The return of the lesser kestrel to Bulgaria

Lesser kestrel. Photo: Oliver Le Que, Prague Zoo

As recently as the mid-20th century, the lesser kestrel (Falco naumanni) was common in Bulgaria. Its population size, however, began to decline, most likely as a result of increasing agricultural intensification and the loss of its natural habitat: warm, dry and open landscapes with low vegetation, suitable for foraging, as well as a sufficient number of cavities and ledges that allow colonial breeding. In 1985, conservationists listed the species as “Endangered” in the Bulgarian Red Book, and by the end of the 1990s, its population was estimated at no more than five breeding pairs. Between 2000 and 2010, no breeding was recorded at all, and the lesser kestrel was reclassified as Critically Endangered.

In 2013, the first in a series of projects aimed at returning this bird of prey to the wild was launched, with Prague Zoo playing an active role. By the end of 2025, a total of 17 individuals has been transported from Prague Zoo, 12 of which originated from its own breeding programme. The organisation Green Balkans, with which the zoo has long cooperated, has also installed more than 130 artificial nest boxes across Bulgaria.

The total population of the lesser kestrel in Bulgaria is now estimated at more than forty breeding pairs in three main colonies. In June 2025, conservationists recorded an exceptional milestone—almost 190 fledged chicks, indicating a high breeding success and thus very promising prospects for the years to come.

Lesser kestrel. Photo: Tereza Mrhálková, Prague Zoo