Thousands of years after first becoming domesticated, the house cat remains a beloved family pet. (Photo: Dave Morris/Flickr via Creative Commons)

Most people view cats as harmless pets, but for birds and small mammals, the domesticated feline can be a deadly killer.

A new study in Nature Communications finds bird and mammal mortality caused by outdoor cats is much higher than has been previously reported. Annual bird deaths in the United States are now estimated to be 1.4 to 3.7 billion, while mammal mortality runs from 6.9 to 20.7 billion individual animals.

Stray cats, as opposed to those that are owned and cared for by humans, cause the majority of these deaths, according to researchers from the US Fish and Wildlife Service (FWS) and the Smithsonian Conservation Biology Institute, who conducted the study.

The study, by two of the world’s leading science and wildlife organizations, offers the one of the most comprehensive analyses on outdoor cat predation.

The ancient Egyptians may have been the first to domesticate the cat more than 4,000 years ago. The animal became a favored household pet over the centuries, in large part due to their natural ability to hunt and eradicate household pests and vermin, such as mice and rats.

But that natural hunting ability could be a key reason cats are listed as one of the 100 worst non-native invasive species in the world, according to the Global Invasive Species Database, which was published in 2000.

A cat with its catch, a bird called the American Coot (Photo: Debi Shearwater)

A separate 2011 study found free-ranging cats have caused or contributed to 14 percent of modern bird, mammal and reptile extinctions on islands. The same report also found that feral cats cause a substantial proportion of total wildlife mortality.

Dr. George Fenwick, president of American Bird Conservancy, a group which has called for action on this issue for many years, reacted to this latest report. “This study, which employed scientifically rigorous standards for data inclusion, demonstrates that the issue of cat predation on birds and mammals is an even bigger environmental and ecological threat than we thought. No estimates of any other anthropogenic [human-caused] mortality source approach the bird mortality this study calculated for cat predation.”

However, the Humane Society of the United States questioned the report’s numbers.  “The HSUS values both cats and wildlife. There is a legitimate issue with free-roaming cats preying on birds and other wildlife, and we are working to change that in a meaningful way,” said Wayne Pacelle, president and CEO of the Humane Society of the US. “Despite the scientific rigor with which this report was prepared, like others recently published, it tries to attach a number to something that is almost impossible to credibly quantify.”

The larger issue, according to the humane society,  is finding practical and humane actions to mitigate the impact of cats in communities.

Current policies for managing feral cat populations and regulating pet ownership usually focus more on animal welfare rather than ecological impacts, according to authors of the latest study.

The domesticated cat’s natural hunting abilities help homeowners keep their homes pest and vermin free. (Photo: Cobalt123/Flickr via Creative Commons)

One of the more popular forms of managing free-ranging cats includes Trap-Neuter-Vaccinate and Return colonies,  a method of humanely trapping feral cats, spaying or neutering them as needed, vaccinating the animals for diseases like rabies, and then releasing them back to the same location where they were collected.

The study asserts these methods of managing feral cats are employed throughout the US without widespread public knowledge, consideration of scientific evidence, or the environmental review processes typically required for actions with harmful environmental concerns.

The researchers recommend scientifically sound conservation and policy intervention to reduce the negative impact of feral cats on wildlife.

Electrodes are placed on the head of lab chimpanzee Mizuki for brain wave measurement. (NIH)

An advisory group has called on the National Institutes of Health (NIH) to retire most of the nearly 700 chimps it owns or supports.

NIH’s Council of Councils also recommended the medical research agency drastically cut back on the various medical studies involving the use of chimpanzees, while making certain those chimps that are still being studied are kept in proper living conditions.

The recommendations, contained in an 84-page report, were in response to a December 2011 review by the Institute of Medicine (IOM), which concluded that while the chimpanzee was a valuable animal model in the past, most current biomedical use of the animal is unnecessary.

The IOM suggested that while chimpanzees could still serve an important role in some research areas, a set of guidelines, principles and criteria must be established to govern that research.

Chimpanzees that had been used for NIH biomedical testing get acquainted with their new retirement home at Chimp Haven in Louisiana. (AP)

Using the IOM report for guidance, NIH’s advisory group recommended the majority of NIH-owned chimpanzees be retired and transferred to facilities within the federal sanctuary system, while immediately planning to ensure proper accommodations and treatment for the chimps.

The advisory group suggested a small population of about 50 chimpanzees be maintained by the agency for future potential research as long it meets the principles and guidelines contained within the IOM report.

