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Male lions form coalitions to protect territory, increase mating opportunities

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Oct. 16 (UPI) — Male animals must compete with one another for food, territory and mates. Despite this, male lions prefer to work with one or more partners.

To better understand the how’s and why’s of coalition-building among lions, biologists from the Wildlife Institute of India and the University of Minnesota turned to the Asian lion, a single lion population confined to the forests of India’s Gir National Park.

In a previous study, researchers were able to show that lion pairs had greater access to mating opportunities and were better able protect their territories than solitary lions.

“However, a lack of genetic data from the population at this stage had prevented us from determining if such cooperation extended to relatives only, or whether non-kin were included as well,” Stotra Chakrabarti, a postdoctoral research associate at the University of Minnesota, said in a news release.

For the latest study, published Friday in the journal Scientific Reports, researchers combined behavioral and genetic records of known mothers, offspring and siblings to better estimate the level of relatedness between cooperating lions.

The lions of Gita don’t just form pairs. Some lions form coalitions of three or four males. Researchers found lion trios and quartets were consistently composed of brothers and cousins. Their analysis also showed more than 70 percent of pairs were formed by unrelated lions.

“Forgoing mating opportunities is generally a severe evolutionary cost, unless in doing so you help related individuals,” said study co-author Joseph Bump, associate professor at the University of Minnesota. “As a consequence, this evidence supports a conclusion that large male lion coalitions are feasible only when all partners are brothers and/or cousins.”

Researchers found larger coalitions fared best, but the fitness of individual lions, the number of possibly sired offspring, was greater among pairs.

“The results of our study show that male coalitions prosper better than loners in established lion societies and this can have crucial implications for their conservation, especially when establishing new populations through reintroductions,” said YV Jhala, principal investigator of the Gir lion project and the dean of the Wildlife Institute of India.

The integration of field observations and genetic data allowed scientists to identify new forms of coalition building, including one team of lions feature a father and sun duo.

Because siblings rarely reach maturity, researchers found larger coalitions are uncommon among Gir lions, making up just 12 to 13 percent of male teams.

Scientists also determined that among pairs, related lions weren’t more likely to support one another during fights than unrelated lions.

“This shows that kin support is not the only reason why males cooperate with each other, but kin support makes the cooperation even more beneficial,” Bump said.

Overall, the findings suggest cooperation among lions is quite complex — a topic ripe for further investigation.

“We have quantified the ultimate reasons why unrelated males team up, but it would be worthwhile to investigate other aspects of male cooperation, including how their bonds are forged in the first place, how they find compatible partners, what breaks the ice between them when they first meet and how they decide who will lead and who will follow,” lead study author Chakrabarti said.



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Scientists program robot swarm to count penguins

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Oct. 28 (UPI) — Penguins occupy ecosystems increasingly vulnerable to climate change. Tracking their abundance and distribution is vital to the project of tracking global warming’s ecological effects — but counting penguins is difficult work.

To make the task of tallying the size of penguin colonies a bit easier, researchers recruited the assistance of not one robot, but a whole swarm of bots.

“The idea actually grew out of a conversation at my sister-in-law’s wedding,” Mac Schwager, an assistant professor of aeronautics and astronautics at Stanford University, told UPI in an email. “I met our co-author Annie Schmidt at the wedding, and learned that she studies penguin populations in Antarctica, and one of their key challenges was counting the penguins.”

“I told her I worked with autonomous groups of drones that could be used to take images for counting the penguins,” Schwager said. “At that point, it was clear that we had a great research synergy.”

Researchers typically use a single drone to conduct aerial surveys of penguin colonies, but the process is slow and requires a lot of time, effort and skill from the drone pilot.

In collaboration with Schmidt and her team of biologists, Schwager and Stanford grad student Kunal Shah programmed a swarm of drones to autonomously survey penguin colonies.

The team of scientists described their novel solution in a new paper published Wednesday in the journal Science Robotics.

“Our main technical innovation is our path planning algorithm, the computer program that decides where each drone should go and when,” Schwager said. “Existing methods typically plan paths like a lawnmower, or a vacuum cleaner, going back and forth over the survey area.”

“It turns out, other paths can be much more effect, in the sense that they can take the same images while requiring less back-tracking, and while making sure that the drone is close enough to the base camp to make it back safely with the remaining battery life.”

Previously, it took scientists three days to survey Antarctic penguin colonies using a solitary, hand-piloted drone. The robot swarm programmed by Schwager and his colleagues completed surveys in just two to three hours.

Time is precious in Antarctica, where animals are often on the move and weather can quickly take a turn for the worse. But speed isn’t the swarm’s only advantage. The self-piloted robots also offer reliability.

“If one drone fails, the other drones can take up the slack and still finish the survey,” Schwager said.

For now, Schwager’s swarm of drones only take pictures. The counting is done back at base after the survey has been completed and the photographs downloaded onto computers. But in the future, Schwager said the drones could use artificial intelligence to count penguins as they go.

Schwager has previously programmed robotic swarms to track the movement of people and cars on the ground in order to analyze pedestrian and vehicular traffic patterns, and he thinks similar algorithms could be adopted to track animal movements.

