40 species of diurnal butterfly have been recorded in the Krka national park including two species of swallowtails. However, data on the ecology of these species is still missing and this project will concentrate on completing Pollard counts of butterfly communities in different 6 vegetation communities and habitats. These 6 habitats/vegetation communities include low open thickets and dry rocky grasslands that have developed in cut areas with degraded forests, mowed meadows along the banks of the Krka river, mixed forests of holm oak and flowering ash (Orno-Quercetum ilicis), mixed forests of downy oak and white hornbeam (Querco-Carpinetum orientalis), and black hornbeam forests with autumn moor grass (Seslerio-Ostryetum), wetland flora along the edge of the river. All butterflies along the Pollard count will be recorded and analysis can compare usage of different habitats/vegetation communities. Observations on food plants, timings of daily activity, heights of flight and other factors can also be included in the analysis for different species.
The Krka Valley runs from the Dinaric mountains bordering Bosnia to the Adriatic and is only 60km in length. However, since the river runs through limestone there are some spectacular gorges and this is one of the most scenic river valleys in Europe. It is also important from a biodiversity viewpoint containing 20 endemic fish species and spectacular cave systems containing a number of potentially new species to science.
Tourism in the Krka Valley is concentrated in the lower end of the valley and few people visit the central and northern parts of the valley. The Krka National Park authorities have built a research centre and museum in a remote part of the valley, in an attempt to attract more visitors away from the tourist hotspots. This project is working with scientists to provide data on the status of the endemic fish species, describing the cave fauna, examining how so many species of snake are separating their niches in the valley and assessing the impact of wolves moving down the valley and on the surrounding plateaus on the native jackal and fox populations. All these data are being fed back to the Krka valley research centre and the Park authorities hope to use this initial work as a way of attracting additional international researchers to the valley.
Silba Island is in the northern Dalmation archipelago and is a car and hotel free island. The island markets itself as a haven of tranquillity and much of the island is still covered by Mediterranean black oak and maquis. The objective of our partners on this island is to map the marine biodiversity around the island and particularly on the rocky reef islets which are currently protected for their breeding bird colonies, but which have no protection for their fish or seagrass communities.
Silba is a small island with no cars or hotels and is currently protected, along with the neighbouring Islets of Grebena, under the Natura 2000 scheme. This is because it has the largest breeding cology of sea cormorants in the Adriatic. However there is currently no protection for the fish and seagrass communities. The seagrass surrounding the island, Posidonia ocieanica (endemic to the Mediterranean), supports high levels of biodiversity and acts as an important nursery for juvenile fish. The increasing numbers of tourists visiting the island, along with the island’s growing population, is beginning to put pressure on Silba’s natural resources (through increased pollution, litter, and land use changes). At present there is no consistent monitoring of the wildlife in the area and Operation Wallacea is therefore involved in establishing a long-term monitoring programme to accurately record the current state and changes in the biodiversity on an around Silba. This information can then be used to inform future decisions and policy making in the area.
Croatia is hot during this time of the year! In both Krka and Silba the daytime temperature rarely drops below 30 degrees and can reach 40 degrees.
Fitness level required
Moderate. Whilst there are not many steep hikes in the forest, the hikes are still quite long and the temperature can make them tiring.
At Krka we are planning on camping – accomodation will be in tents with shared western style bathrooms and toilets, and in Silba it will be in dormitories, again with shared bathroom facilities. There is some limited phone signal in Krka (but not reliable for a data connection), but good phone signal in Silba.