2026 Dates
2 weeks: 1 week terrestrial & 1 week marine – 11 June – 24 June
2 weeks: 1 week terrestrial & 1 weeks marine – 23 July – 5 August
3 weeks: 2 weeks terrestrial & 1 week marine – 23 July – 12 August
3 weeks: 1 week terrestrial & 2 week marine – 23 July – 12 August
4 weeks: 2 weeks terrestrial & 2 weeks marine – 18 June – 15 July
For those booking onto the 3 week course beginning on 23 July, please email expeditions@opwall.com to indicate if you would like to do 1 or 2 weeks terrestrial.
The Mediterranean biodiversity research is carried out in the valley of Krka National Park. At this site you will be working from dawn until late morning and then again in the late afternoon and evening helping a series of different research teams. During the heat of the midday period you will have a series of lectures about Balkans wildlife and conservation and help with data input and lab-work using samples sourced from the field. The projects include standardised transect surveys through a series of different habitats for butterflies (Pollard surveys), herpetofauna (standard search transects), birds (point counts), mammals (standard search transects for scat and tracks and camera trapping) and bats (acoustic surveys). In addition, there are standardised monitoring locations for bird and bat mist netting in a range of habitats and surveys to quantify the habitat at each of these standardised survey locations. On top of these standardised surveys designed to provide long-term data on the different faunal groups there are a series of investigations to describe population densities and ecology of groups such as grasshoppers, crickets, cave fauna (standard search transects and quadrats), nocturnal surveys of cat snakes (Telescopus fallax), Hermann’s tortoise (Testudo hermanni), Dalmation algyroides (Algyroides nigropunctatus) lizards.
For the marine research experience you will be based on the beautiful and peaceful Silba Island. You will start with some training, beginning with the opportunity to complete a PADI Open Water dive training course if you would like to learn and are not already qualified, followed by a compulsory Mediterranean ecology and survey techniques course, with two lectures and two practicals each day (either by diving or snorkelling). After completing this training, those of you staying long enough will move on to assisting with some of the research surveys on Mediterranean fish communities, the impact of sea urchin populations and the role of seagrass meadows in supporting fish and invertebrate biodiversity.
The 77km long Krka Valley runs from the Dinaric mountains bordering Bosnia to the Adriatic. Since the river runs through limestone, there are several spectacular gorges, making this one of Europe’s most picturesque river valleys. Krka National Park is home to the strictly protected wolf and wildcat, along with spectacular cave systems housing the largest colony of long-fingered bat (Myotis capaccinii) in Europe, which is a Natura target species. Opwall together with BIOTA (a Croatian biodiversity research organisation) has built a research centre in the central part of the Krka valley with easy access to the whole park. The centre is based in a restored house and grounds within 100m of the park boundary and has access to all the habitats throughout the park and surrounding countryside. The National Park Authority have requested we perform baseline surveys to increase the known inventory for the Park, as well as collect long-term monitoring data to answer a series of their management questions.
Tourist visits to Krka National Park are heavily concentrated towards the lower stretches of the river and very few people visit the central and northern parts of the valley. The BIOTA/Opwall research centre is within a rural community that has suffered from significant depopulation and land abandonment in recent years. The centre is designed to give benefits to the local community from the visits (e.g. provision of employment etc). Whilst the main research effort each year from this centre comes through the Opwall programme, the centre remains open year-round, providing facilities for Croatian scientists to collect data at any time of year.
Silba Island is in the northern Dalmatian 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 holm oak and maquis. The objective for our partners on this island is to develop the first marine research centre for northern Dalmatia and they have a series of research projects on seagrass, sea urchins, rocky reef biodiversity, as well as marine plastics.
Most of our volunteers fundraise for their expedition costs. Find out more.
Climate
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.
Creature comforts
At Krka you will be staying in dormitories with shared western style bathrooms and toilets. 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.
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