The report stressed that animals remaining in NIH custody should be kept in “ethologically appropriate” settings, which include large, complex social groups, year-round outdoor access and more than 1,000 square feet of living space per chimpanzee.

The size and placement of this colony, according to the NIH group, should also be reassessed about every five years to ensure  a colony of chimps is still needed and that the animals aren’t overused.

With fewer chimpanzees being made available to scientists for research, the advisory group recommended  NIH to encourage and support the development and refinement of other approaches, especially alternative animal models, such as genetically altered mice, for research on new, emerging and reemerging diseases.

A chimpanzee named Lyons sits in a play yard at Chimp Haven in Keithville, La. (AP)

The new recommendations follow last month’s NIH decision to move all 100 of the federally-owned chimpanzees at the New Iberia Research Center in Louisiana to Chimp Haven, a federal chimpanzee sanctuary in nearby Keithville, Louisiana, over the next 12 to 15 months.

A leading animal rights group praised the  recommendations.

“The Humane Society of the United States is extremely pleased that these experts confirm what the public has been urging: move away from invasive chimpanzee experimentation and release these animals to the most appropriate setting available – sanctuary,” said Kathleen Conlee, vice president of animal research issues at the Humane Society. “There are top-notch sanctuaries in the U.S., including federal sanctuary Chimp Haven, that have the capacity to expand and we are ready to work with the government to provide these chimpanzees with the retirement they so greatly deserve.”

The NIH will make a final determination on the recommendations after a 60-day public comment period that begins today and runs until March 23, 2013.

One of the newly identified species of slow loris, Nycticebus kayan. (Photo: Ch’ien C Lee)

An endangered lemur-like primate with two tongues and a toxic bite has more branches on its family tree than originally thought.

Writing in the American Journal of Primatology, Missouri researchers say they’ve identified three new species of the slow loris – the only venomous primate in the world – living on the Indonesian island of Borneo.

At first glance, with its big brown eyes and teddy-bear face, this nocturnal mammal appears cute and cuddly, but it’s got a lethal bite, which can cause fever, pain and swelling. For humans who suffer from allergic reactions, it can also be deadly.

Due to a benign appearance, and its uses in traditional medicine, the slow loris is a favorite of poachers throughout southeastern Asia and its surrounding islands.

The three newly identified species were originally grouped with another species. Now that the slow loris has been divided into four distinct classes, its risk of extinction is greater than previously believed. However, in the long run, it could also help efforts to protect the primate.

“Four separate species are harder to protect than one, since each species needs to maintain its population numbers and have sufficient forest habitat,” says lead author Rachel Munds from University of Missouri. “Unfortunately, in addition to habitat loss to deforestation, there is a booming black market demand for the animals. They are sold as pets, used as props for tourist photos or dismembered for use in traditional Asian medicines.”

The teeth of a juvenile slow loris are removed by an animal trafficker. (Photo: International Animal Rescue)

Munds says slow lorises are not and cannot be domesticated and that keeping them as pets is cruel. The primates are protected under the Convention on International Trade in Endangered Species.

“Zoos rarely succeed in breeding them,” says Munds. “Nearly all the primates in the pet trade are taken from the wild, breaking the bonds of the lorises’ complex and poorly understood social structures.”

Those who breed them as pets often pull out the teeth, depriving the the animal of its venomous bite. Many of these illegally captured primates die due to the foul conditions of pet markets.

“Once in the home, pet keepers don’t provide the primates with the social, nutritional and habitat requirements they need to live comfortably,” Munds says. “Pet keepers also want to play with the nocturnal animals during the day, disrupting their sleep patterns.”

The under-tongue of a slow loris sticks out beneath the primary tongue. (Photo: David Haring – Duke Lemur Center)

The Missouri researchers examined various museum specimens, photographs and actual live animals that had been lumped into the original single species. After noticing the animals had different body sizes, fur thickness, habitats and facial markings, scientists realized they’d identified four separate species of the slow loris rather than just the one.

Now instead of one animal listed as vulnerable by the International Union for the Conservation of Nature, there may be four endangered or threatened species.

Scanning electron micrograph of very small and numerous bacterial cells inhabiting icy brine waters in Antarctica’s Lake Vida. (Photo: Christian H. Fritsen, Desert Research Institute)

Scientists say they have found ancient microbial life in dark and very salty water some 20 meters below the surface of a frozen and isolated Antarctic lake. The finding could provide scientists with insight into how life could possibly exist in the most extreme environments on Earth as well as elsewhere throughout the cosmos.

