We wanted to know which animals come back while a bamboo grove is being converted into a broadleaf woodland. So we left a trail camera running in a stand of madake bamboo in Kameyama, Mie Prefecture, Japan.

We are Senteiyasora, a tree and garden care company in Mie Prefecture, Japan. We have been doing this work since 2015. Most of our year goes into looking after private gardens, and a growing part of it goes into abandoned bamboo groves and neglected satoyama woodland.

We swapped the SD card the other day.

Forty-seven days. Twenty-four visits.

Raccoon dog with mange, raccoon, Japanese macaque, wood mouse, oriental turtle dove, cat. One visit each from what appear to be a wild boar and a weasel, and five we could not identify.

Twelve of the twenty-four were at night. Five at dawn or dusk. The only daytime visitors were the dove, the cat, and one we could not name.

Almost nothing walks through while people are working.

Here is the footage, cut down to the moments an animal appears. One minute fifty-seven seconds.

Cutting the bamboo does not bring the forest back

This grove was dominated by madake bamboo. We have been removing culms a few at a time, letting light down to the floor, and waiting for a broadleaf woodland to come back. The site is designated as a Kameyama City Biodiversity Coexistence Area.

People often assume that if you cut the bamboo, the woodland returns on its own. It does not, and there are four reasons.

First, konara oak acorns do not wait in the soil. They germinate one to two weeks after they fall and they dry out easily. There is no seed bank to wake up when the light arrives.

Second, the animals that carry acorns do not walk into a dark bamboo grove with little to eat. No seed arrives.

Third, the floor of a bamboo grove receives one to five percent of the light outside it. A seedling that does germinate cannot keep up with the bamboo and dies.

Fourth, the fungi that live with oak roots disappear from the soil once the mature oaks are gone. A seedling that germinates cannot establish.

The second reason is where the camera comes in.

The animal that plants the trees was already there

At one minute past midnight on 15 August, a single small mouse walked past the camera.

It is a Japanese wood mouse. The footage is not sharp enough to name the species, but it belongs to the Apodemus group, either the large Japanese field mouse or the small Japanese field mouse.

This animal moves acorns.

It carries them one at a time and buries them under leaf litter or in shallow soil. It digs them up again, moves them somewhere else, and buries them again. In among all that shuffling, some acorns are forgotten. They are already in the ground, so they can simply root.

The second barrier was that no animal carries acorns into a bamboo grove. Here was one, doing exactly that.

Once we started reading about it, this animal turned out to be doing more for the woodland than we had realised.

It also moves fungi. Some fungi fruit only underground, so they cannot release spores into the wind. Instead they give off a strong smell, an animal eats them, and the spores travel in its droppings. Many of those fungi are the same ones that link to tree roots and carry water and nutrients to them.

The fourth barrier was that oak-associated fungi vanish from the soil. An animal that moves fungi is an animal that lets those fungi move back.

Wood mice also eat bitter acorns. Acorns are high in tannins, which are hard on the gut. These mice produce salivary proteins that bind tannins and make them harmless, and they produce more of those proteins the longer they keep eating acorns. They acclimatise as they go.

And they are food. Owls, weasels, martens and snakes all live on this small animal. In a good acorn year their numbers rise; in a poor year they fall. The tree crop sets the balance for everything above it.

The raccoon dog has been coming since spring

The animal photographed most often this time was a raccoon dog that has lost much of its coat. Three visits. It appears to have sarcoptic mange.

This is not the first time we have seen it. It also appears in a three-and-a-half month timelapse we reviewed, running from 29 December 2025 to 14 April 2026. It has been coming to this grove through winter and on through summer.

Raccoon dogs also move seeds. They defecate at fixed latrine sites, and one survey found plant seeds in more than 91 percent of those latrines. Woody plants including konara oak have been recorded germinating around them.

A wood mouse buries acorns to spread a woodland. A raccoon dog spreads it through its latrines.

Birds carry seed the furthest

Among seed carriers, birds cover the most ground.

