RIGA, July 25 (Xinhua) -- A young black vulture born and bred at Riga Zoo has been sent this week to Bulgaria where it will be released into the wild as part of a reintroduction program, the zoo informed on Wednesday.

Riga Zoo, which prides itself on successfully breeding black vultures since 2014, is contributing two young birds that hatched this spring to the European Endangered Species Program for the black vulture.

Representatives of Riga Zoo said that the first nestling was flown by plane to Bulgaria on July 24, to prepare for its first independent flight over Balkan mountaintops. The other bird is scheduled to travel from Riga to Bulgaria in August.

On the same day, two other birds of this species, which has gone extinct as a nestling species in Bulgaria, were sent by Zoo Ostrava (Czech Republic).

The vulture from Latvia was named Riga after the zoo.

Upon their arrival in Bulgaria, the birds from Latvia and the Czech Republic were equipped with GPS tracking devices and taken to an adaptation aviary in the eastern Balkans. When they feel ready, the captive-born vultures would leave the aviary on their own to make the first flight and start their new life as wild birds.

The black vulture (Aegypius monachus) was added to the IUCN Red List of Threatened Species in 1988. The main threats to these birds of prey include shortage of appropriate nesting sites, scarcity of food sources, hunting, destruction of nests and the use of poisoned baits for predator extermination.