Blue Crane (Grus paradisea)

Cover image: Blue Crane by Attie Van Aarde – Albertinia district, Western Cape – BirdPix No. 268829

By Act of Parliament, this is the national bird of South Africa.

Identification

The Blue Crane is a large and striking species. It is conspicuous and unmistakable. The entire body, except for the head, is blueish-grey, and darkest on the nape, upper neck and wing coverts. It has a rounded, almost bulbous head shape and the forehead and crown are white, with this colour extending onto the lores and cheeks. The feathers on the cheeks, ear coverts and nape are elongated and loose and are raised during display.

The feathers of the lower fore-neck too are elongated and used in display. The long ‘tail’ feathers that hang almost to the ground are in fact inner wing feathers (tertials). The bill is dull pinkish-orange and the eyes are dark brown. Legs and feet are dark grey to black. The sexes are alike in plumage coloration.

In flight Blue Cranes show plain grey underwings that differ from the contrasting flight feathers and coverts of the Wattled Crane (Grus caranculata) and Grey Crowned Crane (Balearica regulorum).

Juveniles are paler overall than the adults, especially on the head and they have some buffy feathers on the wing coverts, flanks, belly and thighs. Juveniles lack the bulbous head-shape and elongated tertials of the adults. Juveniles also have black bills with a reddish base and dull brownish-red legs. The wing coverts and flight feathers are brownish-black.

Status and Distribution

The Blue Crane is locally common and is endemic to southern Africa. It is the world’s most range-restricted crane species. Most of its distribution falls within South Africa from the southern parts of the Western Cape, north-east to the southern Limpopo Province. There is an isolated breeding population in Namibia, centred on Etosha Pan and a small breeding population in north-western Eswatini (Swaziland). Elsewhere it occurs as a non-breeding visitor to extreme south-eastern Botswana.

The Blue Crane is listed in the global Red Data Book as Vulnerable. Its conservation status in South Africa varies between the 3 main biomes it inhabits (Nama Karoo, Grassland and Fynbos). Its distribution and abundance appear not to have changed in the Nama Karoo. The Grassland biome was probably the ancestral stronghold, but it has decreased dramatically in this region. This species was originally absent from the Fynbos biome but has expanded its range into the agricultural regions where it is now remarkably common.

The main threats to the species are from poisoning, collisions with overhead powerlines and loss of habitat to afforestation and urban expansion.

Habitat

The Blue Crane favours open grassland and the grassy Karoo shrublands. It also occurs commonly in the fynbos biome. However, it avoids natural fynbos, instead inhabiting cereal croplands and agricultural pastures. In the Nama Karoo, it is largely restricted to the east where summer rainfall exceeds 300 mm per year.

It is frequently found in agricultural fields and croplands across its range, and also inhabits the fringes of wetlands in open areas and is tolerant of intensively grazed and burnt grassland. It extends marginally into light savanna and areas cleared of woodland.

Behaviour

The movements of the Blue Crane are not fully understood. Birds in the Western Cape and the Karoo are largely resident, but those inhabiting the grassland regions, and particularly at higher altitude are known to move to lower lying areas in winter.

When breeding the Blue Crane is mostly encountered in pairs or family groups. The Blue Crane is highly gregarious outside of the breeding season when it is usually found in flocks numbering anywhere from 30 to 300 birds or more. Flocks of up to 1000 have been observed in the Karoo. They are wary when breeding but are otherwise fairly tame.

Roosts communally at night in shallow water or on the ground. They are highly vocal when arriving and departing from roost sites. It flies strongly and soars well, often to great heights, and frequently in ‘V’ formation.

Food is detected by sight and the Blue Crane feeds mostly by pecking, but also digs with the bill. They are omnivorous but the bulk of the diet is vegetarian. They eat small bulbs, green shoots, leaves, seeds and grain, roots, insects, worms, crabs, fish, frogs, reptiles and small mammals. They consume a variety of agricultural pests like bollworm caterpillars, locusts and their eggs and Harvester Termites Hodotermes mossambicus. Commonly feeds at small-stock feedlots, especially in winter.

Leading up to the breeding season pairs engage in spectacular courtship dances involving much calling, wing flapping, jumping and pirouetting.

Breeding takes place from October to February. It is a monogamous, solitary nester. Blue Cranes are strongly territorial and pairs will aggressively defend nesting areas from predators and conspecifics.

The nest is a scrape on the substrate and is lined with a pad of vegetation on damp ground, or in dry places with small stones, mammal dung and pieces of dry vegetation. Nests are frequently situated in damp locations with clear, all-round visibility. Often reuses the same general nesting area over several years.

Normally one or two eggs are laid per clutch at two or three day intervals. The eggs are greyish-brown to brownish-yellow overlaid with darker streaks and blotches. The eggs have hard shells and are fairly well camouflaged.

Birds move away from nest if threatened, but will defend the nest aggressively if needed. They confront threats (including humans) with wings outstretched and the bill pointed at the intruder, ready to kick and peck.

Incubation begins with the first-laid egg and the incubation period lasts for 29 to 30 days. Incubation duties are shared by both sexes. The young are precocial but stay on the nest for the first 12 hours or so after hatching. They grow quickly and attain adult height after just 10 weeks. Strong sibling aggression may result in brood-splitting, where each parent looks after a chick separately to avoid siblicide. Blue cranes only attempt to breed once per season (single brooded).

Further Resources for the Blue Crane

Species text adapted from the first Southern African Bird Atlas Project (SABAP1), 1997.

The use of photographs by Attie Van Aarde, Desire Darling, Gregg Darling, Itxaso Quintana, Richard Johnstone, Sharon Stanton, Sue Gie and Trevor Hardaker is acknowledged.

Virtual Museum (BirdPix > Search VM > By Scientific or Common Name).

Other common names: Anthropoides paradiseus (Alt. Scientific); Bloukraanvoël (Afrikaans); iNdwa (Zulu); Indwe (Xhosa); Mohololi (South Sotho); Mogolodi (Tswana); Paradijskraanvogel (Dutch); Grue de paradis (French); Paradieskranich (German); Grou-do-paraíso (Portuguese)

Recommended citation format: Tippett RM 2024. Blue Crane Grus paradisea. Biodiversity and Development Institute. Available online at https://thebdi.org/2024/04/08/blue-crane-grus-paradisea/

List of bird species in this format is available here.

Bird identification, birding