Over the last ten years in Australia, scientists have unearthed an average of at least two new species a week, WWF said in a recent report.

"The extent of Australia's rich biodiversity is astounding, to the point where science is regularly being used to describe new species," Michael Roache of WWF-Australia said.

Photograph courtesy Ross Knowles, WWF-Australia

Tragically, many of the newfound species may already be heading for extinction. At least 1,300 species are thought to be endangered, according to the report released by WWF to mark Australia's National Threatened Species Day on September 7.

Take the the carbine barred frog (pictured above), for example. It lives only in cool, high-elevation rain forests of the Carbine Tablelands, a region in northern Australia that is vulnerable to the effects of global warming, conservationists say.

"The frog--among 13 new amphibians found in the country in the past decade--may lose its habitat by 2050, due to an intense temperature rise," National Geographic News reported yesterday.

Read more about the the 1,300 new plant and animal species found in Australia since 1999, and see a small gallery of pictures:

NEW SPECIES PICTURES: "Fast Talking" Frog, Snubfin Dolphin Found >>

Same-sex behavior is a nearly universal phenomenon in the animal kingdom, common across species, from worms to frogs to birds, according to a review of existing research, funded by the University of California, Riverside.

"It's clear that same-sex sexual behavior extends far beyond the well-known examples that dominate both the scientific and popular literature: for example, bonobos, dolphins, penguins and fruit flies," said Nathan Bailey, the first author of the review paper and a postdoctoral researcher in the Department of Biology at UC Riverside.

A female-female pair of Laysan albatross. Females cooperatively build nests and rear young when males are scarce, according to biologists at the University of California, Riverside.

Photo by Eric VanderWerf

However, the review paper points out, "same-sex behaviors are not the same across species," and that researchers may be calling qualitatively different phenomena by the same name.

"For example, male fruit flies may court other males because they are lacking a gene that enables them to discriminate between the sexes," Bailey said. "But that is very different from male bottlenose dolphins, who engage in same-sex interactions to facilitate group bonding, or female Laysan Albatross that can remain pair-bonded for life and cooperatively rear young."

An example of existing research was a study by Sara Lewis, an evolutionary ecologist at Tufts University, published in the Journal of Evolutionary Biology in November, 2008. Read the National Geographic News report about it: Homosexual Beetle Activity Offers Reproductive Edge. The picture above shows two beetles in a homosexual encounter.

Photo courtesy Sara Lewis, Tufts University

Published June 16 in the journal Trends in Ecology & Evolution, the review of existing research by Bailey and Marlene Zuk, a professor of biology at UCR, also finds that although many studies are performed in the context of understanding the evolutionary origins of same-sex sexual behavior, almost none have considered its evolutionary consequences.

    "Same-sex behaviors--courtship, mounting or parenting--are traits that may have been shaped by natural selection."

"Same-sex behaviors--courtship, mounting or parenting--are traits that may have been shaped by natural selection, a basic mechanism of evolution that occurs over successive generations," Bailey said. "But our review of studies also suggests that these same-sex behaviors might act as selective forces in and of themselves."

A selective force, which is a sudden or gradual stress placed on a population, affects the reproductive success of individuals in the population, a UCR news release about the research explained.

"When we think of selective forces, we tend to think of things like weather, temperature, or geographic features, but we can think of the social circumstances in a population of animals as a selective force, too," Bailey said. "Same-sex behavior radically changes those social circumstances, for example, by removing some individuals from the pool of animals available for mating."

Bailey, who works in Zuk's lab, noted that researchers in the field have made significant strides in the past two and a half decades studying the genetic and neural mechanisms that produce same-sex behaviors in individuals, and the ultimate reasons for their existence in populations.

Evolutionary Consequences

"But like any other behavior that doesn't lead directly to reproduction--such as aggression or altruism--same-sex behavior can have evolutionary consequences that are just now beginning to be considered," he said. "For example, male-male copulations in locusts can be costly for the mounted male, and this cost may in turn increase selection pressure for males' tendency to release a chemical called panacetylnitrile, which dissuades other males from mounting them."

