Conservation of threatened amphibians in Sweden Claes Andrén Nordens Ark

In 2000, 9 (70%) of 13 amphibian species on the national red list (1 species CR, 3 EN, 2VU, 3 NT following the IUCN critera)

In 2005, 6 (<50%) remaining on the red list, and 5 of these 6 species have a better or much better conservation status

Improvements due to many years of hard work and where zoos like Nordens Ark have played a major role

Combination of monitoring, restoration of habitats, captive breeding and release back in nature within historical range, evaluation, reporting

Conservation of threatened amphibians in Sweden

Claes Andrén Nordens Ark

Reasons for decline

Lowering of shallow lakes to get more arable land from 1850

Large scale draining of the open landscape 1940th and 50th

In 1960th and 70th followed by large scale draining of forest areas for higher timber production

Additionally the quality of remaining water bodies affected by pesticides, fertilzers, heavy metals etc

Other consequences of changed land use as in most western countries, such as eutrophication, overgrowing, cease of grazing

Ecosystem changes may also change the balance in competion and predation

Case studies – What we have done for threatened amphibians in Sweden

The Fire-Bellied Toad Bombina bombina, the Natterjack Toad Bufo calamita & the

Green Toad Bufo viridis

Actions for the Fire-Bellied Toad Bombina bombina

Locality for the last Bombina bombina population, Mölle. Died out 1960.


Population status – trends

1960: Died out

1983: Introductions starts (juveniles)

1990: 25 calling males, 7 breeding ponds, estimated pop size 60 adults

Introduction of juveniles contionous


Restoration of 5 ponds

2004: More than 100 calling males, 6 breeding ponds, estimated po size 400 adults

(capture - marking(photo) – recapture)



Baldringe area

Introductions in new localities 1983-85 (300 juv + 200 larvae) 1987-90 (1500 juv) 1998-99 (470 juv)

Introductions in total 1983-99 (2 270 juv + 200 larvae)



Baldringe

Status1990: 64 calling males, 17 breeding ponds, estimated pop size 140 adults




2006: > 3000 calling males, 130 breeding ponds estimated pop size > 7000 adults


Measured carried out

1. Restoration

Ations for the Fire-Bellied Toad Bombina bombina


1. Restoration

Mölle4 restored ponds

Gislövs Stjärna8 new or restored ponds

Bäckhalladalen10 restored ponds

Baldringe area> 50 ponds


Measures carried out

3. LIFE Bombina project

Starting 2004, 5 years



3. LIFE Bombina project

Genetics, sharing experiences and knowledge betweenSweden, Denmark, Latvia & Germany


Visions and goals for the year 2012

One large metapopulation in Baldringe area with 100-150 breeding ponds and 10 000 dults (no further measures necessary)

One meta population in Simrishamn area, 30 breeding ponds and 2 000 adults (Measures in four local populations)

One population in Mölle fälad (last natural occurrence in Sweden) with 15 breeding ponds and 1 000 adults (Restoring another 10 breeding ponds)

Actions for the Natterjack Toad Bufo calamita


Skin secretion used in defence


Biology, environmental demands and threats

West European species from Portugal to Sweden and Estonia Estland in north, laying eggs in shallow temporary waters, interesting reproductive biology with individual strategies, breeding from end of April to August (main breeding activity in mid May), adapted to disturbed ground and early succesion stages, prefer sand steppe but also bare rocks, serious threats are overgrowing (ceasing of grazing), eutrophication, competition (Bufo bufo), predation (insects on larvae), draining, exploitation



Actions for the Natterjck Toad Bufo calamita




Range and population status – trends

West Sweden (Västra Götaland)

46 local populations in the outer archipelago (2004)

Lack of information on pop. size, distribution and threats


Range and population status - trends

Smögen – northern most locality for the species (close to Nordens Ark)



Mapping of local island populations


Visions and goals for West Sweden (Västra Götaland)

In 2006: The species occurs on 46 islands in 13 areas, no estimates of pop sizes

Goal for 2012:10-15 meta populations including groups of smaller islands, each metapopulation with at least 500 adults and 50 breeding ponds (many are high risk ponds)

Actions for the Green toad Bufo viridis

Actions for the Green Toad Bufo viridis

Mating period late April to late May, eggs are layed in shallow waters, usually without vegetation, breeding ponds often influenced by salt water (upp to (0.8%), adults can stand 2% salinity


Prefer sand steppe but also on bare rocks, serious threats are overgrowing (declining grazing), eutrophication, competion (Bufo bufo), predation and draining

Dying larvae in Eskilstorps ängar, the breeding pond is drying up due to draining


Skåne-Blekinge-Kalmar(Öland)-Gotland

Range and population status – trends

Limhamns limestone quarry


Limhamn Limestone quarry

Swedens most important Green Toad locality, about 300 adults, regular reproduction, measures taken to secure the population,

Eskiltorps ängar


Falsterbo peninsula 50 years ago the most important locality in Sweden

Today < 10 adults within a golf court area, no reproduction

Large scale measures to reduce overgrowing vegetation

Remaining big problems: eutrofication, polluted drainage and run off water from traffic and settlements

Former sandy lagoons at Falsterbo affected by eutrophication

Last locality for the Green Toad on the Baltic island Öland, Högby hamn (-96)


Monitoring of earlier known localities to confirm present status

Collecting eggs in the field and rearing in captivity up to sub adults

Planning and carrying out restoration actions in destroyed habitats

Release of toads in restored areas within the historical range

Evaluation and reporting

Nordens Ark plays a major role in the In Situ work. In 2006 we are releasing 6-8 000 sub adults toads in four regions in Sweden.


Restoration of breeding pond

Clearing of reeds in Falsterbo

Constructing out door enclosures for metamorphosed Green Toads at Nordens Ark

Releasing sub adult Green Toads, Öland Sept -04

Releasing sub adult Gren Toads, Öland Sept -04


7 populations or meta populations each of at least 500 adults within the historical range

Limhamn limestone quarry (Malmö city), coastal meadows SV Skåne (Malmö-Falsterbonäset), coastal meadows and bare rocks E Skåne (Gislövs Stjärna, Gislövs hammar, Brantevik, Bäckhalladalen, Vik), outer archipelago SE Blekinge (Utklippan), Baltic islands Öland and Gotland

Visions and goals 2012

Thank you

Documents

Conservation of threatened amphibians in Sweden Claes Andrén Nordens Ark