Roatan Monitoring 2018
Monitoring an endangered iguana and cultivating the next generation of researchers and managers, 2018 report

IIF Grant report submitted by Stesha Pasachnik (Fort Worth Zoo), Daisy Maryon (University of South Wales), and Ashley Goode (USDA)

A recaptured Roatán Spiny-tailed Iguana that was first marked in 2010. Photo by Daisy Maryon.

 

Overview and Objectives. In order to create a sustainable monitoring program, as well as foster the next generation of iguana researchers and managers, we offer workshops in which students and interested members of governments and NGOs obtain intensive training in the field, while collecting vital natural history data in an ongoing project. Workshop participants gain experience in all the basic techniques of iguana research, but the workshops are specifically catered to the participants’ needs for their programs and interests for study or management. Participants are also able to gain experience working as a team to conduct independent studies. These projects provide an opportunity to analyze and document the vegetation and diet of the Roatán Spiny-tailed Iguana, Ctenosaura oedirhina, run flight distance and behavioral trials, use transect surveys, collaborate with local conservation organizations (e.g., Kanahau), provide information to the community through outreach activates, and prepare an IUCN Red List assessment for publication. Since the workshops are tailored to the participants, we accommodate a range of educational and field experience, while keeping everyone involved and excited about the research. Data collected during these workshops is continually added to the life table for this species in order to inform local management strategies.

 

Outcomes and Impact. To continue monitoring C. oedirhina and keep a visible presence on Roatán, as well as provide training, we held our standard ten-day workshop focusing on field techniques and general conservation and research concepts. We also held a second privately-funded workshop prior to our standard workshop, for a high school group (nine students and two teachers) from Houston, Texas.

Daisy Maryon instructing two participants on processing techniques. Photo by Stesha Pasachnik.

2018 workshop participants at one of our long-term field sites. This site has been supportive of our work since 2010 and has even made iguana informational signs. Photo by Stesha Pasachnik.

Our standard workshop included five participants from five different countries. Our sixth participant had to cancel due to yellow fever-related travel issues. One participant was an undergraduate student (Guatemala), two were conservation technicians (Nicaragua and Jamaica), one was a conservation program volunteer (Bahamas), and one was a museum curator (Cuba). After assessing the varied backgrounds and interests of the participants, we designed the field and lecture components of the workshop to cater to their interests and needs. By training participants, we help to build capacity in the region for those just beginning their research careers and those already involved in iguana projects and management. The undergraduate student was able to get hands-on experience that will help them as they move forward in their academic career: “I enjoyed a lot the group interactions and also the field work. My favorite part was the processing because I learned a lot and also because I have never done some of these things”. While one of the technicians had “the opportunity to work with a different species of iguanas,” the other technician was excited to work on a capture/recapture survey, they said, “me gusto mucho la captura y recaptura de los species”. The participants came with diverse backgrounds in fieldwork, education, and career paths, but all were able to practice common field techniques and surveys they may not have had experience with in their current projects.

Ultrasound exams were performed on captured female iguanas to look for eggs. Photo by Daisy Maryon.

Due to weather conditions we were not able to continue our ongoing dietary study but instead focused on an IUCN Red List assessment for Ctenosaura quinquecarinata. This assessment is one that has needed to be completed for some time, making this activity a great help to the IUCN SSC Iguana Specialist Group. At the same time the participants gained valuable insight into the decision-making process of listing a species and will get a publication out of the experience. The Houston high school workshop was a less intensive program but still provided hands-on experience.

Long-time field assistant Mikel Belcaries working with an upcoming assistant to release an iguana. Photo by Daisy Maryon.

 

The data collected during these workshops marks our eighth year of mark-recapture research. In total, 151 new iguanas were captured and 45 were recaptured across our sites, including a new privately-owned site. The new site is small but has a high density of iguanas. Over the course of this study from 2010 onward, we have seen fluctuations in population size, so continued monitoring of demographic trends is vital to proper management of this species. In addition, maintaining a presence on the island helps to reinforce protection for iguanas, especially at study sites where hunting intrusions occur. The captured and tagged iguanas provide important data points for growth and survival analyses. The recaptured individuals in the last workshop show some of the originally captured iguanas from 2010 and 2011 are still alive, providing longevity information. These demographic data provide the first long-term monitoring effort for this genus and can be used as a model for other species within the genus.

 

Unfortunately, this year also marks the discovery of an invasive population of Útila Spiny-tailed Iguana, Ctenosaura bakeri, the neighboring island endemic from Útila, Honduras. The cay where the population occurs was briefly surveyed and several invasive iguanas were documented. We worked closely with the federal government of Honduras, discussed what actions to take, and have begun moving forward with our joint decision, recognizing that it is ultimately the responsibility of the government agency to take action.

Participants hold an iguana that has been processed and is ready for release. Photo by Daisy Maryon.

 

Future. We plan to continue these workshops to ensure that monitoring of this species persists, while building capacity in iguana range countries. In future years, we will continue to complete IUCN Red List assessments and would like to include additional smaller projects, similar to our ongoing dietary study. This will allow participants to experience managing data collection, analyzing data, and give them the opportunity to publish short articles. We are also beginning a collaboration with Dr. Susannah French (Utah State University) to study stress physiology of iguanas across the sites. In addition to stress-related data, we will work together to better understand the reproductive cycle and behavior of this species, something that has been lacking in our research to date. Lastly, due to our discovery of an invasive Ctenosaura bakeri population on a small cay off Roatán we will focus monitoring and management efforts on this population to reduce risk of hybridization and genetic swamping.