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Anuran diversity and density as measured through mating calls. Firestone Center for Restoration Ecology Barú, Costa Rica Summer 2007 Alicia Hill. Purpose of Study. Expand the comprehensive list of all anuran species present on the reserve
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Anuran diversity and density as measured through mating calls Firestone Center for Restoration Ecology Barú, Costa Rica Summer 2007 Alicia Hill
Purpose of Study • Expand the comprehensive list of all anuran species present on the reserve • Determine anuran diversity and density at each pond during dusk time • Obtain recordings of individual species mating calls • Track changes in anuran diversity on the reserve from the previous year
Why study frog diversity? • Indicators of an ecosystem’s health • Ability to track the status of the restoration progress on the reserve
Previous Study • Summer 2006, baseline of anuran species on the reserve • 14 species were identified, 6 species mating calls were recorded • A. callidryas was dominant at dusk, followed by H. microcephala and H. ebraccata • One pond analyzed
Methods • Recorded mating calls at night using an automated frog logging system • Took six 10 minute recordings every 50 minutes • In this study, only the first 10 minute recordings (dusk time) were analyzed
Collection Sites • Four man-made ponds on the reserve • Each pond isolated from one another • Ponds differ in size, surrounding flora, and organisms living in the water Basilisk Pond
Data Analysis • Identified each anuran species from the recorded data at each pond • Audacity audio editor and Sigview Signal Analyzer • Calculated the average calls per minute(n=10) for each species
Average anuran call frequencies(mean ± SE; n=10) at the four ponds at 6 PM
Data Analysis of H. rosenbergi Figure 1. Oscillogram of H. rosenbergi, average call frequency is 58 calls/minute
Data Analysis of H. rosenbergi Figure 2. FFT of H. rosenbergi, dominant frequency at 0.47 kHz
Results • The dominant species at this time throughout the ponds were Agalychnis callidryas, Leptodactylus pentadactylus, and Hypsiboas rosenbergi species (Chi-square test, p<0.0001)
Other Conclusions • Many Duck Pond anurans are mating • Anurans doing well in/near bamboo forest (Creek, Basilisk, Frog)
Summer 2008 • Continue recording at the ponds and track species changes • Search for more anuran species that have been recorded at Hacienda Barú (e.g. Glass frogs) • Expand time recordings to later in the night
Species List Eleutherodactylus fitzingeri Leptodactylus pentadactylus New Species 2007: Agalychnis spurelli Phrynohyas venulosa Hypsiboas rosenbergi
Hypsiboas rosenbergi The prepollex , concealing the prepollical spine
Acknowledgments • I would like to thank Dr. McFarlane and Keith Christenson for their guidance and teaching • Thank you to Al Binder, Keala Cummings, Sam Scott, and Emily Shultz for their help.