According to UCR, the review paper:

• Examines work done to test hypotheses about the origins of same-sex behavior in animals.
• Provides a framework for categorizing same-sex behavior, for example, is it adaptive, not adaptive, occurs often, infrequently?
• Discusses what has been discovered about the genetics of same-sex behavior, especially in the model organism, the fruit fly Drosophila, and in human beings.
• Examines connections between human sexual orientation research, and research on non-human animals, and highlights promising avenues of research in non-human systems.

The reviewers expected the research papers they read for their article would give them a better understanding of the degree to which same-sex behaviors are heritable in animals, UCR said.

Genes vs. Environment

"How important are genes to the expression of these behaviors, compared to environmental factors?" Bailey said. "This is still unknown.

"Knowing this information would help us better understand how the behaviors evolve, and how they affect the evolution of other traits. It could also help us understand whether they are something that all individuals of a species are capable of, but only some actually express."

Bailey recommends that fellow evolutionary biologists studying same-sex behavior in animals adopt some of the research approaches that have been successful in human studies, UCR said.

"We have estimates, for example, of the heritability of sexual orientation in humans, but none that I know of in other animals," he said. "Scientists have also targeted locations on the human genome that may contribute to sexual orientation, but aside from the fruit fly, we have no such detailed knowledge of the genetic architecture of same-sex behavior in other animals."

Bailey and Zuk plan to begin experimentally addressing some of the many issues raised in their review.

Said Bailey, "We want to get at this question: what are the evolutionary consequences of these behaviors? Are they important in the evolution of mating behavior, or do they just add extra 'background noise'?

"We are pursuing work on the Laysan albatross, in which females form same-sex pairs and rear young together. Same-sex behavior in this species may not be aberrant, but instead can arise as an alternative reproductive strategy."

Related National Geographic News stories:

Homosexual Activity Among Animals Stirs Debate

Damselfly Mating Game Turns Some Males Gay

Rattlesnakes Show Strong Family Bonds, Study Says

Homosexual Beetle Activity Offers Reproductive Edge

This is the official tally board of the Indiana Dunes National Lakeshore BioBlitz when the species count ended after 24 hours, at noon on Saturday, May 16. Species totals were expected to continue to come in throughout the weekend and coming weeks, raising the numbers seen here significantly.

Photo by David Braun

Biologists have discovered that amphibian diseases are spread by bait shops.

National Science Foundation illustration by Nicolle Rager-Fuller

Salamander larvae sold as live bait for freshwater fishing may be spreading amphibian diseases, including the chytrid fungus that is killing many of the world's frogs, the National Science Foundation says.

Waterdogs, as the larvae of tiger salamanders are called, are used to catch largemouth bass, channel catfish and other freshwater fishes.

Fishers may be in for more than they bargained for, the NSF said in a statement released yesterday. "Salamanders in bait shops in Arizona, Colorado and New Mexico are infected with ranaviruses, and those in Arizona, with a chytrid fungus called Batrachochytrium dendrobatidis (Bd)."

These diseases have spread with the global trade in amphibians, says James Collins, assistant director for biological sciences at the NSF. Collins is currently on leave from Arizona State University. "The commercial amphibian bait trade may be a source of 'pathogen pollution,'" he says in the NSF news release. Pathogens are disease-causing agents such as some viruses and bacteria.

The scientists also organized bait-shop surveys to determine whether tiger salamanders are released back into the wild after being housed in shops, the NSF says.

A majority of anglers--as high as 73 percent--in Arizona, Colorado, and New Mexico uses waterdogs as bait.

Photo by Angela Picco, ASU

"We found that all tiger salamanders that ended up in the bait trade were originally collected from the wild," says Picco. "In general, they were moved from east to west and north to south--bringing with them multiple ranavirus strains."

Results of the research show that 26 to 73 percent of fishers used tiger salamanders as bait; 26 to 67 percent of anglers released tiger salamanders bought as bait into fishing waters; and 4 percent of bait shops put salamanders back in the wild after the waterdogs were housed with infected animals.

"The tiger salamander bait trade in the western U.S. is a good model for understanding the consequences of unregulated movement of amphibians and their pathogens," says Collins.

Examples of pathogen pollution are many and dramatic, the NSF statement says.

