Biological Psychology Links

The undersea world isn't as quiet as we thought, according to a New Zealand researcher who found fish can "talk" to each other. Fish communicate with noises including grunts, chirps and pops, University of Auckland marine scientist Shahriman Ghazali has discovered according to newspaper reports Wednesday. "All fish can hear, but not all can make sound -- pops and other sounds made by vibrating their swim bladder, a muscle they can contract," Ghazali told the New Zealand Herald. Fish are believed to communicate with each other for different reasons, including attracting mates, scaring off predators or orienting themselves. The gurnard species has a wide vocal repertoire and keeps up a constant chatter, Ghazali found after studying different species of fish placed into tanks. On the other hand, cod usually kept silent, except when they were spawning. "The hypothesis is that they are using sound as a synchronization so that the male and female release their eggs at the same time for fertilization," he said. Some reef fish, such as the damselfish, made sounds to attempt to scare off threatening fish and even divers, he said. But anyone hoping to strike up a conversation with their pet goldfish is out of luck. © 2010 Discovery Communications, LLC.

Cassowaries’ low-frequency sounds may give insight into dinosaur communications NEW YORK -- A family of huge forest birds living in the dense jungles of Papua New Guinea emit low-frequency calls deeper than virtually all other bird species, possibly to communicate through thick forest foliage, according to a study published by the New York-based Wildlife Conservation Society. Published in the recent issue of the scientific journal The Auk, the study says that three species of cassowaries – flightless birds that can weigh as much as 125 pounds – produce a "booming" call so low that humans may not be able to detect much of the sound. The researchers draw similarities between the birds' calls and the rumbling elephants make to communicate. "When close to the bird, these calls can be heard or felt as an unsettling sensation, similar to how observers describe elephant vocalizations," said WCS researcher Dr. Andrew Mack, the lead author of the study.

By SANDRA BLAKESLEE Every dog lover knows how a pooch expresses its feelings. The muscles on either side of the tail apparently reflect emotions like fear and love registering in the brain. Ears close to the head, tense posture, and tail straight out from the body means “don’t mess with me.” Ears perked up, wriggly body and vigorously wagging tail means “I am sooo happy to see you!” But there is another, newly discovered, feature of dog body language that may surprise attentive pet owners and experts in canine behavior. When dogs feel fundamentally positive about something or someone, their tails wag more to the right side of their rumps. When they have negative feelings, their tail wagging is biased to the left. A study describing the phenomenon, “Asymmetric tail-wagging responses by dogs to different emotive stimuli,” appeared in the March 20 issue of Current Biology. The authors are Giorgio Vallortigara, a neuroscientist at the University of Trieste in Italy, and two veterinarians, Angelo Quaranta and Marcello Siniscalchi, at the University of Bari, also in Italy. “This is an intriguing observation,” said Richard J. Davidson, director of the Laboratory for Affective Neuroscience at the University of Wisconsin in Madison. It fits with a large body of research showing emotional asymmetry in the brain, he said. Copyright 2007 The New York Times Company

By BINA VENKATARAMAN The song of the blue whale, one of the eeriest sounds in the ocean, has mysteriously grown deeper. The calls have been steadily dropping in frequency for seven populations of blue whales around the world over the past 40 years, say researchers at the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration and WhaleAcoustics, a private research company. The scientists analyzed data collected with hydrophones and other tools and found that the songs, which they believe are by males advertising for mates, had lowered by as much as 30 percent in certain populations. Much of the song lies at frequencies too low to be detected by the human ear. The study, though not yet published, has been reviewed by several experts in the field who, in interviews, called the global decline “dramatic,” “significant,” “convincing” and “unequivocal.” Scientists cannot explain why blue whales from places as disparate as the northern Pacific and the Southern Ocean, which surrounds Antarctica, would drop the pitch of their songs. Each blue whale population has a distinct tempo and tone set to its vocals. John Hildebrand, professor of oceanography at Scripps and an author of the study, said the drop might signal a rebound in the population of blue whales since commercial whaling bans began to take effect in the 1970s. Copyright 2008 The New York Times Company