In a study recently published in the Proceedings of the National Academy of Science (PNAS) the researchers say they took the microbes from the Antarctic’s Lake Vida, which contains no oxygen but has the highest nitrous oxide levels found in any natural bodies of water on Earth. The scientists describe the icy environment in which the sample microbes were taken as a briny liquid, about six times saltier than normal seawater and with an average temperature of minus 13.5 degrees centigrade.

“This study provides a window into one of the most unique ecosystems on Earth,” said lead author Dr. Alison Murray from the Desert Research Institute (DRI) in Reno, Nevada. “Our knowledge of geochemical and microbial processes in lightless icy environments, especially at subzero temperatures, has been mostly unknown up until now. This work expands our understanding of the types of life that can survive in these isolated, cryoecosystems (ecosystems found in ice) and how different strategies may be used to exist in such challenging environments.”

Previous studies going back to 1996 show the Lake Vida brine and its microbial residents have had to do without outside resources that normally support life (i.e.: sunlight or oxygen) for more than 3,000 years. Despite what many would consider being an unlivable habitat, the researchers in this project found that the polar lake supports what they call a surprisingly diverse and large community of bacteria that can survive the harsh conditions.

To ensure that their samples and the microbe’s ecosystem weren’t affected or contaminated by human or other external influences, the researchers developed specialized equipment and a set of very strict procedures when they set out to retrieve them during expeditions to the Antarctic back in 2005 and 2010.

Members of the 2010 Lake Vida expedition team use a sidewinder drill inside a secure, sterile tent on the lake’s surface to collect samples for their research. (Photo: Desert Research Institute, Emanuele Kuhn)

Regarding the high levels of nitrous oxide that was found in the lakes salty water, the scientists say that geochemical analyses are suggesting that the N₂O was generated by chemical reactions between the salty water and the lake’s iron-rich sediments. The chemical reaction also produced an amount of molecular hydrogen, which the researchers say may be what has been providing the energy that was needed to sustain the community of diverse microbial life.

“It’s plausible that a life-supporting energy source exists solely from the chemical reaction between anoxic salt water and the rock,” explained co-author Dr. Christian Fritsen, also from DRI.

“If that’s the case,” Murray said, “this gives us an entirely new framework for thinking of how life can be supported in cryoecosystems on earth and in other icy worlds of the universe.”

Murray said that the scientists involved with the project are continuing their research by analyzing the non-organic components, the chemical interactions between Lake Vida brine and sediment, and by using various methods of genome sequencing, and are learning more about their rare microbial find.

They also suggested the research and findings produced for this study could also provide some help to others who conduct investigations into possible cryoecosystems that might be found in the soil, sediments, wetlands, and other lakes that lie beneath the Antarctic ice sheet.

A juvenile Gobidon (goby) fish is shown on an Acropora coral. These fish spend their entire lives with the same coral, protecting it from encroaching seaweed. (Photo: Georgia Tech/Joao Paulo Krajewski)

Coral reefs provide one of the world’s most vital ecosystems and some of these reefs are in danger of being destroyed.

While people are to blame for much of the destruction, nature also plays a role. Encroaching species of seaweed with poisonous compounds on their surfaces are one of nature’s threats.

The toxic seaweed begins its lethal damage upon contact with the coral, killing its tissue within two to three days of contact.

But now scientists at the Georgia Institute of Technology have found that one species of coral near the Fiji Islands  doesn’t sit around waiting to  destroyed; it actually sends out a call for help when it’s threatened by poisonous seaweed.

Small fish, known as gobies, which are about two centimeters long and spend their entire lives in the crevices of the coral, respond to the coral’s alarm within minutes.

The gobies go after the seaweed, chewing and mowing it away from the coral. Not only do the little fish protect their homes, but some species also use the toxic substances from the seaweed to build up their own protective arsenal.

Mark Hay, a biology professor at Georgia Tech and colleague Danielle Dixson conducted the research and published their findings in Science.

Hay said two species of goby serve as coral bodyguards.  One species simply chews away at the harmful seaweed and then spits it out, but the other type of fish actually ingests the poisonous substance. This enhances the fish’s already toxic characteristics, increasing its ability to protect itself from predators.

