【推荐1】Most animal species in the world have developed some sort of natural camouflage that helps them find food and avoid attack. The specific nature of this camouflage varies considerably from species to species.

Camouflage develops differently depending on the physiology and behavior of an animal.    1    

An animal's environment is often the most important factor in what the camouflage looks like. The simplest camouflage technique is for an animal to match the "background" of its surroundings.

Since the ultimate goal of camouflage is to hide from other animals, the physiology and behavior of an animal's predators or prey is highly significant.     2    . For example, there’s no point in an animal replicating the color of its surroundings if is main predator is color-blind.

In addition to background-matching coloration, many animals have distinctive designs on their bodies that serve to conceal them. These designs, which might be spots, stripes or a group of patches, can help the animal in a couple of ways. First, they may match the pattern of "the model", the background of the animal's surroundings. Second, they may serve as visual disruptions. Usually, the patterns are positioned out-of-line with the body's contours (外形).     3    . This makes it hard for the predator to get a clear sense of where the animal begins and ends — the pattern on the body seems to nun of in every direction.

Other animals use a more aggressive sort of mimicry. Several moth species have developed striking designs on their wings that resemble the eyes of a larger animal. The back of the hawk moth caterpillar actually looks like a snake head, a frightening visage for most predators he moth would come across.

Mimicry is a different approach than ordinary camouflage, but it works toward the same end. By developing a certain appearance, an animal species makes itself a harder target for predators and a sneakier hunter for prey. As animal species evolve, they become more and more in tune with their environment.     4    . After all, being entirely overlooked by a predator is preferable to having to put up a fight.

【推荐3】Female birds sing. That is one conclusion of our 2020 study on the barn swallow. It highlights a long-standing scientific bias and helps us think about why that bias persists.

Despite the well over 1,000 scientific publications about this species, female barn swallow song had never previously been the focus of a research article. Conventional evolutionary theory assumes that males compete for access to females, leading them to evolve features that help fight off other males or attract females. Birdsongs can function in both these contexts. In fact, females sing in at least 64% of songbird species, and their songs can serve the same functions as male songs.

A second reason for the neglect of female birdsong stems from geographic bias. Any serious birder working in the tropics (热带) could tell you that females do sing. But early researchers tended to study species near their universities in the Northern Hemisphere (半球), where females have lost or reduced their songs, which may represent evolutionary adaptations to conserve energy for migration.

A final reason for female birdsong being understudied could be gender. Men have ruled birdsong research from its start. As more women enter the field, they are much more likely than men to be first authors on papers on female birdsong.

To overcome such biases in the scientific rule, we need to make science more accessible to all. For example, if we can make people aware that female birds sing, we will enhance their experience of nature and improve their ability to observe it.   People who understand the latest science will create better global data sets, which, in turn, will generate better science. Besides, nonscientists make better observers because they lack preconceived (先入为主的) ideas.

Female birds sing! The truth reflects the constant adjustments to the scientific agreements as new facts become available and new voices are added to the conversation. We welcome a future where research, communication and education combine to deepen our connections to one another and the natural world.