Sound of Silence: In search of Japanese Night Heron in Yadoriki Water Source Forest やどりき水源林

COVID-19 has changed the way people move around. It is said that many people living in downtown are now seriously considering emigrating to rural area. We’ll see if such thing materializes. One thing I’ve personally heard is, experts who had nomadic life in deep mountains as mountaineering guide or similar occupation have adjusted their way of life to “New Normal.” I know a famous guide for Mt. Fuji has now a dual life on the foot of Fujiyama and in a residential area near Niiharu Citizen Forest 新治市民の森. Another guy who helped mountaineers to Mt. Everest has returned to Japan and established a dual life as a community organizer in mountainous community of western Kanagawa Prefecture, and as a mountain cottage manager for one of the peaks of Tanzawa 丹沢.

One such people who decided to settle in Kanagawa, or to be exact Yadoriki community 寄 is Mr. Tomonobu Akiyama, a professional wildlife photographer who’s flying around the world to get rare moments of nature’s wonder, especially of big cats. After he bought an old traditional house in Yadoriki in 2020, he investigated the area and started field research for Japanese dwarf flying squirrel. There are not many experts for this cute creature on this planet. No systematic study has done for them. Kanagawa Forest Instructors Association has started a serious discussion about possible collaboration with Mr. Akiyama to investigate the species especially in Yadoriki Water Source Forest やどりき水源林. And, there is another wildlife Mr. Akiyama has spotted in Yadoriki. It’s Japanese night heron, an endangered species categorized by IUCN.

Japanese night heron is a migratory bird. They spend their autumn and winter in Philippines, coastal area of southeast China, and Taiwan. In early spring they take their annual long-distance travel to Japan in order to have a family and nurture their offspring. When their kids grow adult-enough, the entire family fly back to warmer part of the planet. Once, they were ubiquitous in Japanese rural area where lots of rice paddies provided enough catch, like insects and frogs, for their hungry babies. Asian economic development reduced the environment for their idyllic life in Japan, Philippines and China. At this moment, it is said that there are about 2000-3000 individuals counted in Japan. The number of places people can find the birds are getting smaller and smaller. In order to derail their way to extinction, we must first make it sure the place they are planning to have families. It then can be started to plan restoration of environment for the night heron. That’s the idea of Mr. Akiyama. He collected information about Japanese night heron in western Kanagawa Prefecture. There are several hearsays, like “I think I’ve seen them in such-a-such place,” “I guess that’s their last year’s nest on that bough,” or “I’ve heard their tweet.”

The herons move to Japan normally in the first half of April. When they arrive in Japan, the male night herons start to tweet at the beginning of evenings, normally from 30 minutes to one hour after the night fall. They have a soft and low hoo-hoo voice. They are appealing to females to mate. The dating will be completed roughly within 1 week of their arrival. The first voice we can spot after the sunset should be from the point nearest to a possible nest for hatching eggs. When a male has found his partner, he stops tweeting and a couple construct their nest normally on a bough of broad-leaved tree. They sit on their eggs until they hatch. The babies become teenagers by the end of June. They then begin trainings for long-distance international flight. Sometimes, lonely soul may tweet even in August, but the possibility of such male Japanese night heron having their offspring is quite low. So, when we can spot their voice in April, the probability for this endangered species procreating at that point is higher. Since last year, Mr. Akiyama organizes April event with an army of volunteers to wait quietly for the voice of Japanese night heron. If many people collaborate to record such incidence at one particular date and time, the accuracy of the search for Japanese night heron will be improved. This year is his second trial, and we Kanagawa Forest Instructors joined his endeavor. Why not helping endangered birds? We’re forest instructors!

er, it’s not bird, but boar who dug this place in Yadoriki forest.

