Mate Selection: Honesty In Advertising Pays Off

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ScienceDaily (June 19, 2009) — Throughout the animal kingdom brilliant colors or elaborate behavioral displays serve as "advertisements" for attracting mates. But, what do the ads promise, and is there truth in advertizing? Researchers at Yale theorize that when males must provide care for the survival of their offspring, the males' signals will consistently be honest — and they may devote more of their energy to caring for their offspring than to being attractive.

The idea that males showcase their best qualities to attract females for mating isn't a new one, nor is the idea that they might be deceptive in what they are promoting. Instead, the new findings better predict the requirement for honesty in advertising as a function of the male's suitability for parenting, according to Natasha Kelly, a graduate student in ecology and evolutionary biology at Yale and lead author of the study.
The peacock's ornate fanned tail — or the primping and posturing of a guy in a bar — are "advertisements" or mating displays that take substantial energy to maintain. When a male's energy is heavily focused on keeping up his appearance, he may have little energy to devote to caring for offspring. But that may be okay, say the researchers — in species where he does not really need to tend to the kids.
Previous research suggested that, under certain circumstances, males could be dishonest about their parenting skills and still have high reproductive success. This new model, now appearing in the online version of the Proceedings of the Royal Society B, examines the reliability of males' mating signals when they must care for offspring — an aspect that was missing in earlier studies.
There are many species in which males could, but do not have to, provide parental care — because females will pick up the slack. The Yale researchers focused on those species, like stickleback fish, where females cannot pick up the slack and males who do not provide care risk the survival of their offspring.
"This new work shows that when males can not escape the cost of failing to provide care, their advertisements will tend to tend to reliably indicate how much care they will provide," said senior author Suzanne Alonzo, assistant professor of ecology and evolutionary biology at Yale.
"The qualifier in this case is where males are obligated to provide care," said Kelly. "In that case, the quiet guy in the corner might be giving the more reliable advertisement for fatherhood."
The National Science Foundation and Yale University funded this research.
Journal reference:
Kelly et al. Will male advertisement be a reliable indicator of paternal care, if offspring survival depends on male care? Proceedings of The Royal Society B Biological Sciences, 2009; DOI: 10.1098/rspb.2009.0599
Adapted from materials provided by Yale University, via EurekAlert!, a service of AAAS.

Hunters Are Depleting Lion And Cougar Populations, Study Finds

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ScienceDaily (June 18, 2009) — Sport hunters are depleting lion and cougar populations as managers respond to demands to control predators that threaten livestock and humans, according to a study published in the June 17 issue of PLoS One. The study was led by Craig Packer, a University of Minnesota professor and authority on lion behavior, who worked with an international team of conservationists.

The study looked at numbers of lions and cougars killed by hunters over the past 15 to 25 years in Africa and the western United States. The analysis suggested that management agencies often adjusted quotas to control rather than conserve the big cats in areas where humans or livestock were threatened.
Sport hunting takes a significant toll on these large feline species because replacement males routinely kill their predecessors' cubs to improve their mating opportunities. (Killing cubs forces female lions into estrus or "heat.") The team of scientists confirmed this effect by comparing the impact of hunting on populations of lions, cougars and leopards with its impact on black bear populations because male black bears do not routinely kill infants of other males.
Lion and cougar populations have suffered the greatest decline in African countries and U.S. states where sport hunting has been most intense over the past 25 years, the researchers found. Leopards were not as affected as lions and cougars, most likely because they benefited from reduced numbers of lions. Black bears, by contrast, appear to be thriving despite the thousands of bears killed by hunters.
The study results point to the need for new approaches to protect humans and livestock and to manage sport hunting without endangering these vulnerable species. One possibility would be to restrict sport hunting to older males whose offspring have matured.
"We need to develop scientifically-based strategies that benefit hunters, livestock owners and conservationists," Packer says. "It's important to educate the public about the risks these large predators pose to rural communities and to help hunters and wildlife managers develop methods to sustain healthy populations."
"Packer's colleagues included co-authors Luke Hunter, Executive Director of Panthera and Kristin Nowell from the International Union for the Conservation of Nature Species Survival Commission (IUCN/SSC) Cat Specialist Group, as well as Dave Garshelis, Chair of the IUCN/SSC Bear Specialist Group."
Journal reference:
Packer C, Kosmala M, Cooley HS, Brink H, Pintea L, et al. Sport Hunting, Predator Control and Conservation of Large Carnivores. PLoS ONE, 4(6): e5941 DOI: 10.1371/journal.pone.0005941
Adapted from materials provided by University of Minnesota, via EurekAlert!, a service of AAAS.