Coral protector Gobidon histrio (goby) in its living space on the coral Acropora nasuta. The coral is in contact with the toxic green alga Chlorodesmis fastigiata. (Photo: Georgia Tech/Danielle Dixson)

Researchers were unable to determine whether the fish were saving up the lethal seaweed compounds to use on enemies, or if they were already making their own poisons, and using the noxious material to build up their resistance to the poisons.

Not all fish possess the gobies’ protective instincts. Scientists also studied two other species of small fish that live in the coral.

According to Hay, these damsel fish simply swim away, moving on to other coral, when their homes are threatened.

“They just abandon it, say ‘It’s going to die, we’re out of here,’” Hay says.

Interestingly enough, the gobies are only protective when their particular species of coral is under attack.  The scientists placed the gobies within another closely-related species of coral and found that the little bodyguards did not respond or protect their new home when it was under a similar threat.

Hay hopes to study other species of coral in the future to see if they too are also aided by rapid responding protective fish.

Mark Hay joins us this weekend on the radio edition of Science World.  Tune in (see right column for scheduled times) or check out the interview below.

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A western honeybee (Photo: Wolfgang Hägele via Wikimedia Commons)

A new study finds prolonged antibiotic use by beekeepers might play a role in the mysterious drop in honey bee populations in the United States.

Yale researchers found genetic evidence that helpful bacteria, which normally live the bellies of honeybees, have become highly resistant to the antibiotic tetracycline, possibly weakening the bees’ ability to fight disease.

Researchers say decades of use may have unknowingly encouraged antibiotic resistance by genetically altering the beneficial bacteria.

Past studies show helpful bacterial play an important role in protecting the honeybee by neutralizing toxins found in their diets while also helping fight off various pathogens.

The  researchers have identified eight different tetracycline resistance genes among U.S. honeybees that were exposed to antibiotics.  Those same resistance genes were missing in bees from countries where antibiotic use is banned.

“It seems to be everywhere in the U.S.,” says Nancy Moran of Yale University, a senior author on the study. “There’s a pattern here, where the U.S. has these genes and the others don’t.”

In the 1950s, beekeepers started using the antibiotic oxytetracycline, a compound similar to tetracycline, which is commonly used in humans. They were trying to fight a devastating bacterial disease called foulbrood, which can wipe out a hive more quickly than beekeepers can react to the infection.

But after years of use  the microorganisms eventually acquired a resistance to tetracycline, possibly weakening the honeybee’s resistance to other diseases.

“It seems likely this reflects a history of using oxytetracycline since the 1950s,” says Moran. “It’s not terribly surprising. It parallels findings in other domestic animals, like chickens and pigs.”

A beekeeper tends to a beehive. (Photo: Emma Jane Hogbin via Creative Commons at Flickr)

The researchers took bee samples from the Czech Republic, New Zealand and Switzerland, which do not allow their beekeepers to use the antibiotics.

Researchers found  those bees had only two or three different resistance genes and even then only in very low numbers, suggesting that prolonged antibiotic use in the US bees may have played a role in developing the resistance genes.

Moran  points out that the antibiotic-resistant genes researchers found in the bellies of the honeybee do not pose a direct risk to humans.

Those microorganisms, according to Moran, “don’t actually live in the honey, they live in the bee. We’ve never actually detected them in the honey. When people are eating honey, they’re not eating these bacteria.”

Nancy Moran joins us this weekend on the radio edition of Science World.  She tells us more about how treatment meant to strengthen honeybee hives in the U.S. may have actually weakened them instead. Tune in (see right column for scheduled times) or check out the interview below.

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The land-based hermit crab Coenobita compressus lives inside a discarded snail shell and forages for food along the Pacific coast from Mexico to Peru. (Photo: Mark Laidre, UC Berkeley)

Despite its name, the hermit crab can be a very social creature.  In fact, when searching for a new home, the crustacean gets by with a little help from its friends, according to a new study in Current Biology.

The hermit crab, which is vulnerable to predators, protects itself by making its home in abandoned marine snail shells.

To fit its ever-growing body, the hermit crab will often hollow out and customize their appropriated shells, sometimes doubling its internal size.  But, after a while, the crab is forced to look for a bigger place to live.

There are about 800 species of hermit crabs and most live in the ocean, where empty snail shells are abundant due to the prevalence of predators with an appetite for marine snails. However, competition for shells among land-based crabs can be intense.

California researchers found that once three or more of these crabs congregate, dozens of others eager to find nicer homes also show up.