By Victoria Gill As if flying around in the dark swooping and diving to catch insects was not tricky enough, bats also listen for their fellow hunters. A study has revealed how these winged mammals recognise other bats' voices. They are able to differentiate the ultrasonic "echolocation" calls that other bats make as they navigate. In the journal PLoS Computational Biology, the scientists report that the bats have an internal "reference" call to which they compare others. Yossi Yovel from the Weizmann Institute of Science, Israel, and his colleagues in Germany recorded the echolocation calls of five greater mouse-eared bats The bats use these brief bursts of sound in sonar navigation - bouncing sound waves off their surroundings to find their way and locate prey. Dr Yovel's team tested the bats' ability to identify the others by playing the recorded sounds to them. "Each bat was assigned two others it had to distinguish between," Dr Yovel explained. "So we trained bat A on a platform, playing a sound from bat B on one side and from bat C on the other. He had crawl to where the 'correct' sound was coming from." Each of the subjects was taught that a call from just one of the other bats was correct. So during this training exercise, if the bat A made the right choice, and crawled towards the sound from bat B, it was rewarded with its favourite food - a mealworm. "Then, in the next stage - the test - we rewarded them no matter what choice they made, and they still chose correctly more than 80% of the time," said Dr Yovel. (C)BBC

By Carolyn Y. Johnson To dog owners, their pet’s “arf, arf, arf’’ means “let’s play!’’ To neighbors, it can be annoying noise. But to scientists, barks are an evolutionary puzzle. Why, they wonder, do dogs bark, and bark, and bark, sometimes seemingly for no reason? Researchers at the University of Massachusetts at Amherst and Hampshire College have offered a new explanation for the bark: The rigors of modern canine life trigger a primordial behavior that once helped dogs’ ancestors fend off predators. Animals - including dogs, deer, monkeys, and birds - bark when they feel a conflict, the researchers believe. For example, should an animal run away or defend her young? In the wild, that bark draws the attention - and the barks - of other members of the group, which could scare away the predator. But in domesticated dogs - confined to crates, yards, and houses and beset by passing cars, unfamiliar dogs, and mailmen - such internal conflicts go into overdrive, and so does the barking. The research, published in the journal Behavioural Processes last month, is the latest volley in an ongoing scientific investigation of barking. One question researchers are trying to answer is whether dogs are actually saying something, and, if so, what. The reasons for barking might seem like a frivolous research topic. But to scientists, barking should not be overlooked, considering that it is one of the most conspicuous behaviors displayed by an animal that lives in 40 percent of US households and is often treated like a member of the family. © 2009 NY Times Co.

Jennifer Viegas, Discovery News — What do dog barks have in common with bird tweets and human baby cries? All appear to communicate basic emotions, such as fear, aggression and submission, in somewhat the same acoustic way, according to a new Applied Animal Behavior Science study that suggests a primitive communication system may unite virtually all mammals. The theory could help explain why previous research has found that many mammals, including humans, understand the vocalizations of different species. For example, a Language Communication study determined young children can identify simple emotions conveyed in macaque calls. Another study, published in Primate Cognition, indicated that an African grey parrot could communicate with a bonobo. For the recent research, P�ter Pongr�cz and colleagues studied how well people with varying dog experience could describe the emotional content of several artificially assembled bark sequences. The barks, which were based on sounds made by a Mudi (a Hungarian herding dog), covered five emotional states: aggressiveness, fear, despair, playfulness and happiness. Pongr�cz, a professor of ethology at Eötvös Lor�nd University in Budapest, Hungary, and his team found that even people with little prior dog experience could correctly match the bark sequences with the previously determined emotional intent of the original barks. © 2006 Discovery Communications Inc.

