How a pair of Calgary whooping cranes are helping to save their species

Two young whooping cranes from Calgary have been released into the wild in Louisiana as part of an effort to protect the species among the world's rarest birds from extinction.

The pair of Calgary birds, which hatched at the Calgary Zoo's Devonian Wildlife Conservation Centre, flew free Wednesdayalong with 10 other cranes reared in Maryland, Wisconsin and New Orleans.

• Calgary Zoo whooping cranes set to be released into the wild in Louisiana

The animals are part of an experimental population that now numbers 72 in the Louisiana wild, monitored by American wildlife authorities.

Whooping cranes, which stand nearly six feet tall, are North America's tallest flying birds andamong the world's rarest birds.

In 1944, there were just 21 alive, a number that has grown to about 600 today. Of those, roughly 450 live in the wild and about 150 are in captivity.

Nearly 350 of the wild birds form the only natural flock, which migrates between Canada and Texas.

The remaining 100 are in a flock taught to migrate from Wisconsin to Florida by following ultralight planes.

For its work in advancing the restoration of the species, the Calgary Zoo won an award from the Association of Zoos and Aquariums last year.