Tag Archives: ANIMALS

Sperm whales’ clicks suggest the animals have culture The whales appear to learn sounds to socialize, similar to the way humans learn language

sperm whale

Sperm whales love to chitchat. They talk to each other in clicks. Now, scientists say, those clicks hold hints that the whales have culture.

Culture is a way of life passed on from generation to generation through learning. “There’s a lot of debate if culture is exclusive to humans or if you can find it in animals, too,” says Maurício Cantor. He is a biologist at Canada’s Dalhousie University in Halifax, Nova Scotia. Earlier research had suggested that dolphins, primates, birds and a few other wild animals have culture. Sperm whales should be added to that list, Cantor and his colleagues now argue in the September 8 Nature Communications.Sperm whales can make some of the deepest dives of all the animals in the sea. They can plunge up to 2,250 meters (7,380 feet) below the ocean’s surface. And they can stay underwater for nearly 90 minutes. When diving, the whales send out loud clicks and listen for the echoes that bounce back after the clicks hit something close by. This is calledecholocation. It’s the animal equivalent of sonar, and the whales use it to hunt — mainly for large squid. But when the whales are not hunting, they use those clicks to chat with each other.

Females and their calves do most of the talking. Tens of thousands of them hang out in the warm waters of the South Pacific Ocean. They usually swim in small units of 12 or so moms, grandmas, aunts and friends. These gals all work together to raise their pod’s babies.

These units are part of larger groups of 30 to 300 whales, which belong to even larger communities, called clans. Individuals in each clan talk to each other using distinct patterns of clicks. These varying patterns are similar to dialects in human speech. A dialect is a regional pattern in speech. People in Boston, Mass., and Dallas, Tex., both speak English, for example. Yet they may use words differently or give them a different pronunciation. Those differences reflect their regional dialects.

Cantor and his colleagues wanted to know how the whales got their distinct dialects. The researchers followed groups of whales around the Galápagos Islands, off South America. Along the way, they recorded the whales’ identities and behaviors. The scientists logged the whales’ sounds and tracked with which other groups these sperm whales interacted.

Back in their lab, the scientists loaded all of these data into a computer. Then they programmed it to test different ways the whale dialects could have developed over thousands of generations. Perhaps the dialects developed by chance. Or there might have been some innate bits of sound passed from mom to baby through DNA. The computer program ruled out both of those scenarios. Instead, the analysis showed that the whales had to have learned their distinct dialects from the other whales around them.Scientists refer to this as social learning.

“Social learning is the foundation of culture,” Cantor says. Because sperm whales learn their dialects from their extended family, there are cultural differences between clans. The clans actually exist because of those cultural differences, he says.

Luke Rendell is a biologist at the University of St. Andrews in Scotland. He was not involved in the study. He points out that the new finding is based on a computer model of how the sperm whale dialects came to be. A model, though, can only simulate the real world. It is not a direct observation of what actually occurred. “Like all models, it is wrong, but it is also useful,” Rendell says.

The model suggests whales have a bias for the sounds of their own clan members, which shapes their society, Rendell notes. This kind of conformity, or sticking with individuals who behave the same, is thought to underpin a lot of human culture. In non-humans, however, it is considered rare. Finding hints that it exists in sperm-whale clans “really starts to lift the lid on cultural processes in non-human societies,” he says.

Cantor notes that the scientists are not suggesting that the whales’ sounds or culture are as complex or diverse as human cultures are. But, he says, “Whale culture, like human culture, seems to be very important for the whales’ social structure.”

Power Words

(for more about Power Words, click here)

bias   The tendency to hold a particular perspective or preference that favors some thing, some group or some choice. Scientists often “blind” subjects to the details of a test so that their biases will not affect the result.

biology  The study of living things. The scientists who study them are known as biologists.

clan    A large family or group of families that have much in common, both genetically and culturally.

computer model A program that runs on a computer that creates a model, or simulation, of a real-world feature, phenomenon or event.

culture  (in social science) The sum total of typical behaviors and social practices of a related group of people (such as a tribe or nation). Their culture includes their beliefs, values, and the symbols that they accept and or use. It’s passed on from generation to generation through learning. Once thought to be exclusive to humans, scientists have recognized signs of culture in several other animal species, such as dolphins and primates.

dialect  A form of language or pattern of communication that is distinct to a specific place or a social group.