By Virginia Morell A few years ago, researchers discovered that the babies of at least one species of bat make babbling sounds, much like human infants. Now, it turns out those babbling baby bats aren't just mindlessly cooing--they're imitating the songs of the big guys in their colonies: adult males with territories and harems. Such vocal imitation is rare in the animal kingdom, and it has never been found in nonhuman primates. The discovery should open a new window on the evolution of speech and language, scientists say. Scientists define complex vocal imitation as the ability to learn a call or song from a tutor--and they regard this talent as a key innovation in the evolution of speech. The rarified list of complex vocal imitators includes birds, elephants, cetaceans, seals, and humans. Researchers had long predicted that bats might also be capable of such imitation because of their extraordinary vocal flexibility; they use echolocation calls to navigate the physical world, for example, and social calls to communicate with their fellow bats. As behavioral ecologist Mirjam Knörnschild of the University of Ulm in Germany listened to sac-winged bats (Saccopteryx bilineata), she thought she heard complicated vocal imitation. These insectivorous Costa Rican bats live in harems of one male and as many as eight females, each of which can have one pup annually. The males defend small territories in their day-roosts with unique multiple-syllabic songs. Adult females don't sing, but their pups (males and females) do plenty of babbling. During such "babbling bouts," the pups often sing nearly complete renditions of the territorial songs, Knörnschild says, albeit shakier renditions. But were the pups simply combining fragments or actually listening and imitating their complete songs? © 2009 American Association for the Advancement of Science

by Ewen Callaway The canine phrase book has collected its first entries. Dogs understand the meaning of different growls, from a rumble that says "back off" to playful snarls made in a tug-of-war game. Proving that animal vocalisations have specific meanings – and what they could be – is challenging. In 2008, P�ter Pongr�cz, a behavioural biologist at Eötvös Lorand University in Budapest, Hungary, monitored dogs' heart rates to show that they seem to notice a difference between barks aimed at strangers and those directed at nothing in particular. Now he has gone a step further and shown that dogs respond differently to different vocalisations. Pongr�cz's team recorded growls from 20 pet dogs in three different situations: a tug-of-war game with their owner, competing with another dog for a bone and growling at an approaching stranger. Growls may convey more meaning than barks, says Pongr�cz: wolves rarely bark, and he says dogs may have learned to bark to get human attention. The team played the recordings to 36 other dogs that had each been left to gnaw on a bone. Only those that heard the food-guarding growls tended to back off from the bone and stay away. "It seems dogs can understand something about the context," Pongr�cz says. Back to the bone © Copyright Reed Business Information Ltd

PROVIDENCE, R.I. — Male bullfrogs communicate with other bullfrogs through calls made up of a series of croaks, some of which contain stutters, according to a new Brown University study which describes a pattern not previously identified in scientific literature. Researchers recorded 2,536 calls from 32 male bullfrogs in natural chorus and analyzed the number of croaks in each call and the number of stutters in each croak. It is known that the male bullfrog’s call attracts females for mating, maintains territorial boundaries with other males, and indicates that the frog is healthy and aggressive. “Some animals have evolved large, complex vocabularies to communicate, while others say a lot with very limited numbers of calls,” said Andrea Simmons, professor of psychology, who presented the findings at 75th meeting of the Acoustical Society of America Monday, May 24, 2004. “A fundamental question in the study of communication by sound is ‘how much information can a sender convey in a single sound’?”

AUSTIN, Texas—Having a set of extra genes gave fish on separate continents the ability to evolve electric organs, report researchers from The University of Texas at Austin. Dr. Harold Zakon and colleagues, in a paper recently published in Proceedings of the National Academy of Sciences, show that African and South American groups of fish independently evolved electric organs by modifying sodium channel proteins typically used in muscle contraction. Mutations in sodium channel proteins can cause serious muscular disorders, epilepsy and heart problems in humans and other vertebrates. But fish have two copies of many of their genes, and Zakon found that the duplicate sodium channel gene could mutate and evolve without harming the fish. “The spare gene gave [the electric fish] a little bit of evolutionary leeway,” says Zakon, professor of neurobiology. “This is really one of the first cases that the ancestral gene duplication in fish has actually been linked to a gene that has been freed up and evolving in accordance with a ‘new lifestyle.’” Zakon and colleagues looked at two sodium channel genes in the electric organs and muscles in electric and non-electric fish. Electric fish use their electric organs, which are modified muscles, to communicate with each other and sense their environment.

