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Archive for June, 2007

Feds announce plan to boost desert frog

Posted by Miqe on June 7, 2007

Chiricahua leopard species threatened by drought, growth

B. POOLE
Tucson Citizen

A frog species native to Pima County could be scratched from the federal threatened species list within about 30 years under a U.S. Fish & Wildlife Service plan announced Tuesday.

The Chiricahua leopard frog, whose habitat spans southwest New Mexico, southeast Arizona and northern Mexico, was listed in 2002 as threatened under the Endangered Species Act.

The 430-page recovery plan would rely on cooperation among governments, property owners and public land managers to help stave off the decline of the frogs, which are threatened by drought, disease and cattle ranching.

Noah Greenwald, the Center for Biological Diversity conservation biologist who wrote the petition to have the frog listed, called the plan a good start.

“I think this is one part of a larger plan that is needed to protect all of the species that rely on the rivers and streams of the Southwest,” Greenwald said.

The plan calls on ranchers and property owners to make sure the frogs can survive in backyard ponds and livestock tanks that have replaced natural habitat.

That helps, but the real issue is destruction of natural habitat that has led to declines among other species, as well, Greenwald said.

The Mexican garter snake, declining because it relies on the Chiricahua leopard frog for food, is an example, he said.

The plan calls for starting the delisting process after securing three populations of frogs in each of eight areas across Arizona and New Mexico by 2025-30.

Greenwald thinks such “museum populations” fall short of real recovery in an area where many species are at risk.

“We’re in the midst of an extinction crisis” in the Southwest, he said.

The plan calls for cooperation among U.S., tribal and Mexican governments to identify and restore habitat that has not been claimed by urbanization or other human impact.

The first five years of the recovery process are expected to cost $3.3 million, and costs beyond that would be determined later, the plan says.

Photos & images

The Chiricahua leopard frog is found in Arizona, New Mexico and Mexico.
          Additional information:
Scientific name: Rana chiricahuensis
Description: Adults range from 2 to 5 1/2 inches from nose to tail and have a distinctive pattern of raised, cream-colored spots on their thighs and greenish body color with darker spots.
Habitat: Traditionally the frogs are denizens of cienegas, ponds and streams between about 3,200-8,900 feet elevation. Their range stretches across southwest New Mexico and southeast Arizona into northeast Sonora and northwest Chihuahua in Mexico.
From Tucson Citizen

Posted in Amphibians, Herps in the news, International articles and news. | 1 Comment »

All Caribbean frog species evolved from one South American species

Posted by Miqe on June 7, 2007

Washington, June 7: Nearly all of the 162 land breeding frog species on the Caribbean islands owe their lineage to a single frog species that rafted on a sea voyage from South America about 30-50 million years ago, a new study by Penn State University researchers has revealed.The researchers write in the June 12 issue of the Proceedings of the National Academy of Sciences, that the Central American relatives of these Caribbean frogs also arose from a single species that arrived by raft from South America.

According to Blair Hedges, evolutionary biologist and professor of biology who directed the research, “this discovery is surprising as no previous theories of how the frogs arrived had predicted a single origin for Caribbean terrestrial frogs”.

“Groups of close relatives rarely dominate the fauna of an entire continent or major geographic region. Since land connections among continents allow land-dwelling animals to disperse freely over millions of years, hence the fauna of any one continent is usually a composite of many types of animals,” said Prof. Hedges.

Previously, the anatomy of Caribbean frogs had led to theories that species in Cuba and other western-Caribbean islands were related to different mainland species than were the species on Puerto Rico and other eastern-Caribbean islands.

One prominent theory had proposed that frog species on the large islands of Cuba, Jamaica, Hispaniola, and Puerto Rico had walked there across land bridges that existed when those islands were connected in a geologic arc about 70-to-80-million years ago.

A second major theory proposed that they arrived, instead, by rafting across the Caribbean Sea after the giant asteroid impact near Cuba 65-million years ago, which is widely believed to have exterminated the dinosaurs.

Prof. Hedges said while “both theories acknowledged that the frog faunas must have arrived by rafting over water to the smaller and younger islands, the Lesser Antilles, because they never were connected by land to South America, neither of them proposed that all of the Caribbean island frog species had a single common ancestor”.

As such, “discovering a single origin for all of these species from throughout the Caribbean islands was completely unexpected,” said Prof. Hedges.

Prof. Hedges and coauthor William Duellman, a professor emeritus of the University of Kansas, were involved in much of the fieldwork.

A third co-author of the study, Penn State graduate student Matthew Heinicke, performed DNA sequencing and analyses of nearly 300 species of Caribbean, Central American and South American frogs and used three mitochondrial genes and two nuclear genes to build trees of relationships among the species and timing the divergences of the species with molecular-clock methods.