DNA  (short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.

dolphins  A highly intelligent group of marine mammals that belong to the toothed-whale family. Members of this group include orcas (killer whales), pilot whales and bottlenose dolphins.

echolocation  (in animals) A behavior in which animals emit calls and then listen to the echoes that bounce back off of solid things in the environment. This behavior can be used to navigate and to find food or mates. It is the biological analog of the sonar used by submarines.

generation  A group of individuals born about the same time or that are regarded as a single group. Your parents belong to one generation of your family, for example, and your grandparents to another. Similarly, you and everyone within a few years of your age across the planet -are referred to as belonging to a particular generation of humans.

innate  Something such as a behavior, attitude or response that is natural, or inborn, and doesn’t have to be learned.

model A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes.

pod    (in zoology) The name given to a group of toothed whales that travel together, most of them throughout their life, as a group.

primate  The order of mammals that includes humans, apes, monkeys and related animals (such as tarsiers, the Daubentonia and other lemurs).

programming  (in computing) To use a computer language to write or revise a set of instructions that makes a computer do something. The set of instructions that does this is known as a computer program.

scenario   A possible (or likely) sequence of events and how they might play out.

simulate  (in computing) To try and imitate the conditions, functions or appearance of something. Computer programs that do this are referred to as simulations.

social learning  A type of learning in which individuals observe the behavior of others and modify their own behavior based on what they see.

social network  Communities of people (or animals) that are interrelated owing to the way they relate to each other.

sonar  A system for the detection of objects and for measuring the depth of water. It works by emitting sound pulses and measuring how long it takes the echoes to return.

sperm whale  A species of enormous whale with small eyes and a small jaw in a squarish head that takes up 40 percent of its body. Their bodies can span 13 to 18 meters (43 to 60 feet), with adult males being at the bigger end of that range. These are the deepest diving of marine mammals, reaching depths of 1,000 meters (3,280 feet) or more. They can stay below the water for up to an hour at a time in search of food, mostly giant squids.

zoology  The study of animals and their habitats. Scientists who undertake this work are known aszoologists.

Do animals have a sense of humour?

Right now, in a high-security research lab at Northwestern University’s Falk Center for Molecular Therapeutics in Illinois, scientists are tickling rats. Their goal? To develop a happiness pill. But their efforts might also produce some of the best evidence yet that humour isn’t something experienced exclusively by humans.

Scientists believe human laughter evolved from the distinctive panting emitted by our great-ape relatives during rough and tumble play. That panting functions as a signal that the play is all in good fun and nobody is about to tear anybody else’s throat out.

In a clever bit of scientific detective work, psychologist Marina Davila-Ross of the University of Portsmouth in the UK analysed digital recordings of tickle-induced panting from chimps, bonobos, gorillas and orangutans, as well as human laughter. She found that the vocal similarities between the species matched their evolutionary relationships.

Chimps and bonobos, our closest relatives, boast the most laughter-like kind of panting, while the noises of gorillas, further down our family tree, sound less like laughing. And orangutans, our truly distant cousins, pant in a most primitive way.

Cheeky monkey

Non-human primates don’t just laugh – there is evidence they can crack their own jokes. Koko, a gorilla in Woodside, California, who has learned more than 2000 words and 1000 American Sign Language signs, has been known to play with different meanings of the same word. When she was asked: “What can you think of that is hard?” the gorilla signed “rock” and “work”. She also once tied her trainer’s shoelaces together and signed “chase”.

But what about other members of the animal kingdom – do they have funny bones? Marc Bekoff at the University of Colorado, Boulder, professor of ecology and evolutionary biology and author of The Emotional Lives of Animals, believes they do. In fact, he thinks we are on the cusp of discovering that many animals have a sense of humour, maybe even all mammals.

The idea that animals can appreciate comedy isn’t as far-fetched as it sounds, considering some of the other groundbreaking discoveries scientists like Bekoff are making about animal behaviour. They have found dogs that understand unfairness, spiders that display different temperaments and bees that can be trained to be pessimistic.

