Coqui frog population densities
in Lava Tree State Monument (Pahoa, HI) are the highest in
the state of Hawai’i (>2,000 adults per acre) and
are already more than twice the densities found in their native
Puerto Rico. On some nights, the frogs’ chorus in the
park reaches 70 decibels – about as loud as a vacuum
cleaner. Decibel readings of frog calls were taken, but environmental
factors seem to greatly affect frog-calling behavior; therefore,
estimating frog populations by the level of sound has not
been wellestablished and may require continued improvements
in data collection methodology.
The T-STAR Hawai`i Coqui Frog Invasive Species Project recruited
the expertise of Dr. Larry Woolbright, of Audubon International
and Siena College in New York, to initiate a population monitoring
study at Lava Tree State park and collect baseline ecological
data. Plots measuring 20 x 20 m were surveyed on four consecutive
nights; frogs in the plots were counted and measured. It is
through these studies that Dr.
Woolbright determined that Hawaii has much denser populations
of coqui frogs compared to Puerto Rico.