Irrawaddy dolphins found
Scientists estimate they have found up to 6,000 rare Irrawaddy dolphins on the Bangladesh coast, but warn that the newly discovered population is under threat from climate change and fishing. Researchers found the dolphins living in the freshwater regions of Bangladesh's Sundarbans mangrove forest and nearby waters in the Bay of Bengal.
The species is related to orcas or killer whales, grows to around 2-2.5 metres in length and lives in large rivers, estuaries, and freshwater lagoons in south and south-east Asia.
The previously largest known populations of Irrawaddy dolphins numbered in the low hundreds or less. At least 125 in the Mekong river, 77 in the Malampaya Sound in the Philippines and up to 100 in the Mahakam River, Indonesia.
Until the new population was found figures from the International Union for Conservation of Nature (IUCN) estimated the Sundarbans population to be around 450.
[Wildlife Conservation Society (WCS)]
Cornish rustic sandhill moth
Scientists are trying to save the rare Cornish rustic sandhill moth, Luperina nickerlii leechi Goater, left, from extinction. The moth has astounded experts by surviving on a half-mile of shingle bar and living through winter storms, summer heat and even waves breaking over it.
The moth was discovered on Loe Bar near Helston, Cornwall, in 1974, and a colony of about 200 of the well-camouflaged insects live on the shingle. Researchers say that the moths are at risk from climate change and rising sea levels.
[University of Exeter]
New jumping spiders in Papua New Guinea
Conservationists searching the undergrowth of a remote mountain region have identified up to 50 new species of jumping spiders.
Medical science could benefit from the discoveries, they said, through the study of the chemicals contained in their venoms. Spider venom has evolved for millions of years to affect the neurological systems of the spider’s insect prey and each species of spider gives an opportunity to find medically-useful chemicals.
Along with spiders, which can leap 30 times their own body length, biologists discovered three previously unknown frogs, two plants and a stripy gecko.
Jumping spiders have better sight than other types of spider and two of their eight eyes are especially well developed for high resolution vision. In effect, they have evolved a design that has deconstructed the eyeball and put it together, with modifications, section by section in miniature.
Among the new spiders were types that came from particularly unusual evolutionary branches and zoologists hope that these will offer clues into how jumping spiders evolved, which happened much more recently than other spider species.
Instead of building webs or responding to the motion of prey they have learnt to distinguish between different animals and their attack technique depends on what they are tackling. Jumping spiders don't sit at the centre of a web but roam around their habitat and pounce, like cats, on their prey.
[Conservation International]
Hen birds sing
Researchers have discovered that some female birds whistle loudly to keep males from hearing rivals’ mating calls. They tracked Warbling Antbirds, Hypocnemis cantator, left, in the Peruvian rainforest and played a recording of a female.
Male birds became excited when they heard the sound of “flirting”, but their female mates responded with their own songs to drown out the interloper. The results found that females who “jammed” the mating signals kept their partners.
[Current Biology]
Bees and ants are model citizens?
Bees and ants, long recognised as tireless workers, can also behave like selfless model citizens. Scientists found that some insects, such as honey bees, seem to put the interests of their group above their own selfish interests.
The study found that bees and ants which operate in the best interests of the group create a "superorganism" and can even sacrifice their lives for the greater good of their community.
But scientists also found the same could not be said for other animal groupings, such as herds of bison or shoals of fish. In those instances, where individual animals appear to be acting like team players, they are actually putting their own interests first, zoologists found.
The study used mathematical models to examine the way in which co-operative groups of animals evolve.
It’s thought that the honey bee's behaviour is controlled by an efficient form of "policing", which suppresses conflict between individuals within the group. This means that the bees are united in a common purpose to ensure the survival of the queen bee's offspring.
Superorganisms are rare occurrences in nature. Animals appearing to move in unison, such as fish, are in fact jostling to get to the middle of the group to evade predators.
[Journal of Evolutionary Biology]