Biologist Discovers Pink-winged Moth In Chiracahua Mountains

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ScienceDaily (June 12, 2009) — University of Arizona biologist Bruce Walsh has identified a new species of moth in southern Arizona. Normally, this is not a big deal. The region is one of the most biologically rich areas in the country and collectors have been finding hundreds of new species for decades. This one, however, is different.

Walsh is a professor of ecology and evolutionary biology and a member of the UA's BIO5 Institute. He is best known in the science community as an authority on plant and animal breeding, having written one of the leading textbooks on the subject.
His work also spans several departments and programs, including statistics, applied math, insect science and genetics. He also teaching biostatistics in the UA Zuckerman College of Public Health and has worked with trial attorneys on interpreting DNA evidence. Collecting moths is a hobby.
His new discovery is Lithophane leeae. Walsh found it in the Chiracahua mountains east of Tucson, and reported it in the journal Zoo Keys.
Lithophane moths are members of the noctuid family, which often are dull colored. Walsh's moth, in contrast, is bright pink. He also named it after his wife, Lee, who has an affinity for the color.
Walsh discovered L. leeae while collecting one evening at Onion Saddle, at about 7,700 feet in the Chiracahuas. Collecting involves illuminating a sheet with mercury vapor lamps. Moths are attracted by the lights and will land on the sheet.
"This large moth flew in and we didn't think much of it because there is a silk moth very much like it, a Doris silk moth that feeds on pines that has dark wings with pink on the hind wings. It's fairly common there."
On closer inspection, though, the moth, a female, appeared to be an entirely different species from an entirely different family. Walsh said it currently is the only known individual.
Scientists are generally reluctant to identify a new species based on one individual, but L. leeae appears so distinct from others that Walsh said it is highly unlikely that it is an aberration of an existing species. A DNA barcode later confirmed it as a distinct species.
Walsh said he is confident there are bound to be more. "If this thing is flying at the top of the Chiracahuas, it's probably pretty common," he said.
Finding it is another matter because moths like Lithophane tend to over-winter at higher elevations, hibernating when there is snow on the ground and flying off at the first signs of spring. Walsh said bats are the primary predators of moths, and so if the insects can make it through the winter, when bats hibernate, they will likely do well as the weather gets warmer.
As to why L. leeae hasn't been found before, Walsh theorized that his specimen simply emerged late from hibernation when it was caught. Another theory is that it could be a stray from another mountain range in the region. He said there are a number of species that fly early in the summer and are rare in collections and not often seen in most years.
"We can now add L. leeae to this group of large, but quite elusive, species," he said.
Adapted from materials provided by University of Arizona.

Close Social Ties Make Baboons Better Mothers, Study Finds

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ScienceDaily (June 11, 2009) — Baboons whose mothers have strong relationships with other females are much more likely to survive to adulthood than baboons reared by less social mothers, according to a new study by researchers at UCLA, the University of Pennsylvania and other institutions.

