Stanley crane, Paradise crane
The Blue crane is South Africas national bird. It is small in relation to other cranes and has a large head, a thick neck and beautiful long wing feathers, called tertials, that trail behind it and can be mistaken for tail feathers. It has head feathers that can be erect when it is excited or being aggressive. Males and females have similar plumage but males are larger. The juvenile is a pale gray color, and does not have the elongated tertial feathers. Chicks have dark gray bodies and brown heads. Their feet and legs are black.
Blue cranes are native to southern Africa, more than 99% of them living within South Africa. There is a small breeding population in and around the area of the Etosha Pan in northern Namibia. These birds breed at high elevations in dry grasslands where there is less chance of disturbance. They roost and breed in wetland areas if these are available, some individuals preferring to nest in arable land and pastureland. They generally move to lower altitudes in autumn and winter.
Habits and lifestyle
Blue cranes are more terrestrial than the other large cranes. Their shorter bill is an adaptation to their feeding behavior, as they feed more often in grassland areas than in wetlands. They typically forage in pairs or small family groups during the day. All cranes dance, with movements including bowing, jumping, running, grass or stick tossing, and the flapping of wings. They dance at any age, and although dancing is commonly associated with courting behavior, it is generally thought to be a usual part of a cranes motor development and serves to deal with aggression, relieve tension, and make the pair bond stronger. Blue cranes migrate locally, moving with their chicks in autumn and winter to lower elevations. Flocking occurs throughout the year and is more common in winter when large flocks are formed, numbering several hundred birds.
sedge, seige, herd
Diet and nutrition
Blue cranes feed on plant matter like seeds from sedges and grasses, roots, tubers, and waste cereal grain, including maize and wheat. They also feed on large insects, mainly grasshoppers and locusts, as well as worms, fish, frogs, crabs, small rodents and reptiles.
Blue cranes are monogamous with long-term pair bonds. Courtship involves a dance where the male bird chases the female, interspersed with bows, leaps and bouts of calling. From September to February is the usual nesting time, with the typical nesting site being at high elevations amongst secluded grassland. The eggs are laid on bare ground or in the grass. Two eggs are laid and incubation lasts around 30-33 days, carried out by both parents. Very soon after hatching, the young follow their parents to forage with them. The young fledge from 3 to 5 months, and gain sexual maturity at 3-5 years old.
The biggest threat to Blue cranes is habitat destruction by converting natural biomes to agricultural land. As humans continue to increase in number, agricultural expansion, persecution, disturbance, and the grazing of livestock also intensifies, and these threats will probably become worse. Other threats are colliding with power lines, predation by dogs, and illegal capture of chicks for the pet trade and for food.
According to the IUCN Red List, the total population size of the Blue crane is over 25,580 individuals, with a minimum of 25,520 individuals in South Africa. This species’ numbers are stable currently but it is classified as vulnerable (VU) on the list of threatened species.
Fun facts for kids
- Mated pairs of these cranes take part in unison calling, a complex and protracted series of coordinated calls. The cranes take up a specific posture, typically with heads thrown back and bills skyward during the display. Males always lift up their wings over their backs during the unison calling, while females keep their wings folded at their sides. The male initiates this display and produces one call for each responding female call.
- This crane flies powerfully after running at take off, performing steady, strong beats with its wings, and alighting with dangling legs.
- The blue crane produces a loud, nasal kraaaank as well as low-pitched, raspy sounds, rattling and a far-carrying croak.
- Ancient Greeks had the belief that the flight of the cranes inspired the invention of the Greek alphabet by the god Hermes.