Roxanne Khamsi Birdsongs are so distinctive they are often used by ornithologists to identify individual birds. Now a novel study shows that birds are not "pre-programmed" to sing their song – rather, birds listen closely to their tune to keep their songs note perfect. The same mechanism may operate in humans, perhaps shedding light on speech disorders, the researchers say. Songbirds do not start out life as virtuosos: they often begin by ‘babbling’ random pitches and then advance to sing sophisticated tunes with the help of a tutor. Once they develop their own particular melody, they use it to announce territorial claims or to attract a mate. The slight variations in the song identify one bird from another, so birds take great pains to preserve their unique tune throughout life. To establish how birds keep tabs on their singing, scientists have conducted experiments that involved disabling the birds’ ability to hear by removing a collection of sensory cells known as the cochlea. Over time, each animal produced songs that diverged further and further from its particular identifying tune. But an operation that leaves birds deaf could have other unintended cognitive effects that affect song production, argues Jon Sakata at the University of California in San Francisco, US. He and his colleague, Michael Brainard, set up an experiment that disrupted the hearing of the birds without an invasive procedure. © Copyright Reed Business Information Ltd.

Herring aid DAVID ADAM Fish living in the murky rivers of West Africa have evolved their own hearing-aids. A tiny gas-filled bubble inside the ear of the mormyrid electric fish vibrates as mating calls or alarm signals pass through the water. The fish hears the sounds because the bubble brushes against sensory hairs. Deflating the bubble renders the fish deaf, Lindsay Fletcher and John Crawford at the University of Pennsylvania, Philadelphia, now report. Biologists have suspected that the bubbles are crucial to mormyrid hearing since the 1930s, but advances in surgery have only now allowed the idea to be tested. 1.Fletcher, L. B. & Crawford, J. D. Acoustic detection by sound-producing fishes (Mormyridae): the role of gas-filled tympanic bladders. Journal of Experimental Biology 204, 175–183 (2001). 2.Yan, H. Y. & Curtsinger, W. S. The otic gasbladder as an ancillary auditory structure in a mormyrid fish. Journal of Comparative Physiology A 186, 595–602 (2000). .© Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2000 Reg. No. 785998 England.

CHAMPAIGN, Ill. - A protein targeted by drug treatments in some patients with Alzheimer's disease also appears to play an important role in honeybees (Apis melifera), researchers say. U.S. and Israeli scientists – led by Gene E. Robinson of the University of Illinois – report that forager bees, which work outside the hive collecting nectar and pollen, have lower activity levels of the acetylcholingesterase (AChE) protein in their brains than do younger nurse bees. AChE is an enzyme that breaks down a primary neurotransmitter known as acetylcholine (ACh). Neurons use ACh to communicate with one another. In the human body, ACh signals muscle movement, and, in the brain, it is linked to learning and memory. In many Alzheimer's patients, researchers have noted a loss of neurons that secrete ACh. One treatment is the use of an AChE inhibitor. The scientists, reporting in a recent issue of the Journal of Molecular Neuroscience, showed that the reduction of AChE protein activity is the result of the down regulation of the AChE gene.

Michael L Platt Current Opinion in Neurobiology 10.1016/S0959-4388(02)00302-1 Once considered the province of philosophy and the behavioral sciences, the process of making decisions has received increasing scrutiny from neurobiologists. Recent research suggests that sensory judgements unfold through the gradual accumulation of neuronal signals in sensory–motor pathways, favoring one alternative over others. Stored representations of the outcome of prior actions activate neurons in many of these same areas during decision-making. The challenge for neurobiologists lies in deciphering how signals from these disparate areas are integrated to form a single behavioral choice and the mechanisms responsible for selecting the appropriate information upon which decisions should be informed in particular contexts. © Elsevier Science Limited 2002

By Robert Sanders, Media Relations BERKELEY – The tropical mantis shrimp has the most sophisticated eyes of any creature on the planet, yet it often lives at murky depths where the only light is a filtered, dim blue. Why does it need such complex vision? Marine biologists and physiologists have now discovered at least one use for these eyes in the deep, blue ocean: to see the fluorescent markings mantis shrimp use to signal or threaten one another. The shrimps' characteristic spots are easy to see in shallow water but only dimly visible 40 meters (131 feet) down, so on the ocean floor the crustacean's spots fluoresce yellow-green to enhance their prominence in the dim blue light. Copyright UC Regents

