Despite the fact that parrots are well known for their long lives and complex cognition (认知), it remains unknown whether the two features have influenced each other, “The problem has been sourcing good quality data,” says Simeon Smeele, a doctoral student at the Max Planck institute of Animal Behavior (MIP-AB) and lead author of the study.

To generate a large sample size, the scientists teamed up with Species360, which draws on animal records from zoos. Together, they gathered data from over 130,000 individual parrots sourced from over 1,000 zoos. This database allowed the team to gain the first reliable estimates of the average life expectancy of 217 parrot species.

The analysis revealed an astonishing diversity in life expectancy, ranging from an average of two years for the fig parrot up to an average of 30 years for the scarlet macaw (a large parrot). “Living an average of 30 years is extremely rare in birds of this size,” says Smeele.

Next, the team combined the data and ran models to determine whether or not parrots’ cognitive abilities had an influence on their longevity. Their results provide the first support that increased brain size has enabled longer life expectancy in parrots. Because brain size relative to body size can be an indicator for intelligence, the findings suggest that the parrots with relatively large brains had cognitive capabilities that allowed them to solve problem in the wild that could otherwise kill them, and this intelligence enabled them to live longer lives. “This supports the idea that in general larger brains make species more flexible and allow them to live longer,” says Smeele.

In the future, the team plans to explore if sociality and cultural learning in parrots might have also contributed to long life expectancy. Smeele says, “Large-brained birds might spend more time socially learning foraging (觅食) techniques that have been around for multiple generations. This increased learning period could potentially also explain the longer life expectancy, as it takes more time but also make the foraging techniques more adaptive.”

Many kinds of birds are very successful at fooling other animals. For example, a bird called the plover sometimes pretends to be hurt in order to protect its young. When a predator (猎食动物) gets close to its nest, the plover leads the predator away from the nest. How? It pretends to have a broken wing. The predator follows the “hurt” adult, leaving the baby birds safe in the nest.

Another kind of bird, the scrub jay, buries its food so it always has something to eat. Scrub jays are also thieves. They watch where others bury their food and steal it. But clever scrub jays seem to know when a thief is watching them. So they go back later, unbury the food, and bury it again somewhere else.

Birds called cuckoos have found a way to have babies without doing much work. How? They don’t make nests. Instead, they get into other birds’ nests secretly. Then they lay their eggs and fly away. When the baby birds come out, their adoptive parents feed them.

Chimpanzees, or chimps, can also be sneaky. After a fight, the losing chimp will give its hand to the other. When the winning chimp puts out its hand, too, the chimps are friendly again. But an animal expert once saw a losing chimp take the winner’s hand and start fighting again.

Chimps are sneaky in other ways, too. When chimps find food that they love, such as bananas, it is natural for them to cry out. Then other chimps come running. But some clever chimps learn to cry very softly when they find food. That way, other chimps don’t hear them, and they don’t need to share their food.

As children, many of us learn the saying “You can’t fool Mother Nature.” But maybe you can’t trust her, either.

Chimps live in a male-dominated society, where most of their valuable partners are other males. However, as young male chimps become adults, they continue to maintain tight bonds with their mothers, a new study finds.

The dramatic changes of adolescence (青春期) are difficult for chimps, just like they are for humans, says Elizabeth Lonsdorf, an expert on primates at Franklin & Marshall College who was not involved in the study. “Sure enough,” she adds, “their moms remain a key social partner during this time.”

Previous research has shown chimp mothers provide their sons with support that goes far beyond nursing. Young male chimps that are close with their moms grow bigger and have a greater chance of survival. What’s more, losing their mothers after weaning (断奶), but before age 12, gets in the way of the ability of young chimps to win other males and reproduce.

To see whether this bond extends later into life, researchers followed 29 adolescent (9 to 15 years old) and young adult (16 to 20 years old) male chimps at a research site in Kibale National Park in Uganda and observed them from a distance for 3 years. The team found that the young adult males spent less time with their mothers than the adolescents did — 26% vs. 76%. As the male chimps grew older and more independent, they began to travel over wider ranges and spent more time away from their moms.

However, when these young adult males happened to be in the company of their mothers, they acted just like the adolescents. They groomed (梳理) their moms just as often and kept track of them. “Many mothers remained the males’ ‘best friends’, or ‘social partners’ they associated with most frequently,” says study co-leader Rachna Reddy from Harvard University.

Such persistent ties are also common in humans after sons leave their mothers and live on their own — especially in tough times, Reddy says. “We really feel what it’s like to not be able to see our mothers when we want to in tough times. The importance of those bonds in our lives and the comfort we get from them have deep evolutionary roots.”