1 Amphibian Species Diversity in Primary and
Secondary Growth Forests of Kalu Yala
Alison Cantor and Patrick Ramsay
Biology Program, Summer 2014
30 July 2014
2 Table of Contents
Introduction…………………………………. Pg. 3
Preparation…………………………………. Pg. 4
Implementation…………………………….. Pg. 4
Results………………………………………. Pg. 5
Conclusion..………………………………… Pg. 6
Continuation………………………….…….. Pg. 7
Acknowledgements……………………….. Pg. 7
3 Introduction
Patrick: My interest in science and nature developed at an early age. Growing up in Utah I
was never more than a bike ride away from the mountains. Whether it was catching garter
snakes in the corn fields that now host a Wal-Mart and parking lots or investigating frogs
and salamanders at the pond behind my
grandmother’s house, experiencing nature
was a daily routine. By the time I finished first
grade, I had earned about $12 in late fees at
my local libraries for keeping the books
about frogs for what they considered to be
too long. The Encyclopedia of North
American Amphibians was kept near my
bedside and never gathered dust. I had a
passion for herpetology before I knew what
it was, so naturally I leapt at the chance to
study frogs in Panama for a summer.
Alison: My affinity for animals has been apparent since before I could talk. Since that time,
my idea of the perfect career has undergone many stages of evolution. My work on this
project has been the most productive and rewarding experience in my post-collegiate life,
leading me to believe that field research may be where my career path lies. From
conducting surveys in the field, to
poring over images of frogs we’ve
found in the area in order to identify
them, this summer has been a
perfect example of Alison Cantor in
her natural habitat. Although I have
not settled on a particular group to
focus on, despite inspiration from
Aaron’s passion for insects and
Pat’s natural gravitation to
amphibians, the research I have
conducted during this semester has
brought me one step closer to
reaching professional nirvana.
We are interested in comparing the abundance of amphibian species in the surrounding
primary and secondary growth forests because amphibians are often indicator species of
the health of the environment. By identifying which species are least resistant to
disturbance we can easily recognize disturbed environments. This is important to the Kalu
Yala community because we will be more aware of which amphibian species we may
4 displace during the development of the land and which species have already been
disturbed due to surrounding degradation of the environment.
The goal of this project is to collect species population data from one primary growth
tributary and one secondary growth tributary and distinguish any differences we may find.
We will also attempt to identify any indicator species of primary growth and secondary
growth forests. The analysis of this data will indicate which species are most at risk of
being lost from the Tres Brazos valley when deforestation takes place and which species
are likely to fill in the open niche within secondary growth forest. Lastly, we will analyze the
population statistics in order to get a numerical value of species diversity in each type of
forest. The results of this study will impact Kalu Yala by providing information on which
amphibian species are most in need of our protection.
Preparation
Both interns involved in this project have completed college-level courses involving forest
and population ecology. We referenced Jay M. Savage’s book The Amphibians and
Reptiles of Costa Rica and the field guide Panama Amphibians from Rainforest Publications
during the identification process of this project. No further supplies or budget were used.
Implementation
The first step in implementing
this project was to locate two
tributaries that would provide
locations to survey for
amphibians in primary and
secondary growth forest. The
Tres Brazos valley has a
plethora of tributaries
surrounded by secondary
growth due to the prevalence
of slash-and-burn agriculture
practices, but the search for a
suitable primary growth
tributary proved to be more
difficult. We determined it
would be wise to locate a
primary growth tributary first in order to determine what elevation our secondary growth
location would need to be at. The primary forest tributary we decided to survey is located
at N 09º 16.812’ W 79º 17.598’. From base camp, the mouth of the tributary can be found
by hiking for roughly an hour down the road/trail that travels eastward from the front gate.
The area surveyed at this location spanned roughly from 350 to 360 meters in elevation.
