The largest population of St. Croix ground lizards now reside on Buck Island, a 176-acre island managed by the National Parks Service. In 2008, just 52 lizards were brought to Buck Island from Green Cay National Wildlife Refuge and their population really took off! By 2013 – just five years after this translocation – 1,473 St. Croix ground lizards were estimated to live on Buck Island and occupy almost half its area (Angeli et al. 2018). Another population survey of ground lizards occurred in 2019, but prior to this summer this data had not been analyzed. This is where I come in!

My summer as an SIP Fellow was spent primarily assessing how the distribution and site abundance of St. Croix ground lizards on Buck Island had changed from 2013 to 2019 and setting up an easy-to-use model so that consistent analysis can be done for future surveys. My model showed that there were significantly more ground lizards in 2019 than 2013 and that their range had expanded across the entire length of the island! I am happy to report that the population of St. Croix ground lizards on Buck Island is doing well and now encompasses several thousand individuals. Future research will teach us more about this species to better motivate subsequent translocation efforts back into its historic range.

In addition to the St. Croix ground lizard, I have encountered a variety of other reptile species throughout my time in St. Croix. I’ve swam with sea turtles (green and hawksbill) and seen them nesting at night on the beach (leatherback), saw a tiny blindsnake, and caught a variety of lizard species including St. Croix anoles, Beatty’s least geckos, and even green iguanas. I am grateful I was able to spend my summer on a beautiful island with a such rich culture and remarkable biodiversity!

Reference

• Angeli, N.F., Lundgren, I.F., Pollock, C.G., Hillis-Starr, Z.M., Fitzgerald, L.A. (2018). Dispersal and population state of an endangered island lizard following a conservation translocation. Ecological Applications 0(0). 1-12.

So how does a budding field biologist create this type of project? It is certainly a daunting task as my PhD will take the next four or so years and my chosen project will likely affect my future research career. However, this is also a very exciting time because I have the chance to create my ideal research project and develop into the scientist I want to be.

To generate ideas, I read relevant research papers, discuss with other scientists, and spend time in the field observing the animals and their habitat. Following advice from my advisor, I record my observations, activities, and people I meet in my field journal and write on average one research question per day. This helps me remember what and when various activities occurred and allows me to track my progress over time. I am also able to organize my project ideas so they can be consolidated into fewer, more concrete research directions. By using this approach, I learned that I am much more interested in direct interactions between species than I am in other types of interactions, such as those between the lizards and their physical environment.

Once I have a research question and trajectory, the next step is to figure out the methods I want to use to collect my data. This part is trickier as I must consider not only my interests, but feasibility in time, personnel, resources, and funding. Some ideas may seem really cool in theory, but if they would take many years to generate results or would cost a million dollars, they are well outside my limitations. Reading previously conducted studies and discussing with more experienced scientists is key to developing robust and practical methodology.

My next steps are to apply for grant funding over the next few months, then eventually to collect and analyze data to produce research publications in scientific journals. This process will be long but will (hopefully) lead to some exciting scientific discoveries! My SIP internship this summer has so far been instrumental in shaping my scientific thinking as well as given me much-needed experience working with my study organism and on the beautiful islands of St. Croix.

It’s been over a month since I moved to beautiful St. Croix, USVI and I’ve had a great time diving into data and fieldwork! I am currently a PhD student at Texas A&M University where I study Ecology and Evolutionary Biology, though I primarily identify as a herpetologist (someone who researches reptiles and amphibians). For both my doctoral work and my Scientists in Parks internship, I am focusing on the St. Croix ground lizard (Ameiva polops) which is a small, striped lizard in the family Teiidae (the group containing the whiptails, racerunners, and tegus).

Although it only covers 82 square miles, St. Croix is a remarkably diverse place with steep hills alongside beaches and ecosystems ranging from desert to rainforest. However, much of the island was converted to agricultural fields in the 1800s for the production and processing of sugarcane. The sugar industry is now nearly nonexistent on St. Croix but the effects on people, culture, infrastructure, and the ecosystem persist. For example, farmers imported small Indian mongoose (Herpestes aeropunctatus) to control rat populations. These mongooses failed to eliminate the rats but along with the surviving rats, cats, and other introduced mammalian predators they extirpated the endemic St. Croix ground lizard. The last recorded sighting on mainland St. Croix was in the 1960s.

But it’s not all doom and gloom for these lizards! Despite eradication on mainland St. Croix, small populations were able to survive on two offshore cays (pronounced “keys”): Protestant Cay and Green Cay. In 1990, a number of A. polops were moved from Protestant Cay to Ruth Cay and a similar translocation occurred in 2008 from Green Cay to Buck Island to expand their range. Today, St. Croix ground lizards continue to thrive on all four of these smaller islands and an experimental reintroduction in February brought them back to the mainland for the first time in decades.

This summer I am continuing the work on the Buck Island population of A. polops by updating existing models of where they live and of their (much higher!) current population size. I will also be gathering additional data, working on public outreach projects, and progressing on my dissertation work.

Stay tuned for updates as the summer continues!