Rare Apollo butterfly re-introduced to Krkonoše after hundred years  

After more than a century, the Apollo butterfly, one of Europe’s most threatened butterfly species, has returned to the Krkonoše Mountains, where it once used to thrive. Earlier this month, conservationists reintroduced the first 55 males of the rare species to several locations in the national park.

The Apollo, known in Czech as Jasoň červenooký, is a large white mountain butterfly with distinct red spots on its wings. Once a common sight across Europe, its populations have rapidly declined in recent decades.

“Its populations are dwindling across the whole of Europe, and if nothing is done, it is quite possible that within a few years, there will be nothing left to save.”

In Czechia, it went completely extinct about a century ago as a result of mass catching by butterfly collectors, but mainly due to the loss of its natural habitat.

In the 1980s, it was successfully reintroduced to Moravia, where a small population still survives. Now, the international nature conservation group JARO aims to bring it back to the Krkonoše mountains. The group’s Oto Petřík explains why they have chosen to focus on this particular species:

Larva of the Appolo butterfly | Photo: Jakub Vik,  Český rozhlas

“Actually, the JARO group focuses on the preservation of several endangered species, animals and plants. The Apollo has a special place among them because it is critically endangered. Its populations are dwindling across the whole of Europe, and if nothing is done, it is quite possible that within a few years, there will be nothing left to save. So it's kind of like the white rhinoceros, only among butterflies.”

In order to thrive, the Apollo needs very specific conditions. As a caterpillar it requires open rocky slopes that receive a lot of sunlight. As a butterfly, it feeds on plants with lots of nutrients. To reintroduce it into the wild, conservationists first had to provide such conditions, explains Mr. Petřík:

“It was a demanding job, it required felling trees and exposing rocky slopes, so that the flowering plants and stone crops could grow there. Until this work was done, there was basically no point in releasing the butterflies there, since they wouldn’t be able to survive as a population.”

While preparing a suitable habitat for their reintroduction, conservationists bred the butterflies in captivity, a process that took about two years’ time. Before their release, they branded the butterflies’ wings with red markers to monitor their movement but also to prevent poaching.

The Apollo butterfly larvae are reared in pots wrapped in fabric | Photo: Jakub Vik,  Český rozhlas

The Apollo is a so-called umbrella species, whose protection, if it’s successful, could help the entire ecosystem, explains Mr. Petřík:

“An umbrella species is an organism whose protection benefits the entire ecosystem. A lot of animals and plants share the same habitat and that of the Apollo butterfly is very specific.

“So if a butterfly thrives in a given locality, we know that we have also created a suitable environment for a whole range of other endangered organisms.

“In this case we are already noticing many new species of butterflies and also snakes for example that have suddenly appeared in the given location. So it’s a success so far, in my opinion!”