PLUS MORE WAYS ANIMALS COPE WITH COLD

Even though here in the southern hemisphere summer is getting into full swing, many creatures around the world are experiencing freezing temperatures. Our winter survival skills often involve staying indoors with plenty of blankets, cocoa, and mindless TV at the ready.
                 

But wild animals don't have that luxury—they have to tough it out in the cold. That made Weird Animal Question of the Week wonder: “What are some cool ways animals stay safe and warm in winter?”

WINTER COATS

Some species pile on the layers, like the Arctic musk ox, whose soft undercoat—called qiviut—insulates them from -50 degree Fahrenheit temperatures. Polar bears have an extra layer of fat to keep toasty.
Others grow thicker fur in the fall, like white-tailed deer, and some even grow lighter coats to blend into the snow, Sharon Chester, author of The Arctic Guide, Wildlife of the Far North, says via email.

North American mammals such as the Arctic fox, least weasel, Arctic hare, and ermine have this adaptation, Chester says.
The camo works if snow is consistent, Chester says, but it's tougher if snow arrives late and melts early—which is happening more due to global climate change. A 2016 study reported snowshoe hares in Montana that were mismatched to their environment experienced a 7 percent decrease in survival rate.

Wood frogs, which range from the southeastern U.S. to the Arctic Circle, "hunker down in some leaf litter and freeze solid" into a "frogcicle," says Greg Pauly, curator of herpetology at the Natural History Museum of Los Angeles County.

The Arctic ground squirrel, or siksik, can drop its body temperature below freezing while it's hibernating. This is likely due to another process called supercooling, in which the body temperature can go below the freezing point without forming ice.

Ant genomes rewrite history of Panama land bridge

Colliding tectonic plates pushed up a strip of land from the watery abyss that once divided North and South America, forming the isthmus of Panama. But a study now hints that this happened millions of years earlier than scientists had thought.
               

Evolutionary and population-genetics data from Eciton army ants, which can only travel on dry ground, suggest that the isthmus formed 4–8 million years ago. The research, published on 25 October in Molecular Ecology1, challenges the long-held idea that the link between continents emerged no more than 3 million years ago.

“Our genomic data is very strong evidence that the army ants crossed this region much earlier in time than the model of the simple closure of the isthmus suggests,” says Corrie Moreau, associate curator at the Field Museum in Chicago, Illinois, and co-author of the study. She notes that recent geological studies have also hinted that the isthmus may have emerged earlier than 3 million years ago.

Genetics and geology collide

Moreau and her colleagues used a technique called genotyping to sequence small fragments of DNA from the genomes of multiple individuals from all nine Eciton species, which are found from Brazil to southern Mexico. This allowed the researchers to compare genetic variations both between species and within different individuals of the same species.

Anthony Coates, a geologist at the Smithsonian Tropical Research Institute in Panama City, is sceptical of any evidence contradicting the isthmus’s 3-million-year age. “There are still a series of investigations in different disciplines that all converge on the same number of around three million years ago. This is extremely rigorous evidence,” Coates says.

The geological battle lines, it seems, have been drawn. Whether they can form an ideological land bridge similar to the physical one that researchers are studying remains to be seen.

Delhi zoo shut down after bird flu deaths

The National Zoological Park (Delhi zoo) was shut down indefinitely Tuesday following confirmation that the death of at least eight water birds recently was due to bird flu, said sources. The death of a few ducks had been noticed about “four to five days” ago and a few pelicans were also found dead later, the sources added, terming the shutdown a “precautionary measure”.
Development and General Administration Minister Gopal Rai said, “Officials in charge of the zoo informed us about the flu infecting birds. The flu has been diagnosed as H5 avian influenza. The zoo has been closed for now and we are taking all necessary measures.”
               

