A new study from Lund University in Sweden shows that the presence or absence of moonlight has a considerable effect on when migratory (迁徙的) birds take flight in the autumn.

Together with his colleagues, Gabriel Norevik studied European nightjars (夜莺) and how the lunar cycle and moonlight affect the leaving time when the birds start their three-month-long migration flight to areas south of the Sahara.

Using miniature (微型) data loggers the researchers recorded the activity of 39 European nightjars over a one-year period. The result shows that the birds begin their autumn migration south about ten days after the full moon, and that the individual birds synchronise (同速进行) the migration and fly off more or less at the same time. “It surprised us that the lunar cycle and the time the birds spent in hunting insects covary so well. This in turn affects their migration pattern in such a way that they synchronise their flight so that almost all of them fly off at the same time ten days after the full moon,” says Gabriel Norevik. European nightjars use their sight when they hunt at night. In the moonlight they find it easier to catch flying insects and refill their energy reserves.

The birds migrate in three stages from northern European to wintering sites south of the Sahara. Each stage follows the same pattern: first the moon provides double of the light for the birds to hunt insects, and the next stage of the migration starts ten days after the full moon.

The researchers doubt whether other birds also adapt to the lunar cycle when they migrate. “We will go on to examine that and what effects this type of synchronised migration has on the birds themselves and their surroundings,” says Gabriel Norevik.

Matt Kauffman is a wildlife researcher at the University of Wyoming. He leads the Wyoming Migration Initiative, which studies the migratory (迁徙的) paths of animals like deer and elk (驼鹿) in the American state of Wyoming.

In 2019, Kauffman and other scientists were talking at a conference in Italy. He began learning that wildlife around the world had the same difficulties faced by Wyoming’s migratory deer and elk. “We just naturally got together, and nine or ten of us are working on migrations around the world,” Kauffman told Jackson Hole News & Guide. “We realized that a lot of the same things we were trying to address by mapping migrations in Wyoming were applicable globally.”

Their talk in 2019 was the beginning of an international effort that now includes 92 scientists and environmentalists. Their effort is called the Global Initiative on Ungulate (有蹄类动物) Migration. The aim is to gather information on the seasonal movements of gazelles in Mongolia and Norwegian reindeer. The hundreds of paths would then be presented in an electronic migration map. The researchers wrote a report that recently appeared in the publication Science.

The report describes how animal movements over long distances to get food and other resources are not doing so well. The main reason for the struggles comes from land development by humans. Roads and fences create barriers for the animals, restricting their movement. And the warming of the planet has also unsettled environmental systems.

Joe Ogutu studies migratory east African wildebeest, zebra and Thomson's gazelle for the University of Hohenheim in Stuttgart, Germany. Since 2015, he has watched the ungulate migration called Mara-Loita in southwestern Kenya stop working because of fence-building and sharing land space with hundreds of thousands of sheep and goats. Ogutu hopes that the Global Initiative on Ungulate Migration will bring attention to the Mara-Loita migration and other at-risk paths. “Publicity and attention,” he said, “will hopefully lead to its restoration and protection.”

The microplastics(微型塑料) problem in the oceans has made its way to sea turtles in a big way. A new study has found microplastics in the stomach of every single turtle they tested—a total of 102 sea turtles.

The researchers tested more than 100 sea turtles from all seven kinds and three different oceans, and they were looking for man-made things less than 5 mm long. The most things the team found were fibers, which most likely came from clothing and fishing equipment.

“The influence of these particles on turtles is unknown,” said Emily Duncan. “Their small size means they can pass through the stomach without causing a problem, as is frequently reported with larger plastic pieces.”

The researchers found more than 800 man-made particles in the turtles, but since they only tested part of the stomach, they believe the total number of particles could be 20 times higher. They don’t know how the turtles take in the particles, but they think they are from polluted seawater and polluted plants.

Professor Brendan Godley said that eating microplastics isn’t the biggest problem to sea turtles at the moment, but it is a clear sign that we need to do a better job watching global waste.

This turtle study shows that we need to reduce the amount of plastic waste, so we can keep clean and healthy oceans for future people.