What is a Swan (Hakucho): Features, Types, How to Distinguish, and Food

Swans are the collective term for 6 species of waterfowl belonging to the genus Cygnus of the Anatidae family, possessing among the largest size and weight of extant flying birds. The two species of swans that winter in Japan are the Whooper Swan and the Tundra Swan.
The scientific name for the genus Cygnus is from the Latin "Cygnus," and the English name is "Swan." In Japan, they are called "Hakucho" (白鳥, white bird), but globally, there are also black swans with black feathers and species with black necks.
Depending on the species, they either migrate north-south (migrate) between frigid zones (tundra regions), subfrigid zones (taiga regions), and temperate zones according to the season, or they inhabit specific areas. In Japan, when one refers to swans, it generally means Whooper Swans and Tundra Swans, which breed in the tundra and taiga regions of Russia facing the Arctic Ocean, Sakhalin, Kamchatka Peninsula, etc., and winter in Hokkaido and parts of Honshu in Japan.
They inhabit shallow rivers, lakes, marshes, and inner bays, feeding on aquatic plants' leaves, stems, rhizomes, roots, grains, pasture grasses, seaweed, insects, and other foods.
Swans have exceptionally strong family and pair bonds; a pair remains together until one of them dies.
In their habitats worldwide, swans have had a deep connection with humans since ancient times, being used as symbols of beauty, love, and happiness by countries, states, prefectures, municipalities, and organizations, as names for shops, people, and objects, and as subjects of art, among various other legends.

There are 6 species of swans (genus Cygnus): Whooper Swan, Tundra Swan, Mute Swan, Black Swan, Black-necked Swan, and Trumpeter Swan. Regarding the number of swan species and their names, various sources such as Japan Swan Society (6 species), English Wikipedia (6 species), Japanese Wikipedia (7 species), Ornithological Society of Japan (Japanese Ornithological List 7th edition, 6 species), books on swans, and government bodies or organizations on the internet describe them variously as 8 species, 7 species + 1 subspecies, 7 species, 6 species + 1 subspecies, 6 species, etc. However, if the classification is limited to specific habitats or endemic species, such as in the Japanese Ornithological List of the Ornithological Society of Japan or the Wild Bird Society of Japan, fewer than 6 species may be listed.
In Ibaraki VR Tour, we display the same 6 species (and their names) as the Japan Swan Society and English Wikipedia. The main reasons are as follows:

• The 6 swan species belong to the genus "Cygnus," and the English name for "Cygnus (constellation)" is also "Cygnus," which means swan in Latin.
• Unlike the Japanese Wikipedia as of January 2023, the English Wikipedia limits to 6 species of the genus Cygnus, stating that "coscoroba swan" is not considered a true swan.
• The names of the 6 swan species are included in all species listings other than swan classifications limited by habitat, such as the Japanese Ornithological List and the Wild Bird Society of Japan.
• It is easier to understand if the morphology (size and shape) is the same, even if there are differences in the overall and partial colors depending on the world's habitat.

However, if there are more than 6 species, it means that the subspecies of the Tundra Swan are separated, or the Coscoroba Swan (C. coscoroba) of the genus Coscoroba Reichenbach is added. The Coscoroba Swan inhabits southern South America and differs from true swans in neck length and size.

Reference: <Wikipedia (English) Swan>
There are six living and many extinct species of swan; in addition, there is a species known as the coscoroba swan which is no longer considered one of the true swans.
(Japanese Translation)
There are six living and many extinct species of swan. In addition, there is a species known as the Coscoroba Swan, which is no longer considered one of the true swans.

(1) Distribution and Wintering of Whooper Swans

Whooper Swans that migrate to Japan breed in Siberia and along the Sea of Okhotsk coast, and fly to Hokkaido, Tohoku, Kanto, and Chubu regions via Sakhalin and the Kuril Islands for wintering.

(2) Main Morphology of Whooper Swans

*Both size and weight are among the largest of birds. Females are smaller than males.

