PROJECT DESCRIPTION
BACKGROUND
The fire-bellied toad, Bombina bombina, with its characteristic croak and red and black mottled belly, is listed in Annex II of the Habitats Directive, i.e. as a species which requires special consideration. The fire-bellied toad's preferred habitat is small ponds as breeding sites, and adjacent chalky moraine land for finding food. Such habitats are to be found on the sheltered islands and coastal areas in southern Denmark, where the climate is relatively sunny and warm. These areas also contain good agricultural land, which has led to problems for the fire-bellied toad. The species has declined markedly in the past few decades, especially as a result of the ploughing-up of small biotopes and increasing use of chemical fertilizers, which has led to the eutrophication of small ponds. Towards the end of the 1980s, there were fewer than 100 adult specimens left in Denmark and action had to be taken quickly to remove the species from the acute danger zone, including the protection of the most important core areas and the implementation of a major breeding programme aimed at introducing new specimens into existing populations. These measures were partly successful, but the remaining eight populations were still so small (there were only 500 specimens left) that they were threatened by unforeseen natural events, random changes in the population's demographic structure and increasing in-breeding. The project intended to cover seven of the species' eight existing locations in Denmark, and as a result, 95% of the national population. The aim was to continue the work on improving existing areas via a comprehensive programme for restoring ponds and habitats and administering the adjacent areas, depending on the possibilities for extending them. Since this can only happen through changes in farming, intensive efforts were to be made under the project to persuade local farmers to make use of the EU's subsidy schemes for environmentally-friendly agriculture. The local population had already shown great interest in the fire-bellied toad's well-being and this would perhaps give the species a new chance in Denmark.
OBJECTIVES
The overall objective of the project was to enlarge the minute Danish population of fire-bellied toad (Bombina bombina) on 7 of the 8 sites it was found on, and to secure the important genetic traits before inbreeding occurred and lowered the viability of the species. Large reserve populations were consequently to be created and located in large-scale favourable terrestrial habitats. The focus was on a total of 13 sites: 7 existing sites and 6 planned new sites for the reserve populations, distributed over Fyn, Vestsjælland and Storstrøm counties in SE Denmark. The reference was an effective population (Ne) of 500 individuals, or approximately 1,000 adult individuals. The threats were to be counteracted in 3 ways: 1. Terrestrial and aquatic habitat improvement on original sites (creation or restoration of 47 ponds and land acquisition for 12 buffer-zones). 2. Improvement of the habitats for the planned reserve populations (creation or restoration of 59 ponds and land acquisition for 3 buffer-zones). 3. Rearing and release of offspring at the new sites (egg collecting, rearing and release of around 21,500 tadpoles) The expected results included: · The populations would be safer from future catastrophes, the total population size would increase, the genetic heterogeneity of the population would be kept more intact, and the public would get improved opportunities to encounter the animal. · Further, the creation/ restoration of ponds should have general positive effects on flora and fauna. · Agri-environmental measures were to be used whenever possible, in order to increase landowner willingness to be involved in nature protection. · The demonstration value of this project was expected to go beyond the consolidation of Bombina; it was to be seen as an example of good management practice concerning pond restoration and nature conservation in general. Furthermore, it would enable ordinary people to become familiar with a rare species, and would thus raise environmental consciousness. At the same time it would popularise the work of the EU LIFE-Programme, the three involved counties, and the National Forest and Nature Agency. It was in fact one of the first projects in Denmark to involve three counties at the same time.
RESULTS
· The project was performed largely as foreseen. Various techniques concerning pond digging and restoration, as well as egg-collecting and rearing of tadpoles for release into the wild, were tested and adjusted to various experiences gained, especially during the initial phase of the project. · Action plans were drawn up for all sites. 7 ha land was purchased at one site and buffer zones created at 4 sites. Altogether 127 ponds were dug or restored, which was above the original target, and over 22,000 metamorphosed tadpoles were released back into the original (35%) and reserve sites (65%). · Experiences from the project were used for the preparation of a transboundary LIFE-Nature application in 2004 aimed at the protection and restoration of habitats for threatened and rare amphibians in Germany (Schleswig-Holstein), Latvia and Sweden. For the objective of having a viable population of the target species at each site, the monitoring results are mixed. . The project has stopped a further decline of the target species. · Only at one site (Nekselø) did the estimated population size of 900 adult individuals satisfactorily correspond to an effective breeding population size equivalent to the target of 500 individuals. At other sites the population had not yet increased significantly by the end of the project. · The survival rate of released animals differed substantially between the various sites. · At three of the "reserve sites" (Røsnæs, Asnæs, Klintholm), the initial response gave hope for a future success, after the end of the project. The final test of success for this demonstration project still remains open, considering that released tadpoles or newly metamorphosed adults do not mature until 2-3 years later. The restoration and creation of new ponds has also been to the benefit for other rare or threatened amphibian species, e.g. Bufo viridis, Bufo calamita, Pelobates fuscus, Hyla arborea and Rana dalmatina (in Annex IV of the Habitats Directive), as well as Triturus cristatus (in Annex II of the Habitats Directive). Further, there is the occurrence of the rare phyllopod crustacean Lepidurus apus (tadpole shrimp) at two of the project sites. The beneficiary developed a score system in order to evaluate the quality of ponds, with reference to Bombina. On the basis of experiences from the project, the beneficiary concluded that the "perfect" Bombina pond should satisfy a foraging area of 10-30 m² per adult frog, corresponding to a total need of up to 30,000 m² of pond area for a viable population of around 1,000 individuals (for most of the pSCIs designated for the target species in Denmark, this requirement is not met). For newly created ponds, it is preferable to wait 3 years from when a pond has been created or restored, before Bombina is introduced. The conservation of Bombina necessitates a system of ponds that together builds up the necessary pond area to support a metapopulation of viable size. This means that most sites will consist of several ponds in a "hostile" agricultural landscape. Experiences with "habitat corridors" between ponds indicate that this might be a possible solution (the frogs are able to colonise ponds to a distance of up to at least 1 km). The selection of individual ponds for restoration etc needs to be done in a landscape context, and requires additional measures to be taken to ensure the wider landscape is not inhospitable to the movement of Bombina. During the project work, the need of various additional management measures was identified, e.g.: · Hibernation sites. · Grazing around the ponds. · Reduce predation (removal of fish etc) · Reduced use fertilisers