Research Adventures in the Jungles of Costa Rica Jessica N

Research Adventures in the Jungles of Costa Rica Jessica N. Pita Aquino

Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA ([email protected])

The distinctive calls of the smoky jungle frog (Leptodactylus pentadactylus; Figure 1), “meer”, and the diversity under the lush rainforest canopy sparked my in- terest and admiration for Costa Rica’s na- ture and its landscapes. Have you ever wondered what vibrant colors and species you might encounter when surrounded by the visually stimulating beauty of a rainforest? This life changing experience re- vealed to me one of Earth's most bio- 1 diverse hotspots . In the summer of 2016 I Figure 1. Smoky jungle frog (Leptodactylus pentadactylus) had the opportunity to be part of the from La Selva Biological Station in Costa Rica. Photo- graph by the author. Organization for Tropical Studies’ (OTS) Research Experience for Undergraduates (REU), funded by the National Science Foundation (NSF). As a field biologist in training, being able to live for almost three months in La Selva Biological Field Station was a dream come true. I would gather with other students to explore the forest’s biodiversity, identify different species of amphibians and reptiles (Figure 1 and 2), and question the mysteries that surrounded us. Among the many people who I met during this research adventure, I made a great connection and posteriorly collaboration with Kristi Fukunaga, a former OTS REU student. During the first weeks of the pro- gram the station was full of field biologists. Day in and day out, scientists would immerse into the forest in their khaki cargo shorts to try and answer all their different research questions. This gave me the opportunity to connect with them and to ex- Figure 2. Eyelash pit viper (Bothriechis schlegelii) from La plore the different research questions they Selva Biological Station in Costa Rica. Photograph by the were addressing. Throughout my conversa- author.

1 A significant reservoir of endemic species threatened by habitat loss and other human activities

1 tions with the field biologists I began to notice a peculiar pattern. When describing the diversity and abundance of species, scientists would repeatedly call attention to how it has been changing throughout the years. They noted the massive population declines documented in Central Ameri- ca and continually gathered in Costa Rica to study this phenomenon. Previous studies (Whitfield et al. 2007), conducted at La Selva Biological Field Station, have shown that in a 35-year period 75% of amphibian and reptile populations have declined due to climate change, habitat fragmen- tation, pollution, pesticides, and infectious diseases. These short- and long-term devastating effects alarmed me. These declines and their causes gave me a reason to continue my research path towards conservation biology.

Though they can’t stand the heat, herps2 can’t leave the kitchen Amphibians and reptiles regulate their body temperature through behavior, which allows them to live in different environments. For example, lizards bask in the sun to warm up, or seek shade when it is too hot. Have you ever thought about what behavioral responses organisms may have as a consequence of environmental and human disturbance? Climate change will alter temperature and precipitation, therefore modifying an organism’s micro- habitat3 and causing changes in their dis- tribution. Lizard species adapted to con- stant environmental temperatures are more vulnerable to warming temperatures be- cause their optimal performance is limited to a specific range of temperatures. They perform best when temperatures are at the higher limits of that range but not above it. To cope with increasing temperatures, am- Figure 3. Neotropical green anole (Anolis biporcatus) from La Selva Biological Station in Costa Rica. Photograph by phibians and reptiles will migrate to higher the author. altitudes or invade forest areas, resulting in competition for resources. In Costa Rica, Kristi and I studied the relationship between running abilities and temperature exposure for five species of rainforest lizards. Under the guidence of Dr. Steven M. Whitfield, a researcher in the Conservation and Research Department at Zoo Miami, we aimed to predict how climate change would affect a lizard’s behavior. Like other organisms, lizards have a preferred body temperature at which they feed, reproduce and escape predators. During our work we found that during portions of a day temperatures rise beyond the maximum a lizard could withstand. Lizards who are not able to adjust to these environmental changes would stay in a ref- uge until favorable temperatures are available.