House hunting, hermit crab style. Whenever three or more of these crustaceans show gather, others are bound to join in. A free-for-all takes then place with all crabs intent on displacing someone else to get into a bigger shell. (Photo: Mark Laidre, UC Berkeley)

The crabs form a sort of conga line, from smallest to largest, each holding onto the crab in front of it.Once the largest of the group finds his dream home, he kicks out its current occupant and moves into the new shell. That frees up his old shell for the crab behind him.

This process continues until the smallest of the group moves into a new space.  As a result, like the children’s game musical chairs, the smallest crab is left without a shell of its own, making it susceptible to any predators in the mood for a little crab dinner.

“The one that gets yanked out of its shell is often left with the smallest shell, which it can’t really protect itself with,” says the study’s author, Mark Laidre, from the University of California, Berkeley. “Then it’s liable to be eaten by anything. For hermit crabs, it’s really their sociality that drives predation.”

Laidre conducted his research along the Pacific shore of Costa Rica, where millions of the hermit crab species,Coenobita compressus, can be found along the tropical beaches.

A marine snail shell newly vacated by its original owner (left) and a shell that has been remodeled and hollowed out by a hermit crab (right). (Photo: Mark Laidre, UC Berkeley)

For his study, Laidre  tethered individual crabs to a post, the largest being about three inches long, and then observed the brouhaha which usually took place within 10 to 15 minutes of the crab being  tethered.

After moving into its new home, the crustacean usually gets to work immediately, remodeling and hollowing out the shell.  Laidre discovered how critical those remodeled shells are to the hermit crab after pulling them from their homes and offering newly vacated snail shells instead. He found that none of those crabs survived.

Apparently, Laidre says, only the smallest hermit crabs are able to take advantage of brand new shells, since only the smallest hermit crabs can actually fit inside shells that haven’t been hollowed.  Even if a crab does find a new shell it can fit in, hermit crabs of all sizes would rather not spend all of the time and energy to hollow it out itself.

The hermit crab’s unusual conduct, according to Laidre, serves as a rare example of how evolving to take advantage of a specialized niche – in this case, the hermit crab living on land versus in the ocean – led to an unexpected byproduct: socialization in what is typically solitary animal.

Colorized image of “Medusoid”, the tissue-engineered jellyfish, “swimming” in a container of ocean-like saltwater. (Photo: Caltech and Harvard University)

By combining rat cardiac muscle cells with silicone, scientists have  bioengineered a free-swimming jellyfish which could eventually lead to improved treatment for heart disease.

Researchers from Harvard and California Institute of Technology (Caltech) say  their creation shows  it’s possible to reverse-engineer a variety of muscular organs and simple life forms, allowing for a broader definition of what counts as synthetic life.

They’re hoping their work could one day lead to medical devices, such as pacemakers, which can live independently within the human body, operating without the need for power sources such as batteries.

The jellyfish was selected for this project because it propels itself through water by pumping,  which is similar to the way a human heart moves blood throughout the body.

“A big goal of our study was to advance tissue engineering,” says Janna Nawroth, a biology doctoral student  at Caltech and lead author of the study.

Top: Comparison of real jellyfish and silicone-based Medusoid. Bottom: Comparison of muscle architecture in the two systems (Image: Janna Nawroth)

In fashioning their faux jellyfish, the researchers replicated the functions of a jellyfish, such as swimming and creating feeding currents, instead of trying to duplicate all of the swimming creature’s biological elements.

The team studied jellyfish propulsion in depth before designing their creation, named “Medusoid,” after the Medusa jellyfish and the  snake-haired monster Medusa from Greek mythology.

Researchers discovered a sheet of cultured rat heart muscle tissue would contract when electrically stimulated in a liquid setting, making it  ideal raw material for their creation.

They fashioned a silicone polymer into a thin membrane to create the body of their creature, which looked like a small eight-arm jellyfish.

Once the rat heart muscle tissue was incorporated into its body, the artificial jellyfish was  placed into a container of electrically charged ocean-like salt water. It was shocked into swimming with synchronized muscle contractions that imitate those of real jellyfish.  According to the researchers, the muscle cells began to contract on their own before any electrical power was even applied.

“I was surprised that with relatively few components—a silicone base and cells that we arranged—we were able to reproduce some pretty complex swimming and feeding behaviors that you see in biological jellyfish,” said John Dabiri, a professor of aeronautics and bioengineering at Caltech.

The researchers aren’t done yet. They hope to design a completely self-contained system which would be able to sense and set itself into motion using internal signals, like human hearts do.  They also, eventually, would like to see their creation go out and gather food on its own.