• Overview
  • Objectives
  • Costs to Consider
  • Site Conditions

Hermann’s tortoise (Testudo hermanni) is a data deficient Natura 2000 species and is a priority species for the Park to investigate. In the past this species has been heavily collected for the pet trade but within the park this is now well policed. This project is designed to produce data on the density of this species in different habitats and determine the age group class structure of the population, plus yield additional information on movement patterns and habitat usage. Despite tortoises being relatively slow moving and fairly easy to spot in open terrain, estimating their population levels is surprisingly difficult. During low and high temperatures they tend to hide in the shade under impenetrable thickets of juniper or dig themselves underground, so an area can apparently be searched efficiently with no results, only for the same area to reveal a good population when they come out of hiding during more congenial temperatures! This project will look at how best to assess the populations in 500m x 500m plots using both mark release recapture and from catch per unit effort at the best times of day. All tortoises captured will be given an individual mark by clipping the marginal scutes in a defined pattern, measured (carapace length, plastron length, weight etc) and released at the same site of capture. In addition, movement patterns can be monitored within the study squares using direct observation and also by use of fluorescent powder and tracking the trails after dark using UV light.

Extended Dissertation Summary

If you would like to do a dissertation or thesis with us but your university hasn’t started dissertation planning or the project selection process, that’s no problem. You can cancel your expedition with zero cancellation charges up until the 15th of April of if you provide documentation from your university saying that they won’t support completing a dissertation project with us.

Croatia Terrestrial Research Objectives

Krka National Park

The Krka Valley runs from the Dinaric mountains bordering Bosnia to the Adriatic and is only 77km 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 nine Croatian and three Krka endemic fish species and spectacular cave systems containing a number of potentially new species to science. 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 based 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 will remain open year round in an attempt to attract some of the many visitors to the Croatian coast further inland, increasing revenue for the Park and local communities.

  • Opwall fee.
  • Cost of international flights into and out of Split or Zadar.
  • Cost of internal travel to and from the start and end point of the expedition, plus any hotels you might require. The standard package costs around £154 or $200.
  • Extra nights’ accommodation in Split or Zadar costs £110 or $143 (breakfast included).
  • Park entrance fees £50 or $65.
  • Vaccinations and prophylactic medicines – cost can vary depending on your healthcare provider.
  • All prices in GBP or USD unless specified.
  • Standard travel insurance – cost can vary, for 2 weeks it can range anywhere from £40-80 or $40-150.

Most of our volunteers fundraise for their expedition costs. Find out more.

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 either be staying in dormitories or in shaded tents with shared western style bathrooms and toilets. There is some limited phone signal in Krka (but not reliable for a data connection).


  • Croatia
  • Krka National Park

Want to get involved with this project?


Want to get involved with this project?

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