The reason the birds are on the endangered list is dwindling number of traditional rice cultivating community. In order to record the evidence of their existence it would be wiser for volunteers sit near remaining rice paddies. But the information Mr. Akiyama has collected suggesting more mountainous life of Japanese night herons in Yadoriki Water Source Forest. Maybe, just maybe, they could not find a suitable environment for their kids near more urbanized rice paddies in Kanagawa Prefecture. (Oh-so-modern parenting …) They might have changed their traditional life near Japanese farmers to more remote areas in deep mountains. Thus, a request came for Forest Instructors who are familiar with Yadoriki Water Source Forest. Herons tweet when the forest gets pitch dark. When the research is done in deep mountains, it would be safer to ask people who know the place well, you see? In one weekend of this April, we joined Mr. Akiyama’s event to wait for the tweet of Japanese night heron in Yadoriki forest.

Mr. Akiyama instructed us. “Yadoriki Water Source Forest is not the traditional environment Japanese night herons have their summer. But if you can listen their tweeting, please record the direction the voice comes from. If possible, it would be wonderful recording the voice or taking video of the forest. Please do not go near to the voice itself, though. They are very cagey, especially when they have their eggs and babies. Once they notice some creatures come near to their nest, they abandon warming and nurturing their hatchlings. OK?” We Forest Instructors went in the Yadoriki Water Source Forest in very late afternoon. We dispersed ourselves in a forest, sit and wait at each designated spot where Mr. Akiyama thought the voice of night herons might happen. Each place has registered latitude and longitude. When a volunteer listens the tweet from a direction at one spot s/he stations, we record the time and direction the voice comes, like north or southeast. Somewhere to the direction noted at that point there are places for the heron.

Unfortunately, the weather was not good on that day. It was raining on and off. One moment the rain was like mist, then few minutes later it showered briefly. The afternoon of Yadoriki forest in early April was very cold. I brought in a comfy camping chair, rug, a thermo of hot tea, and chocolate to the place I was assigned. I situated my self in a relaxed position with umbrella and waited for the sunset ... Mr. Akiyama said we must wait until the other birds end tweeting. Japanese night herons love solo recital, not chorus with the others. We sat and waited in a darkening, and occasionally raining, forest.

In the darkening forest, no noise from human settlement came. Instead, from somewhere above, so many kinds of birds were competing each other to attract a proper mate. Is that Blue-and-white flycatcher, or Narcissus flycatcher? Familiar voices of Japanese tit were harmonizing with the call of Eurasian nuthatch. Modest tweet of Grey wagtail were intertwined with singing voice of Varied tit. Coal tit sounded talkative in their own way while Siberian blue robin would be very impatient. I realized an hour or so before sunset was very animated time in Yadoriki’s April. Wild birds are making very comfortable ambient sound … I sat in the forest wrapped in a blanket, and found my mood changed from busy nervousness of downtown to meditative relaxation. That’s … very therapeutic experience. It’s the sound of silence in a forest.

The rain got harder after sunset. That was the time if night heron was/were near us, they started to tweet. Alas, no forest instructors could record Japanese night heron to tweet in Yadoriki in that misty evening. We reported our result to Mr. Akiyama. On that day, in some other two places of Western Kanagawa, the voice of Japanese night heron was recorded. It might be a bit disappointing, but at least I found the experience precious. When another opportunity arises for a similar project, I think I raise my hand to join.

(p.s.) … er, well, I don’t recommend you to be in a dark forest to have a meditation, unless you know the place damned well, or you sit next to a person who’s very familiar to the point. Kanagawa Forest Instructors are thinking to have such event in Yadoriki Water Source Forest for pure visitors … but the Prefectural government, aka the landlord of Yadoriki Forest, does not allow us inviting non-instructors to the forest after dark. Our discussion is continuing. Please cross your fingers for a nice idea to persuade city hall.

If you find environmental issues in Kanagawa Prefecture, please make a contact with Kanagawa Natural Environment Conservation Center 神奈川県自然環境保全センター

657 Nanasawa, Atsugi City, 243-0121
〒243－0121　厚木市七沢657
Phone: 046-248-0323

You can send an enquiry to them by clicking the bottom line of their homepage at http://www.pref.kanagawa.jp/div/1644/