Knowing how animals use their environments to survive and thrive is a key challenge for predicting how global climate change will affect wildlife. A global collaborative study of four species of crane has shed light on the way that migrations are finely tuned to unpredictable and complex environments.

A team from 10 countries combined novel animal tracking technology, remote-sensed information about the environment, and a new statistical framework to gain insight into four iconic species: common cranes, white-naped cranes, black-necked cranes, and demoiselle cranes.

The study, led by scientists from the Max Planck Institute of Animal Behavior and Yale University, was published in Proceedings of the National Academy of Sciences on September 23.

The researchers used tiny GPS tracking devices to follow the movements of 104 cranes in Africa, Asia, and Europe. These devices included unique solar-powered GPS leg bands developed by scientists from MPI-AB. The tracking data revealed the impressive migrations that cranes undertook.

Some of the migratory routes exceeded 6,400 km of travel round trip and required crossing barriers such as the Alps or Himalaya mountain ranges, the deserts of the Arabian peninsula, or the Mediterranean Sea.

In addition to the tracking study, the researchers also developed a statistical framework that revealed how the cranes’ movements relate to aspects of the environment, such as the presence of crops or water bodies nearby, and the temperature and vegetation cover on the land.

“Animals have to satisfy their own needs with what they can get from their environment, but both of these are changing constantly,” says Scott Yanco, first author on the study and a postdoctoral researcher at the University of Michigan.

“This creates an intriguing optimization problem that we wanted to know if cranes were solving through long-distance migration.”

The researchers found that all four crane species experienced starkly different environmental conditions over a year, and that these periods were synchronized with important events in their lives. This was particularly pronounced when comparing temperatures or resource availability on wintering and summer breeding grounds.

For some, the migrations themselves entailed huge shifts in environmental conditions. For example, the demoiselle cranes migrated across the Tibetan plateau and had to contend with massive fluctuations in temperature while doing so.

“We suspect this all has to do with different biological needs during these different times of the year,” adds Yanco, who did the research when he was at the Yale Center for Biodiversity and Global Change. For example, common cranes clearly emphasized agricultural areas during the late summer, a period that aligns with raising juveniles and preparing for fall migration.

“This is exactly when we would expect them to want easy access to food,” he says.

For other species, access to food may come at a cost. The black-necked cranes in the study had to decide between safe roosting habitat and abundant resources.

“Amazingly, the balance between these competing needs changed over the year depending on what the birds were doing,” adds Yanco. During migration they opted for safer roosting conditions, whereas during breeding they leaned towards abundant food.

“This type of shifting emphasis depending on what cranes need at any given time is what we were expecting to see,” says Ivan Pokrovsky, a postdoctoral researcher at MPI-AB and last author on the study.

“But we were blown away by how well the cranes used movement to resolve trade-offs among competing needs and to access certain environments during key periods of the year.”

Understanding how animals interact with their surroundings not only gives us a more nuanced view of how they survive in complex environments—it is crucial for developing policy and management actions to address the dual crises of climate change and biodiversity loss, the authors say.

The study’s framework offers a statistical tool for understanding the complicated relationships between animals and their environments that can be widely applied to conservation and management efforts of wildlife.

“When we know how animals use certain environmental conditions, we can make better predictions about how species might respond to human-caused global change and develop more effective interventions that ensure we preserve the conditions species need to survive,” says Pokrovsky.

Engineers at RMIT University have designed an innovative tubular structural system that can be packed flat for easier transport and pop up into strong building materials. This breakthrough is made possible by a self-locking system inspired by curved-crease origami—a technique that uses curved crease lines in paper folding.

Lead researchers Dr. Jeff (Ting-Uei) Lee and Distinguished Professor Mike (Yi Min) Xie, said that bamboo, which has internal structures providing natural reinforcement, inspired the tube design.

“This self-locking system is the result of an intelligent geometric design,” said Lee, from RMIT’s School of Engineering. “Our invention is suitable for large-scale use—a panel, weighing just 1.3 kg, made from multiple tubes can easily support a 75 kg person.”

Flat-pack tubes are already widely used in engineering and scientific applications, such as in biomedical devices, aerospace structures, robotics and civil construction, including pop-up buildings as part of disaster recovery efforts.

The new system makes these tubes quicker and easier to assemble, with the capability to automatically transform into a strong, self-locked state.

The research is published in Proceedings of the National Academy of Sciences. Other contributors to this work include Drs Hongjia Lu, Jiaming Ma and Ngoc San Ha from RMIT’s School of Engineering and Associate Professor Joseph Gattas from the University of Queensland.

“Our research not only opens up new possibilities for innovative and multifunctional structural designs, but it can also significantly improve existing deployable systems,” said Xie, from the School of Engineering.