NewScientist.com news service Alarm sirens intended to scare highly endangered whales away from ships that often kill them may actually be more likely to cause a collision, suggests new research. North Atlantic right whales are on the brink of extinction, with only 300 left despite being protected from whaling since 1935. The biggest risk to them now is collisions with ships. "Even if one individual is killed – it can be significant," says Douglas Nowacek who led the study at the Woods Hole Oceanographic Institution in Massachusetts. Understanding how whales respond to the sounds of ships is also important because many other whale species die in collisions. © Copyright Reed Business Information Ltd.

Hardly bird brained, the diminutive black-capped chickadee sings one of the animal kingdom’s most intricate alarm calls, a new study reveals. These palm-sized puff balls increase the number of syllables in their battle cry depending on the deadliness of a sitting predator, says a team of US researchers. “We really were surprised at just how sophisticated the alarm call system is and how sophisticated the judgment of predation risk was,” says lead author Christopher Templeton at the University of Washington in Seattle, US. Templeton and his colleagues tested the alarm call responses of a flock of six chickadees against the presence of 13 birds of prey predators, which ranged in size from the 40-centimetre wingspan pygmy owl to the 140-centimetre wingspan rough-tail hawk. They also tested responses against two mammals, a cat and a weasel. Each predator was inserted into the chickadees aviary and tethered to a perch. After analysing 5000 recorded alarm calls, the team found that the number of “dees” in the bird’s trademark “chickadee-dee-dee-dee” call corresponded to the size of the poised predator. Smaller hunters – which pose the greatest risk - received the most vociferous response. The alert causes the flock to mob their sitting foe in an attempt to drive it away. © Copyright Reed Business Information Ltd.

Researchers have developed a new tool to help them study endangered whales – autonomous hydrophones that can be deployed in the ocean to record the unique clicks, pulses and calls of different whale species. Those efforts are leading to some surprising findings, including the discovery by a team of researchers of rare right whales swimming in the Gulf of Alaska. "There has been only one confirmed sighting of a right whale in the Gulf of Alaska since 1980, so discovering them is not only surprising, it is fairly significant," said David K. Mellinger, an assistant professor at Oregon State University's Hatfield Marine Science Center in Newport. "We picked up the sounds of one whale off Kodiak Island, and several others in deep water, which is also something of a surprise, since most right whale sightings have been near-shore." Results of these and five years of studies have been published in the January 2006 issue of the journal BioScience. Mellinger said scientists have been able to use the hydrophones to distinguish sounds made by different whale species. And some species, he added, have different "dialects" depending on where they are from. Blue whales off the Pacific Northwest sound different than populations of blue whales that live in the western Pacific Ocean, and those sound different from populations of blue whales off Antarctica. And they all sound different than the blue whales off Chile.

In a new study from The American Naturalist, researchers from the University of Zurich studied vocal communication between fallow deer mothers and their offspring. They found that only adult females have individually distinctive calls, meaning that fawns are able to distinguish their mother's calls from those of other females, but mothers are not able to distinguish between the calls of their own offspring and other fawns. This is in contrast to previous studies and provides a novel insight into parent-offspring recognition mechanisms. "Newborn fawns lie concealed and silent in vegetation away from their mothers to avoid detection by predators, and mothers return intermittently to feed them," write Marco Torriani, Elisabetta Vannoni, and Alan McElligott. "Vocal communication is very important for ungulate hider species because mothers and offspring rely on contact calls for reunions to occur." The researchers tested vocal recognition on Swiss fallow deer farms using recordings and playback experiments. Similar research on domestic sheep and reindeer has shown that both mothers and offspring are able to recognize each other based on individually distinctive contact calls. However, reindeer and sheep tend to populate open habitats lacking cover, and the researchers argue that the recognition system employed by deer evolved in habitats providing abundant cover for newborns. While sheep and reindeer are mobile soon after birth – and thus remain in constant close contact with the mother – mother-offspring contact for deer is limited during the first few weeks of life to when nursing occurs.

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