In Multi-Pet Homes, Cats Are Top Dogs

- Dogs and cats can make nice with each other, suggests a new study -- so long as the cat is in the home first and introductions are made at a young age.

The paper, according to authors Neta-Li Feuerstein and Joseph Terkel, is the first to examine relationships between dogs and cats living in the same house.

One noteworthy finding of the study, which has been accepted for publication in the journal Applied Animal Behavior Science, is that if the animals are introduced to each other while still a puppy and a kitten, the two can actually learn each other's body language.

Terkel, a professor in the Department of Zoology at Tel Aviv University, told Discovery News that "like children, who learn a new language more easily than adults, so too did the cats and dogs learn their new 'language' more easily, the younger they were."

The scientists gathered their data from two primary sources. The first was a questionnaire directed to people who owned both dogs and cats. It was distributed by veterinarians, on the Internet and through the university in Israel.

The second was direct, in-home observation of dozens of pets by the researchers.

For each visit, they had the owner roll a tennis ball between the dog and the cat, to see if mutual play existed and to determine if one species would dominate the other. They then placed canned cat food (which most dogs will eat) between the two to see how they'd react. Finally, the owners were asked to stimulate positive interaction by playing a game with both the dog and cat.

During the study, the researchers took special note of body language that has the opposite meaning for dogs and cats, according to other studies. For example, tail wagging in dogs can signal amicable and submissive reactions, but the same behavior can be a sign of stress, or even aggression, in cats.

The scientists found the cats and dogs with the best relationships in households where the cat had been in the home before the dog was adopted. But surprisingly, they say, this has more to do with the dog than the cat.

"An analogy can be drawn with homes in which a dog is adopted either before or after a baby is born," according to the scientists. "When the dog enters a home with a baby in residence, the status quo is already in place. However, when the baby is born after the dog has become accustomed to a certain amount of attention, and the focus now turns to the newborn child, the status quo is altered, and the dog will often display behavior resembling jealousy."

The study also found that cats do best with dogs when their age at first encounter is six months or younger. For dogs, which have a longer learning period, that age extends to a year.

Body language was so well read by cats and dogs fitting these scenarios that the researchers were able to document a dog behavior never before described.

Normally dogs sniff each other's nether regions to get information. In the case of successful multi-pet households, the dog may sniff the cat's nose, which is a common habit among cats. The mutual nose-sniffing looks a bit like an "Eskimo kiss," where an individual rubs his or her nose on another person's nose.

John Bradshaw of the University of Bristol School of Veterinary Science believes it's important to remember that, although dog and cat behavior can be somewhat predictable and controlled, each animal is an individual. He said, for example, that some cats seem to be bolder than others, with boldness appearing to be an inherited trait from fathers.

Bradshaw also suggested that home is where the heart is for cats, while dogs are more flexible.

"Cats are territorial animals and are likely to be stressed, and therefore less able to learn, when removed from familiar surroundings, whereas puppies' territories are usually centered on familiar people rather than specific places," he explained.

Birds Thrown Off by Global Warming

- The habitats of wild bird species are shifting in response to global warming, but not fast enough to keep pace with rising temperatures, according to a study released Wednesday.

Researchers in France also found that the delicate balance of wildlife in different ecosystems is changing up to eight times more quickly than previously suspected, with potentially severe consequences for some species.

"The flora and fauna around us are shifting over time due to climate change," said lead author Victor Devictor, a researcher at the French National Museum of Natural History.

"The result is desynchronization. If birds and the insects upon which they depend do not react in the same way, we are headed for an upheaval in the interaction between species," he explained in a telephone interview.

These "mismatches" are likely to become greater over time, and could eventually threaten some birds with extinction, he added.

The study showed that the geographic range of 105 birds species in France -- accounting for 99.5 percent of the country's wild avian population -- moved north, on average, 91 kilometers (56.5 miles) from 1989 through 2006.

Average temperatures, however, shifted northward 273 kilometers (170 miles) over the same period, nearly three times farther.

The fact that some birds have responded to climate change had already been noted in individual species.

What surprised Devictor and his colleagues was that the shift held true for virtually all birds in France, and that the gap with the rising temperatures was big and getting bigger.

"The response is faster than we thought, but it is still not fast enough to keep up with climate change," he said.

