Black-crowned Night Heron
ゴイサギ
Scientific name: Nycticorax nycticorax
The Black-crowned Night Heron is a stocky, medium-sized heron often active in the evening, at night, and early morning. In Japanese it is called ゴイサギ / Goisagi. The adult has a black crown and back, gray wings, pale underparts, red eyes, and short white head plumes during the breeding season.
Young birds look very different from adults. Juveniles are brown with many pale spots and streaks, so they can easily be mistaken for another species. As they mature, they gradually develop the clean gray, black, and white adult plumage.
In Japan, the Black-crowned Night Heron is found around rivers, ponds, lakes, marshes, rice fields, canals, reed beds, estuaries, and wooded wetlands. It often hides quietly in trees or dense waterside vegetation during the day, then comes out to hunt after sunset.
For your map: show it as widespread across Japan in suitable wetland and waterside habitats, especially lowland rivers, ponds, rice fields, marshes, and coastal wetlands. Do not color dry mountains, deep forests, or open grasslands evenly. It is mainly a resident or summer breeder depending on region, with more seasonal movement in colder northern areas.
Key info for card
Habitat: Rivers, ponds, marshes, rice fields, canals, reed beds, estuaries, wooded wetlands
Range in Japan: Widespread in suitable wetland habitats across much of Japan
Diet: Fish, frogs, insects, crustaceans, small reptiles, small mammals, and other aquatic animals
Season: Resident in many areas; summer breeder or seasonal visitor in colder northern regions
Size: About 58–65 cm
Nesting: Nests in trees or reed beds, often in colonies with other herons
Behavior: Mostly active at dusk, night, and early morning; rests quietly in trees during the day
Conservation: Common in suitable habitats, but healthy wetlands, rivers, and safe nesting colonies are important
Short description for your page
The Black-crowned Night Heron is a quiet and mysterious waterside bird of Japan. Adults have a black crown, gray wings, pale body, and striking red eyes, while young birds are brown and heavily spotted. The ゴイサギ usually rests hidden in trees during the day and becomes active in the evening, hunting fish, frogs, insects, and other small animals around rivers, ponds, marshes, and rice fields. Its nocturnal habits make it one of Japan’s most atmospheric herons.
Black-crowned Night Heron ゴイサギ
The Black-crowned Night Heron is a stocky, medium-sized heron often seen
around rivers, ponds, lakes, wetlands, marshes, rice fields, canals, and
wooded watersides in Japan. Adults have a black crown and back, pale gray
wings, red eyes, a short thick neck, and long white head plumes during the
breeding season.
As its name suggests, this heron is most active from evening into night,
though it may also be seen resting quietly in trees during the day. It feeds
on fish, frogs, shrimp, insects, small reptiles, and other water animals,
usually standing still near the water before striking quickly with its bill.
Category
Herons, Night Herons, Wading Birds
IUCN Status
Least Concern
Habitat
Rivers, Ponds, Lakes, Wetlands, Marshes, Rice Fields, Canals
Region
Japan, Asia, Europe, Africa, North and South America
Behavior
Nocturnal Hunting, Still Waiting, Fish Catching, Daytime Roosting
Population
Common in Suitable Waterside Habitat
ゴイサギ Black-crowned Night Heron
ゴイサギは、日本の河川、池、湖、湿地、沼、田んぼ、水路、
樹木のある水辺などで見られる、ずんぐりとした中型のサギの仲間です。
成鳥は黒い頭と背中、淡い灰色の翼、赤い目、短く太い首を持ち、
繁殖期には後頭部から白く長い飾り羽が伸びます。
名前の通り、夕方から夜にかけて活動することが多い鳥ですが、
日中は木の上などで静かに休んでいる姿も見られます。魚、カエル、
エビ、昆虫、小さな爬虫類、その他の水辺の生き物を食べ、
水辺でじっと待ってから、すばやくくちばしで獲物を捕らえます。
Habitat
河川、池、湖、湿地、沼、田んぼ、水路、樹木のある水辺
Region
日本、アジア、ヨーロッパ、アフリカ、南北アメリカ
Behavior
夜間の狩り、じっと待つ、魚を捕る、日中は木で休む
Population
適した水辺環境では普通に見られる
