Bats in the Netherlands, video


This 31 October 2019 video is about bats in South Holland province in the Netherlands.

Saharan silver ants, short-legged but world’s fastest


This 29 October 2019 video says about itself:

Watch Saharan silver ants run | Science News

Slowed-down videos of silver ants on a portable runway in the Sahara sun show how the synchronized movements of three legs at a time let the ants achieve high speeds. As an ant runs, a trio of legs (the right front, right rear and left middle circled) touch down only briefly (white circles, ground phase) and then swing forward rapidly (black circles, swing phase). The final video clip shows an ant rushing by in real-time.

By Susan Milius in Science News, October 29, 2019 at 12:26 pm:

Saharan silver ants are the world’s fastest despite relatively short legs

At top speeds, these scavengers basically gallop, with all six legs in the air at once

The world’s newly crowned fastest known ants don’t look as if they’ve got the legs to be champs.

Saharan silver ants (Cataglyphis bombycina) have merely runner-up proportions, with legs about 18 percent shorter than those of a related desert ant (C. fortis). Yet adjusting for body length, video shows silver ants rushing along about twice as fast as their leggier cousins.

Sarah Pfeffer of the University of Ulm in Germany and colleagues took a high-speed video camera to Tunisia to get that video of the shorter ants in their hot and sandy home. At an oasis on the northern edge of the great dunes, the researchers searched for glimpses of silver.

Tiny silver hairs coat the ants, reflecting some of the sun’s glare and shedding heat (SN: 6/22/15). When Pfeffer, an applied neuroethologist, digs out a nest to study, several thousand ants seething in her transport box look “like quicksilver,” she says.

That silvery protection comes in handy because the ants stay in their nests at night and scavenge for food in the furnace of midday. “The sun really burns down,” Pfeffer says. Surface sand temperatures can soar over 60° Celsius (about 140° Fahrenheit). Even at ant heights, the air is still brutal.

Silver ants, however, get two bonuses for foraging in the worst of the heat. It’s a great time to find fresh carcasses of creatures that the sun fried but that heat-averse scavengers haven’t found yet. Also, ant-hungry predators often take shelter from the heat, so silver ants are less likely to become lunch themselves.

To see how those shortish legs can run through hell, Pfeffer set up an outdoor open-topped metal runway dusted with sand. She then offered a free lunch for ants. “They love mealworms,” she says. As ants rushed along the runway, Pfeffer got high-speed film of the step details. The shorter legs compensate by packing more strides into each second, up to 47 for the silver ants running at top speed versus 36 for their taller relatives, the team reports October 16 in the Journal of Experimental Biology.

Pfeffer clocked speeds as high as 855 millimeters per second. That’s 108 times a silver ant’s body length in a second.

The camera picked up six legs moving in two groups of triplets, like alternating tripods. At higher speeds, an ant gets airborne for just an instant with no legs touching the ground. In horses, that’s galloping. Pfeffer describes it as gliding, since the ants zoom forward smoothly instead of galumphing.

That glide is fast enough to crown the dune dwellers as the fastest ant known so far, though not the fastest insect. They’re beaten, in terms of body lengths per second, by tiny mites in southern California. Young Paratarsotomus macropalpis can zoom across concrete around three times as fast (SN: 6/12/14).

Hygiea, a new dwarf planet?


This 28 October 2019 video says about itself:

A computer simulation shows how a head-on collision between two objects in the asteroid belt more than 2 billon years ago could have formed Hygiea, along with thousands of much smaller companion asteroids. After the impact initially obliterated Hygiea’s parent body, most of the fragments clumped back together into Hygiea, and the strength of their collective gravity molded them into the nearly round dwarf planet seen today.

By Maria Temming in Science News, October 28, 2019, at 12:00 pm:

The solar system may have a new smallest dwarf planet: Hygiea

New images reveal the wee world is round, a final criterion for dwarf planet status

The asteroid belt object known as Hygiea may be the new baby of the dwarf planet family.

Hygiea, currently classified as an asteroid, already met three of four requirements for dwarf planet status: It orbits the sun. It isn’t a moon. And it hasn’t swept its orbital path clear of other space rocks, the way fully-fledged planets are able to. Now, new telescope images reveal that Hygiea is nearly spherical, which checks the last box to qualify as a dwarf planet.

If officially reclassified by the International Astronomical Union, Hygiea would join the handful of dwarf planets, including Pluto, in our solar system (SN: 5/25/18). About 430 kilometers across, Hygiea would unseat Ceres, with its 950-kilometer diameter, as the smallest dwarf planet discovered in our solar system, researchers report online October 28 in Nature Astronomy.