• Adult: Total Length: Approx. 140-160cm*
• Adult: Wingspan: Approx. 210-240cm
• Adult Weight: Approx. 8-15kg

(3) Characteristics of Whooper Swans

• Call: They make loud, high-pitched calls like "Kō," and various calls depending on the situation.
• Takeoff for Flight: Due to their heavy weight, they require a surface run on the water for takeoff.
• Migration Distance: Approx. 3000km
• National bird of Finland

(4) Main Migration Sites of Whooper Swans

• Hokkaido: Lake Kussharo, Lake Tofutsu, Odaito Marsh, Lake Furen, Lake Kussharo, Tokachi Riverbed, Lake Utonai, Onuma, and many others
• Aomori Prefecture: Asadokoro Coast, Ōminato Bay, Lake Jūsan, Lake Ogawara
• Iwate Prefecture: Oozutsumi Park / Shinzutsumi
• Yamagata Prefecture: Mogami River Swan Park
• Miyagi Prefecture: Lake Izunuma, Shiroishi River Park
• Fukushima Prefecture: Lake Inawashiro / Shiratori Beach
• Ibaraki Prefecture: Kotoku Marsh, Shimizu Marsh, Shiratori no Sato
• Niigata Prefecture: Hyoko, Toriyanogata Lagoon, Sakata Lagoon, Fukushimagata Lagoon
• Nagano Prefecture: Lake Suwa

(1) Distribution and Wintering

They breed in the tundra regions of northern Eurasia and migrate to temperate zones such as southern England, the Netherlands, Denmark, and Japan at the same latitude as the Caspian Sea region during winter. In Japan, they are winter birds, with some wintering in Hokkaido due to global warming effects from the Russian tundra, but they migrate via Hokkaido to areas from Aomori Prefecture to Shimane Prefecture on Honshu. Since they migrate from the tundra, their wintering flight distance is longer than that of Whooper Swans.

(2) Main Morphology of Tundra Swans

*Both size and weight: Females are smaller than males.

• Adult: Total Length: Approx. 120-140cm
• Adult: Wingspan: Approx. 180-220cm
• Adult Weight: Approx. 5-11kg

(3) Characteristics of Tundra Swans

• Call: They make calls such as "Koh," "Gwah," "Kō," which are lower pitched than those of Whooper Swans, and various calls depending on the situation.
• Takeoff for Flight: Due to their heavy weight, they require a surface run on the water for takeoff.
• Migration Distance: Approx. 4000km
• Hokkaido is a relay migration site *Some winter in Hokkaido.

(4) Main Migration Sites of Tundra Swans

Tohoku region is excluded as Tundra Swans coexist with Whooper Swans there.

• Ibaraki Prefecture: Sugao Marsh, Oto Marsh
• Nagano Prefecture: Saigawa Swan Lake, Gohyōda Floodway
• Niigata Prefecture: Hyoko, Toriyanogata Lagoon, Sakata Lagoon, Fukushimagata Lagoon
• Shiga Prefecture: Lake Biwa lakeside (Nagahama City)
• Tottori Prefecture: Yonago Waterfowl Park
• Tottori Prefecture / Shimane Prefecture: Nakaumi Lagoon
• Shimane Prefecture: Lake Shinji

(1) Distribution and Wintering

Mute swans are originally swans that live mainly in Europe and Central Asia, and they migrate, but they are an alien species in Japan. The mute swans in Ibaraki Prefecture are believed to have bred from those transferred from the Imperial Palace, Hikone City, Ube City, and other locations. Migration from Lake Utonai in Hokkaido and Lake Ogawara in Aomori Prefecture has been confirmed in Kitaura of Lake Kasumigaura (Itako City: Swan Village).

(2) Main Morphology of the Mute Swan

* Both size and weight are among the largest for birds. Females are smaller than males.

• Adult: Total length: approx. 140-160cm
• Adult: Wingspan: approx. 210-240cm
• Adult weight: approx. 8-15kg

(3) Characteristics of the Mute Swan

• Call: Makes sounds like "gwah" or "gushuu". Does not make high-pitched calls.
• Takeoff for flight: Requires a water surface run-up for takeoff due to heavy weight.
• Migration flight distance: 750km in Japanese cases.
• National bird of Denmark.
• Considered an alien species in Japan, causing problems such as agricultural damage and avian influenza.

(4) Main Habitats of the Mute Swan

• Hokkaido: Lake Utonai
• Aomori Prefecture: Lake Ogawara
• Ibaraki Prefecture: Ushiku Marsh
• Chiba Prefecture: Teganuma Marsh
• Yamanashi Prefecture: Lake Yamanaka
• Yamanashi Prefecture: Lake Shinji
• Kagoshima Prefecture: Imutake Pond

(5) Foreign Related Matters of the Mute Swan

In the United Kingdom, by law, the King retains ownership of unmarked swans (mute swans) in open waters in England and Wales. Swans inhabiting specific parts of the River Thames are annually surveyed and their populations managed through a traditional event called "Swan Upping," which has continued for 800 years. The team of these managers is called Swan Markers.