“The system could also be used to survey forests and other landscapes for wildfire risk, a problem that is very close to home right now for us at Stanford,” he said. “We could also use the drones to survey construction sites, mining sites, agricultural fields, to assess damage after a natural disaster, or to help find lost hikers.”

Biologists and study co-authors Schmidt and Grant Ballard are currently testing the drone aerial survey system in Antarctica. Meanwhile, Schwager and his colleagues at Stanford continue to make tweaks to the system to help the drones make better in-flight decisions and avoid collisions with birds or drones that have gone astray.

“We are passionate about using teams of autonomous drones to help us to understand and take care of the natural environment around us,” Schwager said.



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Fight judges favor aggression over skill, study shows

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Oct. 28 (UPI) — Often to the chagrin of fans and competitors, wrestling matches, boxing bouts, mixed martial arts and other types of combat competitions are frequently decided by judges.

That’s bad news for competitors that rely more on skill than vigor. New research suggests judges are more likely to award victory to aggressive fighters than skilled fighters, all else being equal.

For the study, published this week in the journal Biology Letters, researchers analyzed data collected from 550 men’s and women’s mixed martial arts contests organized by the Ultimate Fighting Championship.

The data included the percentage of strikes that landed firmly and accurately, a measure of skill, as well as the number of strikes attempted per second, a measure of vigor or aggression.

Regardless of the match conclusion, whether decided by knockout or judges’ decision, the data showed the victor was the more vigorous fighter. However, the correlation between vigor and victory was strongest for matches decided by the scores of the judges.

Fighting skillfully wasn’t entirely discounted. The data showed addition of skill enhanced the advantage of vigor, but the research showed vigor was the most important factor for fights decided by the judges.

“MMA is a fast paced sport and one of the suggestions from our research would be that judges may find vigor easier to assess than skill,” lead author Sarah Lane, postdoctoral research fellow at the University of Plymouth, said in a news release. “That, in turn, leads them to overvalue it when making their decisions, especially in longer fights where one fighter tires more quickly and the disparity in vigor is easier to spot.”

“The advance of technology such as instant replays could potentially counter this, but until they are employed more regularly rate of attack is likely to remain the most important performance trait for victory by decision,” Lane said.

The research was funded by the Biotechnology and Biological Sciences Research Council, which supports studies focused on the role of skill in animal contests.

Most of Lane’s time is spent studying hermit crab fighting, but the authors of the latest paper suggest their analysis of human fights could have implications for understanding physical competitions among animals.

There aren’t typically knockouts in fights between rival animals. Often, males joust and tussle to demonstrate their physical dominance to would be rivals and mates. Like in boxing, a competitor’s performance is subjective.

“Human combat sports provide a unique scenario in which to explore how performance traits such as skill and vigor are perceived, both by participants and observers,” said study co-author Mark Briffa.

“However, because of the obvious communication issues, very little is known about the accuracy with which fighting animals more widely judge the abilities of their rivals,” said Briffa, a professor of animal behavior at Plymouth.



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Graphene-based memory resistors could pave the way for brain-based computing

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Oct. 29 (UPI) — Researchers have created a new computer component capable of toggling between 16 possible memory states — the kind of computing versatility provided by brain synapses.

The new component, called a graphene field effect transistor, described Thursday in the journal Nature Communications, could pave the way for advances in brain-inspired computing.

Modern computers are exclusively digital, featuring two states: on-off or zero and one. Engineers at Penn State University are working to build a computer that replicates the brain’s analog nature, capable of hosting many different states.

If a digital computer’s information processing components work like a light switch, toggling only between on and off, then an analog computer is like a light dimmer.

Scientists have been investigating the potential of brain-based computing for decades, but analog computers have been overshadowed by the advances in traditional computing power. However, the rise of big data and smart devices like self-driving cars has highlighted the need for more computing efficiency.

“We have powerful computers, no doubt about that, the problem is you have to store the memory in one place and do the computing somewhere else,” lead researcher Saptarshi Das, an assistant professor of engineering science and mechanics at Penn State, said in a news release.

All the movement of information required by the bifurcation of memory to logic in modern computers puts a strain on speed. It also requires more spaces. Das and his research partners estimate that their graphene field effect transistor can help eliminate this bottleneck.

“We are creating artificial neural networks, which seek to emulate the energy and area efficiencies of the brain,” said study first author Thomas Shranghamer.

“The brain is so compact it can fit on top of your shoulders, whereas a modern supercomputer takes up a space the size of two or three tennis courts,” said Shranghamer, a doctoral student in the Das group.

Brain synapses can be quickly reconfigured to create a variety of neural network patterns. Likewise, the new graphene field effect transistor, formed by a one-atomic-thick layer of carbon atoms, can be used to control 16 possible memory states.

Researchers were able to reconfigure the transistor, effectively toggling between memory states, by applying a brief electric field to the graphene layer.

“What we have shown is that we can control a large number of memory states with precision using simple graphene field effect transistors,” Das said.

Das and his research partners are now looking to work with semiconductor companies to attempt to scale-up the production of the new technology.



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