Tag Archives: species biology

Javan rhino now extinct in Vietnam

BBC News – Javan rhino ‘now extinct in Vietnam’.

A Javan rhino is captured on camera in Vietnam's Cat Tien National Park (Image: WWF Greater Mekong) Genetic analysis of rhino dung samples revealed that there was only one individual left in Vietnam

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A critically endangered species of rhino is now extinct in Vietnam, according to a report by conservation groups.

The WWF and the International Rhino Foundation said the country’s last Javan rhino was probably killed by poachers, as its horn had been cut off.

Experts said the news was not a surprise, as only one sighting had been recorded in Vietnam since 2008.

Fewer than 50 individuals are now estimated to remain in the wild.

“It is painful that despite significant investment in Vietnamese rhino conservation, efforts failed to save this unique animal, ” said WWF’s Vietnam director Tran Thi Minh Hien.

“Vietnam has lost part of its natural heritage.”

The authors of the report, Extinction of the Javan Rhino from Vietnam, said genetic analysis of dung samples collected between 2009-2010 in the Cat Tien National Park showed that they all belonged to just one individual.

Shortly after the survey was completed, conservationists found out that the rhino had been killed. They say it was likely to have been the work of poachers because it had been shot in a leg and its horn had been cut off.

Globally, there has been a sharp increase in the number of rhino poaching cases. Earlier this year, the International Union for Conservation of Nature (IUCN) published a report that said rhino populations in Africa were facing their worst poaching crisis for decades.

An assessment carried out by Traffic, the global wildlife trade monitoring network, said the surge in the illegal trade in rhino horns was being driven by demands from Asian medicinal markets.

Conservation blow

The Vietnam rhino, as well as being the last of the species on mainland Asia, was also the last known surviving member of the Rhinoceros sondaicus annamiticus subspecies – one of three recognised groups of Javan rhino populations.

In detail: Javan rhinoceros

  • Scientific name: Rhinoceros sondaicus
  • The species is listed as Critically Endangered because fewer than 50 individuals remain
  • Weight: 900kg – 2,300kg
  • Height: 1.5m – 1.7m
  • Length: 2.0m – 4.0m
  • Male Javan rhinos possess a single horn about 25cm long
  • It is estimated that they can live for 30-40 years
  • Females reach sexual maturity between 5-7 years, and then give birth to a calf about once every three years

(Source: IUCN/IRF)

Another is already extinct. R. sondaicus inermis was formerly found in north-eastern India, Bangladesh and Burma.

The remaining subspecies, R. sondaicus sondaicus, is now found on Java, Indonesia. However, since the 1930s, the animals – now estimated to number no more than 50 – have been restricted to the westernmost parts of the island.

Bibhab Kumar Talukdar, chairman of the IUCN’s Asian Rhino Specialist Group, said the demise of the Javan rhino in Vietnam was “definitely a blow”.

“We all must learn from this and need to ensure that the fate of the Javan rhino in [Indonesia] won’t be like that of Cat Tien in near future,” he told BBC News.

“Threats to rhinos for their horn is definitely a major problem. But in Indonesia, due to active work done by rhino protection units and national park authorities, no Javan rhino poaching has been recorded in Indonesia for past decade.”

Dr Talukdar observed: “What is key to the success of the species is appropriate habitat management as the Javan rhinos are browser and it needs secondary growing forests.”

He warned that the habitat within the national park on Java serving as the final refuge for the species was being degraded by an invasive species of palm.

“As such, control of arenga palm and habitat management for Javan rhinos in Ujung Kulon National Park is now become important for future of the species.”

Melting Antarctic Ice Causing Penguins to Starve

Melting Antarctic Ice Causing Penguins to Starve – ScienceNOW.

sn-penguins.jpg

On thin ice. Global populations of chinstrap (left) and Adelie (right) penguins have declined by more than 50% over the past 30 years.

