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.

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 15: Language and Lateralization
Link ID: 4432 - Posted: 06.24.2010

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, Péter Pongrácz, 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. Pongrácz'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 Pongrácz: 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," Pongrácz says. Back to the bone © Copyright Reed Business Information Ltd

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 13851 - Posted: 06.24.2010

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

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 15: Language and Lateralization
Link ID: 13332 - Posted: 06.24.2010

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.

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 9361 - Posted: 06.24.2010

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’?”

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 15: Language and Lateralization; Chapter 8: Hormones and Sex
Link ID: 5508 - Posted: 06.24.2010

by Holly Hight OREGON, U.S.: The high-pitched, maniacal 'laugh' of the hyena is not used by all individuals equally, but mostly by subordinates as a sign of frustration. "The hyena's laugh is a multi-informative signal," said Nicholas Mathevon, a biologist at the University of Jean Monnet, in Saint-Etienne, France, who studied captive hyenas, recording their laughs and subjecting them to sophisticated acoustical studies. The hyena has up to 20 vocalisation types, but only two had previously been studied. One is a 'whoop', used as a long-distance call, while the other is a groan, used for communication over short ranges. Mathevon found that the laugh tends to occur when subordinate animals are attacked or chased away by dominant hyenas during feeding times and "is mainly emitted when [the animal] is frustrated," said Mathevon, who presented his results this week at the Acoustics Society of America's annual conference in Portland, Oregon. The spotted hyena (Crocuta crocuta), which is found widely across Africa, has a complex social structure – as complex as the social systems of primates such as baboons and macaques. It is a savage hierarchy; subordinates are frequently attacked and denied access to food and mates. ©2007 Luna Media Pty Ltd,

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 12887 - Posted: 06.24.2010

Matt Kaplan The splashes, barks and grunts of baleen whales carry much more meaning than biologists thought, according to the latest survey of the marine mammals. The scientists behind the study say that these noises could be the ideal characteristics for conservationists to monitor to understand the growing impact of noises made by humans on the underwater environment. The songs of baleen whales — which have characteristic mouth combs, which they use for filter feeding — have been studied extensively, as have the non-song communications of toothed whales. But non-song communication in baleen whales has received little attention. “Most people focus on the song,” says Rebecca Dunlop at the University of Queensland in Australia. “It is simply amazing how much we were missing by not paying attention to all of the other [sounds] that the animals actually make.” Although studies of humpback whales, Megaptera novaeangliae, in the 1980s had noted these sounds, Dunlop and her colleagues took things a step further by monitoring a population of humpbacks every year between 2002 and 2005 as they migrated from Australia’s Great Barrier Reef to the Antarctic. © 2008 Nature Publishing Group –

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 11859 - Posted: 06.24.2010

Debora MacKenzie Chameleons are famed for changing colour to blend in with their surroundings and hide from predators – but new research on chameleons in their native habitat shows some of their colour changes evolved for exactly the opposite purpose – attracting attention. African dwarf chameleons live in habitats in southern Africa ranging from grassland to rainforest. They engage in complex social signalling, with bright colour changes along their flanks used by females to signal interest or rejection to males, and by males to signal aggression or submission to other males, and interest towards females. Males even square off in rapid-fire, colourful signalling duels. "Chameleons use colour change for camouflage and communication, but we don't know why some species change colour much more than others", says Devi Stuart-Fox of the University of Melbourne in Australia. She and colleague Adnan Moussalli reasoned that if these differences evolved solely to enable the chameleon to match itself to its surroundings, chameleons living in backgrounds that vary a lot in colour should produce a wider palette, whereas chameleons in less colourful environments should not. © Copyright Reed Business Information Ltd.

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 11248 - Posted: 06.24.2010

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.

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 15: Language and Lateralization; Chapter 8: Hormones and Sex
Link ID: 9295 - Posted: 06.24.2010

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.

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 7544 - Posted: 06.24.2010

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

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Lateralization
Link ID: 4534 - Posted: 06.24.2010

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.