2 Amphibians and reptiles 3 Small specialized habitat within a larger habitat

2 Pesticides, agriculture and the new canaries Human population growth increas- es food demand as well as the amount of agricultural land needed to grow crops. To prevent large crop losses (e.g. pest con- trol), pesticides are applied to agricultural lands. Previous studies (Colborn et al. 1993) have shown that pesticides are harmful for wildlife and humans. In many parts of the tropics crops ripen year round. This exposes tropical species to consecu- tive and high concentrations of pesticides, resulting in greater sensitivity to contami- Figure 4. Amplexus. Male grasping a female with his front nants. There are few to no regulations on legs. Red-eyed tree frog (Agalychnis callidryas) from La Selva Biological Station in Costa Rica. Photograph by the pesticide use in the Neotropics, a region of author. the world with high species richness and biodiversity. Currently Costa Rica is one of the largest consumers of pesticides worldwide. Agricultur- al lands surrounding La Selva Field Station have a high consumption of pesticides and amphibian populations are on a steep decline within this region. We began to wonder, what if pesticides are an important clue to the mystery of amphibian disappearance? There is increasing evidence that chemical exposure alters growth, development and behavior in amphibians. In our first week of fieldwork we went to a local agricultural center where we bought six commonly used fungicides (i.e. a pesticide used to kill fungi or fungal spores) in Sarapiquí, Costa Rica. We exposed Red-Eyed Tree Frog’s (Agalychnis callidryas) larvae (Figure 5) to different fungicide concentrations to determine how growth and survival were affected. Our results suggest that commonly used fungicides have a negative effect on A. Figure 5. Red-eyed tree frog (Agalychnis callidryas) larvae callidryas larvae. For all treatments, from La Selva Biological Station in Costa Rica. Photo- survival rate and body mass decrased with graph by the author. increasing fungicide concentrations. We found that commonly used fungicides are both lethal and sublethal to larvae, depending on the concentration they are exposed to.

3 Education and public outreach During my participation in OTS’s REU, I assisted and led outreach activities for Costa Rican communities, specifically middle and high school students. I shared my research experience and demonstrated experimental procedures used in our projects, ultimately highlighting impacts of climate change on lizards, the effects of pesticide exposure on amphibians, and encour- aging students to participate in research. Also, for a week a group of science teachers from Cali- fornia assisted me in the field. Kristi and I taught them field and laboratory techniques, as a way to inspire them to incorporate research in their classroom practices. It was a very rewarding experience to see both students and teachers embracing what we have taught them and receiving innovated ideas and feedback. Currently, it is my goal to continue engaging diverse communities in my research.

Increasing human populations have negative impacts on ecosystems all over the world. Climate change, along with habitat destruction and pollution, poses a fundamental threat to global biodiversity. By altering the composition of biological communities we have increased the rate of population declines and species extinctions at all scales, from local to global. Changes in species composition can alter ecosystem function and have economic impacts such as goods and services provided to humanity. Educating communities about current and future impacts can sig- nificantly improve species conservation in all ecosystems. Improvement can also result from studying reptile and amphibian response to human-induced stressors and disturbances, such as climate change and pesticide exposure. This allows us to identify which species are more vulnerable, ultimately developing objective conservation strategies. My REU experience allowed me to witness how we as humans affect wildlife and gave me a significant reason to continue studying and conducting research in the field of conservation and global change biology.

Acknowledgements These research projects were funded by the National Science Foundation and the Organi- zation for Tropical Studies’ Research Experience for Undergraduates. I would like to thank Dr. Steven M. Whitfield for his guidance through this project, Dr. Carissa Ganong and Leticia Classen- Rodríguez for their support throughout this experience, and Kristi Fukunaga for her endless assis- tance in the field. I appreciate the valuable help of Christian A. Pérez, Georgia Hernández-Corrales, Figure 6. Jessica Pita and Anolis capito. Photo- Edauri Navarro-Pérez, Chloe Boehlke, and Ben- graph by Kristy Fukunaga. ton Taylor.

4 Literature Cited Colborn, T., F. S. Vom Saal, and A. M. Soto. 1993. Developmental effects of endocrine- disrupting chemicals in wildlife and humans. Whitfield, S. M., K. E. Bell, T. Philippi, M. Sasa, F. Bolaños, G. Chaves, J. M. Savage, and M. a Donnelly. 2007. Amphibian and reptile declines over 35 years at La Selva, Costa Rica. Pro- ceedings of the National Academy of Sciences of the United States of America 104:8352–6

Venue: International Reptile Conservation Foundation (IRCF) Journal Reptiles & Amphibians: Conservation and Natural History Category: Travelogues