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)

• 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

Why are amphibians important?

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.

• Habitat Loss and Degradation

• Climate Change

• Chemical Contamination

• Infectious Disease

• Invasive Species

• Over-Harvesting

Complex Causes

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 frogXenopus laevis

• 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

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Aug-03 Oct-03 Dec-03 Jan-04 Mar-04 May-04 Jun-04 Aug-04 Oct-04 Nov-04 Jan-05

Date

Co

lost

eth

us

cap

s/m

tr/p

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)

1987-88

20042002-03

1996-97

1993-94

~28 km/yr

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

• 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 SummitDeclaration

• 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 SummitDeclaration

• 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 SummitDeclaration

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