Photo by Julie Larsen Maher © WCS

"You say tomato, I say tomaaato, let's fall in love!" Tomato frogs are a favorite among visitors to New York's Bronx Zoo as they venture through the new permanent Madagascar! exhibit. The frogs enjoy a diet of ants and in nature are terrestrial and often make their home in waterlogged ditches, the Wildlife Conservation Society said.

Photo by Julie Larsen Maher © WCS

Bronx Zoo's lions, male M'wasi and female Sukari, have recently been introduced on the Zoo's Africa Plains exhibit. A typical lion greeting last less than a minute, and includes touching heads, WCS said.

"Outside of Africa's largest national parks, lions are disappearing rapidly. They are losing habitat to human encroachment. Field scientists Luke Hunter and Laurence Frank of the Wildlife Conservation Society, headquartered at the Bronx Zoo, are working to maintain African predators in unprotected areas, by helping people and livestock to live with lions," WCS said.

Photo by Julie Larsen Maher © WCS

Wildlife Conservation Society's New York Aquarium's twenty-month-old baby Pacific walrus, Akituusaq, shows his love to Keeper Paul Moylett for Valentine's Day. "The winter months are the best time to visit the Aquarium when the walruses enjoy the cold weather," WCS said.

Photo by Julie Larsen Maher © WCS

Residents of the Bronx Zoo Monkey House, these squirrel monkeys' native range includes Brazil, Bolivia, and Peru in South America.

Related NatGeo News Watch posts:

Love Looms Large at the Zoo

U.S. Zoos Feel Pain of Budget Cuts

Zoo News

Species of rain frog potentially new to science.

Conservation International-Colombia/Photo by Marco Rada

Ten amphibians believed to be new to science -- including a spiky-skinned, orange-legged rain frog, three poison frogs and three glass frogs -- have been found in Colombia's mountainous Tacarcuna area of the Darien, near the border with Panama, Conservation International announced yesterday.

The species were discovered during a recent Rapid Assessment Program (RAP) expedition in the area, the Washington, D.C.-based charity said in a news statement.

"This area of the Darien is isolated from the Andes Mountain range. It is recognized as a center of endemism and valuable for its high biological diversity," CI said. "Historically it has served as a bridge for flora and fauna exchange between North and South America."

Over a period of three weeks, the scientists identified some 60 species of amphibians, 20 reptiles and almost 120 species of birds, many of them apparently found no where else.

Photo by J. Holden FFI

A frog with green blood and turquoise bones has been discovered in Cambodia's remote Cardamom Mountains, international conservation organization Fauna & Flora International (FFI) announced today.

The Samkos bush frog (Chiromantis samkosensis) is thought to be extremely rare, the UK-based charity said in a news statement. "Its strange colored bones and blood are caused by the pigment biliverdin, a waste product usually processed in the liver.

"In this species, the biliverdin is passed back into the blood giving it a green color; a phenomenon also seen in some lizards. The green biliverdin is visible through the frog's thin, translucent skin, making it even better camouflaged and possibly even causing it to taste unpalatable to predators."

Photo by Brian Kubicki/Courtesy Conservation International

Adding to the urgency of the looming extinction crisis, conservationists today declared that 43 percent of amphibian species are declining, 32 percent are threatened with extinction, and as many as 122 species may have become extinct since 1980.

"This study confirms one of the greatest species conservation challenges of our time," said Simon Stuart, chairman of the International Union for Conservation of Nature (IUCN) Species Survival Commission (SSC) biodiversity assessment sub-committee. "In just the past 20 years, the number of known amphibians has increased by 48 percent. Tragically, we are losing them almost as fast as we find them."

Valerie Clark has a quick way to determine whether a frog is toxic or not. She licks them.

If it is not dangerous it is certainly nasty. "I don't recommend this," Clark told National Geographic News earlier this year. "If you lick the wrong frog it can be very bad." (Read the story.)

Clark studies frog chemical defenses. She earned her master's degree at Columbia University in New York City, and has received funding from National Geographic to do research on the ecology and evolution of chemical defense in the poison frogs of Madagascar.

Watch a video and read more about Valerie Clark's research in the extended entry.