Progress 10/01/02 to 09/30/05
Outputs
The Coqui Frog Working Group (CFWG) was organized in October 2002 by representatives from the University of Hawaii, state and federal Departments of Agriculture, the County of Hawaii, plant growers, and the community to address the coqui frog problem primarily on the Big Island. Under the advisement of the Coqui Frog Working Group, Mayor Harry Kim issued an Emergency Declaration against the coqui frog for the County of Hawaii on April 12, 2004, facilitating acquisition of state and federal funding. To estimate the economic impact of coqui frogs in Hawaii County, members of the Hawaii Island Board of Realtors were surveyed. More than 65% of 73 respondents were involved in real estate transactions affected by the coqui frog on the Big Island. Loss of sales was estimated to be at least $11 million (approximately 250 properties) when buyers declined to close a deal after hearing the frogs on or near the properties. A trial was conducted at the University of Colorado,
Boulder (Cynthia Carey, Department of Integrative Physiology) to determine the susceptibility of coqui frogs captured in Hawaii to Batrachochytrium dendrobatidis, which causes chytridiomycosis, a fungal disease suspected in a global decline of amphibians. All boreal toads (susceptible species used as controls) exposed to the fungal organism died within 31 days after exposure, while most of the coqui frogs survived the 103-day duration of the trial and did not test positive for B. dendrobatidis DNA. Dr. Lawrence Woolbright, Siena College, New York, NY, revisited coqui-infested sites on the Big Island to follow up on population surveys initiated during his visit a year ago. The SD of the mean of the adult counts from test plots at Lava Tree State Monument (Pahoa, HI, elevation 122m-152m, annual rainfall 200cm) ranged from 54.4 to 77.8 over three surveys. The high degree of variation may be due to extreme variation in forest plant communities within the plots. Increasing plot numbers or
size, or the number of nights of surveying will also increase labor intensity. His conclusion, however, was larger-scale density estimates derived for areas of Hawaii that are formulated without such effort will likely be flawed and lack value. Requests for education and outreach prompted the production of a 21-minute video 'Coqui frog invasion in Hawaii', which covers biology and behavior of the frog, non-chemical methods of control, and the roles of communities and government in the eradication of the frog in Hawaii. Members of the Coqui Frog Working Group are encouraged to use the video as part of any presentations they are requested to do in communities and for civic and agricultural commodity associations. The video may also be viewed on the UH CTAHR coqui frog website at http://www.ctahr.hawaii.edu/coqui/gallery.asp
Impacts
Discussion and efforts initiated by members of the Coqui Frog Working Group directed the pursuit of an Emergency Declaration and securing of funds to establish an eradication program on the Big Island that will serve as a model for the rest of the state. Since coqui frogs are not susceptible to infection or mortality by chytridiomycosis, the fungal pathogen will not be pursued as a potential biological control agent unless there is evidence of conditions under which the coqui frog becomes susceptible (environmental or physical stress). High, variable coqui frog populations found in Hawaii have implications for researchers attempting to accurately quantify densities over large areas. Improvements in sound pressure level (SPL) survey methods that do not provide actual numbers of frogs can be more fully utilized as a monitoring tool and serve as an independent measure for estimates derived from censuses. It may be possible to create a model that can estimate calling males
within a population based on recorded SPL and other criteria. More than 1,000 DVDs and VHS videotapes of 'Coqui Frog Invasion in Hawaii' were distributed to public libraries, community associations, agricultural and landscaping organizations, agricultural support businesses, and schools and colleges in the state. The UH CTAHR's 'Control of Coqui Frogs in Hawaii' website http://www.ctahr.hawaii.edu/coqui/ has been visited by over 32,000 people since its inception in 2003.
Publications
- Coqui Frog Working Group. 2004. (A.H. Hara, ed.). Coqui Frog Invasion in Hawaii. Jay Harada Productions, Hilo, HI. 21 min.
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Progress 10/01/03 to 09/30/04
Outputs
The Coqui Frog Working Group (CFWG) organized in October 2002, continued to convene during 2003 and through the discussion and efforts of the CFWG, the County of Hawaii issued an Emergency Declaration in April 2004 to secure state and federal support to combat the coqui frog infestation. A website, Control of Coqui Frogs in Hawaii, was created and the purpose of this site is to provide a comprehensive resource for biological and control aspects of the coqui frog invasion in Hawaii, including original research summaries, tips for homeowners, photos, and links to other web sites and articles. To date, the site has received more than 10,250 hits (from unique IP addresses). Dr. Larry Woolbright, Professor of Biology and Director of Environmental Studies at Siena College, New York, NY, who has done extensive work studying the coqui frog populations in Puerto Rico, was invited to study infested sites on the Big Island. Methods used in Puerto Rico were also used to conduct
population density surveys in Hawaii. Habitat modification was suggested as a possible control measure. Comparisons revealed that adult population numbers at Lava Tree State Monument (LTSM) in Pahoa, Hawaii were 4 to 6 times higher than recorded in Puerto Rico. Male coqui frogs appeared to be the first to migrate and establish new populations, with higher male to female ratios at newly infested sites (e.g., Hilo) as compared with established populations (e.g., Puerto Rico, LTSM). Maximum juvenile coqui frog counts and numbers of recaptures over the four night survey were higher in established populations and lower at newly infested sites. Woolbright concluded that, due to habitat availability and lack of potential predators, the potential exists for continued range expansion and population increase of the coqui frog in Hawaii. Dr. Richard Speare, School of Public Health and Tropical Medicine, at James Cook University, Townsville, Queensland, Australia was invited to share his
expertise with chytridiomycosis and amphibian decline. Speare gave his input by suggesting studies on this fungal agent as a possible biocontrol agent for the coqui frog. A researcher, Dr. Cynthia Carey was identified at the University of Colorado at Boulder to test the susceptibility of the coqui frog to chytridiomycosis.
