Within the project period from 2004 to 2009 it was planned -except for the strong Swedish populations- to dig and restore ponds, establish hibernation sites, purchase land, establish robust grazing, collect eggs, rear and release toadlets etc. on both public and private land. For many of these actions the quantitative results have been higher than expected. I.e. it was possible to dig 192 ponds increasing the expected aim by 65 ponds, create 75 hibernation sites and to collect over 48.000 eggs (planned 33.000) and rear and release to nature over 29.000 toadlets. The release strategy was based on population genetics performed by Prof. R. Tiedemann and his working group form University of Potsdam. How the scientific data were used in practise is described in the “Genetic report”.
By the intensive habitat management the realised habitat capacity for adult toads (30m² of pond per adult) in all sites increased from 3.220 to 10.500, whereas 6.600 were planned. By this these additional habitats the project has laid a basis for a substantial improvement of the conservation status of the fire-bellied toad populations in the project sites at the northern edge of the distribution range. The number of calling males -one of the key quality parameters of the project- increased from 268 to 678 (planned 568 calling males). This increase could even have been higher, but there are differences in the implementation between the sites and member states. On those sites where it was possible to implement the habitat actions in the beginning of the project the fire-bellied toad populations have increased during the project, e.g. at most of the sites which are public owned.
In Denmark the project was mainly operating on private land. The habitat improvement was mainly possible in the second half of the project and therefore the populations had not reacted to the increase of habitat during the project. The population aim “calling males” therefore was not fully reached in Denmark.
Within the next 10 years the populations will be able to use the extra habitats and hopefully increase to the planned numbers of calling males. The further process and the pond habitat quality will be monitored by the state monitoring and if necessary with further management supported.
The further increase of calling males in some of the project site monitored in 2010 was promising: some populations reacted by doubling the number of management supported.
The further increase of calling males in some of the project site monitored in 2010 was promising: some populations reacted by doubling the number of calling males. This happened especially there where the complete habitat complex could be created with all necessary features without compromises:
• a broad pond network
• in extensive grazed areas
• adjacent to broad leaved woodland and alder carr.
All experiences gathered during the project are compiled in the “Bombina guideline. The layman report is summarising the projects activities and experiences.
The success of the project was presented by the Bombina song contest during the project. Annual frog concerts are offered even after the project ended by the beneficiary Stiftung Naturschutz Schleswig Holstein.
Expert network and “flow of experience”
The participants of the project were exchanging experiences on many topics during workshops, as well as during joint work on habitat construction and population management. During these meetings intensive discussion was possible and the results from these discussions could be implemented directly on the site to improve habitat.
Successful habitat improvement (digging and grazing) by incorporating best available knowledge on sites
Even before the project started an intense exchange of knowledge on field techniques for population and habitat management took place between the site and project managers of Stiftung Naturschutz and Amphi Consult. The good cooperation was intensified during the project always focusing on direct challenges on sites to achieve the best outcome of the coming and ongoing actions.
Amphi Consult has many years of experience with digging ponds that functions as breeding or foraging ponds for B. bombina. This experience was highly valued in Schleswig-Holstein when the work to build habitat capacity started. Amphi Consult worked supervised the digging of ponds and thereby incorporated the latest Danish knowledge in to the sites.
On the other hand Stiftung Naturschutz has a solid experience and innovative approach towards managing habitats sustainably with robust grazers. The input and support from Stiftung Naturschutz inspired and assured the onset of robust grazing on the Danish sites.
Managers of both Amphi Consult and Stiftung Naturschutz has visited the two Latvian sites and given the sum of the experiences of the project team to the Latvian managers, as:
• Collection of eggs from small isolated populations
• Catching females full of eggs and by using cages to reach amplexus and egg laying
• Rearing methods
• Restoration of ponds and digging of new ponds on top of hills have been demonstrated
Fine tuning of skills for breeding of B. bombina in captivity
Breeding and rearing of amphibians in captivity started in Denmark in 1983. During the project the work has been intensified covering more populations at the same time. The techniques have been developed further and the skills and capacity within the experts has been increased. Hjortø animals were already during the previous LIFE project kept in ZOO and in Amphi Consult and breeding experience gathered. Larger and better facilities for breeding have been constructed in Copenhagen ZOO and Amphi Consult during this project. The fast reaction and rescue for the population on Fehmarn and Enø shows that the knowledge and capacity is in place to be able react fast if a small population suddenly is threatened. This is a vital assurance of the small populations in the future.