As Bekoff points out, Darwin argued that the difference between human and animal intelligence is a matter of degree, not kind. Or as Bekoff put it: “If we have a sense of humour, then non-human animals should have a sense of humour, too.”

Let’s go tickle some rats

A similar sentiment inspired psychologist Jaak Panksepp to enter his lab at Bowling Green State University in Ohio one day in 1997 and tell undergraduate Jeffrey Burgdorf: “Let’s go tickle some rats.” The lab had already discovered that its rats would emit unique ultrasonic chirps in the 50 kilohertz range when they were chasing one another and engaging in play fighting.

Now the researchers wondered if they could prompt this chirping through tickling. Sure enough, when the researchers began poking at the bellies of the rats in their lab, their ultrasonic recording devices picked up the same 50 kilohertz sounds. The rats eagerly chased their fingers for more. Soon, as the media trumpeted the existence of rat laughter, people the world over were opening up their rat cages and engaging Pinky and Mr Pickles in full-scale tickle wars.

We met Burgdorf at his office at Northwestern’s Falk Center, where as a biomedical engineering professor he has continued his rat-tickling efforts. He was cautious, however, about overselling what is happening with his rodents. “I don’t necessarily call it laughter, I call it a signal of positive affect,” Burgdorf told us.

His careful choice of words makes sense. Not everyone was convinced he and Panksepp had uncovered real rat laughter when their rodent-tickling activities first went public. But whatever you want to call it, Burgdorf, a quick-witted man with a boyish face and a sign on his office door that reads “Know It All,” has been obsessed with that strange rat noise he first heard in 1997.

Laughing pill

He seems to be on to something. While tickling isn’t always pleasant – thus the term “tickle torture” – in multiple experiments Burgdorf has demonstrated the rats’ 50 kilohertz chirping is only associated with positive experiences. For example, the rats only made this sound during rough and tumble play when the animals were of similar size. The vocalisations changed when one of the animals involved was much larger than the other, when it was no longer fun and games and instead looked more like bullying. And when given a choice, Burgdorf’s rats would push a bar to play a recording of the 50 kilohertz chirp as opposed to other rat noises, suggesting they had a preference for the sound.

Finally, when Burgdorf and his colleagues used electrodes, opiates and other manipulations to stimulate the reward centres of rats’ brains, the rats produced that same noise.

Whether you call it laughter or not, Burgdorf is convinced the ultrasonic noises signal the rats are experiencing happiness. Hence the “laughing pill” experiment: he and his colleagues are testing a new antidepressant medication on rats, to see if it makes them “laugh”, or chirp happily. If all goes well, Burgdorf believes the resulting medication could eventually be approved for humans. Rats, so often seen as a malicious pest, could end up making the world a happier place.

Ice-age animals live on in Eurasian mountain range

Image

IT’S the land that time forgot. Not only have conditions in the Altai-Sayan region in central Asia barely changed since the last ice age, but the mix of mammals that lives there is also almost the same.

Věra Pavelková Řičánková and colleagues at the University of South Bohemia in České Budějovice, Czech Republic, compiled lists of mammals living at 14 sites across Eurasia. They compared them with mammals that lived at seven Eurasian sites during the last glacial period 35,000 to 12,000 years ago.

The team discovered that the combination of mammals found together in the Altai and Sayan mountains of western Mongolia and southern Russia – such as horses, reindeer, saiga antelopes and wolverines – is similar to the ancient glacial communities. There are a few obvious differences, however, such as the lack of mammoths.

These animals do not normally live together anymore, says Pavelková Řičánková. She says the Altai-Sayan is one of the last places on Earth to retain an ice age fauna (PLoS One, doi.org/q2n).

“You’ve basically got a really good modern analogue for the Pleistocene communities,” says John Stewart of the University of Bournemouth, UK.

The Altai-Sayan has not been fully explored, so could hold more surprises. In 2010, snails thought to have died out when the ice melted were found alive there (Journal of Biogeography, doi.org/d4vn4n).

The cold, arid climate is key to the animal community, says Pavel Tarasov of the Free University of Berlin, Germany. The last ice age had a similarly dry climate, so Eurasia was surprisingly free from snow. Grasses flourished, helping feed the many herbivores.

