The Mystery of Japan’s Vanishing Sparrows—The Unexpected Reason, According to Asahiyama Zoo’s Director

Are eco homes, which are supposed to be environmentally friendly, actually pushing sparrows toward extinction!?

“When I wake up in the morning and hear sparrows chirping, it puts me at ease. It makes me feel like, okay, let’s do our best today.”

So says Gen Bando, the general director of Asahiyama Zoo in Asahikawa, Hokkaido—the person who first introduced the now-famous behavioral exhibits in Japan, designed so visitors can observe animals behaving naturally. And Bando’s favorite animal of all is the sparrow.

“Sparrows are unique creatures—wild birds that live within human living spaces. Even as we humans have artificially reshaped the environment, sparrows have always stayed close to us.

In spring, they start chirping around 4 or 5 a.m., feeding their chicks. Seeing those ordinary scenes—that’s what makes me feel happy.”

Sparrows have long been loved by Japanese people, as seen in stories like Shita-kiri Suzume (“The Tongue-Cut Sparrow”) and Sparrow School. They are thought of as birds you can see anywhere in Japan. But something unusual is happening to them.

According to a monitoring survey conducted from 2005 to 2022 at about 1,000 locations nationwide by the Ministry of the Environment’s Biodiversity Center, NGOs, researchers, and citizens, the annual decline rate of sparrows is at a level equivalent to species listed in the Ministry’s Red List as at increasing risk of extinction.

There are also survey results showing that between the 1980s and the 2020s, Japan’s sparrow population has fallen to one-third to half of what it once was.

“With all the talk about climate change and environmental issues these days, I think that an environment where sparrows can no longer live alongside us means that humans are also facing a threat to our own survival.”

Why have sparrows decreased so much?

“First, sparrows have lost places to build nests. They used to nest in gaps between roof tiles, vents, attics but now houses are much more airtight, and those gaps have disappeared.

Second, sparrows have lost their food. To raise their chicks until they fledge, sparrows must bring food 2,000 to 3,000 times—mostly insects. Without small insects, sparrows can’t raise their young. In the past, empty lots always had bugs. But now empty lots are fewer, and many parks even spray insecticide because people don’t like insects.

We humans are steadily taking away the places where sparrows can live.”

Come to think of it, we don’t seem to see swallows much anymore either.

“Swallows mix water, mud, and saliva to build nests on walls under the eaves. But modern houses often don’t have eaves, or use exterior materials that don’t get dirty easily—smooth surfaces. So swallows can’t attach their nests.

A clean, highly airtight house may be comfortable for us. But the result is that we are creating spaces where sparrows and swallows cannot live. They call these environmentally friendly eco homes, but I can’t help wondering—is this really eco-friendly?”

 

A global shift toward returning to nature

Until now, humans have reclaimed land from the sea, altered the flow of rivers, cut down forests to build homes, and reshaped nature to make it more comfortable for ourselves. As a result, global warming has progressed, and we now experience torrential downpours—like linear precipitation bands—that didn’t even exist as a concept ten years ago.

“To halt this trend, the world is now adopting the concept of ‘Nature Positive,’ which aims to prevent the loss of natural ecosystems and restore nature. One of its goals is 30 by 30.

This means restoring more than 30% of land and sea to their original, untouched state—ecosystems where the living creatures that inhabit them take priority over human convenience.”

Restoring 30% of land and sea to natural conditions it might be possible in Hokkaido.

“No, no—even in Hokkaido, it’s said that less than 20% of the mountains remain untouched by humans.”

Then what percentage would Tokyo have? The plan sounds vast and overwhelming—but is there anything we can do closer to home?

Gardens with native Japanese plants—not roses or tulips

“In Europe now, there is a movement to create gardens using native plant species—plants that originally grew in that region. When you do that, the flowers bloom and fruits appear in rhythms that match the local climate. As a result, birds and insects return in astonishing numbers—this is clearly shown in the data.

It’s important for governments to invest heavily in achieving the 30 by 30 goal, but I believe nature can change if each of us makes even a small effort.”

Roses and tulips are beautiful, but they are not originally Japanese flowers. Creating gardens with native species—such as fukujusō, violets, or black lilies—could allow us to feel the seasons even more deeply.

“You don’t have to pull out every weed. And I’d like people to refrain from using so much insecticide just to kill bugs. I actually like gardens with weeds—it feels full of life. Rather than eliminating everything just because it’s unpleasant, we should try—even little by little—to acknowledge the various creatures around us. If insects increase, sparrows will be able to survive.”

The environment, Bando says, has become far too focused on human convenience.

“If we learn to accept the living things around us—to say, ‘There are a few insects here, but that means sparrows can be happy’—then I think we can live a little more kindly toward the Earth.”

▼Gen Bando

General Director, Asahiyama Zoo (Asahikawa City). Director of Borneo Conservation Trust Japan. After completing a master’s program in veterinary medicine at Rakuno Gakuen University, he became a veterinarian and joined Asahiyama Zoo in 1986. As a keeper and exhibit coordinator, he was responsible for developing the zoo’s famous behavioral exhibits, designing all facilities including the “Kids’ Farm” (1997), “Penguin House,” “Seal House,” “Chimpanzee House,” “Red Panda House,” “Ezo Deer Forest,” and “Giraffe/Hippo House.” He launched the construction of a wildlife rescue center in Sabah, Malaysia, completing the first stage. In 2009 he became the zoo’s director, and has held his current position since 2024. His books include “Hito to Ikimono: Hitotsunagari no Inochi — A Message from Asahiyama Zoo” (Tenrikyo Doyusha).