I recently finished a book by one of my favourite authors, Simon Winchester. It was called Korea: A Walk Through the Land of Miracles, and in it, he describes his journey walking across South Korea. It was an interesting read, but the point is that he describes some of the endangered wildlife that makes its home in Korea, and the red-crowned crane caught my eye, so I decided to blog about it.
Red-crowned cranes are found in Eastern and southeast Asia. They spend their summers in Russia, China and Mongolia, migrating south to Korea and central China during the winter. There is also a non-migratory population on Hokkaido, Japan. They are found in marshes and wetlands, preferring areas with deep water, which is unusual among crane species.
These birds get quite big, reaching 1.5 to 1.58 meters in height, with a 2.2 to 2.5 meter wingspan. Red-crowned cranes are on average the heaviest cranes in the world, with weights ranging from 4.8 to 10.5 kilograms. The birds get their names from the red patches on their tops of their heads, which may look like feathers, but are actually areas of bare skin. The rest of the body is a mix of black and white, with black on the wings, and males having black cheeks, throats and necks.
Red-crowned cranes have long, sharp beaks. In fact, their beaks almost seem too large for their heads (that’s what I thought when I was drawing one, anyway. I had to keep checking the proportions to make sure they were right). These are used in a spearing motion to collect food. Red-crowned cranes are omnivorous, feeding on insects, fish, amphibians, small reptiles and other birds, as well as plants and seeds. To gather food, the cranes wander through the mud, keeping their heads close to the ground. When they find something they like, the birds jab their beaks into the ground, grasping their prize in their impressive beaks.
Another benefit of that unwieldy beak that it makes an excellent weapon. The sharp beaks, along with the cranes’ enormous size, means that adult birds are quite well protected against predators. Eggs and nestlings are often the target of predators, though it takes a ballsy hunter to go after a red-crowned crane nest, as the parents will defend it aggressively, sometimes killing smaller predators that attempt the feat. Introduced mink on Hokkaido are one of the few predators that successfully raid red-crowned crane nests.
Reproduction in red-crowned cranes occurs in the spring and summer. Cranes are big dancers throughout the year, but they dance a bit more during the breeding season, where pairs dance together to establish or strengthen a bond. The dances can include bows, head bobs, leaps, and calls performed in unison by both partners. Once a pair is formed, the two tend to stick together year after year.
During nesting, red-crowned cranes are territorial, and both sexes help to build nests on the ground, often on wet ground or shallow water. Females lay two eggs, which hatch after about a month. Both parents incubate the eggs and care for the chicks. The chicks leave the nest and accompany their parents on foraging trips at around three months after hatching; they fledge about 70 days after hatching. The young birds stay with their parents for a while longer, however, getting assistance from their mother and father until nine months of age. Red-crowned cranes are some of the longest-lived birds in the world, with wild birds living to 30 to 40 years, and captive birds reaching 70 years of age.
Unfortunately, these beautiful birds are also some of the rarest cranes in the world. There are only about 2,750 birds left in the wild. As predation is not much of an issue for this species, their main threat is the destruction of the wetlands that they live in. There is some good news. Human conflict, has, unwittingly, given some land back to the red-crowned crane and other species: the 250km long Demilitarized Zone between North and South Korea is undisturbed by people, and has become an accidental nature reserve. It gives homes to many endangered species, including the red-crowned crane. It may be an uneasy place for animals to make their homes, but at least their habitat remains undisturbed, for now.
Cover image credit: Petra Karstedt via Wikipedia