“When NASA deploys solar arrays, for example, the booms used are tubes that were packed flat before being unfurled in space,” Lee said. “These tubes are hollow, though, so they could potentially deform under certain forces in space. With our new design, these booms could be a stronger structure.”

Xie explained that their smart algorithm enabled control over how the structure behaved under forces by changing the tube orientations.

“With our origami-inspired innovation, flat-pack tubes are not only easy to transport, but they also become strong enough to withstand external forces when in use,” Xie said. “The tube is also self-locking, meaning its strong shape is securely locked in place without the need for extra mechanisms or human intervention.”

Next steps

The team will continue to improve the design and explore new possibilities for its development.

“We aim to extend the self-locking feature to different tube shapes and test how the tubes perform under various forces, such as bending and twisting,” Lee said. “We are also exploring new materials and manufacturing methods to create smaller, more precise tubes.”

The team is developing tubes that can deploy themselves for a range of applications without needing much manual effort.

“We plan to improve our smart algorithm to make the tubes even more adaptable and efficient for different real-world situations,” Xie said.

Many sharks and rays are known to breach, leaping fully or partly out of the water. In a recent study, colleagues and I reviewed research on breaching and ranked the most commonly hypothesized functions for it.

We found that removal of external parasites was the most frequently proposed explanation, followed by predators chasing their prey; predators concentrating or stunning their prey; males chasing females during courtship; and animals fleeing predators, such as a ray escaping from a hammerhead shark in shallow water.

We found that the highest percentage of breaches, measured by the number of studies that described it, occurred in manta rays and devil rays, followed by basking sharks and then by eagle rays and cownose rays. However, many other species of sharks, as well as sawfishes and stingrays, also perform this behavior.

Why it matters

It takes a lot of energy for a shark or ray to leap out of the water—especially a massive creature like a basking shark, which can grow up to 40 feet (12 meters) and weigh up to 5 tons (4.5 tonnes). Since the animal could use that energy for feeding or mating, breaching must serve some useful purpose.

Sharks that have been observed breaching include fast-swimming predatory species such as blacktip sharks and blue sharks. White sharks have been seen breaching while capturing seals in waters off South Africa and around the Farallon Islands off central California.

However, basking sharks—enormous, slow-swimming sharks that feed by filtering tiny plankton from seawater—also breach. So do many ray species, such as manta rays, which also are primarily filter feeders. This suggests that breaching likely serves different functions among different types of sharks and rays.

The most commonly proposed explanation for breaching in planktivores, like basking sharks and most rays, is that it helps dislodge parasites attached to their bodies. Basking sharks are known to host parasites, including common remoras and sea lampreys. The presence of fresh wounds on basking sharks that match the shape and size of a lamprey’s mouth suggests that breaching has torn the lampreys off the sharks’ bodies.

Other species may breach to communicate. For example, white sharks propelling themselves out of the water near the Farallon Islands may do so to deter other sharks from feeding upon the carcass of a seal.

Researchers have seen large groups of mantas and devil rays jumping together among dense schools of plankton—presumably to concentrate or stun the plankton so the rays can more easily scoop them up. Scientists have also suggested that planktivorous sharks and rays may breach to clear the prey-filtering structures in their gills.

Understanding more clearly when and how different types of sharks and rays breach can provide insights into these animals’ life habits, and into their interactions with their own species and competitors.

How we did our work

I worked with marine scientists Tobey Curtis, Emmett Johnston, Alison Kock and Guy Stevens. Across our various projects, we have seen breaching in bull sharks in Florida, basking sharks in Ireland, white sharks in South Africa and central California, and manta rays in the Maldives. Each of us has proposed different explanations for why the animals did it.

We reviewed scientific studies and video footage to see what species had been observed to breach, under what conditions, and the functions that other researchers had proposed for them doing so. This included information gathered from data logging tags attached to sharks and rays, digital photography, and imagery from underwater and aerial drones.

Our review proposes further studies that could provide more information about breaching in different species. For example, attaching data loggers to individual animals would help scientists measure how quickly a shark or ray accelerates as it propels itself out of the water.

Experiments in aquarium tanks could provide more insight into why the animals breach. For example, scientists could add remoras to a tank containing bull sharks, which can live in an aquarium environment, and observe how the sharks respond when remoras attach themselves to the sharks’ bodies.

In the field, researchers could play audio recordings of splashes from breaches to elicit withdrawal or attraction responses from sharks tagged with ultrasonic transmitters. There remains much to learn about why these animals spend precious energy jumping out of the water.

This article is republished from The Conversation under a Creative Commons license. Read the original article.