Every year since 1979, marine biologist Wayne Trivelpiece and his wife, Susan, both of the National Oceanic and Atmospheric Association’s Antarctic Ecosystem Research Division in San Diego, California, have braved frigid temperatures and wind speeds that average 40 kilometers per hour to track the feeding, breeding, and migrating of chinstrap and Adelie penguins. During this time, populations they studied on the West Antarctic Peninsula and in the nearby Scotia Sea have declined drastically, and a few have gone extinct, victims of a warming planet that deprives them of their sea ice habitat. Now, in a compilation of over 30 years of data collected from numerous bases around Antarctica, the researchers conclude that the penguins are not only running out of room but also starving.

In 1992, the pair published a paper with ecologist William Fraser, now president of the privately owned Polar Ocean Research Group based in Sheridan, Montana, proposing what they deemed the “habitat hypothesis,” the idea that melting sea ice along the Antarctic coast was harming penguins. The average temperature in the region of the Scotia Sea, one of the most rapidly warming places on the planet, has increased by 5?C to 6?C over the past 50 years, drastically reducing the amount of sea ice present and the length of time that the ice exists. The researchers proposed that losing their habitat was what was killing Adelie penguins, which need ice to survive. By contrast, the numbers of chinstrap penguins, which avoid sea ice as much as possible, were booming.

But by incorporating data from land-based stations and tourist ships that moonlight as penguin-counting research vessels, the researchers have expanded their data set and reexamined it. In a paper published today in the Proceedings of the National Academy of Sciences, the Trivelpieces and their colleagues propose that a decrease in krill—shrimplike crustaceans that are a staple food for penguins—is to blame for the decline in Adelie penguins and chinstrap penguins, whose populations are now shrinking by 2.9% and 4.3%, respectively, each year. As it turns out, krill larvae are as dependent on sea ice as Adelie penguins are, feeding on algae that grow on the underside of ice packs; krill numbers have dropped by 80% since 1981. Independent of whether they like ice, Adelie and chinstrap penguins like to eat krill.

Back in the 1980s, Wayne Trivelpiece says, when researchers first started noticing a rapid decline in penguin populations, it was unclear what the reason was. To check their hunch that the cause was a food shortage, they began forcing penguin parents returning from the sea to vomit by inverting them over a bucket and pushing on their stomachs. Chinstrap penguins, they and other researchers found, eat krill exclusively; Adelie penguins are dependent on it as well. Continuing research through the 1990s showed that the size of the krill was uniform, suggesting that only a few krill populations were maturing over the years and were available for penguins to eat. Satellite data showed that krill numbers fell in areas where sea ice dwindled. “As aggravating as it was to see penguins declining, it was rewarding to have finally figured out the correlation,” Wayne Trivelpiece says.

He believes that the shrinking population is due to the deaths of baby penguins. After their parents leave them to fend for themselves, young penguins stand around before venturing into the sea to search for a decreasing number of krill. Without any guidance, their probability of encountering a krill and knowing what to do with it is very low. Some years, only 10% of the young penguins return, down from 50% in the 1970s. By contrast, Gentoo penguins take their young on hunting trips before abandoning them; their numbers haven’t fallen as severely.

Penguins, Fraser says, are a bellwether for how global warming will harm species across the globe. “If what we’ve seen in 35 years is just the precursor to what occurs across the planet, it’s reason to be very concerned,” he says. Although he still believes that sea ice loss is responsible for penguin decline in at least some areas, he calls the new study “one of the best papers I’ve read in quite a while so far as providing a description of the complexity and issues involved” in tracking food webs in the Antarctic.

Fraser calls the data set “formidable” evidence for long-term warming trends, adding that Antarctic research is the longest database in the world of population trends in large animals. “It’s a great piece of work and I’m thankful for scientists like them who make such a commitment,” adds oceanographer Oscar Schofield of Rutgers University in New Brunswick, New Jersey.