The DNA research revealed that, while many ocean dispersals might have occurred over time, only two led to the current faunas: one for the Caribbean islands and another for Central America.

“The asteroid impact generated giant waves that devastated the islands, probably eliminating any existing fauna at that time. The original frogs that successfully colonized the Caribbean islands likely hitched a ride on floating mats of vegetation called flotsam, which is the method typically used by land animals to travel across salt water,” said Prof. Hedges.

“Some rafts of flotsam, if they are washed out of rivers during storms and caught in ocean currents, can be more than a mile across and could include plants that trap fresh water and insect food for frogs. It is not likely that the frog species dispersed simply by swimming because frogs dry easily and are not very tolerant of salt water,” he said.

From DailyIndia

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Tuatara faces gender bending climate threat

Posted by Miqe on June 5, 2007

The tuatara has survived ice ages and volcanic eruptions but New Zealand’s last survivor of the dinosaur age may become extinct because of global warming.

The lizard-like reptile, one of the world’s oldest living creatures, is vulnerable to temperature change because temperature determines the sex of its young.

According to Jennifer Moore, a Victoria University researcher investigating the tuatara’s sexual behaviour, a temperature above 21.5 degrees celsius creates more male tuatara while a cooler climate leads to females.

Already male tuatara on a tiny predator- free island near the top of the South Island outnumber females by 1.7 times, she says.

“They’ve certainly survived the climate changes in the past but most of them (past climate changes) have been at a lower rate,” she said.

“So you wouldn’t expect these guys to be able to adapt to a climate that’s changing so rapidly.”

The tuatara, whose Maori name refers to the spines on its back, is the only survivor of a species of reptile that flourished during the age of the dinosaurs, about 200 million years ago. It can grow up to 50 centimetres long and weigh up to one kilogram and like its reptile relative, the turtle, the slow-moving tuatara can live more than 100 years, feeding mainly on insects.

But scientists say its long lifespan as well as its four-year breeding cycle – relatively slow for a reptile – will make the adaptation process more difficult.

Peter Gaze, a senior conservation officer at the Conservation Department, says global warming has become a new challenge for many of New Zealand’s wildlife. “I think the impact of temperature change is widespread and diverse,” he said.

He said rare species such as the rock wren – an ancient, tailless bird found only in the South Island mountain ranges – could become extinct if the warmer climate let predators, such as rats, live in higher altitudes.

The United Nations Intergovernmental Panel on Climate Change, the world’s top authority on global warming, predicted in a report in February that global temperatures would rise by 1.8 to 4 degrees this century.

The group has predicted a severe impact for New Zealand, with forestry and agriculture likely to be hit hard by global warming.

On a global level, the report predicts large numbers of plant and animal species could die out by 2050 because of global warming.

It says billions of people around the world will face floods and famine and millions will die as crops fail and diseases take hold.

From Stuff

Posted in Herps in the news, International articles and news., Lizards | 1 Comment »

Slithery customer just adder be a grass snake

Posted by Miqe on June 5, 2007

A RANGER got a shock at the Avon Heath Country Park near Ferndown when he opened up a jammed printer to find a snake looking back at him from inside the machine.

The wily grass snake got into the visitor centre at the park a week ago and has been eluding attempts to capture it ever since, popping up in unlikely places and causing havoc.

The slithery intruder was first spotted by park ranger Katy Thompson. She said: “I just saw a tail disappearing under my desk and I spent about two hours tentatively moving the furniture because I didn’t know if it was a grass snake or an adder. I found it and saw it was a grass snake but then it disappeared up into the cavity wall.”

A couple of days later ranger Carol Dawkins was sitting at her desk when she heard a rustling but the snake again disappeared before she could grab it.

On Thursday Ian Cross went to print some paperwork in the office and an error message came up on the printer.

He opened up the section where the cartridges were and found the snake looking up at him from inside the machine.

This time he managed to get hold of it and returned the animal, completely unharmed by its adventures, to the outside world.

Grass snakes are the largest reptiles native to the UK. They have been widespread across England but have become rarer in recent years.

They are non-venomous and completely harmless but Mrs Dawkins said: “I am glad it was Ian that found it because it would have given me a shock. I am fairly used to them but there is something about the way snakes slither.”

From Daily Echo

Posted in Herps in the news, International articles and news., Snakes | 2 Comments »

Purple frog may croak it soon

Posted by Miqe on June 5, 2007

A purple fluorescent frog is one of 24 new species found in the South American highlands

purple frog

of Suriname, according to conservationists who warn that these creatures are threatened by illegal gold mining.