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 154 - Posted: 06.24.2010

by Virginia Morell East Africa’s elephants face few threats in their savanna home, aside from humans and lions. But the behemoths are terrified of African bees, and with good reason. An angry swarm can sting elephants around their eyes and inside their trunks and pierce the skin of young calves. Now, a new study shows that the pachyderms utter a distinctive rumble in response to the sound of bees, the first time an alarm call has been identified in elephants. “It’s an important finding,” says Karen McComb a behavioral ecologist at the University of Sussex in the United Kingdom. “It not only provides the first demonstration that elephants use alarm calls but also shows that these may have very specific meanings.” Indeed, the study suggests that this alarm call isn’t just a generalized vocalization but means specifically, “Bees!” says Lucy King, a postgraduate zoologist at the University of Oxford in the United Kingdom and the study’s lead author. Several other species, including primates and birds, make calls that warn others of danger. Because elephants also have an extensive repertoire of vocalizations, researchers have long suspected that certain calls have specific meanings. But it’s not easy for researchers to link the pachyderms’ calls—many of which are beyond the range of human hearing—to particular events. A few years ago, however, King and colleagues documented the fear elephants have of bees via a series of playback experiments: When they hear buzzing bees, the pachyderms turn and run away, shaking their heads while making a call that King terms the “bee rumble." © 2010 American Association for the Advancement of Science.

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 14017 - Posted: 06.24.2010

By Clara Moskowitz Some songbirds can contract their vocal muscles with the fastest muscle movements yet described — about 100 times faster than humans can blink an eye, according to new research. The study found that two types of songbirds produce their tunes with superfast muscles, similar to those used by rattlesnakes, several fish and the ringdove (a type of pigeon). "We discovered that the European starling (found throughout Eurasia and North America) and the zebra finch (found in Australia and Indonesia) control their songs with the fastest-contracting muscle type yet described," said Coen Elemans, who conducted the study as a postdoctoral researcher in biology at the University of Utah. © 2008 LiveScience.com.

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 15: Language and Lateralization; Chapter 5: The Sensorimotor System
Link ID: 11801 - Posted: 06.24.2010

By NATALIE ANGIER WOODS HOLE, Mass. — It is summertime, when people everywhere honor the 40 percent of body mass devoted to skeletal muscle tissue by doing what they avoid doing the other 75 percent of the year — putting those muscles to strenuous, possibly dangerous use. They hike, bike and run very long distances, or they take up a new hybrid water sport like kitesurfing, which sounds sweet in concept but often looks embarrassing in execution. They may even make an inexcusably heroic sprint through four lanes of high-speed traffic, as my husband did the other day when the bicycle rack on our car broke and he decided he had to retrieve my instantly totaled bike from the middle of the interstate because, he said, “somebody could get hurt.” Yes, dear, like you, or the woman hyperventilating hysterically on the side of the road. This is why I argue that, when it comes to a sensible display of excessive muscular activity, the male toadfish has the right idea. A male toadfish may not look the part of an animal Olympian. He spends his time sitting nearly motionless on the bottom of a marsh, his body like a smeared scoop of pudding and old coffee beans, his full, fleshy lips pulled downward in a perpetual Churchillian scowl. Yet it turns out that inside the belly of this gelatinous, seemingly languorous beast are some of the fastest muscles in the vertebrate world, and the most instructive. Copyright 2008 The New York Times Company

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 5: The Sensorimotor System
Link ID: 11789 - Posted: 06.24.2010

By HENRY FOUNTAIN Songbirds have long been studied for insight into how the brain learns motor tasks — in a bird’s case, singing its characteristic song. Juvenile birds babble in screechy random bursts before they eventually develop a tonally and rhythmically precise song. Researchers have long known that a pathway called the high vocal center, or H.V.C., controls adult song, but whether that same pathway is responsible for babbling and changes as the bird ages has been an open question. “The general view that I had and others in the field had is that vocalization at any age is a function of the H.V.C.,” said Michale S. Fee, an associate professor at the Massachusetts Institute of Technology who has studied bird song for about a decade. But Dr. Fee and two graduate students, Dmitriy Aronov and Aaron S. Andalman, have reached a different conclusion. In experiments on zebra finches, they showed that the H.V.C. had no bearing on babbling. Instead, they report in Science, the behavior is controlled by a different circuit, with the tongue-twisting name of lateral magnocellular nucleus of the nidopallium, or LMAN. Copyright 2008 The New York Times Company

