How female hyaenas came to dominate males

November 19, 2018, Forschungsverbund Berlin e.V. (FVB)

In most animal societies, members of one sex dominate those of the other. Is this, as widely believed, an inevitable consequence of a disparity in strength and ferocity between males and females? Not necessarily. A new study on wild spotted hyaenas shows that in this social carnivore, females dominate males because they can rely on greater social support than males, not because they are stronger or more competitive in any other individual attribute. The main reason for females having, on average, more social support than males is that males are more likely to disperse and that dispersal disrupts social bonds. The study by scientists of the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW, Germany) and the Institut des Sciences de l'Evolution de Montpellier (ISEM, France) was published in the journal Nature Ecology & Evolution.

Spotted hyaena females are often portrayed as archetypes of powerful and ferocious females. They are on average heavier than the males, have highly masculinised outer genitalia (a 'pseudo-penis' and a 'pseudo-scrotum'), and usually occupy the highest position in the society. But according to the new study, it is not their manliness that allows them to dominate males. "When two hyaenas squabble, the one that can rely on greater social support wins, irrespective of sex, body mass or aggressiveness," explains Oliver Hoener, head of the Ngorongoro Hyena Project of the Leibniz-IZW. Differences in social support between two individuals correctly predicted who will be the dominant in almost all encounters and in all contexts—between natives and immigrants, members of the same and different clans, residents and intruders, and individuals of the same and opposite sex. Female dominance thus emerges from females being more likely to receive greater social support than males. "What is so fascinating is that it all works without any direct involvement of other hyaenas," says Colin Vullioud, Hoener's colleague at Leibniz-IZW and first author of the study. "In the end, it's all about assertiveness and how confident a hyaena is of receiving support if needed."

For their study, the scientists analysed the outcome of 4133 agonistic interactions between 748 hyaenas from eight different clans monitored for 21 years in the Ngorongoro Crater in Tanzania. To estimate potential social support, they developed an algorithm that predicted for each clan member, which of two interacting hyaenas it would support; this algorithm was derived from behavioural observations of social support and relatedness estimates based on one of the most comprehensive pedigrees of a free-ranging mammal. "To tease apart the effects of social support and intrinsic attributes such as body mass, one needs to evaluate each effect while controlling for the presence of the other" explains Francois Rousset (ISEM), who has developed statistical methods for such purposes. "When this is done, the effects of sex and body mass appear negligible."

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4,000-year-old termite mounds found in Brazil are visible from space

November 19, 2018, Cell Press

Researchers reporting in Current Biology on November 19 have found that a vast array of regularly spaced, still-inhabited termite mounds in northeastern Brazil—covering an area the size of Great Britain—are up to about 4,000 years old.

The mounds, which are easily visible on Google Earth, are not nests. Rather, they are the result of the insects' slow and steady excavation of a network of interconnected underground tunnels. The termites' activities over thousands of years has resulted in huge quantities of soil deposited in approximately 200 million cone-shaped mounds, each about 2.5 meters tall and 9 meters across.

"These mounds were formed by a single termite species that excavated a massive network of tunnels to allow them to access dead leaves to eat safely and directly from the forest floor," says Stephen Martin of the University of Salford in the UK. "The amount of soil excavated is over 10 cubic kilometers, equivalent to 4,000 great pyramids of Giza, and represents one of the biggest structures built by a single insect species."

"This is apparently the world's most extensive bioengineering effort by a single insect species," adds Roy Funch of Universidade Estadual de Feira de Santana in Brazil. "Perhaps most exciting of all—the mounds are extremely old—up to 4,000 years, similar to the ages of the pyramids."

The mounds are largely hidden from view in the fully deciduous, semiarid, thorny-scrub caatinga forests unique to northeastern Brazil. They'd only really come into view by "outsiders," including scientists, when some of the lands were cleared for pasture in recent decades.

Soil samples collected from the centers of 11 mounds and dated indicated that the mounds were filled 690 to 3,820 years ago. That makes them about as old as the world's oldest known termite mounds in Africa.

The researchers investigated whether the strangely regular spatial pattern of the mounds was driven by competition amongst termites in neighboring mounds. Their behavioral tests found little aggression at the mound level. That's compared to obvious aggression amongst termites collected at greater distances from one another.

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The scoop on how your cat's sandpapery tongue deep cleans

November 19, 2018 by Lauran Neergaard

Cat lovers know when kitties groom, their tongues are pretty scratchy. Using high-tech scans and some other tricks, scientists are learning how those sandpapery tongues help cats get clean and stay cool.

The secret: Tiny hooks that spring up on the tongue—with scoops built in to carry saliva deep into all that fur.

