Thursday 19 October 2017 News Updated at 12:10 PM IST
Custom Search
Web
 
 
 
Snippets, Nature - Deccan Herald
Snippets, Nature
NYT, Science Daily
More... A A
Threatened: Snow leopards still face a high risk of extinction for reasons such as habitat loss and degradation, and decline in prey populations.
Extinction threat

Snow leopard is still at risk

The snow leopard is no longer an endangered species, but its population in the wild is still at risk because of poaching and habitat loss, conservationists said recently. The International Union for Conservation of Nature said new data taken through 2016 prompted the reclassification of the snow leopard from the endangered list to the vulnerable category.

The difference means that the animals have gone from 'very high risk’ to 'high risk’ of extinction in the wild.

The global population of the snow leopard is estimated at 2,500 to 10,000 mature animals. But the leopard could still face a population decline of 10% or more over the next three generations in its habitats, which are mostly mountainous areas of Central Asia, including Kyrgyzstan and Pakistan. It "still faces a high risk of extinction,” International Union for Conservation of Nature said, due to habitat loss and degradation, decline in prey populations, and poaching for illegal wildlife trade, among other reasons. Snow leopards range across 12 countries in Central Asia in remote and rugged terrain.


Silvered rice

Harvesting silver alongside rice

Could farmers be looking at harvesting the precious metal silver alongside paddy from their crop fields? Yes, if they cultivate the rice variety Garib-sal, scientists at the Indian Institute of Technology Madras (IIT-M) report. While screening 505 native varieties of rice for different heavy metals, the team led by chemistry professor Thalappil Pradeep noticed that nine of them were capable of absorbing silver, which occurs naturally in soil. Among these, Garib-sal, a landrace from West Bengal was found to accumulate silver at an exceptionally high concentration. The researchers claim that this is the first investigation of the deposition of silver in rice grains. Debal Deb, one of the authors and head of the Basudha farm, located in Odisha’s Rayagada district, where the rice varieties were grown, says the discovery will be patented. "Presently, Garib-sal is not very popular among farmers because it is not high yielding. But the finding that silver comes as a bonus may change that,” he said.


Ancient behaviour

The jellyfish can sleep

Worms and fish do it. Birds and bees do it. But do jellyfish fall asleep? Answering the question required a multi-step investigation by a trio of California Institute of Technology graduate students. Their answer, published in Current Biology, is that at least one group of jellyfish called Cassiopea, or the upside-down jellyfish, does snooze.

The finding is the first documented example of sleep in an animal with a diffuse nerve net, a system of neurons that are spread throughout an organism and not organised around the brain. It challenges the common notion that sleep requires brain.

It also suggests sleep could be an ancient behaviour because the group that includes jellyfish branched off from the last common ancestor of most living animals early on in evolution.


Reducing precipitation

The wind sublimates snowflakes

Researchers have observed and characterised a weather process that was not previously known to occur in Antarctica’s coastal regions. It turns out that the katabatic winds that blow from the interior to the margins of the continent reduce the amount of precipitation. By forming a very dry layer of air in the first kilometre or so of atmosphere, the winds turn the falling snowflakes during their fall directly from their solid state into water vapour. The authors of this study used new data collected at the coast of Adelie Land over a year.

They estimated that, across the continent, cumulative precipitation near the ground was 17% lower than its maximum level higher in altitude. Their measurements indicate that precipitation may be as much as 35% lower in the region around East Antarctica. Their study has been published in Proceedings of the National Academy of Sciences.


Robust toes

How horses got their hooves

All four-limbed, land-based vertebrates came from a common ancestor with legs that ended in five toes. Over time, many animals lost some of their digits: hippos, rhinos and camels have four, three and two toes on each leg. But only one living group of animals ended up with a single toe per foot: the group containing horses. A study in Proceedings of the Royal Society B, lends support to existing hypotheses about the dramatic transformation in horses’ hooves. As horses evolved and got larger from their ancestral, dog-sized form, it was better to have one very robust toe to support their increased body mass. Also, having just one toe reduced the weight horses had to carry at the end of each leg, making it easier for them to run and manoeuvre.


Documentary

Blackfish

Blackfish, directed by Gabriela Cowperthwaite, details the mistreatment of orca whales at SeaWorld, particularly in Orlando, Florida, where killer whale Tilikum was involved in three deaths. It also sends out a powerful message that there is a heavy price to pay for removing whales from their natural habitat, where they are used to swimming 100 miles a day, and forcing them to swim round and round a man-made pool. To watch the movie, visit www.blackfishmovie.com/watch.
A A