Trust who originally captured the new carnivore, commented: “We have known for some time that a carnivore lives in the Lac Alaotra marshes, but we””ve always assumed it was a brown-tailed vontsira that is also found in the eastern rainforests. However, differences in its skull, teeth, and paws have shown that this animal is clearly a different species with adaptations to life in an aquatic environment. It is a very exciting discovery and we decided to honour our founder, the world renowned conservationist Gerald Durrell, by naming this new species after him. However, the future of the species is very uncertain because the Lac Alaotra marshes are extremely threatened by agricultural expansion, burning and invasive plants and fish. It is a highly significant site for wildlife and the resources it provides people, and Durrell Wildlife Conservation Trust is working closely with local communities to ensure its sustainable use and to conserve Durrell””s vontsira and other important species.”

Article Continues -> http://www.sciencedaily.com/releases/2010/10/101011083904.htm

Tube-Nosed Bat, More Rare Species Found

A Nose for Fruit

Photograph courtesy Piotr Naskrecki, Conservation International

This tube-nosed fruit bat is just one of the roughly 200 species encountered during two scientific expeditions to Papua New Guinea in 2009—including a katydid that “aims for the eyes” and a frog that does a mean cricket impression, Conservation International announced late Tuesday.

Though seen on previous expeditions, the bat has yet to be formally documented as a new species, or even named. Like other fruit bats, though, it disperses seeds from the fruit in its diet, perhaps making the flying mammal crucial to its tropical rain forest ecosystem.

In all, the expeditions to Papua New Guinea”s Nakanai and Muller mountain ranges found 24 new species of frogs, 2 new mammals, and nearly a hundred new insects. The remote island country”s mountain ranges—which have yielded troves of new and unusual species in recent years—are accessible only by plane, boat, foot, or helicopter.

(Also see pictures of new species from Papua New Guinea”s “Lost World.”)

—Rachel Kaufman

Experts baffled by ''small'' Bangladesh tigers

Roar data: Sunderbans tigers were found to weigh nearly half as much as their cousins in the region

By Ethirajan Anbarasan BBC News, Dhaka

Tigers prowling the famous mangrove forests of Bangladesh are about half the weight of other wild Bengal tigers in South Asia, a study has found.

The average weight of female tigers in the Sundarbans forests was 76.7kg (170lb), according to the US Fish and Wildlife Service research.

But other wild Bengal tigers in the region tipped the scales at 138.2 kg on average.

Researchers said this could be because Sundarbans tigers ate smaller deer.

The team believes the big cats found in the mangrove forest, which stretches from Bangladesh to India, could be among the world”s smallest tigers.

They belong to one of nine sub-species of Bengal tiger in India, Nepal, Bangladesh and Bhutan.

Smaller dinner

Researchers from the University of Minnesota and the Bangladesh Forest Department – who carried out the study for the US Fish and Wildlife Service – weighed three Sundarbans tigers.

Two of the animals were captured and sedated, but the other one had been killed by villagers.

Adam Barlow, one of the authors of the research, said they do not know why the Sundarbans tigers are so small.

“This could be related to the small size of deer available to tigers in the Sundarbans, compared to the larger deer and other prey available to tigers in other parts,” he said.

It is estimated that between 300 and 500 Bengal tigers live in the Bangladesh side of the Sundarbans alone.

They are isolated from the next tiger population by a distance of up to 300km (190 miles).

Tigers are an endangered species. There are only about 3,500 left in the wild worldwide – less than one third of them breeding females.


Patagonia''s Pristine Wild Rivers Threatened by Dams

The Aysén region of Chilean Patagonia is threatened by a plan to build five dams on the Baker and the Pascua rivers – two of the wildest most pristine rivers on the planet. The Rapid Assessment Visual Expedition (Rave), an initiative of the International League of Conservation Photographers (ILCP), set up to address the challenges of modern conservation, visited the area in February this year to assess what impact the dams would have on the surrounding area and its way of life.

The expedition team included the Pulitzer prize winner and National Geographic photographer Jack Dykinga and twice World Press winner and Prince”s Rainforest Project award winner Daniel Beltra.

The three dams on the Pascua River (below) would create artificial lakes flooding more than 1,600 hectares (about 4,000 acres). Flooded lands would include some of the world’s rarest forest types, including the critically endangered plants. Other rare species that would be harmed by the Pascua dams include the torrent duck and the white-bellied seedsnipe.

The water supplying 80 per cent of the world”s population is exposed to “high levels of threat,” according to a study that surveys the status of rivers throughout the world, and looks at their effects on both humans and the ecosystem at large.

Writing in this week”s Nature (vol 467, p 555), Charles Vorosmarty of the City College of New York and colleagues presented data on factors affecting water security, from dams that reduce river flow in Patagonia, for example, to the pollution and destruction of wetlands.

They produced two maps showing the levels of threat to humans and to ecosystems that rely on rivers. The maps are virtually identical, with the continental US, Europe and south-east Asia facing the greatest threats, to both humans and the wider ecosystem.

Via The Guardian