"If you're a baboon, the strength of your mother's relationship with other females is the best predictor of whether you'll live to have children yourself," said Joan Silk, the study's lead author and a UCLA professor of anthropology. "The study adds to mounting evidence of the biological benefits of close relationships among females."
The findings are significant because "survivorship to reproduction is the gold standard in evolutionary biology," said co-author Dorothy Cheney, a professor of biology at the University of Pennsylvania. "Females who raise offspring to a reproductive age are more likely see their genes pass along, so these findings demonstrate an evolutionary advantage to strong relationships with other females. In evolutionary terms, social moms are the fittest moms — at least when it comes to baboons."
The study appears online in the Proceedings of the Royal Society B, a peer-reviewed journal published by the national academy of science of the United Kingdom and the Commonwealth.
Silk, Cheney and seven other researchers from the University of Pennsylvania, the University of Michigan and the University of St. Andrews in Kenya analyzed 17 years worth of records on more than 66 adult female baboons in the Moremi Game Reserve, a 2,000-square-mile national park in Botswana that teems with wildlife.
Collected on the ground by primatologists who tracked the baboons six days a week, 12 months a year, the records reflected the sex and survival rates of baboon offspring, as well as telling details of the mothers' social lives, including their ranking within the group, as measured by the direction of approach/retreat interactions, and the amount of social interactions they had with each of the group's other females.
In addition to showing how often one animal approached another, the records of social interactions included details of grooming, which is known to be the primary form of social interaction in Old World monkeys. The researchers noted how much time — frequency and duration — the females spent grooming each other and how often they solicited grooming from other females.
Of all the factors studied, the strength of a mother's social bonds with another female had the most significant effect on the survival rates of offspring. A mother's dominance rank proved to have no affect on the survival rate of her offspring.
"We really expected dominance status to be more influential than it proved to be," Silk said.
Offspring from the most social mothers turned out to be about one-and-a-half times more likely to survive to adulthood than offspring from the least social mothers.
The strongest social bonds were measured between mothers and adult daughters, followed by sisters and all other potential relationships, including aunts, nieces, cousins and baboons with no familial ties. Bonds between mothers and adult daughters proved to be three times stronger than those between sisters and 10 times stronger than relationships with other females.
"What really matter to these girls are mother-daughter bonds," Silk said. "They're really strong, and they last forever. If your mom is alive, she's one of your top partners, always. But more importantly, it's the strength of these bonds, because females whose bonds with their mothers and daughters were strong had higher offspring survival than females whose bonds with these relatives were weak."
Silk's past research with Jeanne Altmann, the Eugene Higgins Professor of Ecology and Evolutionary Biology at Princeton University, and Susan C. Alberts, a professor of biology at Duke University, on baboons in the Amboseli Basin of Kenya had found a higher survival rate for baboons with social mothers, but the research only tracked offspring through the first year of life.
For the new study, researchers followed offspring from 1 year of age through sexual maturity — roughly 5 years of age. The new study also differs from past baboon research by focusing on the strength and duration of relationships between pairs of females rather than on the amount of social interactions in general.
"The benefit comes not from being wildly social — it's about having close social bonds," said Cheney, who runs the Moremi baboon-tracking project with University of Pennsylvania psychology professor Robert M. Seyfarth.
"These females form strong relationships with particular partners," Silk said. "They don't treat everyone the same. They spend a lot more time with — and a lot more time grooming — some females than others, and these relationships tend to be very long-lasting."
Additional research is needed to determine how the female bonds improve infant survival, but it may have to do with such stress hormones as cortisol, Silk said. Research has shown that prolonged elevations of stress hormones in primates can lead to cardiovascular disease and other serious health problems. Research has also shown that grooming tends to lower these stress hormones in baboons.
"Our research suggests that somehow there is a link between the kind of social relationships you form and the natural, normal stresses that occur in everyday life, and that seems to have — at least in baboons — a long-term effect on reproductive success," Silk said.
Said to share 92 percent of their DNA with humans, baboons are close relatives of humans. Baboons and humans last shared a common ancestor about 18 million years ago. The new findings on social interactions among mothers parallel recent research that has shown health benefits for humans who enjoy particularly close social networks.
"Our findings suggest benefits from forming close relationships are built into us from a long way back," Silk said.
The research received funding from the National Geographic Foundation, the Research Foundation of the University of Pennsylvania, the Institute for Research in Cognitive Science at the University of Pennsylvania, the National Institute of Health and the National Science Foundation.
Adapted from materials provided by University of California - Los Angeles.

Female Water Striders Expose Their Genitalia Only After Males 'Sing'

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ScienceDaily (June 11, 2009) — Chang Seok Han and Piotr Jablonski at Seoul National University, Korea have found that by evolving a morphological shield to protect their genitalia from males' forceful copulatory attempts, females of an Asian species of water strider seem to "win" the evolutionary arms race between the sexes. Instead, females only expose their genitalia for copulation after males produce a courtship "song" by tapping the water surface.

150 years after the publication of Charles Darwin's On the Origin of Species, Han and Jablonski used common insects, water striders, to study the intricacies of evolutionary conflict between males and females. The mechanisms for the way Darwinian natural selection, acting separately on males and females, result in different traits in males than in females (for example, different body sizes to guarantee the highest number of offspring during an individual's lifetime) are already quite well understood.
Sometimes, however, a behavioral trait, such as mating frequency, depends on both the male and the female characteristics. Natural selection favors higher mating frequency in males than in females in many animals, including humans. This leads to an evolutionary "arms race" where males evolve adaptations that force females to mate, while females evolve defenses against males' attempts.
As in the arms races between countries and political powers, it is rare for one sex to "win" in this evolutionary race.
However, in the study by Han and Jablonski, carried out at the Laboratory of Behavioral Ecology and Evolution at Seoul National University, females of an Asian species of water striders, Gerris gracilicornis, do seem to win this race as they have evolved a morphological shield behind which their genitalia are hidden from males, protecting them against the males' forceful attempts to mate.
In an apparent response to the female adaptation, after the violent mounting onto the female's back (typical in water striders), males of this species produce courtship signals by tapping the water surface with their middle legs. It is only after receiving the male's "song" that females expose their genitalia for copulation
Journal reference:
Han et al. Female Genitalia Concealment Promotes Intimate Male Courtship in a Water Strider. PLoS ONE, 2009; 4 (6): e5793 DOI: 10.1371/journal.pone.0005793
Adapted from materials provided by Public Library of Science, via EurekAlert!, a service of AAAS.