With advice from Aaron Prairie, we determined that we must conduct our secondary
growth survey within 100 meters of that elevation in order to eliminate the difference in
5 elevation as a variable effecting which species we would see. The area surveyed on the
secondary forest tributary we selected begins at N 09º 15.056’ W 79º 17.087’. From base
camp, this location can be found by hiking up Suicide Hill a short way until going through
the “Finca Velasquez” gate on the right hand side and following the road until it meets the
tributary. The area surveyed at this location spanned roughly from 320 to 330 meters in
elevation. Each location was surveyed three times. We strove to do surveys on days that
were rainy and therefore optimal for frog catching, but the weeks during which we
completed the surveys were unseasonably dry. The surveys were completed by carefully
searching through leaf litter and
piles of rocks for frogs. Any
species that we could identify
by sight were simply counted.
Any frogs we did not recognize
were photographically recorded
and later identified. The data
collected was used to
determine proportions of
species present in each location
and later evaluated with
Simpson’s Diversity Index to
give us a numeric
representation of amphibian
biodiversity in the given area.
Results
New Growth
7-7-14: 18 Silverstonneia flotator (Striped Rocket Frog), 2 Colostethus panamensis
(Panamanian Rocket Frog), 1 Colostethus pratti (Pratt’s Rocket Frog), 1 Pristimantis
cruentus (Golden-Groined Rain Frog)
7-9-14: 23 Striped Rocket Frog, 2 Panamanian Rocket Frog, 4 Pratt’s Rocket Frog, 1
Hyalinobatrachium colymbiphyllum (Bare-Hearted Glass Frog)
7-21-14: 12 Striped Rocket Frog, 4 Panamanian Rocket Frog, 4 Pratt’s Rocket Frog
Total: 53 Striped Rocket Frog, 8 Panamanian Rocket Frog, 9 Pratt’s Rocket Frog, 1
Golden-Groined Rain Frog, 1 Bare-Hearted Glass Frog
Simpson’s Diversity Index: .436
6 Old Growth
7-10-14: 1 Craugastor fitzingeri (Common Rain Frog)
7-12-14: 3 Common Rain Frog
7-18-14: 4 Common Rain Frog
Total: 8 Common Rain Frog
Simpson’s Reciprocal Diversity Index: 0
Conclusion:
We hope that the information
garnered by performing this study will
aid future Kalu Yala interns and
residents by raising awareness of the
impact humans have on the balance
of amphibian populations when we
disturb environments. Our results
show that Common Rain Frogs are
especially at risk of losing their habitat
from the practice of removing primary
growth forest to make room for
human settlement. Another factor
that may be threatening Common
Rain Frog populations is the spread of
7 the Chytrid fungus throughout Central America. On the other hand, rocket frogs appear to
thrive in secondary growth forests. This information will hopefully be helpful to future Kalu
Yala interns and residents when trying to determine whether an area is composed of
primary or secondary growth. An added benefit of completing this study was it allowed us
to expand the catalog of amphibians found in the Tres Brazos valley. During this semester
the frogs we encountered on hikes were well documented and successfully identified,
broadening the knowledge base of local species available to future interns.
If the Kalu Yala community finds this study to be particularly useful, it can easily be
expanded upon. It is clear that more research is necessary in the primary growth forest.
More species had been seen at higher elevations on the tributary we surveyed for primary
growth before we had started this study, such as poison dart frogs and glass frogs.
Different elevations and locations can be surveyed to uncover more connections,
similarities, and differences in the amphibian species populations.
Continuation
Kalu Yala biology director Aaron Prairie intends on using this data to continue investigating
biodiversity in the Tres Brazos valley. He also plans to share this information with
resources who can provide assistance in testing frog populations for the the Chytrid
fungus.
Acknowledgements
Special thanks to all of the biology interns who helped us complete the frog surveys
(Arthur Abrams, Andi Antal, Chelsea Bratton, Jacob Rumschlag, Molly Short, and Danielle
Spence). Also to Aaron Prairie for his exceptional directing and never-ending enthusiasm
for biology.
The accompanying scientific report for this project can be viewed at:
https://docs.google.com/document/d/1fVAhmUn8CzX4lIwBza45I2X1CGVyruRIPqgGf
WsPlSM/edit?usp=sharing