A Year in the Life of a Red-Crowned Crane
In Japanese, red-crowned cranes are called tancho, which refers to the patch of red skin on their forehead. It is believed there are just 2,750 red-crowned cranes left globally. They inhabit eastern Siberia, part of northeastern China, and eastern Hokkaido. They were once found throughout western Japan in the Edo period (1603–1867), although it was believed that overhunting had led to their extinction during the Meiji period (1868–1912). However, ten birds were discovered in Kushiro Marsh in 1925. Conservation programs were immediately implemented to protect this rare species, and by 2006 their numbers had recovered to more than 1,000.
During the cold months, from around November to February, the cranes roost along frozen rivers. Winters here are harsh and the cranes are sometimes unable to find food in the frozen lakes and waterways. Consequently, many birds gather at designated feeding sites where food is provided for them.
Courting takes place around February. To find a suitable partner, male and female cranes perform a beautiful mating dance. They raise their heads in unison, open their wings, and leap in the air while calling. Many bird enthusiasts flock to the snow-covered fields around Kushiro to witness this “crane dance.” Around mid-March, the mating pairs build a soft nest made of withered reeds in the marshlands. Circular in shape and with an indent in the middle, the nest is approximately 30–50 cm deep, and 160–200 cm wide.
A red-crowned crane usually produces two eggs at a time, which are laid between March and April. The oval-shaped eggs are 10–12 cm long and 6–8 cm wide. A standard egg weighs 230–240g. The shell is the same light-brown color as the reeds and is covered in specks of various sizes. From April to May, both the male and female cranes take turns incubating the eggs. On average, they switch places four times a day, all the while rotating the eggs to ensure an even distribution of warmth. In May, around 28 days after starting incubation, the chicks begin to hatch; it takes about two days for them to fully emerge. The hatchlings have soft, caramel-brown feathers, and are able to open their eyes and begin walking immediately.
From June to October, the parents get their appetites back. They eat small fish such as stickleback and lake minnow, as well as crayfish, worms, and insects. When the chicks are a few days old, they begin foraging for their own food. As they grow they start to eat larger fish such as dojo loach, crucian carp, and Japanese dace, as well as shellfish and frogs. By the time the chicks are three months old they have the same diet as their parents, consuming mainly insects, aquatic invertebrates, fish, rodents, and amphibians.
Juvenile cranes grow quickly, reaching adult-size when they are three months old. Around this time, they begin to practice flapping their wings, and by their 100th day, most cranes are able to fly. They stay by their parents’ side until they are around ten months old, which is the start of the next breeding season. During this time, their brown feathers gradually turn black, but the red patch on their head does not appear until they are around two years old. It takes approximately three to four years for cranes to reach breeding maturity.