Basking Sharks: Disappearing Act Of World's Second Largest Fish Explained

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ScienceDaily (May 14, 2009) — Researchers have discovered where basking sharks – the world's second largest fish – hide out for half of every year, according to a report published online on May 7th in Current Biology. The discovery revises scientists' understanding of the iconic species and highlights just how little we still know about even the largest of marine animals, the researchers said.

"While commonly sighted in surface waters during summer and autumn months, the disappearance of basking sharks during winter has been a great source of debate ever since an article in 1954 suggested that they hibernate on the ocean floor during this time," said Gregory Skomal of Massachusetts Marine Fisheries. "Some 50 years later, we have helped to solve the mystery while completely re-defining the known distribution of this species."
Using new satellite-based tagging technology and a novel geolocation technique, the researchers found that basking sharks make ocean-scale migrations through tropical waters of the Atlantic Ocean during the winter, traveling at depths of 200 to 1,000 meters. Their data show that the sharks sometimes stay at those depths for weeks or even months at a time. "In doing so, they have completely avoided detection by humans for millennia," Skomal said, emphasizing that as one of the very largest of marine animals, the sharks grow to over 10 meters and weigh as much as seven metric tons.
Skomal said they were "absolutely surprised" when they first received a signal from the tagged sharks coming from the tropical waters of the western Atlantic, in the vicinity of the Caribbean and Bahamas. After all, basking sharks were always believed to be cool-water sharks, restricted to temperate regions.
Several factors had made basking sharks a challenge to study. On top of the fact that they disappear for long periods of time, they also feed exclusively on plankton. That means they can't readily be captured with traditional rod-and-reel methods. And even when the sharks are found closer to the ocean surface, they spend their time in the cool-temperature, plankton-rich waters that limit underwater visibility and make diving difficult.
The findings could have important implications for the conservation of basking sharks, which have shown some signs of dramatic decline in the last half century and are listed as threatened by the International Union for Conservation of Nature.
"Coupled with recent genetic data, our finding indicates that the Atlantic population – and perhaps the world population – are connected and may constitute a single population," Skomal said. "Hence, the global population of basking sharks may be even smaller than previously thought." Efforts to boost basking sharks' numbers will therefore need to be coordinated at a global scale.
The authors include Gregory B. Skomal, Massachusetts Division of Marine Fisheries, Oak Bluffs, MA; Stephen I. Zeeman, University of New England, Biddeford, ME; John H. Chisholm, Massachusetts Division of Marine Fisheries, New Bedford, MA; Erin L. Summers, Maine Department of Marine Resources, Boothbay Harbor, ME; Harvey J. Walsh, Woods Hole Oceanographic Institution, Woods Hole, MA; Kelton W. McMahon, Woods Hole Oceanographic Institution, Woods Hole, MA; and Simon R. Thorrold, Woods Hole Oceanographic Institution, Woods Hole, MA.
Journal reference:
Gregory B. Skomal, Stephen I. Zeeman, John H. Chisholm, Erin L. Summers, Harvey J. Walsh, Kelton W. McMahon, and Simon R. Thorrold. Transequatorial Migrations by Basking Sharks in the Western Atlantic Ocean. Current Biology, 2009; DOI: 10.1016/j.cub.2009.04.019
Adapted from materials provided by Cell Press, via EurekAlert!, a service of AAAS.

US-Russia Polar Bear Treaty Ratified

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http://www.sciencedaily.com/releases/2007/10/071014202952.htm

Science Daily — The US and Russia have ratified a bilateral agreement for the long-term conservation of shared polar bear populations in Alaska, the US and Chukotka, Russia.

