【推荐1】Spider monkeys have long, thin arms with hook-like hands that allow them to swing through the trees. They do not have opposable thumbs (对生拇指).

The brown-headed spider monkey has a prehensile (缠绕性的) tail, which means it can grasp and can be used like a fifth leg to grab trees. During the day, the spider monkey searches for fruits, which make up the main part of its diet. They will also eat flowers, seeds，leaves, and small insects during the dry season when fruits aren’t available. They spend most of the daylight hours climbing and swinging through the high branches of trees.

The brown-headed spider monkey lives in a large community of about 20 to 100 male and female monkeys. They split into smaller groups for feeding. Females usually give birth to only a single baby each year or two. Young monkeys are carried on their mothers’ stomachs until about 16 weeks old. Then they are strong enough to ride on their mothers, backs. All brown-headed spider monkey babies are born with pink faces and ears.

Spider monkeys hug each other and wrap their tails around each other. They are very intelligent and have strong memories. They were named spider monkeys because they look like spiders as they hang upside down from their tails with their arms and legs swinging. Their genus (属) name is Ateles, which means “imperfect”. This refers to the fact that they don’t have thumbs.

Hunting the brown-headed spider monkey is now barred in Ecuador, a country in northwestern South America, but humans have killed them for their meat for hundreds of years.

【推荐2】I fell in love with rhinos when I worked in a zoo in the 80s, and spent much of the next 20 years as the keeper of the largest captive (圈养的) group of rare black rhinos.

There’s a popular misconception that rhinos are aggressive and stupid, but I found them sensitive and affectionate animals. Weighing over a ton, black rhinos are unexpectedly agile (敏捷的) and have an unpredictable nature — but, given reassurance, they tend to believe people. In the past few decades, their numbers have dropped dramatically. In recent years, I’ve helped look after rhinos being moved to the reserve so they can form new populations in countries that have few left. Last year, I helped on a project to fly five black rhinos from a private reserve in South Africa to the Serengeti National Park. Once there, the animals had to be kept captive for a few weeks to adapt to the new environment, in which time they lived in “bomas” — wooden enclosures with “bedrooms”, designed to create a calm space.

A couple of weeks before their planned release, the sky filled with smoke. Watching the flames rushing through the bush toward the bomas, I froze. Terrified that it would catch fire, my instinct was to release the rhinos, but they hadn’t yet been fitted with transmitters (发信器). If I let them out into a bushfire and they were injured, we’d have great difficulty tracking them down. So I dashed back to the bomas and called the rhinos to the bedrooms. Sensing the fear in my voices, they moved without hesitation and remained astonishingly calm. It was crucial the rhinos didn’t panic — they can easily hurt each other if they do.

That we and the rhinos had escaped safe and sound was a miracle. The teamwork of everybody there played a large part, and the rhinos were very much a part of that team. The relationships we’d built with them had proved crucial — had they or we panicked, all our work would have been in vain.

【推荐3】One of the great concerns that ornithologists have is that climate change will throw the nesting activities of birds out of sync (同步) with the availability of food for the raising of chicks. For one species, the pied flycatcher, a new study shows that some of its clan are proving to be remarkably adaptable.

Upon returning to Europe from their African wintering grounds, the flycatchers time their egg-laying to the short period when juicy caterpillars (毛毛虫) are most abundant. During the past three decades this caterpillar peak has advanced by three weeks. Pied flycatchers initially had difficulty adjusting, but over time have started laying their eggs earlier to grab the caterpillars. Some, though, are doing a lot more to improve their reproductive chances of success, according to a study in the Journal of Avian Biology led by Christian Both of the University of Groningen, in the Netherlands.

Like most bird species, pied flycatchers have long been thought to lay a single clutch of eggs during the breeding (繁殖) season. This was widely considered to be a trait that wouldn’t change. Then, in 2007, a Swiss team led by Dr Ravussin began to suspect that clutch numbers were flexible. They discovered a female pied flycatcher that immediately produced a second brood with a new male after raising an early set of chicks. Aware of Dr Ravussin’s findings, Dr Both wondered whether this was just a single, odd instance or if second broods might be happening on a larger scale driven by the arrival of earlier springs. So, they cooperate to delve into the data to find out.

The team studied pied-flycatcher populations in the Netherlands and Switzerland that were known to be among the earliest nesting members of the species. In total, they tracked the egg-laying times and hatchling-rearing success of 8,848 breeding pairs in the Netherlands and1,372 in Switzerland between1980 and 2018. They found that since 2006, 11 cases of second broods were observed, all of them among the earliest breeders in both populations.

Further studies ruled out that the birds were making up for a failed first attempt at raising chicks or that the second group of nestlings suffered.

With no obvious downside to laying a double clutch, Drs Both and Ravussin conclude that the birds are attempting to double their annual reproductive output. While this behavior is still rare, they argue that if the tendency is driven by heritable genes (which it may well be) , then a succession of early springs could make the strategy much more common.

【推荐2】Since we are vulnerable when we sleep, sleep must play a critical role, or evolution wouldn’t have selected for it. Early humans had to hunt, gather food and protect themselves. Those activities consumed much time, so unless sleep served very important purposes, those who slept less would have an advantage. Yet sleeping for long hours of the night was kept for years, but scientists had only general ideas about what happened during sleep. Recently, Dr. Chiara Chiarelli, a neuroscientist, shared what sleep neuroscience research has discovered.

Neural (神经的) networks in the brain are connected through synapses (神经突触) which allow signals to flow throughout the brain and onto cells. During waking hours, new learning can strengthen the connections. You can think of knowledge acquired over a long time as a group of well-connected neural paths. When you learn something new, new paths are connected to the old. During the waking hours, your brain processes massive amounts of new insignificant information, say remembering where you parked your car. But that memory has to be preserved at least until you reach the car. It establishes a new connection to your memory of what your car looks like, a well-established “old” memory. The brain creates so many connections daily that particular circuits can be heavily burdened.

Dr. Cirelli explained that during sleep, a great many synaptic connections are weakened so that connections are more available for new learning the next day. Continuing with the parked car example, the exact location of the parked car is not needed again, so the connections are weakened. In fact, if it were not, you might memorize hundreds of places where you have parked, leading to considerable confusion!

You don’t have to be a scientist to understand that not sleeping well affects next day functioning — this is common cultural wisdom. Dr. Cirelli’s research is an example of science showing the “why” and “how” mechanisms that underlie that wisdom.