Amphibian Conservation in the New Century: Mitigation of Disaster
Maureen A. Donnelly
Florida International University
Acknowledgements
Collaboration: Kristen E. Bell, David M. Bickford, Michael Britton, Alessandro Catenazzi, Lilly Margaret Eluvathingal, Brian Folt, Craig Guyer, Luke J. Linhoff, Karen R. Lips, Vivian Maccachero, Joseph Mendelson, A. Justin Nowakowski, Kelsey Reider, Ralph A. Saporito, Jay M. Savage, Michelle Thompson, Rudolf von May, Graham G. Watkins, James I. Watling, Steven M. Whitfield
Organizations/Funding: ACA, American Museum of Natural History, EPA, Florida International University, Iwokrama International Rainforest Centre, Organization for Tropical Studies, National Geographic, NSF, Smithsonian Institution, Smithsonian Tropical Research Institute, United States National Museum
I. Declines of Tropical Amphibians
II. Research Directions
Amphibian Conservation in the New Century: Mitigation of Disaster
Amphibian Conservation in the New Century: Mitigation of Disaster
I. Declines of Tropical Amphibians
Declines as part of the Biodiversity Crisis
Why the Tropics?
Applied research in response to the crisis
• 1/3 earth’s terrestrial surface in tropics
• variety of habitat types
• 50% biodiversity
• latitudinal gradient in diversity
• 50 million square km land in the tropics; 1/2 in Africa
• organisms do not follow latitudes very well; many factors influence distributions
• tropical forests, mangroves, and coral reefs are tropical
• 57% world’s rainforest in Neotropics
• 30% of the world’s rainforest in Brazil
• current rates of deforestation could result in loss of rainforest in 170 years
• 5% of world’s rainforest is protected
Conservation Threats: Habitat Modification Habitat Fragmentation Overharvesting Invasive Species Pollution UV-B Radiation Pathogens Climatic Change Synergistic Interactions
I. Declines of Tropical Amphibians
Declines as part of the Biodiversity Crisis
Why the Tropics?
Applied research in response to the crisis
Amphibian Conservation in the New Century: Mitigation of Disaster
Amphibian Diversity - IUCN 2008 Update
Brazil 798 Colombia 714 Ecuador 467 Peru 461 Papua New Guinea 376 Mexico 364 Indonesia 363 China 333 Venezuela 311 United States 272
http://images.google.com/imgres?imgurl=http://www.iucnredlist.org/images/amphibians/maps/gaa_all_species_with_legend_540x286_v1227155283.jpg&imgrefurl=http://www.iucnredlist.org/amphibians/geographic_patterns&usg=__H7zvVq1RPP8EAig2aNSq__oSW1E=&h=286&w=540&sz=36&hl=en&start=24&sig2=7vUm-aMwsloUZm290cY5xQ&tbnid=m1fJ91bROfA8gM:&tbnh=70&tbnw=132&ei=W3OxSfWfLYrKtQOxoI2IAg&prev=/images%3Fq%3Dglobal%2Bamphibian%2Bassessment%2Bmap%26gbv%3D2%26ndsp%3D20%26hl%3Den%26sa%3DN%26start%3D20
Amphibian Biodiversity: IUCN Redlist
Conservation Threats: Habitat Modification Habitat Fragmentation Overharvesting Invasive Species Pollution UV-B Radiation Pathogens Climatic Change Synergistic Interactions
Conservation Threats: Habitat Modification Habitat Fragmentation Overharvesting Invasive Species Pollution UV-B Radiation Pathogens Climatic Change Synergistic Interactions
Chytrid - An Emerging Pathogen
Discovered from Dendrobates tinctorius (= D. azureus)
Batrachochytrium dendrobatidis
aquatic, flagellated basal lineage in Chytridiomycota unique thallus development zoospore ultrastructure unique Koch’s postulate fulfilled
Voyles et al. 2009 (Science 326:582-585)
Voyles et al. (2009): Green tree frog (Litoria caerulea)
electrolyte transport inhibited by more than 50% plasma sodium reduced by ~20% plasma potassium was reduced by ~50%
death from asystolic cardiac arrest
disruption of cutaneous function is mechanism
New Emerging Disease – Batrachochytrium salamandrivorans
Skin infections Mortality in 7 days 10-15 degrees C vs. 17-25 degrees C
I. Declines of Tropical Amphibians
II. Research Directions
Amphibian Conservation in the New Century: Mitigation of Disaster
Conservation Threats: Habitat Modification Habitat Fragmentation Overharvesting Invasive Species Pollution UV-B Radiation Pathogens Climatic Change Synergistic Interactions
STUDY SITES
0
5
10
15
20
25
0.25 0.5 1 2 4 8 16 32 64 12
826
452
810
56
Fragment area (ha)
Freq
uenc
y (%
)
Nine forest fragments: 1 to 7 ha in size
La Selva, 1100 ha
La Selva Biological Station is a lowland reserve of old-growth forest We analyzed population trends sampled over 35 years with a single method We reviewed density of forest-floor frogs, using forest-floor lizards to help sort hypotheses Two datasets: old-growth forest, abandoned cacao plantations