Good impact of robust grazers on habitats
The robust cattle have shown very good effects on the vegetation in the ponds and the surroundings. Problematic plants as Typha latifolia and Phragmites australis as well as Salix sp. bushes have been diminished significantly to allow a more diverse and lower swamp vegetation to colonise the ponds. B. bombina is dependent on a semi-open vegetation structure on the shallow banks of the ponds allowing the sun to warm the water effectively but also providing shelter against predators. The desired vegetation structure is achieved by robust grazing and cannot be reached by i.e. grazing with sheep. Thus the onset of robust grazing has improved the quality of existing ponds and thereby increased the area of suitable habitat for a no. of sites. Hereby the aim of releasing robust cattle and horses has been reached.
In Denmark robust grazing has been initiated on private land on 7 sites. On some sites the negotiations were long and tough but in the end the land owners were convinced to the idea of a more natural and sustainable grazing regime. After initiation of robust grazing it is often seen that the concept spreads to other land owners. Thus the project has had an important impact in initiating and facilitating robust grazing. Without the grazing action of the project robust grazing would probably not be occurring on the sites. Now it looks like the concept will spread on the sites as the “lending cattle” are given back to DFNA and they provide these cattle for new landowners, with in the project period the first cattle were given back from Ærø South and are now grazing new not planned areas with B. bombina ponds.
During the many site visits it was noticed that some Scottish Highland cattle has a tendency to stand for hours in shallow water in ponds to cool down during warm days. On sites where ponds have been restored or new dug the re-growth of the important vegetation on the shallow banks is inhibited significantly by the cattle. In this case a temporary fence should be set up to allow the vegetation to re-grow.
In all cases it is important that the no. of cattle is corresponding to the length of the banks of the ponds on the site. As a rule of thumb about 75 m of bank per cattle is needed to avoid too hard trampling of the pond edges.
Very successful habitat improvement on public owned land
The habitat improve on the land owned by Stiftung Naturschutz could be initiated at the first two years of the project since no land owner talks were needed. Another crucial advantage of operating on the public owned land was that the amphibian experts could have free hands to implement the actions wished for. This is a unique situation compared to the reality of work on private land where every step has to be negotiated and agreed and most often free hands are not given on a site. On the sites owned by Stiftung Naturschutz the hydrology was as standard restored to natural by blocking all drainage systems.
In some cases the site was even made more wet and more amphibian friendly than expected by judging from the different soil layers. Very high density of ponds in clusters could be made and the terrestrial habitat in between was managed with robust cattle grazing to provide as amphibian friendly a terrain as possible.
After digging of the ponds it was possible to go back and improve certain ponds when needed to make the habitat as good functioning as possible. The habitat complex was analysed based on the full life cycle of fire bellied toad and lacking features were added. So the full habitat complex could be improved soon after project started.
The work on public owned land was also a very good opportunity to develop, test and finally approve the ideas and strategies for a good B. bombina habitat. Afterwards the same actions were implemented in Denmark with the latest understanding and approval of the method in Schleswig-Holstein as a valuable support.
Frog concert and Bombina song contest as effective PR initiatives
Already the pond digging activities received good attention from the press and on most sites each start of digging was started with a public ground break. But to reach the attention of TV and radio stations this was not enough. One the other hand the project also would like to present the success in Nature value for the fire bellied toad. So the idea came up to make a frog concert festival and Bombina song contest. These events were noticed both by media and by the public expressed by visitors on the sites.
The results from the Bombina song contest were:
• Many articles in press and web, ranging even from Russia to Brussels
• Good coverage by TV and Radio:
• Sweden 2007: first time ever in 8 o’clock pm TV news about threatened Swedish amphibian specie
• Denmark 2007: Several radio stations commenting the „Eurovision Song Contest“ two weeks later: „Much nicer was the 1. European Bombina Song Contest two weeks ago: Fyn was the main aspect of the event.“
• Germany 2007: Invitation for song contest at www.tagesschau.de with link to project web page.
