European Pond Terrapin Conservation
To introduce a nest adoption scheme to promote the survival of European pond terrapins in Austria
The European Pond Terrapin, Emys orbicularis, is the only
Chelonian species occurring in Central Europe, all other Euroepan
tortoises and terrapins being restricted to the warmer Mediterranean
area. The European pond terrapin is a highly endangered species in
Austria. The only confirmed population is resident in the Donau Auen
National Park and consists of a few hundred individuals. 1997 a
conservation programme was initiated by the National Park in order to
support the native stocks, to contain further releases of allochthonous
turtles and to make the public aware of this sensitive topics. The
scientific part of this programme covers ecological studies to optimise
the basics of conservation management and genetic studies to
distinguish autochthone and allochthone (released) turtles.
As a broad study of a mitochondrial gene called cytochrome-b had already been carried out in the greater part of the distribution area of the species, this gene was chosen to determinate the origin of the resident turtles. Salivary samples were taken from individuals of 9 different locations within the national park. Investigations of the mitochondrial cytochrome b resulted in a high frequency of different allochthone cytochrome-b haplotypes (n=28), particularly in the areas close to the city of Vienna. These allochthone cytochrome-b haplotypes indicate a large number of released specimens, mainly from the Adriatic coast-region and even more Southeast from there. Surprisingly, the results also showed a dominance of a so far unknown haplotype (n=34) in the most isolated parts of the National Park area, which is considered to represent an endemic genotype. Conservation measures are therefore focussed now on turtles carrying this haplotype.
To study the possibility of inbreeding within this group, investigations of nucleus-genes were initiated. The genetic diversity of two isolated locations was analyzed using 5 microsatellites. The number of alleles varied between 5 and 16. Both locations showed individual alleles. The Hardy Weinberg test showed significant heterozygote deficit at the majority of the loci. The mean observed heterozygosity (47,80%; 49,87%) was lower than the mean expected heterozy-gosity (63,32%; 80,32%) in both locations. Nevertheless, the results were not considered to be close to inbreeding.
To secure its survival, the population needs to continue to grow to
conquer back lost living space in other Austrian wetlands. In addition
to habitat loss, which has been largely halted within the Danube
wetlands, primary causes for the population decrease are predators
foraging on freshly laid eggs.
The conservation programme “European pond terrapin” comprises research, conservation and public education. So far more than 150 animals are individually marked, genetically identified and behav-iorally analyzed. Exhibitions and guided tours enable visitors to get to know Austria’s native turtle face to face.
To conserve the European pond terrapin in its natural habitat foremost challenge is the protection of the nest sites, which is very time consuming, since measures have to be taken right after egg laying.
- Sturdy metal grids are being secured on top of the nests right after egg-laying is completed by the turtle to protect the nests from predators.
- Regular checks of the nest sites provide valuable information on reproduction and population development.
- Damaged nests and nests on unfavourable sites are removed, artificially in-cubated and re-introduced to the wild.
- Injured animals are given veterinary care.
On initiative of the Tiergarten Schön-brunn a nest-adoption programme was started in 2007. For € 100,-the sponsor receives a certificate with a nest number. The location of the nest remains secret, but a guided tour with the program leader, Mag. Maria Schindler, is arranged to receive direct and detailed information on the Danube wetlands, the European pond terrapin, and the status of the pro-ject. At the end of the season, the sponsor receives a report revealing the fate of “his” nest. In addition the “Friends of the Zoo” of Schönbrunn provided initial financial support, offers veterinary help, and allocates facilities and personnel to incubate and raise offspring if necessary.
Through the implementation of the nest-adoption programme the protection of the nest sites reached an unprecedented dimension. In the year 2007 42 nests of the European pond terrapin were successfully protected. At least 346 offspring hatched that year – a rate of 86%, which is in-credibly high. (In the preceding year by comparison and without the adoption programme, only 7 nests could be protected.) 30 females could be observed during egg-laying of which 11 were already known. 19 new ones were individually marked, measured and photographed.
WAZA Conservation Project 08030 is implemented by Vienna Zoo as part of a wider conservation programme. Financial support from the Friends of the Zoo Society.
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