Focus on the Apollo Butterfly in Pieniny National Park, Poland/Slovakia.
The Apollo butterfly [Parnassius apollo] is a magnificent species mainly inhabiting mountain ranges. Due to its highly specialised requirements, vulnerability to anthropogenic disturbances [the effects of human activity on the natural world], a clumsy flight and remarkably easy approachability while feeding on thistles and knapweeds, this attractive butterfly is susceptible to local extinction. Having been lost from several countries, it is evaluated as Near Threatened. It occurs in suitable habitat in parts of Central, Southern, Eastern and Northern Europe typically between 1,000 and 2,400 metres. One example of how vulnerable it is to human activity comes from near Bozen in the South Tyrol region of Italy where a motorway constructed in Apollo habitat resulted in large numbers of Apollos being killed. The butterfly flies low, typically 30 – 60 cm above the ground and with their heavy bodies and slow flight they become traffic casualties [See Collins, N.M. and Morris, M.G. (1985) Threatened Swallowtail Butterflies of the World. IUCN, Gland, Switzerland and Cambridge, UK. ]. The fact that the Apollo shows great variations make it attractive to collectors who find no difficulty in obtaining the butterfly because it is oblivious to danger and easily taken; it is perhaps the tamest European butterfly.
The text that follows is an edited translation of the Apollo information leaflet obtained from Pieniny National Park, Southern Poland. The translation is courtesy of Sylvester Grabia.
The Apollo butterfly that lives in the Pieniny National Park in Southern Poland was described as a separate sub-species in 1955. It is one of the most beautiful and largest butterflies in Poland with a wingspan of up to 9 cm. The edges of the forewings resemble thin tracing paper. Their colouring blends effectively with the white limestone and white flowering rush plants found in the Pieniny National Park. The forewings often hide the hindwings which are more vivid and hold the striking red eyelets. When alarmed, the butterfly reveals these eyelets and rubs the underside of its wings with its legs, making rustling sounds. The hindwings also contain hairs which are used to make a sound to ward off potential attackers. The Apollo is declining throughout its European range and in Poland this decrease has been ongoing since the eighteenth century, and it is now found only in the Pieniny area and possibly in the Tatra Mountains, where there are open areas on limestone slopes and xerothermic vegetation [hot, dry vegetation]. In Pieniny it would be likely to be extinct without human intervention. In 1991 there was only one station where the butterfly was still found and only about 30 individuals were counted. Because the butterfly was on the brink of extinction a rescue plan was launched involving the Pieniny National Park, the Institute of Nature Protection based in Krakow and the Slovak Pieniny National Park [the park lies on both sides of the Poland/Slovakia border]. There was a breeding farm established the main objective of which was to maintain and increase the wild population by introducing grown butterflies into the wild. Another task that was undertaken was the restoration of the once existing breeding stations of the Apollo, which were formerly open and exposed to strong sunlight. This restoration was needed because the cessation of grazing [by sheep] led to the areas becoming overgrown. These overgrown areas were regarded as wasteland and were afforested in the mid-twentieth century. It was necessary to remove the trees and scrub to create the conditions for the butterflies to be released. An important part of the programme is monitoring which has been carried out continuously from the start of the active programme to determine the size of the population and the extent of migration of individuals between the different stations. The people involved in the programme catch the butterflies and mark them by writing numbers on their wings and release them. This process does not negatively affect the future life of the butterflies but the results allow the conservationists to assess the effects of the programme. In the course of the restoration programme a number of difficulties appeared.
One of the biggest problems was the degeneration of the genetic make-up of the population living in the Polish part of the Pieniny. It was noted during the breeding programme that part of the wings of the butterfly were deformed. With such a small population, this feature began to appear in an increasing number of individuals, so it became necessary to take immediate action to enrich depleted gene pools. With the consent of the Polish and Slovak Ministries of Environmental Protection exchange of individuals was initiated between the two countries. Ongoing observations confirm flights between individuals of once isolated populations. In its natural environment the Apollo is exposed to many dangers, such as habitat loss, parasites, predators, competitors, pollution by heavy metals and poaching.
In recent years the population of the Apollo in Pieniny National Park was between 800 and 1,000 butterflies. In 2004 there was a significant decline in the population, probably caused by cool conditions and prolonged rainfall during the period of intensive foraging and growth of the caterpillars. The figures for 2005 showed a recovery. It is hoped that the measures taken to conserve and expand the population will allow the Apollo to survive and that the experience gained can be applied in the rescue of other endangered species.
Life Cycle of the Apollo
The story of the life cycle begins during the Pieniny summer when mated females lay up to 150 pinhead-size ova. The ova are placed directly on soil or on plants, always in the vicinity of the host plant of the caterpillars which in Pieniny is a large Sedum maximum, a species of stonecrop [a succulent plant adapted to survive in dry conditions]. The egg is the stage that over-winters. Caterpillars may appear as early as the last days of February when the sun melts the snow on the southern slopes of Pieniny. Night temperature drops or temporary cooling does not harm them. In favourable conditions caterpillars warm up and begin eating Sedum maximum. In later stages the caterpillars may feed on other plants such as Jovibara hirta, [another succulent plant] but Sedum maximum remains the staple food plant. After four moults the caterpillar is fully fed by May at which time it reaches about 50 mm in length. During the second half of May the caterpillar seeks a quiet place and pupates within a cocoon. It hatches after three to four weeks. Males appear before the females. Males patrol in open spaces seeking their less active partners. After mating the male protects the female from other males by sealing her with a chitinous structure called the sphragis. [This is black in colour, is found on the underside at the end of the abdomen of the mated female and is quite conspicuous]. Butterflies survive, on average, for 20 to 30 days. At the end of August, the last butterflies die leaving their eggs behind to survive through the cold winter and at the arrival of spring another life cycle begins.