He added, “We do not know how many birds have been infected but tests are being conducted.” Rai said the government would issue additional information after getting more test results. He did not say how long the zoo would remain shut.
Sources told The Indian Express that samples of the ducks that died were sent to Jalandhar this week for ascertaining the cause of death and it was found that they succumbed to bird flu. “The samples of dead pelicans too were sent for testing and the results are awaited,” said a source.
The samples were also sent to another laboratory for a second opinion, said sources. A central team will be visiting the zoo Wednesday, the sources added. The curator and spokesperson of the zoo could not be reached for comment.
Ducks and pelicans are kept in separate ponds at the zoological park. Before the bird deaths were spotted, the zoo had nearly 40 pelicans and 20 ducks.
The Indian Express could not officially confirm the number of deaths of ducks and pelicans, but sources confirmed that at least 8 water birds had died due to bird flu. The sources also said this was the first time in at least 10 years that bird flu was reported at the zoo. Avian influenza, commonly called bird flu, is an infectious viral disease of birds. According to the World Health Organisation, most avian influenza viruses do not infect humans.
The zoo came under the spotlight in May after the death of 46 spotted deer due to rabies. The deer deaths have been reported since January this year. The zoo got 22 lakh visitors last year.

Fish Are A Bunch Of Lame Posers

A new study has found that “schooling” is a horrendous process in which an individual’s unique personality is unceremoniously supplanted by group-think and the notion of bravery is cast aside when a danger to the overall status quo is presented. School, in this case, is the group that fish swim in. What did you think we were talking about?

        

Dr. Christos Ioannou and his fellow researchers at the School of Biological Sciences have concluded an investigation into the individual and group behaviours of the three-spined stickleback. They found that much like humans, the bravest fish tend to lead the herd. But when a group decision is necessary, such as in a situation of danger, even the brave individual who stood out from the pack tucks tail and becomes a cautious follower.

Who knew the stickleback was so spineless?

“This is the first time that the suppression of personality in groups has been linked to its underlying cause, which is conformity in group decision making,” Ioannou says.

Interestingly, the fish in the study didn’t seem to retain their conformist predilections when tested again in isolation. According to Ioannou, “The behaviour of the fish seems to be ‘plastic’ to the social situation — they show consistent individual differences in behaviour when tested alone — reflecting personality, but they are also happy to suppress this to be able to stick together with their shoal mates if there are others around.”

Tropical flower production booming thanks to warm Top End dry season

A Northern Territory cut flower grower is struggling to keep up with demand and production is booming thanks to a warm Top End dry season.
         

Mike Braun, who runs a farm at Herbert in Darwin's rural area, thinks it is just a sign of things to come as the climate changes.

Mr Braun said he could not produce enough water lilies, and the Heliconias or lobster claws were also doing very well.

An investment in a second Heliconia plantation just over a year ago is paying off.

Mr Braun cuts flowers every Friday morning, selling around 250 stems to a wholesaler.

The flowers end up in markets and flower shops in Darwin and, in the warmer southern months, they are flown interstate.

Mr Braun said conditions were also good for Heliconia chartacea or "sexy pink", a valuable but temperamental variety that often succumbs to root rot.

"It's very hard to grow, a lot of growers can't grow it any more," he said.

The sexy pinks command a premium in the market place.

Near-blind shark is world’s longest-lived vertebrate

A large, almost-blind shark that lives in the freezing waters of the North Atlantic and Arctic oceans is officially the world’s longest-living vertebrate, scientists say.

The Greenland shark (Somniosus microcephalus) has a lifespan of at least 272 years, and might live as long as 500 years1. That is older than the 211-year lifespan of the bowhead whale (Balaena mysticetus), the previous record-holder in the scientific literature2. It also beats the popular — but unconfirmed — tale of a famous female Koi carp called Hanako, who supposedly lived to 226 years old.

Marine scientists already knew that the Greenland shark was long-lived, says Peter Bushnell, a marine physiologist at Indiana University South Bend and a co-author of the study, published in Science. The fish are enormous but grow slowly, suggesting a long lifespan. Adult Greenland sharks have been measured at more than 6 metres long — and researchers think that they could grow even longer. One 1963 study estimated that the species grows at less than 1 centimetre per year3.

The eyes have it

Instead, the team decided to measure levels of radioactive carbon-14 in fibres in the centre of the shark’s eye lens. Such measurements reflect levels of radiocarbon in the ocean when the lens was first formed. Measurements of 28 female Greenland sharks, made during surveys in 2010–13, suggested that the largest of them (at 5.02 metres long) must have been between 272 and 512 years old at the time.