High-resolution images from the Very Large Telescope in Chile confirmed that Hygiea is about as round as Ceres — and that its surface isn’t marred by a huge impact basin. That was a surprise for the researchers, led by astronomer Pierre Vernazza of the Laboratoire d’Astrophysique de Marseille in France. They had expected to see an enormous crater from a collision billions of years ago that formed Hygiea’s entourage of over 6,800 small asteroids. By comparison, the asteroid Vesta sports a huge scar from the formation of its own, smaller asteroid swarm.

Computer simulations run by Vernazza’s team offer a possible explanation: More than 2 billion years ago, a space rock about 100 kilometers across completely shattered Hygiea’s parent body. When most of the remnants clumped back together into the space rock now known as Hygiea, they formed the smooth, spherical body seen today. By contrast, Vesta — about three times as massive as Hygiea and struck by 65-kilometer object — merely had some of its material carved out, leaving behind a big divot.

Freed bats keep friends from captivity days


Thus 2012 video says about itself:

When it comes to feeding, this thumb-sized bat definitely sides with Dracula. Vampire bats are the only mammals on an all-blood diet — and an unsuspecting cow is the perfect prey.

From ScienceDaily:

After release into wild, vampire bats keep ‘friends’ made in captivity

October 31, 2019

Vampire bats that share food and groom each other in captivity are more likely to stick together when they’re released back into the wild, find researchers in a study reported on October 31 in the journal Current Biology. While most previous evidence of “friendship” in animals comes from research in primates, these findings suggest that vampire bats can also form cooperative, friendship-like social relationships.

“The social relationships in vampire bats that we have been observing in captivity are pretty robust to changes in the social and physical environment — even when our captive groups consist of a fairly random sample of bats from a wild colony,” said Simon Ripperger of the Museum für Naturkunde, Leibniz-Institute for Evolution and Biodiversity Science in Berlin. “When we released these bats back into their wild colony, they chose to associate with the same individuals that were their cooperation partners during their time in captivity.”

He and study co-lead author Gerald Carter of The Ohio State University say their findings show that repeated social interactions they’ve observed in the lab aren’t just an artifact of captivity. Not all relationships survived the transition from the lab back into the wild. But, similar to human experience, cooperative relationships or friendships among vampire bats appear to result from a combination of social preferences together with external environment influences or circumstances.

Carter has been studying vampire bat social relationships in captivity since 2010. For the new study, he wondered whether the same relationships and networks he’d been manipulating in the lab would persist or break down after their release in the wild, where the bats could go anywhere and associate with hundreds of other individuals.

Studying social networks in wild bats at very high resolution hadn’t been possible until now. To do it, Simon Ripperger and his colleagues in electrical engineering and computer sciences developed novel proximity sensors. These tiny sensors, which are lighter than a penny, allowed them to capture social networks of entire social groups of bats and update them every few seconds. By linking what they knew about the bats’ relationships in captivity to what they observed in the wild, they were able to make this leap toward better understanding social bonds in vampire bats.

The researchers found that shared grooming and food sharing among female bats in captivity over 22 months predicted whom they’d interact with in the wild. While not all relationships survived, the findings suggest that the bonds made in captivity weren’t just a byproduct of confinement and limited options. The researcher report that the findings are consistent with the idea that both partner fidelity and partner switching play a role in regulating the bats’ relationships.

“Our finding adds to a growing body of evidence that vampire bats form social bonds that are similar to the friendships we see in some primates,” Carter said. “Studying animal relationships can be a source of inspiration and insight for understanding the stability of human friendships.”

The researchers say they’ll continue to work on individual differences in cooperativeness among vampire bats and exploring how individuals go from being strangers to cooperation partners. Taking advantage of their newfound abilities to measure relationships in the wild, they’re also looking into social foraging and whether bats that cooperate within their day roost also go hunting together at night.

This work was supported by the Deutsche Forschungsgemeinschaft, a Smithsonian Scholarly Studies Awards grant, and a National Geographic Society Research Grant.

See also here.

Rare Bermuda petrels are back on their nest


This video from Bermuda says about itself:

Adult Cahow Makes First Visit of the 2020 Breeding Season — Oct. 23, 2019

An adult [male] cahow returned to the Cahow cam nesting burrow on October 23, meaning the November courtship period will likely soon be underway for the pair inhabiting this nest site. Now we wait for its mate to return!

Both the 2017-2018 cam burrow and the original 2013-2014 burrow are visible, as well as two different views of Nonsuch Island (where the cams are based).

The CahowCam is a collaboration between the Cornell Lab of Ornithology and the Nonsuch Expeditions. You can watch the cam live here.

and learn more about Nonsuch Island’s environs (including the cahow) here.

The Cornel Lab of Ornithology writes:

The cahows will spend the next few weeks courting, copulating, and preparing their nest scrape for what’s to come. Watch while you can, because they won’t stay for long. Both adults will head back out to sea near the start of December before the female ultimately returns to lay a single egg in early January.