A two-year survey at Schönbrunn Zoo in Vienna has documented 134 species of butterflies and moths, revealing a surprisingly rich diversity within the zoo grounds. Of the species recorded, only 12 were butterflies active during the day, while 122 were moths, highlighting a largely unseen side of urban biodiversity.
The monitoring project was carried out between April 2024 and May 2026, with particular attention paid to nocturnal species. While butterflies are commonly associated with colourful insects flying during daylight hours, more than 90% of butterfly and moth species are actually nocturnal.
Among the species identified at Schönbrunn were the lime hawk-moth and the leopard moth. One of the most significant findings was the presence of the giant peacock moth (Saturnia pyri), Europe’s largest moth. The species was found at the zoo both as a cocoon and as an adult, suggesting that it is successfully reproducing on the grounds.
Different methods to uncover nocturnal biodiversity
Butterflies and moths play an important ecological role as pollinators and as a food source for birds, bats and numerous other animals. They are also highly sensitive to environmental changes and can therefore provide valuable information about the condition of an ecosystem.
Around 4,000 butterfly and moth species are known in Austria, approximately 3,800 of which are moths. Because different species have very different ecological requirements and behaviours, butterfly expert Alexander Dostal used several methods to document those living at Schönbrunn.
These ranged from nocturnal light stations and light bucket traps to the inspection of dead tree trunks. Whenever possible, the insects observed were photographed and recorded as part of the survey.
“The diversity of butterflies and moths at the zoo is a very encouraging sign. It shows that semi-natural areas and specifically created butterfly islands can provide valuable habitats for native species even in the middle of the city,” Dostal said.
Creating habitats for native wildlife inside the zoo
According to Schönbrunn Zoo Director Stephan Hering-Hagenbeck, the results are linked to measures introduced over the years to create suitable habitats for native wildlife, particularly insects, alongside regular monitoring of their effectiveness.
The survey therefore provides a picture not only of the species found within the zoo but also of the potential role that green spaces can play in supporting biodiversity in an urban environment.
Schönbrunn also points to a simple principle that can be applied in private gardens: less intensive management can benefit butterflies. Areas left relatively wild and planted with native flowering species can provide both food and shelter for insects.