However, there is a better model for conditions in northern Eurasia, says Tarasov. Wrangel, a small island in the Arctic Ocean, retains the plant community of that time. And the last mammoths lived on Wrangel, vanishing just 4000 years ago.

The Altai-Sayan may also have been vital for humanity’s success. The mountains are home to Denisova cave, famous for the 2010 discovery of 50,000-year-old fossils of a new kind of human, the Denisovans. Since then, Neanderthal bones, and tools crafted by Homo sapiens have also been found in the cave. This makes it the only place where we know all three hominins lived.

That may be no coincidence, says Pavelková Řičánková. Conditions in the Altai-Sayan are fairly stable, so ancient humans may have taken refuge there and lived off the diverse game species.

“It looks increasingly like the east [of Eurasia] may have been a refugium,” agrees Stewart.

When the ice age ended, the Altai people left the mountains and spread far and wide. Recent genetic evidence suggests that the first Americans can trace their ancestry to the Altai-Sayan (American Journal of Human Genetics, doi.org/fxq8gx).

Flower loss doomed the mammoths

Studies of ancient animal poop paint a new picture of why woolly mammoths disappeared
BY STEPHEN ORNES   FEBRUARY 27, 2014
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Where have all the mammoths gone? A new study suggests flowering plants called forbs sustained wooly mammoths. When forbs began vanishing from the Arctic around the end of the last Ice Age, so did the mammoths. Pictured is a mammoth tusk found in Russia.
 

Losing much of their favorite food may have caused woolly mammoths to go extinct, a new study concludes.

Elephant-sized woolly mammoths roamed the upper reaches of North America, Europe and Asia long ago. But these plant-eating giants and other supersized animals largely disappeared by about 10,000 years ago. Researchers now think the mega-mammals might have vanished because they could no longer find enough of the plants, called forbs, on which they had dined. The abundance of these mostly flowering plants nosedived as the Ice Age began to end.

Eske Willerslev of the University of Copenhagen, in Denmark, is an evolutionary geneticist. He and his coworkers had wanted to find out what plants grew in the ancient Arctic. So they focused on plant genes. Genes tell cells how to build the molecules that make life possible.

The researchers worked with 212 samples of permanently frozen soil. Called permafrost, it can be found throughout many polar regions. The ancient soil for this study came from 21 sites in Alaska, Canada and Siberia. By comparing each soil sample’s age with the plant genes preserved within it, the scientists put together a picture of what plants had flourished at the time of the mammoths.

Researchers used to think the northern Arctic would have been a sea of grass. It now appears that between 50,000 and 12,000 years ago, this area looked more like a meadow. The mammoths roamed dry plains that would have been bursting with vibrant colors. Some of the most abundant forbs, the data show, included relatives of prairie sagewort, yarrow, chrysanthemums, asters and tansy.

But as the Ice Age ended, the abundance of forbs started to plummet. As temperatures rose, the glaciers began to thaw and the land became wetter. Woody plants such as horsetails, cotton grass, and willows liked these conditions. Forbs didn’t.

And that would have left the mammoths rather hungry, additional research shows.

To find out what mammoths and other large animals ate, the scientists studied coprolites, which are fossilized feces. The researchers also examined the preserved stomach contents found with the remains of eight giant animals, including four woolly mammoths. (The other animals: two woolly rhinoceroses, one bison and one horse.)  All of these animals lived between 55,000 and 21,000 years ago.

Forbs made up 63 percent of the plant content in the animals’ poop and stomachs, it turns out. Grasses accounted for only about 27 percent. These data suggest the mammoths and other animals ate a diet that was about two-thirds forbs. If true, then mammoths would have had a hard time getting enough nutrition from the grasses and woody plants that edged out the forbs after the Ice Age.

“I’m not saying that they weren’t eating grasses, but our data suggest the forbs were sustaining them,” Willerslev told Science News. His team described its findings February 6 in Nature.

Other scientists find Willerslev’s approach to better understanding the ancient landscape exciting. However, many say blaming the mammoth die-off on too few forbs may be overly simplifying the situation.