Also, the coat of arms of Buckinghamshire, where Oxford University and Windsor Castle are located in England, and the mark of Swan United FC in Australia, feature the mute swan. Even with swan illustrations on flags and marks, you can quickly tell the difference if you know the how to distinguish swans (beak differences) below.

Whooper swans, Tundra swans, and Mute swans are all white and similar in size, making them indistinguishable when viewed individually or from a distance.

＜Differences (How to Distinguish) Between Swans and Whooper Swans＞

Whooper swans and Tundra swans differ in size (weight, total length, wingspan, etc.) and calls. However, size varies with growth stage, and calls are difficult to distinguish as Whooper swans and Tundra swans often coexist, and their calls change depending on their behavior. The difference can be seen at a glance by looking at their beaks.
<Beak Differences>
The yellow part of the Whooper swan's beak is pointed at the tip, while the Tundra swan's is not. Also, the yellow part of the Whooper swan's beak is more than half of the beak, while the Tundra swan's is less than half. Furthermore, the Whooper swan's beak is slender and pointed at the tip, while the Tundra swan's has a rugged appearance with a rounded tip.

＜Differences and Distinguishing Features Between Whooper/Tundra Swans and Mute Swans＞

Whooper swans/Tundra swans and Mute swans can be distinguished at a glance by looking at their beaks.
<Beak Differences>
Whooper swans and Tundra swans have beaks composed of black and yellow, while Mute swans have orange beaks. Additionally, Mute swans have a black, knob-like fleshy protuberance at the base of the upper part of their beak.

In Japan, **Whooper Swans and Tundra Swans** migrate for wintering.

The **conditions for a swan wintering ground** require three elements to be simultaneously met: **a safe roosting place, the presence of food, and being within the migratory flight distance limits.**

Swans' natural enemies include carnivorous animals such as foxes, raccoons, and weasels, as well as large birds of prey like goshawks. The conditions require a safe, non-freezing inland sea, lake, pond, marsh, or river, located not in mountainous areas but in open plains with good visibility, wetlands/shallows or fences that carnivorous animals cannot approach.
Also, due to their weight, swans need a run-up (about 10m) to take off from the water surface, requiring a large body of water with good visibility. If the above conditions are met, marshes and ponds within urban and residential areas can also be suitable.
Furthermore, swans are intelligent, and if they experience danger, they may stop migrating to that location from that day or the following year. Examples include gunshots from hunting/shooting ranges, fishing spots (rods, hooks, lines), and protective nets in lotus fields, etc.

Swan food includes stems and roots of reeds, cattails, and wild rice, stems and roots of lotus (renkon), aquatic algae, fallen grains, pasture, and insects. Therefore, a feeding ground must be present in or around the marsh or pond designated as their roosting place. Due to biodiversity concerns, there are also increasing numbers of places where feeding is prohibited.

Swans have different sizes (weights) depending on the species, so there are limits to their flight distance from breeding grounds. Whooper Swans are said to fly approximately 3,000 km, and Tundra Swans approximately 4,000 km. Mute Swans also migrate as needed. Mute Swans from Lake Utonai in Hokkaido have been confirmed by a survey by the Ornithological Society of Japan to winter in the Kitaura area of Lake Kasumigaura in Ibaraki Prefecture, a distance of about 750 km.
**The southern limit for Whooper Swans' migration is around the Tone River in Kanto, from Hokkaido (Itako Swan Village), while Tundra Swans are found from Miyagi Prefecture southwards in Honshu to the Shimane Prefecture area on the Sea of Japan side**.

Swan food includes stems and roots of reeds, cattails, and wild rice, stems and roots of lotus (renkon), aquatic algae, fallen grains, pasture, and seaweed, but varies depending on the migration site conditions. Also, the marsh, lake, or inland bay of the migration site itself may be a feeding ground, or the roosting place and feeding ground may be different.
Furthermore, a feeding ground must not only have food but also be a safe place where they are not targeted by natural enemies, such as open fields or pastures with good visibility.
If there is food in the roosting place itself, swans can be observed all day; otherwise, they can only be observed in the morning or evening. Urban park ponds and agricultural reservoirs, which are feeding grounds not targeted by natural enemies, typically do not have much food. However, if the pond or marsh is a famous spot with lotus or water lily fields, swans may be seen all day.

