January 05, 2018

By, Laura Kleinschmidt, DVM 

During the last two weeks of October 2017, Dr. Ainoa Nieto and I collected samples for the Galapagos tortoise health project in Santa Cruz, Galapagos for the Saint Louis Zoo Institute for Conservation Medicine in partnership with the Galapagos National Park Directorate and the Charles Darwin Foundation. Dr. Nieto is based at the Charles Darwin Foundation on Santa Cruz Island, the most populated island in the Galapagos, Ecuador. I am in my final year as the Veterinary Resident for the Department of Animal Health at the Saint Louis Zoo in Saint Louis, Missouri, USA. The Saint Louis Zoo has a long history of supporting global conservation as well as post-graduate training in zoological veterinary medicine. The Saint Louis Zoo veterinary residency is a post-graduate, 3-year appointment designed to develop a board-certified specialist of the American College of Zoological Medicine (ACZM), and a veterinarian who makes significant contributions to the field of zoological medicine. These contributions may include field conservation projects such as this program in the Galapagos designed to assess the overall health of animal populations and their interactions with humans and domestic animals.

The goals of the project include identification of disease threats to the endangered Galapagos tortoise and determination of the effect of human encroachment (including livestock, agriculture, roads) into the tortoises’ natural habitats. On the island of Santa Cruz, we sampled tortoises in three zones: urban (those living closest to the city), rural/agricultural (those living/traveling through farmland), and protected areas (those living farthest away from humans and domestic animals on National Park grounds). Thirty tortoises were included in this initial two-week pilot sampling period. Depending on the results obtained from these first 30 tortoises, Drs. Nieto and Deem, and the team may sample up to 200 tortoises over the next couple of years.

The first step once in the field was finding the tortoises, which was harder than you would think!  Each morning, the team would head up towards the highlands, where the temperatures are cooler and the air more moist, creating perfect climatic conditions for the Galapagos tortoise. Though the tortoises are large, they are excellently camouflaged in the brush of the forest habitat in which they live and on farm pastures, they look like large boulders from a long distance! In order to find the tortoises, the team would hike through the habitat looking for clues such as feces and tortoise trails (flattened grasses).  Tortoises also take advantage of human-made paths and roads that cross through the landscape.

After locating a tortoise, the team would get to work with the first step being to set up a mobile laboratory for processing collected samples. We recorded the GPS location, habitat type, weight, and sex of the tortoise. Each tortoise then received a physical examination including body measurements, blood draw, fecal sample and swabs for disease screening. The tortoise would be identified with a microchip (similar to the type used for dogs and cats for identification) and then left to return to its daily activities.

Once we collected all the samples for the day, the team returned to the Charles Darwin Research Station to finish processing the samples. The blood samples were used to perform blood cell counts and blood chemistry testing to assess the overall health of the tortoises. The collected swabs were frozen for future molecular testing for viruses that may affect tortoise health, such as ranavirus, herpesvirus, or adenovirus, and bacterial diseases such as mycoplasmosis. Fecal samples were also frozen and will be tested for antibiotic resistance, which has become a worldwide issue in many species including humans. It is suspected that the tortoises that are closer to the urban or agricultural habitats with exposure to humans and domestic animals (and their antibiotics) may have increased patterns of antimicrobial resistance themselves.

The Galapagos tortoise is iconic and unique in the world, plays an important role in a unique ecosystem, and is the protagonist of the archipelago that has given them their name. Given the social and ecological importance of these giant tortoises for the local community and the Galapagos National Park, a UNESCO World Heritage Site, a complete and extensive knowledge of the disease threats these gentle giants face is necessary for effective conservation plans for this species. These health assessments will help us to gain a better understanding of both current and future issues that may impact not only the health the giant tortoises, but also the well-being of all inhabitants (animal and human) of the Galapagos Islands. 

Click on a photo below to see a larger image.

Photo1: Tortoises traveling through farmland are found in the same pastures as cattle.

Photo 2: We preserved the samples in a “mobile laboratory” for later processing at the research station.

Photo 3: Body measurements were taken of all the tortoises as part of their complete physical examination.

Photo 4: We collected swabs from each tortoise during their evaluation.

Photo 5: The samples were processed at the Charles Darwin Research Station laboratory after returning from the field. 

Photo 6: Galapagos tortoises are sharing their habitat with domestic animals and humans, which could expose them to antibiotic resistance.

Photo 7: Our hard-working team celebrated with a photo after hiking over four kilometers on the final sampling day.