Transcript No Slide Title

The scope and scale of the
amphibian crises
Joe Mendelson, ASG Executive Officer
The scope and scale of the
amphibian crises
Joe Mendelson, ASG Executive Officer
Bob Lacy, CBSG Chair
(Kevin Zippel, CBSG/WAZA APO)
Why are amphibians important?
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source of human medicine
indicators of environmental health
control insects and insect-borne diseases
vital role in ecosystems
role in culture/religion
aesthetics
amphibians are declining
Global Amphibian Assessment
• 5,743 species of amphibians
– 43% in decline
– 32% threatened
– 168 presumably extinct (122+ since 1980)
– 23% data deficient
- many probably endangered
• Worse than birds (12%) or mammals
(23%)
Beginnings of a mass extinction
• Nearly one-third (32%) of the world’s
amphibian species - representing 1,856
species - are threatened with extinction.
• Up to 122 species may have gone extinct
since 1980.
• At least 43% of all species are declining in
population size.
Complex Causes
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Habitat Loss and Degradation
Climate Change
Chemical Contamination
Infectious Disease
Invasive Species
Over-Harvesting
Non-random extinctions
• High-risk regions (#declining species)
– Neotropics (279)
– Aus & NZ (174)
• High-risk habitats
– Forests (365)
– Lotic habitats (277)
– Tropical montane (251)
• Causes
– Enigmatic (207)
– Habitat loss (183)
– Over exploitation (50)
Enigmatic declines caused by
chytridiomycosis
• Globally distributed pathogen
– Genetically identical
• Emerging infectious disease
– First record 1938: South Africa
• No interactions necessary
– Koch’s postulates fulfilled
• Unstoppable & untreatable in wild
African clawed frog
Xenopus laevis
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native to South Africa
earliest record of chytridiomycosis (1938)
used in human pregnancy tests (1930s-1970s)
amphibian ‘lab rat’ (immunology, embryology)
distributed around the world by 1000s-10,000s/year
Case study: Colostethus spp.
0.45
0.4
Colostethus caps/mtr/p
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
Aug-03
Oct-03
Dec-03
Jan-04
Mar-04
May-04
Date
Jun-04
Aug-04
Oct-04
Nov-04
Jan-05
347 dead individuals of 40
species:
• Bufonidae - *Atelopus zeteki (26), * Bufo coniferus, *B. haematiticus (12)
• Dendrobatidae - Colostethus inguinalis (24), C. nubicola (48), C. flotator
(5), C. talamancae (6), Dendrobates vicente, D. auratus, Phyllobates
lugubris
• Centrolendiae - *Centrolene prosoblepon (4), C. ilex (16), Cochranella
albomaculata (9), C. euknemos (2), Hyalinobatrachium colymbiphyllum
(6)
• Leptodactylidae - *Eleuth. bufoniformis (7), E. bransfordii (2), E.
caryophyllaceus, E. crassidigitus (10), E. cruentus (14), E. museosus (5), E.
“podi-noblei” (28), *E. punctariolus (4), E. azueroensis, E. tabasarae (3), E.
talamancae (21), E. fitzingeri, Leptodactylus pentadactylus (2),
Physalaemus pustulosus
• Hylidae - *Hyla colymba (41), *H. palmeri (22), H. miliaria (2),
Gastrotheca cornuta, Phyllomedusa lemur (2)
• Ranidae - Rana warszewitschii (6)
• Microhylidae - Nelsonophryne aterrima (7)
• Plethodontidae Bolitoglossa schizodactyla (2), Oedipina collaris (2), O.
parvipes complex
(*in mark-recapture program; arboreal; fossorial)
~28 km/yr
1987-88
1993-94
2002-03
1996-97
2004
Why is impact so severe in Latin
America?
• <4 months to 90% loss
• High endemism of montane amphibians
• Cloud forests are perfect environment
for Bd (cool, moist conditions allows
year-round growth)
What can we
expect next?
• Continued expansion into eastern
Panama, Colombia, Ecuador, Peru
• Invasion into tropical montane Africa
& Asia
• Madagascar, Indonesia, India, and
others at risk
Amphibian Extinctions Globally
Declines are now predictable
• Species that occupy high-elevation habitats
• Species that breed in streams
• Species that occupy small ranges
Chytrid update
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Not all species are susceptible
Salamanders apparently are at risk
Link between climate & Bd outbreaks
Bd occurs in wild shrimp
Skin peptides protect against pathogens (HIV but
not chytrid)
• Inhibition of Bd by members of 8 genera of
bacteria isolated from the skin of 2 amphibian
species that exhibit parental care behavior
• Ecosystem-level effects of amphibian declines
Long-term Prognosis
• Bd does not cause immune response
• Bd can survive in habitat or on other organisms
• new lab tests show anurans from affected
populations die more slowly than naïve
• reports of a small minority of populations recovering
• environmental conditions may increase or decrease
susceptibility
• uncertain future
Because, in many cases, chytrid is decimating populations from
otherwise pristine habitat, conventional in situ conservation
techniques aren’t going to work………
The only immediate hope of survival for many
hundreds of amphibian species will be in ex situ
assurance populations.
Amphibian Conservation Summit
• 17-19 September 2005, Washington, DC
• A lot of people (academic researchers,
conservation NGOs, Z&As, IUCN, press)
• Brasil, Ecuador, Mexico, USA, UK, France,
Italy, Sri Lanka, Australia, PNG …
• Create an Amphibian Conservation Action
Plan (ACAP)
Amphibian Conservation Summit
Declaration
• Crisis – currently occurring decimation of a
vertebrate class
• Major and scary ecological consequences
• Implications about the state of the environment
• Fungal disease as a new threat, on top of ongoing
threats of habitat loss, global climate change, toxins
• Causes of decline not well understood, nor easily
reversible, nor immediately preventable
Amphibian Conservation Summit
Declaration
• Traditional conservation approaches are
inadequate to meet the challenge
• A large, multifaceted, coordinated, global
response is needed
• … by governments, NGOs, IUCN, Z&As,
business, scientific communities
Amphibian Conservation Summit
Declaration
Interventions needed:
• Expanded understanding of causes of declines and
extinctions
• Ongoing documentation of amphibian diversity
and distribution – and changes
• Development and implementation of long-range
conservation programs
• Emergency responses to immediate crises
Emergency Responses
• Rapid response capacity – regionally based
teams: field surveys, disease, rescue,
treatment and maintenance
• Captive survival assurance programs
• Saving sites about to be lost
• Saving harvested species about to disappear
Captive survival assurance programs
• primarily in-country
• coupled to obligation to deliver in situ
threat mitigation
• stop-gap measure to buy time for species
we would otherwise lose
• Prioritization based on predictive models
of imminent threats
• Decision process includes range country,
ASG, field researchers
Captive survival assurance programs
• 100s to 1000 or more species face threats
that cannot be addressed quickly with
existing approaches
• Secure in captivity and then breed
• Coordinate with and support research,
reintroduction initiatives, capacity-building,
education
ex situ vs. in situ
• In situ refers to activities within the natural
habitat and native range of a species
• Ex situ refers to anything outside of the
natural habitat (including range-country
zoos) and everything outside of the range
ex situ AND in situ
• Traditional conservation measures are not
enough
• … but they are still needed
• We need an integrated conservation strategy
• We need collaboration and mutual support
• This is our big chance … and responsibility