Earlier studies looked at the impact of global warming by comparing "snapshots" -- taken years or decades apart -- of the range across which a given species lived.

But trying to define the outer boundary of a shifting habitat is extremely difficult because data is, by definition, scarce.

Devictor took another approach, taking advantage of France's French Breeding Bird Survey, which has gathered data collected by hundreds of ornithologists from more than 1500 well-defined plots since 1989.

This made it possible to look at the entire distribution of a species over a continuous period, he explained.

The northward shift of most species "is most likely changing at its maximal possible rate, which is insufficient to catch up to climate change," Devictor said.

"This discrepancy may have profound consequences on the ability of species to cope with climate change in the long run."

Wind Turbines Kill Bats Without Impact

- Researchers have found the cause behind mysterious bat deaths near wind turbines, in which many bat carcasses appeared uninjured.

The explanation to this puzzle is that the bats' lungs effectively blow up from the rapid pressure drop that occurs as air flows over the turbine blades.

"The idea had kind of been floating around, because people had noticed these bats with no injuries," said Erin Baerwald of the University of Calgary and lead author of a study about the finding in the journal Current Biology.

Researchers examined a large sample size of hoary and silver-haired bats found under wind turbines, performing necropsies on the bats within hours of their death.

The damage from rapidly expanding air in the lungs caused by the sudden drop in pressure was clear. Ninety percent of the bat deaths at the southern Alberta site involved internal hemorrhaging consistent with such damage, called barotrauma, while only 50 percent showed signs of collision with turbine blades.

For those overlapping cases, it may be that the bats flew through the pressure drop, suffered barotrauma, and then were struck by a blade. It is also possible that they were struck first, causing internal hemorrhaging.

But, Baerwald said, "When people were first starting to talk about the issue, it was 'bats running into the turbine blades.' We always said, 'No, bats don't run into things.' Bat's can detect and avoid all kinds of structures."

In fact, they are even better at detecting moving objects, Baerwald said.

"This kind of answers that mystery," she added. "It was something nobody could have predicted."

The bat fatalities appear to be a more significant problem than bird deaths from wind turbines in most locations. "Here we're picking up ten bats for every bird," Baerwald said.

"I can pick up nine different species of bird. I can pick up two species of bat," she added. "The impact on the populations is very different."

Whether these deaths are having a significant effect on the bat populations in Alberta or elsewhere is difficult to gauge because so little is known about the bats.

Cows Use Inner Compass to Point North-South

- Talk about animal magnetism, cows seem to have a built-in compass. No bull: Somehow, cattle seem to know how to find north and south, say researchers who studied satellite photos of thousands of cows around the world.

Most cattle that were grazing or resting tended to align their bodies in a north-south direction, a team of German and Czech researchers reports in Tuesday's issue of Proceedings of the National Academy of Sciences.

And the finding held true regardless of what continent the cattle were on, according to the study led by Hynek Burda and Sabine Begall of the faculty of biology at the University of Duisburg-Essen in Germany.

"The magnetic field of the Earth has to be considered as a factor," the scientists said.

This challenges scientists to find out why and how these animals align to the magnetic field, Begall said in an interview via e-mail.

"Of course, the question arises whether humans show also such a spontaneous behavior," she said, adding, what "consequences does it have for their health."

The study sent Tina Hinchley, who with her husband Duane operates a dairy farm in Cambridge, Wis., to take a new look at an aerial photo taken of their farm a few years ago.

"The cows that were in the pasture were all over the place ... about two-thirds were north-south," Hinchley said.

Two-thirds is close to what the researchers found in their look at 8,510 cattle in 308 pastures. In the study, 60 percent to 70 percent of cattle were oriented north-south, which Begall termed a "highly significant deviation from random distribution."

Hinchley stressed that one factor that must be considered is cow comfort.

"They don't like to get hot. Their body temperature is 102, and they are wearing black leather jackets, literally! If turning north-south would keep them cooler, they would stand that way."

The research team noted that in very windy conditions cattle tend to face the wind, and have been known to seek out the sun on cold days. But they said they were able to discount weather effects in the study by analyzing clues such as the position of the sun based on shadows.

"This is a surprising discovery," said Kenneth J. Lohmann of the biology department at the University of North Carolina. "Nothing like this has been observed before in cattle or in any large animal."