A team of mechanical engineers reported the findings Monday, and say they're more than a curiosity. They could lead to inventions for pets and people.

"Their tongue could help us apply fluids, or clean carpets, or apply medicine" to hairy skin, said Georgia Tech lead researcher Alexis Noel, who is seeking a patent for a 3D-printed, tongue-inspired brush.

Cats are fastidious, spending up to a quarter of their waking hours grooming. Noel's interest was piqued when her cat, Murphy, got his tongue stuck in a fuzzy blanket. Scientists had long thought cat tongues were studded with tiny cone-shaped bumps. Noel, working in a lab known for animal-inspired engineering, wondered why.

First, CT scans of cats' tongues showed they're not covered in solid cones but in claw-shaped hooks. They lie flat and rear-facing, out of the way until, with a twitch of the tongue muscle, the little spines spring straight up, she explained.

The big surprise: Those spines contain hollow scoops, Noel found. Turning to zoos and taxidermists for preserved tongues to examine, she found bobcats, cougars, snow leopards, even lions and tigers share that trait.

When Noel touched the tips of preserved spines—called papillae—with drops of food dye, they wicked up the liquid. A housecat's nearly 300 papillae hold a small amount of saliva that's released when the tongue presses on fur, and then they wick up some more. 

The tongue's surface is wetter. But Noel saw clues that the spines were key to deep cleaning.

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NW Hawaiian Island Vanished: Was Critical Breeding Ground for Turtles, Monk Seals & Birds - via Herp Digest

Sorry, A Belated Difference of Opinion- Variations of this article appeared all over the net, including the New York Times. But George Balazs, who has been studying green turtles in Hawaii for over 40 years has a less sensational view of the story. (See bottom)

Attribution: U.S. Dept of Fish & wildlife

East Island of French Frigate Shoals after major hurricane Walaka. The sand that made up the island can be seen underwater in the center of the image. Waves pushed it into a deep lagoon in the center of the shoals that were around the island.

Oct 23, 2018 

Seven government scientists, who were on teams that had been studying and protecting endangered monk seals, green turtles and sea birds at French Frigate shoals East Island for decades, had to evacuate East Island on October 2 ahead of category 4 hurricane Walaka, one of the strongest hurricanes on record in the central Pacific. The island was the breeding ground for about half of Hawaii’s endangered green sea turtles and 30% of Hawaii’s highly endangered monk seals. When scientists recently examined satellite photos after the hurricane they discovered the whole half-mile long 400 ft wide island had vanished.

East Island, French Frigate shoals, NWHI, before & after Hurricane Walaka About Hawaiian Hurricane Walaka washing away the green turtle (honu) nesting island of Hikina (East) in the Northwestern Hawaiian Islands:

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https://bit.ly/2PUruct

For another point of view, less alarmist, from someone who has been studying Hawaiian sea turtles for 40 years George Balazs

“Surely this is one of the most exciting times of my 48-year career working with Hawaiian green turtles! The loss of East Island at French Frigate Shoals started decades ago documented by photo evidence. It is part of a natural long term process where sand, unlike stone, comes and goes, accumulates and then washes away in cycles. Sea turtles for millennia have always been able to adapt to such changes. If they hadn't they would all have gone extinct long ago. The Hawaiian green turtle population is robust, durable and incredibly adaptive. They will figure out where to nest new and it will be insightful and amazing to watch it happen over the next few years. With Confidence in both Mother Nature and the Honu,” 

Earth's Smallest Ape Weighed 8 lbs., Lived 12.5 Million Years Ago

By Owen Jarus, Live Science Contributor | November 6, 2018 04:00pm ET

The remains of the smallest ape ever known to walk the Earth may have been discovered in the hills of Kenya, scientists say.

Weighing around 7.7 pounds (3.5 kilograms), the ape lived around 12.5 million years ago in Kenya. While other species of small ape are known to have existed, this one may be the smallest, scientists wrote in a paper set to be published in December in the Journal of Human Evolution.

Named Simiolus minutus, the new species is known from only three tiny teeth, one of which was discovered by James Rossie, an anthropology professor at Stony Brook University in New York, during fieldwork in Kenya's Tugen Hills, in 2004. [In Photos: A Game-Changing Primate Discovery]

Rossie and his co-author, Andrew Hill, an anthropology professor at Yale University who died in 2015, examined the tooth to see if it matched any known species of ape. It did not, though the tiny tooth is anatomically similar, they found, to two other teeth uncovered in previous paleontological expeditions in Kenya. They concluded that the three teeth belong to a new species of ape.

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