Clouded Apollo

The clouded apollo butterfly (parnassius mnemosyne) is one of Sweden's most endangered butterfly species and is found only in small and fragmented populations in Blekinge, in the border areas between Uppsala and Stockholm County and in Västernorrland County.  The species has declined sharply since the 1960s. The cause is not fully understood, but probably it's mainly due to changes in the habitat of the butterfly.

In Sweden, its habitat is mosaic meadows and pastures adjacent to deciduous forest edges with an abundant occurrence of the host plant corydalis.  This type of habitat has disappeared in large parts of Sweden, partly due to overgrowth, afforestation, exploitation and excessive grazing.

In order to slow down and reverse this negative trend, great efforts are required. The habitats of the species must be restored and appropriate management of the areas must be put in place.  As the species has a low dispersal capacity, breeding and release  are also an important measure to bring the clouded apollo butterfly back into its former range.

What we do at Nordens Ark
Nordens Ark has been commissioned by the County Administrative Board of Blekinge and Uppsala Counties to initiate breeding work for the clouded apollo butterfly in order to eventually be able to contribute animals for release on suitable premises. The work takes place within the framework of  action programmes for threatened species, where the County Administrative Board of Blekinge is the national coordinator for the action programme.

In order to build a breeding population of this species on Nordens Ark, a number of eggs have been collected from the populations of Blekinge, Uppsala and Stockholm. The collection is done without harming the existing wild population.

The breeding takes place in a purpose-built butterfly greenhouse on Nordens Ark. The eggs hatch in April and then the delicate larvae must directly find leaves of corydalis to eat. A month later they pupate. At the beginning of June, the fully formed white butterflies hatch and soon begin to mate and lay eggs. The eggs remain there until next spring.

Current in the project
Work is currently underway to build a self-sufficient breeding population at Nordens Ark. Hopefully we will be able to send animals for release to restored premises within the next few years.

In 2020, a genetic study was initiated in collaboration with researchers at Uppsala University to, among other things, map possible inbreeding defects and the need for genetic reinforcement.  The results of the study are expected in 2022.

In cooperation with County Administrative Board of Blekinge and Uppsala