2 . If you’ve ever seen elephant seals (象海豹) lying on a beach, you might think that they’re always. sleeping. But in fact, they spend about seven months of the year in the ocean. So how do they sleep while they’re in the ocean?

Even though elephant seals are large animals, they have to be careful in the ocean. Near the surface, some dangerous animals like sharks might attack(攻击)them. So elephant seals spend most of their time diving (下潜) deep underwater, looking for food.

To find out how they sleep in the deep, a scientist named Jessica Kendall-Bar created a special cap. She and her team put the caps on thirteen female young elephant seals. The caps recorded the elephant seals brain activities. They also collected information on the elephant seals’ heart rates (心率), how their bodies were moving, and how deep they were.

The scientists learned that elephant seals sometimes sleep for a short time while they are diving. They only sleep for about 10 minutes at a time. As they begin to sleep, the elephant seals can control their bodies. But when they are deeply asleep, they simply begin to fall, spinning (快速旋转) in a circle “like a falling leaf”. The elephant seals wake up in time to go up for more air. In shallower (较浅的) areas, the elephant seals sometimes wake upon the seafloor.

Using the information they collected from the cap-wearing elephant seals, the scientists created a computer program to study older records of elephant seal trips. The scientists found that elephant seals only sleep for about two hours a day when they’re in the ocean. That means that the rest on land is very important for them. Back on land, they sleep for about 10. 8 hours a day.

The scientists hope that their work will help to protect the places where elephant seals sleep when. they’re on land.

3 . Tiny, black-capped chickadees (北美山雀) have big memories. They store food in hundreds to thousands of different locations in the wild—and then come back to these places when other food sources are low.

Scientists have known that chickadees have incredible memory skills. That memory can be a matter of life or death for these birds when there are no enough food resources in colder months.

Some researchers thought that neurons called place cells (细胞) would explain these birds’ ability to remember where their food is stored. These cells are known to include information about where things are in space. But recently, Selmaan Chettih and his team found that each time a chickadee hides a seed (种子) in a specific location, a unique brain pattern appears—separate from place cells.

To observe this, Chettih and his team created special areas with lots of feeders filled with sunflower seeds. They put small flaps (片状下垂物) where birds could hide seeds.

The scientists tracked the activity in their brains. Each time a bird hid a seed under a flap, researchers saw a brief unique brain pattern appear—what they called the bar code. Different patterns appeared even if the birds hid many seeds in the same location. When the birds revisited these sites and retrieved the hidden seeds, the same bar code-like pattern appeared again, as though all the information about each location and seed were related to a unique brain pattern.

The researchers compared these memories to episodic memories in humans, which are memories of specific events or personal experiences. They’re important to how humans connect time, people, places and sensory information together.

Chettih says that this seed-hiding behavior has a clear pattern of activity, which may help researchers build a structure for how the brain creates and stores memories.

6 . Lucy was rescued from a rural farm in New South Wales, Australia, two years ago. She was suffering from chlamydia (衣原体病), a disease widespread among koalas. Today, she is one of “the lucky” living creatures in tree corridors (走廊) that have been created by volunteers to protect koalas and other animals by saving their quickly shrinking habitats, or natural environment.

The corridors, planted by the local conservation group Bangalow Koalas, are made up of large systems of plants. They are intended for koalas and other animals like the glossy black cockatoos, possums, and wallabies. All of them are endangered, or at risk of becoming extinct. The corridors provide a safe path across the koala’s increasingly broken habitat. “Our corridors are actually trying to get them away from humans, from cars and from dogs,” said Linda Sparrow, president of Bangalow Koalas. “They can safely move across the landscapes and don’t have to put up with us humans.”

The koala is predicted to be extinct in the wild in New South Wales by 2050. Some of the biggest dangers include wildfires and habitat loss through land clearing for development. Koalas have already been declared endangered in several Australian states. A recent report by the Australian Koala Foundation said the animal was worth an estimated $3.2 billion per year to the tourism industry.

Founded in 2016, Bangalow Koalas has planted over 936,000 trees on 119 properties, helping koala conservation and improving the local ecosystem. The group, which depends on com munity volunteers, aims to plant 500,000 trees by 2025. Volunteer Lindy Stacker, who has been planting trees for over five years, still remains devoted to the cause. She said the activity is good for mental health and has brought the community together. “I can’t imagine a world where there’s no koalas in the wild. We’re going to do everything we can possibly to. make sure that won’t happen,” Lindy said.

9 . Bees are responsible for one in every three bites of food: from almonds (杏仁) to berries and the alfalfa (苜蓿) that feeds dairy cows. Our diets and agricultural economy hinge on a healthy bee population.

However, rapid declines in bee population around the world put additional stress on an already unstable food supply by depressing yields and agricultural efficiency. While bee biologists do not foresee upcoming food system collapse without honey bees, we do know that agriculture would quickly become unrecognizable—and much more limited.

Farmers are on the frontlines of the economic impacts of bee decline. For example, the cost of almond pollination (授粉) has nearly tripled since colonies began collapsing in 2004, costing that industry over $83 million per year.

The causes behind recent bee declines are not a “mystery”. Independent scientists now largely agree that bee declines are caused by a combination of several factors, including: poor nutrition, habitat loss and pesticide (杀虫剂) exposure.

In the last several years, pesticides — both alone and in combination with other pesticides — have emerged as a key catalyst (催化剂) behind this disturbing phenomenon, both because of their direct toxicity to bees and their indirect and cascading effects.

Scientists know that individual bees can be acutely poisoned while flying through pesticide-contaminated planter dust in a recently planted corn field. More commonly, they are chronically poisoned at sublethal (亚致死) levels by eating and drinking contaminated pollen, nectar and water over time. Bees are then more likely to get sick.

As an indicator species, honey bees are sounding an alarm that we ignore at our peril. Among their lessons: industrial agriculture has gone off the rails. The pesticide treadmill has kicked into high gear with a class of dangerous systemic pesticides—while regulators were asleep at the switch. So let’s keep the heat on decision makers to take meaningful action.