The discovery of so many species outside the insect realm is extraordinary and points to the need to survey distant regions, says Dr Leeanne Alonso of Conservation International, which led the expedition that found the new species.

“When you go to these places that are so unexplored and so remote, we do tend to find new species … but most of them are insects,” Alonso says.

“What’s really exciting here is we found a lot of new species of frogs and fish as well.”

The two-tone frog, whose skin is covered with irregular fluorescent lavender loops on a background of aubergine, was discovered in 2006 as part of a survey of Suriname’s Nassau plateau, the conservation group says.

Frogs, fish, dung beetles and ants

Scientists combing the plateau and Lely Mountains found four other new frog species apart from the purple one, six species of fish, 12 dung beetles and a new ant species, the organisation says.

Thirteen scientists discovered the creatures when exploring a region about 130 kilometre southeast of Suriname’s capital Paramaribo.

The region includes areas with enough clean fresh water sources to support abundant fish and amphibians.

The scientists also found 27 species native to the Guayana Shield region, which spreads over Suriname, Guyana, French Guiana and northern Brazil.

One of these is the rare armoured catfish, which conservationists feared was extinct because gold miners had contaminated a creek where it was last seen 50 years ago.

Including the new species, the scientists observed 467 species at the two sites, ranging from large cats like panthers and pumas, to monkeys, reptiles, bats and insects.

Illegal gold mining

While these places are far from human civilisation, they are totally unprotected and may be threatened by illegal gold mining, Alonso says.

These highland areas have also been investigated as sources of bauxite, used to make aluminium, but will most likely not be mined in the future, she says, at least not by the two mining companies that sponsored the study.

The sponsors are BHP Billiton Maatschappij Suriname (a subsidiary of BHP Billiton) and Suriname Aluminium Company LLC (a subsidiary of Alcoa Inc).

“It’s an opportunity now for all the players, the mining companies who still have mining concessions there, the local communities, the government, the [non-governmental organisations], to try to make a regional plan for the area,” Alonso says.

From News in science

Posted in Amphibians, Herps in the news | 2 Comments »

Cane toads cannibalise their young

Posted by Miqe on June 5, 2007

Cane toads wiggle their toes to lure their young, then eat them up in an act of cannibalism, Australian researchers say.

They say the young toads move towards the adults, possibly mistaking the wiggling toes for a tasty morsel, like an insect.

Instead the youngsters themselves end up as the tasty morsel.

But harnessing this cannibalistic behaviour may have some benefits, at least in Australia, where cane toads are an invasive pest.

Scientists say it could be the key to getting cane toads to eat themselves out of existence.

Professor Rick Shine of the University of Sydney and PhD student Mattias Hagman will report their findings in the journal Animal Behaviour.

The researchers noticed that when baby toads are around adult toads, the adults start wiggling the middle toes on their hind feet.

camera See a video of cane toads wiggling their toes here (Real Media) or here (Windows Media).

The baby toads appear to respond by hopping towards the adults.

The researchers wondered whether this toe waving is an adaptation for cannibalistic behaviour and set up an experiment to check.

Toads were separated by clear glass and not allowed to eat each other because it would have gone against the rules of ethical animal experimentation.

The researchers found that baby toads only move towards adults that wave their toes.

“[The toe waving] seems to be beautifully designed to arouse the feeding responses of a small cane toad,” says Shine. “They presumably think it looks like a small insect.”

Fake toes

The researchers also used freeze-dried toad to which they attached mechanically controlled fake toes.

They measured how far the baby toads moved towards the artificial toe as they wiggled it at different rates and changed its colour.

“We showed that the way that the real toads do it is in fact the best possible colour and speed … to lure baby toads in,” says Shine.

He says the findings strongly support the idea that cannibalism is an important enough behaviour among toads for it to have led to the evolution of the special toe-luring trick.

mating toads

Shine says confirming that toads have evolved to be cannibalistic could be useful in trying to control them.

Shine says males are most likely to cannibalise their young because they congregate around the ponds where females come to lay their eggs.

But females tend to spend more time roaming around the countryside looking for food. This means they are harder to find but present a greater risk to native predators.

While males are easier to find than females, Shine says it could be helpful to keep them alive and focus on knocking off the harder-to-find females.

“We might end up with a group of toads that were very good at eating smaller toads,” he says.

Shine also says outnumbering female toads with males would increase the number of female toads drowned by numerous males trying to copulate with them in the water.

He says this selective culling could be combined with a parasite, from native frogs, that has recently been found to kill or stunt the growth of cane toads.

“At the moment it’s an idea and we need to run a bunch of trials trying to see how effective that’s going to be because at the moment we don’t know,” says Shine.

From News in science

Posted in Amphibians, Herps in the news, International articles and news. | Leave a Comment »

 
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