The new genetic data are “fascinating,” says Michael Hofreiter. He is a biologist at the University of Potsdam in Germany. “If you look closer at the data,” he argues, “the story is not as straightforward as they make it.”

In fact, the biggest decline in the abundance of Arctic forbs didn’t occur until thousands of years after the mammoths and other giant animals went extinct, he says. That suggests vanishing forbs did not necessarily trigger the animals’ extinction.

Power Words

Arctic Circle  The northernmost point at which the sun is visible on the northern winter solstice and the southernmost point at which the midnight sun can be seen on the northern summer solstice.

coprolite  Fossilized feces. The word coprolite, in Greek, means “dung stones.” Coprolites are very important because they can provide direct evidence of what ancient creatures ate.

extinct  An adjective that describes a species for which there are no living members.

evolutionary genetics  The science of how plants, animals and people change over long periods of time by studying genes. Scientists who work in this field are known as evolutionary geneticists.

feces A body’s solid waste, made up of undigested food, bacteria and water. The feces of larger animals are sometimes also called dung.

forb  A type of flowering plant.

glacier  A slow-moving river of ice hundreds or thousands of meters deep. Glaciers are found in mountain valleys and also form parts of ice sheets.

Ice Age  Earth has experienced at least five major Ice Ages, which are prolonged periods of unusually cold weather experienced by much of the planet. During that time, which can last hundreds to thousands of years, glaciers and ice sheets expand in size and depth. The most recent Ice Age peaked 21,500 years ago, but continued until about 13,000 years ago.

permafrost  Permanently frozen ground.

woolly mammoth  An extinct relative of elephants that was adapted to cold temperatures, with a long shaggy coat, small ears and a thick layer of fat. Individuals are sometimes found frozen in the permafrost of Siberia.

courtesy by: https://student.societyforscience.org/article/flower-loss-doomed-mammoths

Sharks become science helpers

Sensors stuck to sharks have begun gathering climate data throughout the Pacific
BY BETH MOLE   FEBRUARY 20, 2014Image
Fitted with special sensors, hammerhead sharks (like the one seen here) can collect valuable data as they take deep nightly dives and long trips through the Pacific. Those data will help the computer programs used to predict weather and climate.
 

CHICAGO — Those gray triangles that peek above ocean waves can terrify beachgoers. They flag a cruising shark. But those same fins could mark science at work for climate researchers. Some scientists have begun strapping sensors to the sharks’ otherwise ominous fins. Now when those fish travel the seas, they can collect a rich trove of data from the far reaches of the Pacific.

Maintaining devices that monitor conditions in the ocean is expensive, notes Kim Holland. He’s a marine scientist of the University of Hawaii at Manoa. Using sharks instead could provide a new and less costly source of data for those scientists who use computers to try to understand and anticipate weather and climate conditions.

“Sending sharks to do the heavy lifting makes a lot of sense,” Holland says.

Other animals have proven useful as climate-data collectors. These include elephant seals. But to date, sharks represent an untapped resource.

Holland and his team recently discovered that sharks take nightly dives to depths of as much as 800 meters (2,600 feet). Some of the fish also embark on unexplained 1,000-kilometer (620-mile) cruises to the center of the Pacific. These long and deep jaunts provide unmatched access to parts of the subsea world that scientists never visit, Holland says. He presented his latest findings February 14, here, at the annual meeting of the American Association for the Advancement of Science.

Off the coast of Hawaii, Holland and his team have begun fitting the fins of tiger and hammerhead sharks with sensors, calledtags. Each device, which doesn’t hurt the fish, is about the size and shape of an ice cream cone. Holland began tagging sharks to get information on their behavior. Soon, however, he realized the data that these ferocious fishes were bringing back could help scientists in other fields as well.

His team’s tagged sharks are now collecting ocean temperature data. These can help map how those temps vary with depth.

Future shark tags will record oxygen levels in the water. Some will measure other chemical properties, including electrical conductivity, a gauge of the water’s saltiness.  Every time a shark surfaces, its sensors can beam data it has collected to a satellite system above the ocean.