A large Japanese field mouse moves an acorn about two hundred metres at most, and cannot cross a river. A Eurasian jay has been recorded carrying one 1.2 kilometres.

The roles divide up. Birds bring new seed in from outside the woodland. Mice and raccoon dogs bury it and move it around inside.

No jay has appeared on this camera yet. It is one of the birds we most want to see.

There is very little life in bamboo soil

There is a second reason we pay so much attention to which animals arrive.

In July 2026 we opened up one of the brushwood terraces we build on this slope, and found a working community of animals breaking down the leaf litter inside it.

A few metres away, in the bamboo soil itself, we dug and found almost no earthworms and very little microbial activity.

Bamboo leaves and culms are hard food for soil life. They are high in resistant compounds, and the microbes attempting to break them down draw nitrogen out of the soil while they work. Below ground, the fungi that partner with broadleaf trees become scarce.

An abandoned bamboo grove is covered in dead culms, has no understorey, and holds almost no sign of animals.

So we thin the bamboo and let light in. The understorey returns. Insects arrive. Animals that eat those insects arrive. Animals that carry seed arrive.

The camera is there to check that this sequence actually happens.

This year is the baseline

Forty-seven days. Twenty-four visits.

On its own, that number means nothing yet. There is nothing to compare it against.

Only when we film the same place in the same season next year will it start to mean something. This is year one.

The camera also logs air temperature alongside the timestamp. This time it ranged from 24 to 29 degrees Celsius. We are keeping that too, in case it connects to something later.

The smallest animal in the footage turned out to be one of the ones building the forest.

Without the camera, we would not have known it was there.

Looking after a bamboo grove and looking after these animals turn out to point in the same direction.

Who we are

Senteiyasora is a small firm. Two of us run it, and we bring in other craftsmen when a job needs more hands. We are based in Komono, a town at the foot of the Suzuka mountains in Mie Prefecture, and we work across the northern and central parts of the prefecture.

Our founder trained in Japanese garden work in Mie after living in Brazil and moving here on a friend's invitation. He holds qualifications as a garden manager and an environmental restoration practitioner, and has completed the Mie Forestry Academy.

We describe ourselves with the word niwashi written a little differently from usual. The standard word for a gardener is written with a character meaning master. We write it with the character meaning intention or resolve. The point is that we are not standing above the garden telling the owner what to do. We are standing next to them, working out what the garden needs.

Two ideas run through everything we do.

The first is that success looks like disappearing. The brushwood terraces we build on slopes are made of the bamboo and branches we cut on site. They rot. They are meant to. By the time they have gone, plant roots should be holding the slope instead. The structure is a starting point for the plants, not a permanent object.

The second is that you read water rather than control it. We look at where water already wants to go on a slope before we put anything in its way.

We also measure. Soil hardness, soil temperature, surface temperature with a thermal camera, bird calls, canopy openness, seedling counts, and now a trail camera. Very little of this is normal for a garden company in Japan. We do it because a client deserves to be shown what changed, not just told that it improved. This bamboo grove has eleven years of records behind it.

One of the groves we look after is certified as a Kameyama City Biodiversity Coexistence Area, the municipal scheme that sits alongside Japan's national 30 by 30 commitment.

About our bamboo and woodland work

We take on the clearing of abandoned bamboo groves, the gradual conversion of bamboo to broadleaf woodland, slope stabilisation using traditional Japanese brushwood terracing, vegetation and wildlife surveys, and the design and installation of nest boxes and artificial tree cavities.

We also do the ordinary work: pruning, hedge cutting, pine training, felling and difficult removals, and year-round garden maintenance contracts.

We are honest about what a job will and will not achieve, including when the answer is that you should not do it. If that is the kind of company you want to talk to, we would be glad to hear from you.

Senteiyasora, 2304-1 Sugitani, Komono-cho, Mie-gun, Mie 510-1326, Japan

TEL +81-59-340-7479

https://www.senteiyasora.com