However Lohmann, who was not part of the research team, cautioned that "the study is based entirely on correlations. To demonstrate conclusively that cattle have a magnetic sense, some kind of experimental manipulation will eventually be needed."

Joseph L. Kirschvink of the California Institute of Technology said he wondered if fences around the pastures could affect cattle orientation.

Passive alignment of animals to magnetic fields has been reported in honeybees and termites, he noted. It requires some type of special sensory organ to detect the magnetic field.

"If they have evidence suggesting that mammals are using magnetic fields to orient their movements, this is very cool," said Mark A. Willis, an associate professor of biomedical sciences at Case Western Reserve University in Cleveland.

Willis, who was not part of the research team, added, "We have only in the last few years begun to understand the mechanisms underlying magnetic field orientation in birds and other smaller animals."

Indeed, it's small animals that led to this study, Begall explained. They were researching the magnetic field effect on African mole-rats.

"At one point last year the question came up whether large animals could also sense the Earth's magnetic field or not. But of course, it is difficult, or maybe impossible, to do these studies in the lab," she said. "So, the idea arose to look for other large mammals like cattle, and Hynek Burda was fascinated when he recognized that cattle could be found on Google Earth satellite images."

With satellite images they could tell the north-south orientation of the animals, but not whether an individual cow was facing north or south. You have to get closer to tell which end is which.

Now the researchers are moving on to study sheep, goats, horses, wild boar and some further deer species, Begall added.

The current study said red and roe deer also were found to orient in a north-south direction when grazing and resting, but unlike the worldwide cattle study, the deer portion was limited to the Czech Republic.

Monkeys Reward Friends, Family

- For capuchin monkeys, it seems, it's better to both give and receive, than just to receive. At least, that's what researchers at the Yerkes National Primate Research Center at Emory University in Atlanta have found.

Monkeys were given a choice of receiving a food reward, or receiving a food reward and also having another monkey receive food.

When paired with relative or "friend" the monkeys primarily went for the double reward, known as the "prosocial" choice, researchers led by Frans de Waal report in Tuesday's edition of Proceedings of the National Academy of Sciences.

"The fact the capuchins predominantly selected the prosocial option must mean seeing another monkey receive food is satisfying or rewarding for them," said de Waal.

But the monkeys weren't so generous with strangers, choosing the so-called "selfish" option instead.

"We believe prosocial behavior is empathy based. Empathy increases in both humans and animals with social closeness, and in our study, closer partners made more prosocial choices. They seem to care for the welfare of those they know," de Waal said in a statement.

Now the question is whether giving is self-rewarding to capuchins because they can eat together, or if the monkeys simply like to see the other monkey enjoying the food.

In the study, eight adult female capuchins were given tokens to exchange for food. One token got them a slice of apple. The other also got an apple slice, plus a similar slice was given to another monkey they could see.

In a series of tests, when the "partner" monkey was a relative or a familiar female from the same social group, the one choosing the token moved closer to the partner and primarily choose the prosocial token that got them both food. But when the second monkey was a stranger, the selfish token was more likely to be chosen, often with the lead monkey turning her back to the stranger.

Since the reward was the same for the monkey making the choice, de Waal suggested there must be some intangible benefit to the prosocial choice, perhaps an indication of empathy.

Living Cells Reprogrammed to Make Insulin

- Talk about an extreme makeover: Scientists have transformed one type of cell into another in living mice, a big step toward the goal of growing replacement tissues to treat a variety of diseases.

The cell identity switch turned ordinary pancreas cells into the rarer type that churns out insulin, essential for preventing diabetes. But its implications go beyond diabetes to a host of possibilities, scientists said.

It's the second advance in about a year that suggests that someday doctors might be able to use a patient's own cells to treat disease or injury without turning to stem cells taken from embryos.

The work is "a major leap" in reprogramming cells from one kind to another, said one expert not involved in the research, John Gearhart of the University of Pennsylvania.

That's because the feat was performed in living mice rather than a lab dish, the process was efficient and it was achieved directly without going through a middleman like embryonic stem cells, he said.

The newly created cells made insulin in diabetic mice, though they were not cured. But if the experiment's approach proves viable, it might lead to treatments like growing new heart cells after a heart attack or nerve cells to treat disorders like ALS, also known as Lou Gehrig's disease.