Swans migrate to Japan for wintering, and in summer, they migrate to reproduce in the Arctic tundra and taiga regions.
Why do swans undertake migrations of over 3,000 kilometers one way, risking such dangers?
It is not simply because the tundra and Siberia are cold, so they spend time in warm Japan.

As a premise for migration, swans are the largest flying birds in the world and are herbivores.
Swans require about one month from egg to hatching, and the hatched chicks need to grow into one of the world's largest adult birds in about five months, thus requiring a large amount of food. In the summer, the Arctic tundra and taiga regions have abundant food for swans.
However, the Arctic region has two seasons, summer and winter, and as soon as summer ends, winter arrives, causing lakes and marshes to freeze. When lakes and marshes freeze, not only does food become scarce, but swans also become prey for carnivorous animals like Arctic foxes and large raptors like gyrfalcons.
On the other hand, Japan has many safe, non-freezing lakes and marshes that serve as feeding grounds in winter.

The main reasons why they must migrate despite the risks are the following two points, in short, it is "to ensure the survival of swan offspring."

(1) Large amounts of food are required in a short period for breeding.

Swans are fundamentally 'herbivores' that primarily feed on grass; Whooper swans lay 4 to 7 eggs, and Bewick's swans lay 2 to 6 eggs. The hatching rate of eggs is unknown, but typically 2 to 4 chicks survive. Chicks must grow to roughly the size of their parents in about five months to prepare for the winter migration. The subarctic and arctic regions, such as the tundra and taiga, are where swans can obtain this food. Plants that grow in harsh environments like the tundra and African savannas experience short-term, explosive growth due to the arrival of thawing periods or rainy seasons. In the tundra and taiga regions, not only grasses and aquatic plants but also underwater algae grow rapidly. There is abundant food for swan chicks (Hina) to grow rapidly.

(2) Safe places with fewer natural enemies.

In tundra regions (cold zones) and taiga regions (subarctic zones), there are fewer birds of prey and carnivorous animals compared to temperate regions.
Furthermore, the places where swans breed are locations with good visibility, such as lakes and marshes, and as long as they are on the water or in water-borne thickets, their chances of being preyed upon are low.
According to the confirmedswan flight routesto Japan (Ministry of the Environment project "Elucidation of Migratory Bird Flight Routes"), the breeding grounds for Tundra Swans are in thetundra region (around Sylgy-Ytar), and the breeding grounds for Whooper Swans are in thetaiga region (around Nyadobaki). Looking at the aerial photos on Google Maps, you can see countless lakes and marshes in a vast flat area. Their scale is not comparable to the level of wintering grounds in Japan.
Additionally, swan eggs and cygnets have natural enemies such as red foxes, arctic foxes, raccoons, eagles, and hawks. Therefore, cygnets must learn to swim and hide in thickets on the lake as quickly as possible.
Just as savanna herbivores can stand and walk immediately after birth,swan cygnets can walk immediately after hatching and can swim with their parents in 2-3 days. They can also feed themselves rather than being fed by their parents. This means that for cygnets to grow into one of the world's largest adult birds capable of flying over 3000 km in 5 months, they need to practice flying and eat continuously.

References: NHK Archives: "Siberia: Tundra Swan Family Practicing Swimming in a Puddle", "Siberia: Tundra Swan Cygnets Eating Water Plants"

(1) Seasonal Environment for Swans in Japan

• Summer: Grasses and algae increase. Birds of prey and carnivorous animals, which are natural enemies, become active for breeding, increasing the likelihood of swans being preyed upon.
• Winter: There is adequate food such as reeds, cattails, and wild rice, and many lakes and marshes do not freeze. The activity of natural enemies decreases in winter.

(2) Seasonal Environment in Tundra Regions, etc.

• Summer: Ice melts, and plants increase rapidly and explosively for a short period. Although there are fewer natural enemies than in Japan's summer, eggs and cygnets may still be preyed upon.
• Winter: The ground and lake surface freeze, making food unavailable. With no open water on the lakes, they are easily preyed upon by natural enemies.

As described above,swans cannot survive without migrating to secure food during normal times, secure food during breeding, and for their personal safety, including egg-laying and raising young.It is rational for them to winter in Japan and breed and raise their young in tundra regions during the summer. This means that swans have adapted their migration patterns through a long evolutionary process to secure food and protect their safety, leading them to winter in Japan.
It is said that the British naturalist, biologist, and geographer Alfred Russel Wallace (1823-1913) was the first to advocate that "the amount of food greatly influences bird migration."
*Reference: 100 Years of Ornithology, Author: Tetsuji Ida