The treaty unifies US and Russian management programmes that affect this shared population of bears. Notably, the treaty calls for the active involvement of native people and their organizations in future management programmes. It will also enhance such long-term joint efforts as conservation of ecosystems and important habitats, harvest allocations based on sustainability, collection of biological information, and increased consultation and cooperation with state, local, and private interests.
"WWF is pleased that this treaty will finally go into effect and formalize the increasing cooperation between US and Russian management agencies, scientists, and native communities in an effort to conserve our shared population of polar bears," said Margaret Williams, director of the WWF Bering Sea-Kamchatka Ecoregion Programme.
“With the rapid decline of arctic sea ice, now more than ever, we need to work together to ensure that polar bears have a chance to survive difficult times ahead."
Polar bears typically occur at low densities over vast areas of the Arctic. Current estimates of the world's 19 separate populations range from 20,000 to 25,000 bears. Two populations of the bears occur in Alaska: the southern Beaufort Sea population (about 1,500 animals), shared with Canada; and the Alaska-Chukotka (Chukchi Sea) population (approximately 2,000 bears), which is shared with Russia.
"While we are very pleased the treaty is coming into effect and support its goals, we urge the US government to take more courageous and bold actions to address the factor now widely recognised as the source of global climate change and resulting warming in the polar bears' arctic habitat: CO2 emissions," Williams added.
The treaty fulfills the spirit and intent of the 1973 multilateral Agreement on the Conservation of Polar Bears among the United States, Russia, Norway, Denmark (for Greenland) and Canada by allowing a sustainable harvest by Alaska and Chukotka natives, but prohibiting the harvest of females with cubs or of cubs less than one year old. It also prohibits the use of aircraft and large motorized vehicles in the taking of polar bears and enhances the conservation of specific habitats such as feeding, congregating, and denning areas.
Note: This story has been adapted from material provided by World Wildlife Fund.

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Sea Otter, Peregrine Falcon Back From The Brink Of Extinction But Other Species At Risk In Canada

Source:

http://www.sciencedaily.com/releases/2007/09/070928210151.htm

Science Daily — There’s good news and bad news in the report the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) just dropped on the Minister of the Environment’s desk.

The good news: The peregrine falcon and the sea otter no longer face extinction.
The not-so-good news: COSEWIC proposes adding another 36 species to Canada’s official List of Wildlife Species at Risk. Species from all regions of the country, on the land and in the sea, are at risk of extinction.
“Our job is to assess species based on the best available scientific, community and aboriginal traditional knowledge available,” says Jeffrey Hutchings. The Dalhousie biology professor has served as the chair of the committee for more than a year. “What we don’t take into account are the political or socio-economic consequences of our assessments.”
COSEWIC is a national scientific advisory body that assesses the status of wild species, subspecies, varieties, or other important units of biological diversity, that are considered to be at risk in Canada. As an arm’s length body, COSEWIC reports annually to the Minister of the Environment, who can accept the body’s recommendations, reject them or send species back to COSEWIC for further evaluation.
The peregrine falcon was almost wiped out in the 1950s and ‘60s because of pesticide contamination that thinned their eggshells. But since the 1970s, particularly after DDT was banned in Canada, this impressive bird of prey has made a strong recovery.
The resurgence of the sea otter — its rich brown pelt was once prized the world over — is even more dramatic. Extirpated on Canada’s west coast because of the fur trade more than a century ago, sea otters from California were reintroduced to British Columbia in the early 1970s. They’ve since repopulated a third of their historic range along the province’s coastline, and although numbers are still small, the population is healthy and expanding.
"It’s very satisfying to witness the successful recovery of species that were on the edge of extinction. It highlights the importance of endangered species legislation and associated recovery programs in protecting and recovering Canada’s wildlife," says Dr. Hutchings.
If only that legislation could help species like the basking shark, a plankton-feeding fish that grows to the size of a bus; the Eastern pond mussel, decimated by the introduction of the zebra mussel into the Great Lakes; and the Eastern flowering dogwood, one of Canada’s showiest trees which is being destroyed by an invasive species of fungus.
“Habitat loss and disturbance are the biggest threats facing species. This could be the result of factors as diverse as forestry, housing development, or changes to the natural flow of rivers,” says Dr. Hutchings. “Another major threat is the invasion of exotics that can have devastating effects on Canada’s native species.”
“Habitat loss and disturbance are the biggest threats facing species. This could be the result of factors as diverse as forestry, housing development, or changes to the natural flow of rivers,” says Dr. Hutchings. “Another major threat is the invasion of exotics that can have devastating effects on Canada’s native species.”
The legal list has expanded to include 389 species, which are categorized as extirpated, endangered, threatened or special concern.
Note: This story has been adapted from material provided by Dalhousie University.

Fausto Intilla

www.oloscience.com