Thursday 29 December 2016

Study tracks trillions of insects migrating in the UK


December 23, 2016

by Chuck Bednar


After a decade’s worth of effort, an international team of researchers has for the first time been able to track the swarms of migratory insects that soar above the skies of southern England each year, according to a new study published online Friday by the journal Science.

What they found was that approximately 3.5 trillion bugs and butterflies migrate annual above the region, and that together they comprise 3,200 tons of biomass – seven times greater than the mass of songbirds that travel from the UK to Africa each year, and equal to some 20,000 flying reindeer, scientists from the University of Exeter and Rothamsted Research reported. According to BBC News, the researchers counted the swarms of insects using a combination of vertical radar and balloon-mounted insect nets. They calculated the numbers of insects that flew at altitudes of 150 and 1,200 meters, both during the day and at night, for a total of 10 years.

“Insect bodies are rich in nutrients and the importance of these movements is underappreciated,” co-author Dr. Jason Chapman from the Centre for Ecology and Conservation at the University of Exeter's Cornwall-based Penryn Campus explained in a statement. “If the densities observed over southern UK are extrapolated to the airspace above all continental landmasses, high-altitude insect migration represents the most important annual animal movement in ecosystems on land.”

Sprinting towards extinction? Cheetah numbers crash globally


Scientists confirm just 7,100 cheetahs remain, call for uplisting to 'Endangered' on IUCN Red List 
 
Date: December 26, 2016
Source: Panthera

The world's fastest land animal, the cheetah (Acinonyx jubatus), is sprinting towards the edge of extinction and could soon be lost forever unless urgent, landscape-wide conservation action is taken, according to a study published today in the journal Proceedings of the National Academy of Sciences.

Led by Zoological Society of London (ZSL), Panthera and Wildlife Conservation Society (WCS), the study reveals that just 7,100 cheetahs remain globally, representing the best available estimate for the species to date. Furthermore, the cheetah has been driven out of 91% of its historic range. Asiatic cheetah populations have been hit hardest, with fewer than 50 individuals remaining in one isolated pocket of Iran.

Due to the species' dramatic decline, the study's authors are calling for the cheetah to be up-listed from 'Vulnerable' to 'Endangered' on the IUCN Red List of Threatened Species. Typically, greater international conservation support, prioritization and attention are granted to wildlife classified as 'Endangered', in efforts to stave off impending extinction.

Dr. Sarah Durant, ZSL/WCS lead author and Project Leader for the Rangewide Conservation Program for Cheetah and African Wild Dog, said: "This study represents the most comprehensive analysis of cheetah status to date. Given the secretive nature of this elusive cat, it has been difficult to gather hard information on the species, leading to its plight being overlooked. Our findings show that the large space requirements for cheetah, coupled with the complex range of threats faced by the species in the wild, mean that it is likely to be much more vulnerable to extinction than was previously thought."

continued

Bat calls contain wealth of discernible information

Analyzing some 15,000 bat vocalizations, researchers identify speakers, objectives and contexts of bat conversations Date:December 27, 2016Source:American Friends of Tel Aviv University

Bats, like humans, are extremely social mammals. They enjoy an average lifespan of 20-30 years, settle in large colonies, and rely heavily on social interactions for their survival, using vocalizations -- or calls -- for communication. There is very little known about the purpose and content of these noises.

A new Tel Aviv University study published in Scientific Reports extracts critical information from bat vocalizations to offer a rare, informative look into the world of bat communication. The new research, led by Prof. Yossi Yovel of the Department of Zoology at TAU's Faculty of Life Sciences, delves into the veritable cacophony emitted by bats to identify concrete evidence of a socially sophisticated species that learns communication, rather than being born with a fixed set of communication skills.

"When you enter a bat cave, you hear a lot of 'gibberish,' a cacophony of aggressive bat noise -- but is this merely 'shouting' or is there information amid the noise?" said Prof. Yovel. "Previous research presumed that most bat communication was based on screaming and shouting. We wanted to know how much information was actually conveyed -- and we wanted to see if we could, in fact, extract that information."



Read on

Tuatara numbers boosted at Orokonui Ecosanctuary - via Herp Digest

Press release from Orokonui Ecosanctuary and the University of Otago
15 December 2016

Modest tuatara numbers will be boosted at Orokonui Ecosanctuary with the release of 17 juvenile tuatara this Thursday, 15 December.

The young tuatara, aged 3-4 years, have been reared at the University of Otago. They join the population at Orokonui that was founded in 2012 when 87 adult and juvenile tuatara were released.

The tuatara have their genetic origins in the population on Stephens Island (Takapourewa) in Cook Strait, where they are recognised as a taonga and under the kaitiakitanga (guardianship) of Ngāti Koata iwi.
Kāti Huirapa Rūnaka ki Puketeraki will be present, alongside Ecosanctuary staff, Department of Conservation staff and others to warm their arrival and support any ceremonial duties.

Support for the release of more tuatara at Orokonui was made possible following positive results of monitoring last summer led by research assistant Scott Jarvie and Associate Professor Alison Cree of the University’s Department of Zoology.