Impacts
Comparisons between coqui frog populations in its native Puerto Rico and in Hawaii revealed that adult populations, such as Lava Tree State Monument (LTSM), were 4 to 6 times higher in Hawaii than in Puerto Rico. Due to habitat and prey availability and lack of predators, the potential exists for continued range expansion and population increase of the coqui frog in Hawaii. Through the discussion and efforts of the CFWG, the County of Hawaii declared a State of Emergency against the coqui frog in an effort to secure state and federal support to combat infestations. The web site http://www.ctahr.hawaii.edu/coqui/ continues to serve as a comprehensive resource of nearly all aspects of the coqui frog in Hawaii, and has been accessed by over 10,250 users.
Publications
- Web site 2004: Control of Coqui Frogs in Hawaii http://www.ctahr.hawaii.edu/coqui/
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Progress 10/01/02 to 09/30/03
Outputs
The Coqui Frog Working Group (CFWG) was formed before funding was released (October 7, 2002) for this project because of the urgency of the coqui frog invasion. Representatives from the University of Hawaii at Manoa, College of Tropical Agriculture & Human Resources, University of Hawaii at Hilo, College of Arts & Sciences and College of Agriculture, Forestry and Natural Resource Management, Hawaii Department of Agriculture, Plant Industry Division, Hawaii Department of Land & Natural Resources, Division of Forestry & Wildlife, Big Island Invasive Species Committee, Maui Invasive Species Committee, County of Hawaii, Office of the Mayor, Hawaii Agriculture Research Center, U.S. Department of Agriculture, Animal & Plant Health Inspection Service, Wildlife Services, U.S. Fish & Wildlife Service, and the nursery industry were invited to develop strategies for research, control and abatement of coqui frogs in Hawaii. The purpose of the CFWG is to serve as a source of
diverse technical and scientific expertise, provide a forum for presenting and sharing results of laboratory and field research, encourage networking between representatives from various government agencies and the private sector, share and consolidate government agencies manpower, assets, and expertise to improve cost effectiveness, increase productivity, and to reduce possible redundancy of multi organizational efforts in controlling the coqui frog. An educational website based on input from the CFWG (http://everyfroghasastory. tripod.com/otheroptions.html) was posted and is maintained by Kim Tavares, Big Island Invasive Species Committee, three videos featuring presentations by Dr. Arnold Hara (UH CTAHR), Mr. Larry Nakahara (HI DOA), and Dr. William Mautz (UH Hilo) were produced for Hawaii Public Access TV channels, and information on the coqui frog was presented at numerous public events, including county fairs (Kona, Hilo), community and grower association meetings. A laboratory
colony was established to study their life cycle and identify stages that will be most vulnerable to control strategies and to produce sufficient numbers of individuals in order to minimize individual variation and draw valid conclusions during control treatment testing. Observations have shown that each mating pair can produce a clutch of eggs averaging 34 to 75 eggs every 2.5 weeks. Egg incubation of these direct development frogs (no tadpole stage) ranges from 14 to 17 d. Compared to Hawaii, field data from northeastern Puerto Rico reported average clutch size of 28 eggs. This may indicate a higher reproductive capacity for the coqui frog in Hawaii as compared to Puerto Rico. It is apparent that the spread of coqui frogs is due to movement of infested plant material, including potted plants and plant materials, to non-infested sites.
Impacts
The formation of the Coqui Frog Working Group was critical in coordinating government resources available to tackle the coqui frog invasion. Community associations on the Big Island have been in contact with the CFWG for assistance in controlling the coqui frog on residential lots.
Publications
- Chun, S., Hara, A.H. and Niino-DuPonte, R.Y. 2003. Greenhouse frog or a coqui frog? Difference between two Eleutherodactylus species found in Hawaii. Cooperative Extension Service. University of Hawaii CTAHR PIO. Miscellaneous Pests MP-3.
- Hara, A.H. 2003. Coqui frog control for homeowners. Coqui Frog Working Group, Cooperative Extension Service, University of Hawaii CTAHR PIO.
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Progress 10/01/01 to 09/30/02
Outputs
No progress to report. This project was initiated on October 1, 2002.
Impacts
(N/A)
Publications
- No publications reported this period
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