Download AndrenNordens

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
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.
Actions for the Fire-Bellied Toad Bombina bombina
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
2002: 13 calling males, 5 breeding ponds, estimated
pop size 30 adults
Restoration of 5 ponds
2004: More than 100 calling males, 6 breeding ponds,
estimated po size 400 adults
(capture - marking(photo) – recapture)
Actions for the Fire-Bellied Toad Bombina bombina
Population status – trends
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)
Actions for the Fire-Bellied Toad Bombina bombina
Population status – trends
Baldringe
Status
1990: 64 calling males, 17 breeding ponds,
estimated pop size 140 adults
2000: 202 calling males, 32 breeding ponds,
estimated pop size 450 adults
2002: 710 calling males, 54 breeding ponds,
estimated pop size 1560 adults
2004: 2320 calling males, 93 breeding ponds,
estimated pop size 5000 adults
2006: > 3000 calling males, 130 breeding ponds
estimated pop size > 7000 adults
Actions for the Fire-Bellied Toad Bombina bombina
Measured carried out
1. Restoration
Ations for the Fire-Bellied Toad Bombina bombina
Measured carried out
1. Restoration
Mölle
4 restored ponds
Gislövs Stjärna
8 new or restored ponds
Bäckhalladalen
10 restored ponds
Baldringe area
> 50 ponds
Actions for the Fire-Bellied Toad Bombina bombina
Measures carried out
3. LIFE Bombina project
Starting 2004, 5 years
Actions for the Fire-Bellied Toad Bombina bombina
Measured carried out
3. LIFE Bombina project
Genetics, sharing
experiences and
knowledge between
Sweden, Denmark,
Latvia & Germany
Actions for the Fire-Bellied Toad Bombina bombina
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
Actions for the Natterjack Toad Bufo calamita
Skin secretion used in defence
Actions for the Natterjack Toad Bufo calamita
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 Natterjack Toad Bufo calamita
Actions for the Natterjack Toad Bufo calamita
Actions for the Natterjck Toad Bufo calamita
Actions for the Natterjack Toad Bufo calamita
Actions for the Natterjack Toad Bufo calamita
Actions for the Natterjack 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
Actions for the Natterjack Toad Bufo calamita
Range and population status - trends
Smögen – northern most
locality for the species
(close to Nordens Ark)
Actions for the Natterjack Toad Bufo calamita
Measures carried out
Mapping of local island populations
Actions for the Natterjack Toad Bufo calamita
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
Actions for the Green Toad Bufo viridis
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
Actions for the Green Toad Bufo viridis
Range and population status – trends
Skåne-Blekinge-Kalmar(Öland)-Gotland
Limhamns limestone quarry
Actions for the Green Toad Bufo viridis
Limhamn Limestone quarry
Swedens most important
Green Toad locality, about 300
adults, regular reproduction,
measures taken to secure the
population,
Eskiltorps ängar
Actions for the Green Toad Bufo viridis
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)
Actions for the Green Toad Bufo viridis
Measures carried out
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
Actions for the Green Toad Bufo viridis
Visions and goals 2012
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
Thank you