Category Archives: 自然環境

Egret Rookery

Great egrets (ダイサギ), cattle egrets (アマサギ), and other birds nest in the woods at Hyozu Shrine (兵主大社) in Yasu City, Shiga Prefecture, Japan. I recorded the sounds of the rookery on Sunday, May 27, 2018, and posted a six-minute sample on radio aporee ::: maps and SoundCloud.

The woods are between a large shrine and Yasu City athletic facilities (野洲市中主B&G海洋センター). The white spots in the satellite image of the woods are egrets.

The recording location was not very photogenic. White bird droppings covered everything in the area. On the ground near the tree that held my recorder broken eggshells and a feather indicated young egrets above.

Eggshell below a great egret nest

Eggshell below a great egret nest beside Hyozu Taisha (兵主大社) in Gojo, Yasu City

Short feather below a great egret nest

Short feather below a great egret nest beside Hyozu Taisha (兵主大社) in Gojo, Yasu City

Nests and young birds were hidden in the treetops.

Egret nests and young great egrets (ダオサギ)

Egret nests and young great egrets (ダオサギ) in the woods beside Hyozu Taisha (兵主大社) in Gojo, Yasu City

Now and then an adult egret appeared, and I was lucky to see a cattle egret carrying a branch for a nest.

Cattle egret (Bubulcus ibis, アマサギ)

Cattle egret (Bubulcus ibis, アマサギ) in the woods beside Hyozu Taisha (兵主大社) in Gojo, Yasu City

Recording and post-processing

This recording was made with a Sony PCM-M10 recorder and FEL Communications Clippy Stereo EM172 Microphone tied to a tree. Since I was near the south edge of the woods, I placed the mics placed slightly forward of center facing north.

Audio post-processing was done with Audacity on Fedora Workstation, a Linux system running on a Lenovo ThinkStation 20 computer. I trimmed this excerpt from a longer recording and raised the overall volume. No other digital signal processing was done.

Flowering Weeds in Early Spring

In March and April the Japanese countryside comes to life as weeds appear along fields and streams, anywhere with soil. Some of these plants are known for medicinal properties, and some are gathered as food. Most are ignored or cut down.

This year I’m trying to learn the names of flowering weeds as they appear in nearby fields and along the Yasugawa riverbank in Shiga Prefecture, Japan. This photo gallery includes some of the flowers I’ve seen from the beginning of March until mid-April, 2018.

Many of the flowers are tiny! Most of these photos were taken with an Olympus OM-D E-M1 Mk. II camera and a 60mm f/2.8 macro lens, which I showed on Twitter.

Crows along Yasugawa

On Sunday, March 18, 2018, I was cycling down the north bank of Yasugawa when I heard some noisy crows perched in nearby trees.

When I ride my touring bike, I carry a small audio recorder and microphones. For this recording I used a Sony PCM-M10 recorder and Clippy Stereo EM172 mics by FEL Communications Ltd. To mimic human hearing, a quasi-binaural sound image was made by placing the mics on either side of my bicycle handlebar bag. I prefer to use trees about the diameter of an adult human head, but I use the handlebar bag when I cannot find a tree.

Trek 520 touring bike with audio recorder and mics on handlebar bag in Yasu City

The Compass app on my iPhone shows the location, direction, and time.

Compass and geolocation app on bicycle handlebar bag in Yasu City

As we can see on the map, this location is between a river and near the edge of a suburban area. With aircraft overhead, vehicles on nearby roads, and rural and suburban human activities, this place is quite noisy, even on Sunday.

In everyday life we filter out much of the noise. When the crows are not so noisy, I suppose most people experience this environment as a peaceful and quiet little park, just as it appears in photographs.

Trek 520 touring bike in Yasu City

Trek 520 touring bike in Yasu City

Chinese Pond Turtles (クサガメ)

Migration in November

On November 19, 2017, I was surprised to see three Chinese pond turtles (Mauremys reevesii, Reeve’s turtle, クサガメ) crawling up a nearly empty irrigation canal. The was my first time to see turtles like these with three ridges along their backs. I later learned that this small turtle is an endangered species on the IUCN Red List of Threatened Species (Japan Ministry of the Environment: 環境省レッドリスト).

