The year 2025 in China is the “Year of the Snake”.

Here in my back yard it has been the “Fall of the Butterfly”. I wrote about a monarch butterfly caterpillar and about the monarch butterfly migration, which, by the way, has been amazing this year. Then I had a problem with my eye and was sitting in Kim Johnson’s waiting room. I picked up a magazine with an article about a Japanese biologist, Akito Kawahara, who has spent the last 23 years studying the evolution and distribution of butterflies. I learned a couple of tidbits about butterflies that I did not know.

Biologists have always believed that butterflies evolved in North America because that is where the oldest fossils of butterflies have been found. With the help of thousands of helpers and literally millions of DNA samples from living, preserved, and fossil butterflies, Kawahara’s team has verified that butterflies were once moths that moved into the daylight.

The butterflies arose in western North America, then moved east to the coast, down to South America and across to Australia and Antarctica where it is now too cold for butterflies…but there are fossils.

While that was going on, the butterflies moved across the Bering land bridge to Asia, then south to Africa, then, relatively recently, back north to Europe.

Europe today has the lowest diversity of butterflies of any continent.

It was once thought that bats drove the butterflies to the daylight because the oldest fossils of butterflies and bats were about the same. We now know that butterflies are twice as old as bats and the prevailing thoughts are that butterflies moved to daylight to take advantage of the rapidly expanding world of flowering plants.

Most moths are drab; picture a miller moth. Butterflies, for the most part however, are brightly colored.

Kawahara believes the bright colors aide the butterflies in two ways. First it helps the butterflies attract mates, indicating that butterflies see in color, and secondly to let predators know they don’t taste good.

The monarch caterpillars feed on poisonous milkweeds and the adults tend to still taste bad. When predators, birds for example, try and eat the adults they learn how bad the butterfly tastes and the bright orange color of the butterfly is easy for the bird to remember. Other butterflies, like the viceroy, look like a monarch, so predators don’t eat them either. A great defense from predators! But there is more!

Butterflies can hear! I know, a lot of insects can hear, which is why they sing, to attract mates, but while butterflies can hear, they don’t make sounds! So, what is the purpose of being able to hear if it is not to sing and attract a mate? Being able to hear can tell the butterfly if a predator is coming up behind them!

They can hear the wing beats of a bird! Moths go even further. Moths can hear the high frequency squeaks of a bat’s echolocation, also known as bat “sonar.” They know when a bat is zeroing in on them and they can dodge, duck, dive, dip, and dodge (thank you “Dodgeball”), and, yet, they go even farther. Some moths can emit sounds that interfere with the echolocation frequencies of the bat!

Some butterflies have abandoned the life in the light and have returned to being nocturnal. Like the moths, these butterflies have also developed an ability to emit sounds that mess up the hunting of the bats. It is a slow motion, time consuming arms race in the world between predators and prey. Predators figure out ways to catch prey and the prey figure out ways to interfere with the predators! That is just one of the things that has made me a naturalist. Just seeing the beauty, complexity, and wonder of the natural world has me looking around in amazement.