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 11600 - Posted: 06.24.2010

By Noreen Parks It seems the harder scientists listen to animals, the more they end up eavesdropping on their conversations. Take butterflyfishes—flamboyantly colored, hand-sized denizens of coral reefs, known for their monogamy, gregariousness, and fierce territoriality. New research, reported Wednesday at the joint meeting of the Acoustical Society of America and Acoustical Society of Japan, shows that butterflyfishes make a variety of sounds to communicate among themselves. The fish may have evolved unique anatomy to enhance their use of sound, the researchers say. All fish have internal "ears," air-filled swim bladders sensitive to sound waves, and "lateral line" sense organs that detect motion in surrounding water. However, only in one genus of butterflyfishes are these body parts connected—a discovery made some years ago. Scientists have speculated that the unusual anatomical arrangement is involved in sound perception, but no one knew what role, if any, sound plays in butterflyfish lives. To find out, marine biologist Tim Tricas of the University of Hawaii, Manoa, and colleagues dove to a Hawaii reef and located several pairs of banded butterflyfish (Chaetodon multicinctus) observed maintaining feeding territories. In multiple experiments, the researchers placed one pair in a glass bottle and positioned the bottle inside another pair's territory for up to 40 minutes. The results, recorded by a video camera and underwater microphone, revealed territory defenders aggressively charging the intruders, while making rapid, sound-generating moves, such as flicking and erecting their fins, "jumping," and turning. In response, the bottled fish grunted repeatedly. Only paired fish grunted—not single individuals—so Tricas suspects grunts are distress signals to mates. © 2006 American Association for the Advancement of Science.

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 9682 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — Termites are known to send underground SOS signals to each other by banging their heads against tunnel walls, and now scientists have filmed them in the act. The high-speed video, which captured the frantic behavior at 10,000 frames per second, reveals that some termite species are faster head bangers than others. With each hit, the Formosan subterranean termite raises its head about 1 millimeter off the ground before slamming it into tunnel walls at a rate of about 100-200 millimeters per second. A termite native to New Orleans is even faster, with head bangs at around 400 millimeters per second. Their heads bounce and rebound off the walls like a rhythmic drum roll. The researchers suggest the rattling noise — audible sometimes even to people — could help locate infestations. "If a house is very infested with termites, you might be able to hear them head-banging (without special equipment), especially if you removed an infested board or crushed their galleries or part of their carton nest," said Tom Fink, who will present his findings on the head-banging behavior Saturday at the Acoustical Society of America Meeting in Honolulu, Hawaii. © 2006 Discovery Communications Inc.

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 9681 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — It may not be language as we know it, but whales have no shortage of ways to make themselves understood. So broad is their vocal repertoire, in fact, that whales can call to their young, woo potential mates and even express emotions, according to researchers who have identified 622 social sounds in humpback whales. Their work will be presented at the upcoming joint meetings of the Acoustical Society of America (ASA) and the Acoustical Society of Japan in Hawaii. Social sounds are brief, unpatterned sounds that are distinct from lengthier, complex whale songs. The new research adds to a growing body of evidence that whales convey more meaning through vocalizations than previously thought. "I wouldn't say (whales possess) language, as that's a human term," Rebecca Dunlop told Discovery News. Dunlop, who worked on the study, is a researcher in the School of Veterinary Sciences at the University of Queensland, Australia. "Whales don't string these sounds together like words and form sentences. It's more like a simple vocabulary," she said. The scientists visually tracked 60 pods of whales migrating along the east coast of Australia. The researchers used a static hydrophone array — sensitive equipment that detects sound waves — linking the whale sounds to various activities and contexts. © 2006 Discovery Communications Inc.

Related chapters from BN: Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 9635 - Posted: 06.24.2010

Susan Milius On his first trip into Namibia, Chris Faulkes woke up in his tent with a peculiar kink in his back. The ground beneath him had been flat enough when he went to sleep. Yet the next morning, "there was a whopping great lump," he says. A mound of dirt had arisen under Faulkes. He'd inadvertently found—or been found by—Damaraland mole rats, the very creatures he'd come to study. With one of the oddest social systems yet found in mammals, these sub-Saharan rodents spend their lives in networks of underground tunnels that they continually excavate. These mole rats and a better-known species called naked mole rats survive in land that goes months without rain. When rain finally comes, the animals go into a frenzy of digging to expand their tunnels before the ground bakes again. With the mole rats' extreme social system, individuals labor for the sake of the colony. Since the early 1980s, mole rats have been used as models of social organization. The wrinkled, hairless rodent known as the naked mole rat has achieved celebrity status even outside science. In Faulkes' office at Queen Mary College of the University of London stands a cardboard cutout of the Disney-cartoon character of the naked mole rat Rufus. Even the Wall Street Journal has run a page-one story on naked mole rat charms. The subhead read: "What Is Whiskered and Ugly and Has Little Squinty Eyes?—No, Not Your Former Spouse. . . ." Copyright ©2006 Science Service

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 9051 - Posted: 06.24.2010