Species Declining
Species Increasing
17 0
12
0
5 0
FROG AND LIZARD POPULATIONS SHOW SIMILAR DECLINES IN OLD-
GROWTH FOREST
Entire herpetofauna
Frogs
Lizards
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
1970 1980 1990 2000 2010
Den
sity
100
m
- 2 0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
1970 1980 1990 2000 2010 Year
- 2
Entire herpetofauna
Frogs
Lizards
Species Declining
Species Increasing
17 9
0 4
12 8
0 1
5 1
0 3
TOTAL DENSITY INCREASED IN ABANDONED CACAO PLANTATIONS
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
1970 1980 1990 2000 2010
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
1970 1980 1990 2000 2010 Year
Den
sity
100
sq m
» Amphibian populations naturally variable
» Population variability tied to unpredictable aquatic habitats
» Synchronous declines unlikely
» Dramatic synchronous declines indicate external driver
NATURAL POPULATION VARIABILITY CANNOT
SUFFICIENTLY EXPLAIN DECLINES
Entire herpetofauna
Frogs
Lizards
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
1970 1980 1990 2000 2010
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
0.1 1.0 10.0 100.0
1970 1980 1990 2000 2010 Year
Den
sity
100
sq m
FRAGMENTATION CANNOT EXPLAIN DIFFERENCES IN POPULATION TRENDS
BETWEEN HABITAT TYPES
» La Selva essentially isolated from similar lowland forest
» Declines not symptomatic of usual fragmentation effects (no extinction of uncommon species)
» Cannot explain differences in trends between forest types
PESTICIDE DRIFT CANNOT EXPLAIN DIFFERENCES IN POPULATION TRENDS
BETWEEN HABITAT TYPES
» Banana, pineapple plantations directly upwind from La Selva
» Parsimonious explanation for declines in frogs, lizards, insectivorous birds
» Cannot explain differences in trends between forest types
CHYTRID CANNOT EXPLAIN HABITAT TYPES DIFFERENCES OR
LIZARD DECLINES
» Chytrid is present at La Selva, but no mass mortality as seen in other sites; seasonal infection
» No evidence that chytrid affects lizards or other reptiles
» Cannot explain cacao habitat trends
CLIMATE CHANGE MEDIATED THROUGH LITTER DYNAMICS CAN
EXPLAIN TRENDS IN BOTH HABITATS
» Depth of leaf litter is proximate determinant of abundance
» Litter decomposition related to climate
» Litterfall rates high in old cacao groves
» Lowlands are not safe from declines
» Gradual declines may be less conspicuous that mass die-offs
» Our understanding of faunal declines is still poor
» Habitat protection may not be sufficient to maintain biodiversity
FUTURE DIRECTIONS – COSTA
RICA
» Litter addition/removal experiment – Whitfield et al.
» Diseases & Pesticides in Costa Rican amphibians – Whtifield
» Fragmentation studies - Nowakowski
» Secondary Forest Herpetofaunas - Thompson
» Testing Release Strategies for Reintroduction– Linhoff
FUTURE DIRECTIONS – COSTA
RICA
» Litter addition/removal experiment – Whitfield et al. (in press)
» Diseases & Pesticides in Costa Rican amphibians – Whtifield
» Fragmentation studies - Nowakowski
» Secondary Forest Herpetofaunas - Thompson
» Testing Release Strategies for Reintroduction– Linhoff
FUTURE DIRECTIONS – COSTA
RICA
» Litter addition/removal experiment – Whitfield et al. (in press)
» Diseases in Costa Rican amphibians – Whtifield
» Fragmentation studies - Nowakowski
» Secondary Forest Herpetofaunas - Thompson
» Testing Release Strategies for Reintroduction– Linhoff
FUTURE DIRECTIONS – COSTA
RICA
» Litter addition/removal experiment – Whitfield et al. (in press)
» Diseases in Costa Rican amphibians – Whtifield
» Fragmentation studies - Nowakowski
» Secondary Forest Herpetofaunas - Thompson
» Testing Release Strategies for Reintroduction– Linhoff
FUTURE DIRECTIONS – COSTA
RICA
Amphibian Ark (AArk)
Execute ex situ conservation components of Amphibian Conservation Action Plan (ACAP)
World Association of Zoos & Aquariums (WAZA) IUCN/SSC Conservation Breeding Specialst Grp. (CBSG) IUCN/SSC Amphibian Specialist Group (ASG)
FUTURE DIRECTIONS – COSTA
RICA
Baby Caecilians Feeding – 33 second youtube: https://www.youtube.com/watch?v=6K6szXrBHwM New Breeding ball – first 30 seconds: https://www.youtube.com/watch?v=dtYjJwknBx4 Cute Screaming Frog – 30 second youtube: https://www.youtube.com/watch?v=cBkWhkAZ9ds First four minutes of “The Last Dragons” http://vimeo.com/108512185