If you're like most pet owners, you probably talk to your pet all the time, even if you feel a little silly about it. But experts say your pet is actually “talking” back to you, even if you don't totally understand what they're' trying to say. Cats and dogs are extremely cognitive(认知的)beings and communicate with us all the time. A pet's cognition starts developing as soon as they're born and changes with age just like humans.

What is cognition? 【小题1】 It involves memory, the ability to deal with a changing environment and interacting with other individuals. Just like people, pets go through age-related cognitive changes, but these changes can often be confused with physical issues because they look similar.

How do you notice cognitive changes? 【小题2】 The following could be clues that your pet's cognition is off.

●They appear confused or cannot remember their training. Forgetting tricks or house training can be clues.

●【小题3】 If your pet is showing less affection, it may be a sign that they're having trouble remembering people.

●Aggression. Sudden aggression toward strangers and even family members can be a sign that they've lost the ability to recognize people.

● Lack of appetite. 【小题4】

●Change in sleep-wake cycle. Sleeping all day and staying up all night is not normal behavior and may be a sign of something more.

Giving your pet good nutrition is extremely important. 【小题5】Certain nutrients like antioxidants(抗氧化物) from vegetables, along with vitamins and fats from coconuts, can all help boost an aging dog's brain. And, if your pet is over the age of 7, it's time to start looking for a senior brand of food. If your pet is exhibiting strange behavior, talk to your vet(兽医) about what next steps you can take.

Robin Hood famously stole from the rich and gave to the poor. Young, newly hatched barn owls (猫头鹰) do something similar.

On average, barn owls raise six chicks at once-and sometimes as many as nine. But they don’t all hatch at the same time, which means the older owlets are generally larger and healthier than their younger brothers and sisters. As long as the little owls remain in the nest, they’re completely dependent on their parents for food. The problem is that the small meat that they eat can’t be divided. So when Mom or Dad returns to the nest to feed their babies only one chick can eat a time.

In many bird species, the oldest would simply outcompete the youngest, but barn owls are different. It turns out the older, healthier birds sometimes donate their meals to their hungrier siblings (兄弟姐妹).

Adults in other animal species share their food. “It’s mainly observed when males want to reproduce with females, so there are many exchanges of food. Or in primates (灵长类动物), there are many of food and grooming (cleaning and brushing) but only in adults.”

Evolutionary biologist Pauline Ducouret from the University of Lausanne in Switzerland said “And in chicks, it is really rarely observed. So it’s quite impressive that in this species, there are so many cooperative behaviors.” She and her team wanted to know how this unique behavior developed. It could be explained by the direct benefits gained through cooperation, such as trading food for grooming. Or it could be explained by the indirect benefits gained from helping others that share your genetic heritage — also known as relative selection.

They found that the answer was both. Younger birds groomed older ones more often than older ones groomed the youngsters. And in return, the older birds fed their younger siblings. In addition, older owlets preferentially offered food to their hungriest siblings, even in the absence of grooming.

But food sharing only happened when the researchers artificially provided the owlets with extra food. So it’s not that the owls risked their own survival to help their siblings. But when there was more than enough to go around, they shared instead of storing. The results are in the journal the American Naturalist.

Ducouret says that evolutionary biologists usually characterize sibling relationships as competitive. But remarkably complex examples of cooperation can still be found among animal brothers and sisters. It seems that even newly hatched barn owls know that sharing is caring.

In the busy and crowded Mexico City, an excellent woman has managed to build a shelter (庇护所) for one of nature’s most beautiful creatures—the hummingbird (蜂鸟) . Meet 73-year-old Catia Lattouf, an eager bird lover who has turned her apartment into a home for these tiny, lively birds.

In a city where green spaces are not enough, and city wildlife is often pushed to the edges, Lattouf’s love for hummingbirds began in 2011, just a year after recovering from a deadly illness, when she began caring for a hummingbird that had an eye injured by another bird. She named the bird Gucci after the brand (品牌) of the eyeglasses case where she kept it and soon they became the best of friends. The tiny hummingbird rested on Lattouf’s computer screen while she worked.

“It was a good medicine for my spirit,” Lattouf said of Gucei, adding, “It gave me a new life.” Gucci was the first, but many hummingbirds came to be cared for by Lattouf.

For years Lattouf’s home had been a bird shelter, but she was concerned about whether she would be able to meet the requirements of hummingbirds. However, since then, Lattouf has worked to make the public realize the importance of hummingbirds and has saved and freed hundreds of them.

Hummingbirds are an important part of the American food web. They help control the population of insects. Although they’re small in size, their diet includes the mosquitoes, spiders and fruit flies. Hummingbirds also pollinate (授粉) a wide variety of flowering plants from Alaska to the southernmost point of South America, which is especially important for native plant species. In fact, some plants depend almost completely on hummingbirds for pollination.

Through her effort, Lattouf has shown that even in the heart of a big city, it is possible to coexist (共存) with and protect the natural world. In a city that can sometimes feel disconnected from nature, Lattouf’s apartment is a wonder that can be found when we make space for the wild in our everyday lives.