“We recaptured more than half of the tuatara that had been released about three years earlier and they appeared healthy and well,” said Jarvie.
 
“We are delighted to be able to provide a home for these additional tuatara” said Chris Baillie, general manager of the ecosanctuary.
 
Orokonui is the only fenced ecosanctuary in the South Island where tuatara roam freely in the absence of predatory mammals such as cats and stoats. Until a few hundred years ago tuatara lived throughout much of the eastern South Island, but quickly disappeared following the arrival of humans and other land mammals.

“We see the establishment of a tuatara population at Orokonui as part of our commitment to help tuatara survive the challenges of climate change” says Associate Professor Cree. “Cooler, southern locations are likely to become increasingly important to tuatara as sea levels rise and conditions become hotter and perhaps drier on some northern islands.”
 
Members of the public who see free-roaming tuatara in the ecosanctuary are encouraged to take good-quality photographs without disturbing the reptiles and to show these to Orokonui staff or University researchers. Idiosyncracies of the spines or other body markings may enable individual tuatara to be identified.

Background information
Tuatara, known to scientists as Sphenodon punctatus, are the world’s only surviving rhynchocephalian reptiles. Rhynchocephalians or beak-headed reptiles were common about 200 million years ago. Tuatara are the closest living relatives of lizards and snakes, although their common ancestry is distant in time.

Like many other New Zealand reptiles, tuatara have “slow” life histories. Their eggs take about a year or more to incubate in the ground, hatchlings take about 15 years to reach maturity and females typically produce only about nine eggs every 2-5 years. The life span of a wild tuatara can reach about a hundred years.

Tuatara once lived on the North and South Islands, but became extinct there and on many offshore islands following the arrival of humans. Today they survive naturally on about 32 islands in Cook Strait and off the North Island coast. Since 1995, tuatara have been reintroduced to at least nine islands and four North Island sanctuaries, in addition to Orokonui.

Deer study shows bigger brains in females lead to longer lives and more offspring



December 14, 2016 by Bob Yirka report
 
(Phys.org)—A team of researchers working on the Scottish Isle of Rum has found evidence of larger brains in female red deer conferring longer lifespans and more offspring raised to adulthood. In their paper published in the journal Royal Society Open Science, the researchers describe their study and what they found.

A lot of research has been done comparing brain size between species, but there are few comparisons of brain size between individuals of the same species or group. In this new effort, the researchers sought to learn more about what it means for a mammal to have a larger brain than others in its group. They focused on red deer living on the Isle of Rum because other researchers have been tracking them for approximately 40 years—a time span that has covered seven generations. The researchers were able to measure brain size by measuring the skulls of 1,314 deer that had died.

Surprisingly, the team found a 63 percent variation among the deer on the island. They also found that females with larger brains tended to live longer and produced more offspring that for unknown reasons managed to live to become adults themselves. Females also passed on the trait to their offspring. Perhaps even more surprising was that the team found no discernible differences between males with brains of different sizes. The team also reports that they were unable to find any downside to larger brains in deer of either gender. Theories have suggested large-brained individuals might have weaker immune systems or fewer offspring due to the higher energy demands of larger brains—but that did not seem to be the case with the deer.

The researchers suggest physical strength and agility might be the overriding factor leading to male success as a possible explanation for why larger brain size did not confer positive attributes. Larger brains in the females, on the other hand, might have made them smarter in the sense that they were better able to find new food sources when old ones dried up or when dealing with other stressful situations. On the other hand, they note, it might be the case that it was simply coincidence—the researchers cannot say for sure.
The study was the first of its kind, which suggests that other studies need to be done with other species to learn more about why some individuals have larger brains and what it means for them.

Wednesday 28 December 2016

These dinosaurs lost their teeth as they grew up



December 22, 2016
 
By comparing the fossilized remains of 13 ceratosaurian theropod dinosaurs known as Limusaurus inextricabilis collected from the Upper Jurassic Shishugou Formation of northwestern China, researchers have been able to reconstruct the dinosaur's growth and development from a young hatchling of less than a year to the age of 10. The findings, reported in Current Biology on December 22, uncovered something unexpected: the dinosaurs had teeth as young juveniles that were gradually lost as they grew up.

"We found a very rare, very interesting phenomenon in a ceratosaurian dinosaur whereby toothed jaws in juvenile individuals transition to a completely toothless beaked jaw in more mature individuals during development," says Shuo Wang of Capital Normal University in Beijing, China.

The findings make Limusaurus the first known reptile with the characteristic known as ontogenetic edentulism (meaning tooth reduction or loss in development). Together with other evidence, they led the researchers to conclude that the toothed juveniles were probably omnivorous meat-eaters. The beaked adults most likely transitioned to a plant-based diet.

Wang and colleagues first reported on this ceratosaurian back in 2001. At that point, they had collected just one fossilized juvenile, and they didn't yet know what it was. Over the course of the next several years, more specimens were found. But it wasn't clear that they all belonged to the same species.

"Initially, we believed that we found two different ceratosaurian dinosaurs from the Wucaiwan Area, one toothed and the other toothless, and we even started to describe them separately," Wang says.

Related Posts with Thumbnails

ShareThis