Great Bustard – Otis tarda
The Largest Flying Bird is Vulnerable but Increasing in Some Places
Jul 29, 2007
The Great Bustard, Otis tarda, occupied the open grasslands of Eurasia before humans converted much of this habitat into farmland. Adaptable and tough, the Great Bustard has expanded its range with the clearing of forests, but overall, numbers have declined due to hunting and habitat loss. Today, the species is listed as vulnerable on the IUCN Red List.
The Great Bustard in England
The fortunes of the Great Bustard in the UK are typical of the situation throughout its range, except that in England the birds were extinct by the 1840s while they still remain in fragmented populations in areas of Europe and Asia. (The largest population is in Spain.) Large and rather slow to flush, they have been hunted for food and for trophies, and they were considered good quarry for hunters because they can move fast and would rather run than fly.
Good habitat for Great Bustards is still found in England, particularly on Salisbury Plain, near the south coast. Here, open grasslands in close proximity to cereal crops can provide both breeding habitat and food for the birds. A reintroduction project is underway.
Great Bustard Conservation
The same factors that allowed Great Bustards to expand their range in Eurasia have largely been their undoing—though there are abundant open agricultural areas, nests located in cultivated fields are frequently plowed under. Even where farmers are actively trying to spare the nests, many are destroyed because sitting females are difficult to see and don’t flush until the last minute. When the nest survives the plow, it is often left exposed to predators because the plow passes too close.
Conservation in Russia now uses a captive rearing technique where eggs are removed from doomed nests and then hatched and raised in captivity. Captive-reared birds are released back into the wild, thus increasing wild numbers. The population of Great Bustards in Russia is thought to be stable at about 8000 birds, and the conservation program has been able to provide captive reared birds for release in the UK.
Interesting facts about Great Bustards:
- It’s estimated that there are about 35,000 Great Bustards alive today.
- The Great Bustard is the world’s largest flying bird – fully grown males are just over a metre long (3.5 feet) and weigh about 13.5 kilograms (30 lb).
- Great Bustards cannot perch—they spend all of their time on the ground.
- Male Great Bustards usually don’t breed until they are four or five years old.
- Birds of dry habitats, Great Bustards lack a preen gland for waterproofing feathers.
- The male Great Bustard engages in an elaborate display to attract females. He expands a neck pouch and extends his wings down while twisting his wing feathers out to form a white fan or rosette.
- Growing chicks eat mostly insects, while adults feed on insects when they are plentiful in summer, but rely on plant parts and seeds during the colder months.
- Female Great Bustards incubate one to three eggs and raise young without any help from the male.
- A Great Bustard that survives the first year of life can live up to 20 years.
Other bird reintroduction projects:
Sources:
“Great Bustard Reintroduction Project.” The Royal Society for the Protection of Birds
Firefly Encyclopedia of Birds. Perrins, Christopher ed. Buffalo: Firefly Books, 2003
