Humans are not the animal world’s only fashion followers. Tits (山雀) can be one of them, too. A study by Sonja Wild and Lucy Aplin shows that, given the chance, they make their nests (巢穴) with this season’s must-have color.

Dr. Wild and Dr. Aplin followed up on a study which noted that the blue tits preferred to put the same plants into their nests. This also suggested fashion-following—and it led Dr. Wild and Dr. Aplin to imagine that birds were studying the nests of others and copying them.

The birds they followed carried instruments on them. That allowed researchers to follow a large number of tits by their arrival at food dispensers (自动取物装置) throughout the woods.

One day in March 2021, Dr. Wild and Dr. Aplin used five dispensers with wool rather than food. Each contained two colors—either orange and pink or blue and purple—but all were rigged to give only one of these. This remained so until at least one local nest was seen to include wool from a dispenser. At that moment, the other color was discovered, too. As a comparison, Dr. Wild and Dr. Aplin set up four wool dispensers in a separate area, each providing two colors from the beginning.

Of 68 tits’ nests, 26 included wool from a dispenser. Of these, 18 were built after both colors had been gotten from all dispensers. Even so, 10 of that 18 included only the color of wool first chosen by a nest makers. By contrast (相比之下), all 8 nests with wool have mixed colors, which showed a clear difference in the record.

Tits, then, do seem to be “in fashion” when it comes to nest-building materials. Tits like those of the leaders of human fashions and it is worth more deep research.

Emotions (情感) are an essential part of how we experience our world. We humans can express emotions by telling others how we feel — but what about animals? Since animals cannot tell us how they feel, how can we know whether they experience emotions? Researchers have only started to find out truth about this in the past few decades.

The most easily noticeable reaction of an animal to an event is how it changes its behaviour. Humans often change facial expressions and gestures depending on whether we experience a pleasant event or not. If you look at your friends’ faces, you can often very quickly tell if they are happy, fearful, or angry. Animals show these characteristic facial expressions as well! So-called grimace scales (表情量表) for horses, pigs, sheep, rats, and cats have already been developed. For example, changes in ear position, the amount of visible eye white, and tension in the chewing muscles can indicate different levels of pain or fear in animals.

Another example of animal behaviour that is linked to emotions involves vocalisations (发声), such as grunts, bleats, and moos, which can indicate stress in many species. We know this is true for humans too: imagine you are singing a song in front of many people; your voice might get shaky if you are nervous or experiencing stage fright. Researchers have found that the vocalisations of pigs, goats, and cows also change and get less harmonious when these animals are under stress. For example, when they are separated from the group, they produce the sound that indicates negative emotions

The evidence of emotions in animals might encourage us to rethink the environments in which we keep the animals that are under our care — on farms, in zoos, or in our houses. If we can better understand how animals interact and react to their environments, we can ultimately improve these environments, and thus improve human-animal relationships. It must be our ethical goal to decrease the negative emotions these animals experience, as well as to increase their experience of positive emotions.

When I started school, my hands kept shaking. I went to a doctor and was told that I had a nervous system disorder that can cause a person’s hands to shake. I had no idea what I was going to do. One day, I saw a woodcock outside my apartment window, and I had never seen anything like it. So I read about the bird online and took an ornithology class. The professor asked me if I was doing research. I had no idea that undergraduates could even do anything like that. That professor became my undergraduate advisor, and I started working in her lab. She was also my PhD advisor. I stayed in her lab for 11 years.

Now I have a paper coming out soon that looks at the global diversity of parrots. One figure in it is, I think, the best thing I’ve ever done. It shows the family tree of parrots, over a picture of Gondwana breaking up. Gondwana is the supercontinent that South America, Africa, Australia and New Zealand all used to be part of. As that broke up into the continents that we know better now, some families of parrots parted.

My biggest failure in science thus far is my inability to explain how the Carolina parakeet went extinct. I’ve been working on this for seven years. I’ve read lots of historical books and travel diaries. And I never figured it out.

That’s the thing about science. Most of the time, you start out with a really clear idea of what you think is going to happen. And it almost never happens that way. I’ve got a lot out of this research. I’ve learned a lot about the species. But there are just some things that we’ll never know. Finally, I have to accept that maybe I’ll figure it out one day, maybe I won’t. But that’s OK.