Douglas Melton, co-director of the Harvard Stem Cell Institute and a researcher with the Howard Hughes Medical Institute, cautioned that the approach is not ready for people.

He and his colleagues report the research in a paper published online Wednesday by the journal Nature.

Basically, the identity switch comes about by a reprogramming process that changes the pattern of which genes are active and which are shut off.

Scientists have long hoped to find a way to reprogram a patient's cells to produce new ones. Research with stem cells, and similar entities called iPS cells that were announced last year, has aimed to achieve this in a two-step process.

The first step results in a primitive and highly versatile cell. This intermediary is then guided to mature into whatever cell type scientists want. That guiding process has proven difficult to do efficiently, especially for creating insulin-producing cells, Gearhart noted.

In contrast, the new method holds the promise of going directly from one mature cell type to another. It's like a scientist becoming a lawyer without having to go back to kindergarten and grow up again, Melton says.

So, he says, someday scientists may be able to replace dead nerve or heart cells in people by converting some neighboring cells. At the same time, he stressed that it's still important to study embryonic stem cells and iPS cells.

The Melton team started its work with pancreas cells that pump out gut enzymes used in digestion and turned them into pancreatic "beta" cells, which make insulin.

The researchers destroyed beta cells in mice with a poison, giving the mice diabetes. Then they injected the pancreas with viruses that slipped into the enzyme-making cells. These viruses delivered three genes that control the activity of other genes.

Just three days later, new insulin-secreting cells started to show up. By a week after that, more than a fifth of the virally infected cells started making insulin. That shows "an amazingly efficient effect," commented Richard Insel, executive vice president of research at the Juvenile Diabetes Research Foundation.

Scientists found evidence that the newcomers were converts from mature enzyme-making cells. They identified the new cells as beta cells by their detailed appearance and behavior, and Melton said they've continued functioning for months.

The new cells didn't fully replenish the insulin supply, but maybe there were too few of them, or they were hampered by not forming clusters like ordinary beta cells do, researchers said.

The work brings "more excitement to the idea of using reprogramming as a way to treat diabetes," said researcher Mark Kay of Stanford University, who is studying the approach with liver cells.

Christopher Newgard, who studies beta cells at Duke University Medical Center, called the work convincing but cautioned that significant scientific questions remained about using the approach in treating disease.

Melton, who began his diabetes research in 1993 when his infant son was diagnosed with the illness, said he's obsessed with trying to find a new treatment or cure for Type 1 diabetes, in which beta cells are destroyed.

"I wake up every day thinking about how to make beta cells," he said.

Melton said he hopes drugs can replace the virus approach because of concern about injecting viruses into people.

As for converting other kinds of cells, scientists noted that the two cell types in the mouse experiment are closely related, and it remains to be shown whether the trick can be achieved with more distant combinations. In any case, scientists would have to deliver different reprogramming signals to other kinds of cells, Melton said.

Cattle, Deer Graze Along Earth's Magnetic Field

Cattle and deer all over the world tend to align themselves with Earth's magnetic field, according to new research. Both types of animals appear to graze in a north-south direction that aligns with magnetic north, not geographic north, according to European researchers who scrutinized thousands of Google Earth images. Birds, turtles, and fish are known to use magnetic guidance in migration. And among small mammals, a handful of rodent and one bat species have been shown to possess a magnetic compass.

Sabine Begall, a zoologist at the University of Duisburg in Essen, Germany, and her colleagues propose that large mammals may also sense Earth's magnetic field.

But why the nonmigrating animals would align themselves according to Earth's magnetism is still a mystery, the authors say.

The study appears in this week's issue of the Proceedings of the National Academy of Sciences.

Big Discoveries

Begall said her team first got the idea to look for cows' sensitivity to magnetism after one of the co-authors, Hynek Burda, also of the University of Duisburg, discovered such sensitivity in African mole rats.

(Related story: "Rat Radar: Rodent Uses Natural 'GPS'" [January 29, 2004])

"At one point last year the question came up whether large animals could also sense the Earth's magnetic field," she wrote in an email. "But of course, it is difficult, or maybe impossible, to do these studies in the lab."

Instead, Begall and her team surveyed Google Earth images of 8,510 cattle in 308 pastures and plains around the world and examined other data collected on 2,974 deer in more than 225 locations in the Czech Republic.

They found that the animals, when grazing or resting, tended to face either magnetic north or south.