• After publication of a report about the LIFE Bombina song contest on Danish farmer information platform on web (www.landbrugsavisen.dk) a significant increase of visits to the webpage was monitored.
• People calling from time to time in office and offering their land or donations for amphibian conservation: 12 projects on amphibian initiative realized.
3.1 “Genetic approach” to populations to preserve genetic authenticity
One of the innovative project strategies was to respect the genetic authenticity of each single population and thereby respecting and conserving whole genetic diversity in the northern and north-western distribution range on its original sites (and on its reserve sites). For this a strategy was developed and followed. Following principles have been respected (in order of importance) in cases when a genetic investigation was not available for a population:
• Isolated populations were improved by supportive breeding. No other animals were mixed in from other populations.
• Translocations were done from one site to another only, if animals could migrate the same distance. Thus only short distance translocations were made on main land over a maximum distance of about 5 km.
• Reserve populations were made for isolated populations to have a genetic copy at a site with good habitat quality and good expectations for survival. This was done within 6 km of the original populations on mainland’s, for the future possibility to re-establish a meta–population. In some cases reserve populations were established on isolated island/sites to keep them pure on long term.
When the genetic study was made management units could be defined within the Danish, German and Latvian populations. One management unit contains all populations which have been in genetically interaction as a population until the decline during the last 50-100 years. This could be proven based on genetic similarity analysis. Also genetic weaknesses can be detected and actions to improve the genetic diversity can be outlined.
After a genetic study the following additional options for the population management are available as also described in the genetic report for the LIFE-Bombina project sites :
• Within a management unit translocations can be done over longer distances to improve genetic diversity within a management unit.
• New mixed populations on isolated sites can be created to improve the genetic diversity and maintain it for future
• Creation of a meta-population concept within management units to re-connect isolated populations via corridors and stepping stone sites
The population management techniques have been improved as e. g.
• Securing small populations in captivity and re-establishing populations in nature with off-spring from these animals
• Rearing indoor in tanks
• Rearing outdoor in net cages
• Up-growth of toadlets to a size of 2 cm in “kindergarten set-up” in net cages in ponds to get strong and viable animals for release.
• Improve of release strategies to avoid high predations from herons and green frogs
3.2 “Habitat complex approach”
All habitat components within the fire-bellied toads life cycle and the yearly cycle were analysed at each project site. Then it was tried to create missing habitat components for –if possible- a population of 1000 individuals.
Habitat component Biological function
Spring foraging pond Near hibernation site, feeding, females matures eggs
Breeding ponds Calling males and breeding success
Summer foraging pond Adults and juveniles feeding, good survival and
with eutrophic water and low predation rate
rich in structure and
Terrestrial foraging Adults and juveniles feeding, good survival and
habitat in wet and low predation rate
woodlands or scrub
Hibernation site close Frost proof hibernation, low loss rates on migration
to ponds, easy access to the site and during hibernation
If perfect conditions were achieved in a project site often the populations were reacting soon with an increase first of reproduction and then after 3 to 4 years also with an increase of calling males.
3.3 Long term indicators of the project success
The long term goal is that fire bellied toad population develop and increase up to the level of the carrying capacities calculated for each of the project sites. This will take several years because as a rule of thumb a population can increase to the double size within a period of 3 to 4 years in optimal cases. For some of the populations, which start with low number of reproducing individuals e.g. island of Fehmarn, this process can take 20 to 30 years.
Parameters for the success on the way to the fulfilling the carrying capacity are:
- Colonisation of 50% of the new created breeding ponds within the period of 5 to 10 years after digging.
- Reproduction in at least 3 breeding ponds on a yearly basis with good reproduction success (30 fresh metamorphosed toads countable on the banks of a pond in August) on each project site.
- Colonisation of 75% of the foraging ponds within a period of 5-10 years after digging.
- Good survival rate of about 75 %on a yearly basis in the habitat complex supported by the right land management.