Sharks: A relatively inexpensive alternative

Tagging sharks? “It’s a great idea,” said James Overland at the Chicago meeting. An oceanographer, he works for the National Oceanic and Atmospheric Administration in Seattle, Wash. The bonus ocean data that sharks glean will certainly be useful, he says. Using tags also is relatively cheap. By comparison, the cost each day to operate some of the research ships used for ocean monitoring is $10,000 to $20,000 each.

U.S. scientists had set up an array of buoys across the Pacific to collect data and to monitor El Niños and La Niñas. (These common, years-long climate events get their start in the Pacific.) But recently, money problems have put the usefulness of this Tropical Atmosphere Ocean array in jeopardy. Right now, roughly half of the buoys are in need of repair and are no longer collecting data.

Overland also notes that curious, chomping sharks can destroy robotic vehicles that monitor the ocean, such as gliders. But putting those sharks to work by ferrying tags around the ocean makes sense.

Jennifer Francis agrees. An oceanographer at Rutgers University in New Brunswick, N.J., she has not been part of the shark-monitoring team. In addition to providing inexpensive ocean data, she says, tagging also can track variations in shark behavior, where the fish hang out and where they dine.

“All of this gives us clues as to how the ocean is changing,” said Zdenka Willis. She is director of the U.S. Integrated Ocean Observing System in Silver Spring, Md. It’s a government project involving many U.S. agencies. And this system is building a broad network for collecting data from tagged animals. 

“It is hard to pinpoint a single data stream as being most important,” Willis said. But given that the Pacific is large and sampled nowhere nearly enough, she argues that data from tagged animals are certainly poised to become more important.

Power Words

array  A broad and organized group of objects. Sometimes they are instruments placed in a systematic fashion to collect information in a coordinated way. Other times, an array can refer to things that are laid out or displayed in a way that can make a broad range of related things, such as colors, visible at once.

behavior  The way a person or animal acts towards others, or conducts itself.

climate  The weather conditions prevailing in an area in general or over a long period.

data  Facts and statistics collected together for analysis but not necessarily organized in a way that give them meaning.

El Niño  Extended periods when the surface water around the equator in the eastern and central Pacific warms.  Scientists declare the arrival of an El Niño when that water warms by at least 0.4 degree Celsius (0.72 degree Fahrenheit) above average for five or more months in a row. El Niños can bring heavy rainfall and flooding to the West Coast of South America. Meanwhile, Australia and Southeast Asia may face a drought and high risk of wildfires. In North America, scientists have linked the arrival of El Niños to unusual weather events — including ice storms, droughts and mudslides.

glider  A vehicle (such as a plane in air or uninhabited submarine) that takes advantage of currents to travel long distances using little or no fuel. It also tends to move smoothly, creating few disruptions in the fluid or airstream through which it moves.

habitat  The area or natural environment in which an animal or plant normally lives, such as a desert, coral reef or freshwater lake. A habitat can be home to thousands of different species.

La Niña  Extended periods when the surface water around the equator in the eastern Pacific cools for long stretches of time. Scientists will announce the arrival of a La Niña (lah NEEN yah) when the average temperature there drops by at least 0.4° C (0.72° degree F). Impacts on global weather during a La Niña tend to be the reverse of those triggered by an El Niño: Now, Central and South America may face severe droughts while Australia floods.

oceanography  The branch of science that deals with the physical and biological properties and phenomena of the oceans. People who work in this field are known as oceanographers.

electrical conductivity  The ability of some substance (such as water or metals) to transport an electrical charge or current.

sensor  A device that picks up information on physical or chemical conditions — such as temperature, barometric pressure, salinity, humidity, pH, light intensity or radiation — and stores or broadcasts that information. Scientists and engineers often rely on sensors to inform them of conditions that may change over time or that exist far from where a researcher can measure them directly.

shark  A type of predatory fish that has survived in one form or other for hundreds of millions of years. Cartilage, not bone, gives its body structure.

tagging  (in biology) Attaching some rugged band or package of instruments onto an animal. Sometimes the tag is used to give each individual a unique identification number. Once attached to the leg, ear or other part of the body of a critter, it can effectively become the animal’s “name.” In some instances, a tag can collect information from the environment around the animal as well. This helps scientists understand both the environment and the animal’s role within it.

courtesy by: https://student.societyforscience.org/article/sharks-become-science-helpers