The turtles were making their way upstream, probably migrating to a small pond along the canal.

Chinese pond turtles (Mauremys reevesii, クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ) walking up the the canal in Tsuji, Ritto City.

The closest one withdrew into its shell as soon as it noticed me.

Chinese pond turtle (Mauremys reevesii, クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ)

I backed away, but turtle was surprised by a white wagtail (Motacilla alba, ハクセキレイ).

White wagtail (ハクセキレイ)

White wagtail (ハクセキレイ) and Chinese pond turtle (クサガメ)

White wagtail (ハクセキレイ)

White wagtail (ハクセキレイ) and Chinese pond turtle (クサガメ)

Eventually the turtle posed before returning its journey.

Chinese pond turtle (クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ)

Sighting in January

On January 2, 2018, I spotted a Chinese pond turtle upstream in the canal near the pond, which had dried out. It was basking in the sun under a little waterfall where food was plentiful.

The turtle was covered with mud and some vegetation.

Chinese pond turtle (クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ)

Chinese pond turtle (クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ)

This small turtle is not very photogenic, but the survival of Mauremys reevesii as a threatened species makes this Chinese pond turtle a beautiful creature.

Chinese pond turtle (クサガメ)

Chinese pond turtle (Mauremys reevesii, クサガメ)

Egrets in September

September at Yasugawa (野洲川) begins gently as the hot, lazy days of summer continue. Great egrets and grey herons stand patiently in and along the river.

Great egret (ダイサギ)

Great egret (ダイサギ) at Yasugawa in Moriyama

Grey heron and great egret (アオサギとダイサギ)

Grey heron and great egret (アオサギとダイサギ) at Yasugawa below the Shinkansen tracks

As the river rises in early September, we see fewer egrets at popular summer locations such under the Shinkansen (新幹線) bridge.

Shinkansen (新幹線)

Shinkansen (新幹線) crossing Yasugawa (野洲川)

Many egrets gather at the dam between Yasu City and Moriyama City.

Great egret (ダイサギ)

Great egret (ダイサギ) at Yasugawa below the dam in Moriyama City

Some pursue fish in the river below the dam.

Great egret (ダイサギ)

Great egret (ダイサギ) at Yasugawa below the dam in Moriyama City

Great egret (ダイサギ)

Great egret (ダイサギ) at Yasugawa below the dam in Moriyama City

Great egret (ダイサギ)

Great egret (ダイサギ) at Yasugawa below the dam in Moriyama City

Some perch on the dam and hunt for small aquatic animals.

Great egret (ダイサギ)

Great egret (ダイサギ) at Yasugawa above the dam in Moriyama City

Great egret (ダイサギ) and little egret (コサギ)

Great egret (ダイサギ) and little egret (コサギ) at Yasugawa on the dam in Moriyama City

Great egret (ダイサギ)

Great egret (ダイサギ) at Yasugawa on the dam in Moriyama City

Great egret (ダイサギ) and little egret (コサギ)

Great egret (ダイサギ) and little egret (コサギ) at Yasugawa on the dam in Moriyama City

Some hunt in nearby fields, eating grasshoppers and other insects. Sometimes they find larger prey.

Great egret (ダイサギ)

Great egret (ダイサギ) with a large frog in Tsuji, Ritto City

Fall weather begins in early October. Many birds begin to migrate to warmer locations, while some egrets and herons remain at Yasugawa.

Little egret (コサギ)

Little egret (コサギ) at Yasugawa below the dam in Moriyama City

Grey heron (アオサギ)

Grey heron (アオサギ) at Yasugawa on the dam in Moriyama City

Grey heron (アオサギ)

Grey heron (アオサギ) at Yasugawa on the dam in Moriyama City

Little egret (コサギ)

Little egret (コサギ) at Yasugawa below the dam in Moriyama City