Author: Lisa Marie Mahlknecht

By Vlado Vancura

This article is Part 2 of a series on the benefits of grazing for Apollo. You can read Part 1 here.

Forest and shrubs used to cover a much larger territory in Europe than they do today. Each part of Europe has its own history by which the forest was extensively logged and finally removed. In the case of the Carpathian mountains, this process began as early as the 14th century. It was a time when a growing density of human settlements in specific areas created pressure on the forest, with intensive logging that continued for centuries (Fred & Brommer, 2005).

This trend started to change in the last few decades, when large areas of forest were declared as protected areas. The tree line in particular became the subject of strict protection in many mountains in Europe. On top of that, large areas of the recently grazed land were abandoned, sheep were taken away and forest and shrubs spontaneously re-occupied the land. This process dramatically reduced the available habitat for Apollo, and still continues in some parts of Europe.

Active protection – grazing to stabilise the Apollo population

Like several other endangered species, the well-being of Apollo depends to a large extent on appropriate habitat and available food. Large areas which have been favourable for Apollo for several centuries are now more and more occupied by forest and shrubs. Maintaining the locality once inhabited by Apollo by removing trees and bushes have become important management activities.  

Removing the bush often creates appropriate conditions, particularly enlarging food-plant resources, for the larvae and butterflies. That activity can create fundamental conditions to support a stable Apollo population.There are arguments that maintaining the Apollo population means keeping and protecting the open landscape as much as possible. This is particularly important in the areas where fragments of the Apollo population have survived.

Grazing is a well-tested method to maintain open landscape and keep the pressure of trees and shrubs succession under the control. Well-managed grazing can significantly contribute to controlling the self-recovery of trees and shrubs and provide favourable habitat important for Apollo, as well as provide food, nutrition and other benefits to Apollo as well as livestock.

Carefully managed grazing is just one practical example of how to support the shrinking Apollo population. Long-term cooperation between nature conservationists and managers of grazing can even help to set up Apollo reintroduction projects and to try to breed completely new colonies of this butterfly. This activity can become an interesting example not only to implement sophisticated grazing methods but also to maintain and support the protection of Parnassius apollo.

By Vlado Vancura

This article is Part 1 of a series on the benefits of grazing for Apollo. Part 2 will be published next week.

Parnassius apollo is under threat. Populations of the butterfly species have dramatically decreased in the last couple of decades. There are countries with about a 20% decrease, but also some with a much more dramatic decline of around 50%. This very much depends on the geographical region.

The analysis provides evidence that the most fragile subspecies and forms of Apollo are those from a low altitude in East and Central Europe, while forms inhabiting the higher parts of the Alps and other, mostly south European, high mountain ranges are still relatively large and strong.

Disappearing habitats – Apollo requires open habitats

One hypothesis explaining these differences is that low-altitude areas in East and Central Europe have been heavily impacted by industrialization, new development and unprecedented intensification of agriculture in the last 20 years. A significant amount of habitat and food for Apollo disappeared.

Continuing on this hypothesis, we see that this kind of development was not so obvious 20 years ago in higher mountain areas. Open landscape developed by humans in previous centuries and maintained by grazing still provided fragments of suitable habitat for Apollo. This happened despite more and more massive abandonment of the traditionally grazed landscape (Fred & Brommer, 2005).

Since the Ice Age, shrinking steppe biotypes imposed selective pressure onto local Apollo populations due to a changing climate. That pressure resulted in the adaptation to new habitats, such as mountains, screes and meadows.

Gradually, Apollo shifted from a typical steppe into a mountain-steppe species. This occurred in the Alps and probably at the southern, calcareous slopes of the Carpathian Mountains, and resulted in the emergence of numerous forms and Apollo subspecies.

Current habitat of Apollo

As a steppe and mountain-subalpine-subboreal species, Apollo occupies  different habitats within its range. It is found in heaths, shrubs, various grasslands communities in lowland biotopes, and also in small clearings in forest. Among the most typical habitats, there are alpine and subalpine grasslands, dry calcareous grasslands and slopes in upland areas.

Open landscapes such as screes, rocky habitats high in the European mountain ranges such as Alps or Carpathians, are also suitable for Apollo. To maintain stable Apollo populations, the habitat must provide food-plant for the larvae, particularly the Sedum, Serpenvivum and Teleephium sp.

Nowadays, particular Apollo forms and subspecies occupy small areas, sometimes limited to single mountain massive or even hillside, as it was documented in the Alps and the Carpathians.

Parnassius apollo seems to be a quite adaptable species. History shows that it survived dramatic weather changes and even skills to adapt to these changes significantly. That provides hope that this species, with  l support and care for its habitat from us, can survive the coming years.