Conservation of Giant Tortoises

Conservation of Giant Tortoises

Galapagos Tortoise Movement Ecology Programme

This project is currently Active

Galapagos tortoise migration plays a fundamental role to maintain healthy tortoise populations. Understanding the ecological, social, and sanitary implications of these movements allows us to reduce the threats the tortoises are facing and contributes to their conservation.

This program is a multi-institutional collaboration between the Charles Darwin Foundation, Max Planck Institute for Ornithology, Galapagos National Park Directorate, Saint Louis Zoo Institute for Conservation Medicine, Houston Zoo, and Galapagos Conservation Trust. Drs. Stephen Blake and Sharon Deem lead the program with the support of a local team based in Galapagos and a large number of international collaborators/partners.

Our Research Team

Stephen Blake

Principal Investigator

Dr. Stephen Blake has been involved in ecology and conservation in the tropics for nearly 30 years. He worked on forest conservation in Central Africa for nearly 20 years before moving to Galapagos....

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Sharon Deem

Principal Investigator

Dr. Sharon Deem is a wildlife veterinarian and epidemiologist. She also is a Diplomate of the American College of Zoological Medicine (ACZM). Sharon first came to the Galapagos in 2007, living there...

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Ainoa Nieto

Investigator

Ainoa is a Spanish wildlife veterinarian from Complutense University of Madrid. Since 2016, she has been the laboratory manager of the Charles Darwin Research Station, and she is also working for...

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Freddy Cabrera

Investigator

Freddy is a field researcher, born and raised in the Galapagos Islands. He has a broad experience in wildlife monitoring and tracking. Since 2009, Freddy has been working for the Charles Darwin...

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Anne Guezou

Investigator

Environmental educator and botanist with a MSc in Tropical Plant Biodiversity (Montpellier University, France), Anne has over 20 years of experience in Ecuador and Galapagos. She first joined the...

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José Haro

Field Assistant

José is a field assistant, born and raised in the Galapagos Islands. Since 2015, he has been working together with Freddy for the Charles Darwin Foundation as field assistant. Jose is mainly based...

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Other collaborators:

James Gibbs, Martin Wikelsky, Diego Ellis-Soto, Kyana Pike, Guillaume Bastille-Rousseau, Charles Yackulic, Jamie Palmer, Kathleen Apakupakul.

Project Details

How did we start?

We started our programme in 2009, with a few GPS devices, a field notebook, and a bike. We wanted to show, for the first time, whether Galapagos tortoises truly migrate; with the following questions in mind: where do the tortoises go every year? How and why do they move? And more important, how do human impacts may affect the conservation of such emblematic species?

Stephen Blake tagging a Galapagos tortoise with a GPS device in Alcedo volcano (2010)
Stephen Blake tagging a Galapagos tortoise with a GPS device in Alcedo volcano (2010). Photo by: Christian Ziegler.

Ten years of dedicated research and tons of data support now our theory: Galapagos tortoises can move long distances every year, and their movements vary according to islands, species, ecosystems and health condition.

Stephen Blake monitoring tagged tortoises wih¡th a telemtry antenna
Stephen Blake monitoring tagged tortoises with a telemtry antenna. Photo by: Christian Ziegler.

What do we do?

We work in three islands (Española, Santa Cruz and Isabela) with four different tortoise species (Chelonoidis hoodensis, C. porteri, C. donfaustoi and C. vandenburghi). We use tracking devices such as GPS and VHF to understand the movements of adult and juvenile tortoises in their natural environment. We also study the tortoise diet, the reproductive success of the nests, the survival of baby tortoises, and the impact of physical barriers (fences, roads, etc.) that tortoises may encounter along their migratory routes.

Left: Ainoa taking measurements of a newborn tortoise before tagging it with a telemetry device. Right: Freddy programming a VHF device to tag a baby tortoise
Left: Ainoa taking measurements of a newborn tortoise before tagging it with a telemetry device. Right: Freddy programming a VHF device to tag a baby tortoise. Photos by: Joshua Vela, CDF.

Our team includes nowadays a large number of experts; biologists, ecologists, veterinarians, sociologists, geographers and educators work together to produce cutting edge applied science and information that can be used by local institutions to maximize the conservation of these species.

In addition to ecological, reproductive and social studies, the programme has a strong research component focusing on tortoise health. We are assessing the health of giant tortoises and how the interaction with humans and domestic animals may affect their well-being.

José and Freddy in Alcedo volcano
José and Freddy in Alcedo volcano with a telemtry antenna. Photo by: Joshua Vela, CDF.

Video of Alcedo trip in July 2018. By: Joshua Vela, CDF.

The main goal of this project is to better understand Galapagos tortoise migrations, and the social, ecological and sanitary aspects that may affect their conservation.

Our results

We have movement ecology data of more than 100 tortoises from three different islands. We know, for example, that Española tortoises do not migrate, whereas tortoises from Alcedo volcano (Isabela) can migrate long distances every year. We did calculate that one tortoise can walk up to 10 km in two weeks and spread thousands of seeds during its journey. We also know that migratory animals use the same routes year by year, and that, on Santa Cruz Island and Alcedo volcano, both males and females migrate from the dry lowlands within the National Park area to the humid highlands where food is available all year round.

(A) Map of the Galapagos archipelago and habitat types (e.g., humid, transition, lowlands). (B) Migration tracks of Santa Cruz giant tortoises. (C) Movement tracks of Española tortoises. (D) Migration tracks of Alcedo tortoises (Isabela). Data collected with GPS devices
(A) Map of the Galapagos archipelago and habitat types (e.g., humid, transition, lowlands). (B) Migration tracks of Santa Cruz giant tortoises. (C) Movement tracks of Española tortoises. (D) Migration tracks of Alcedo tortoises (Isabela). Data collected with GPS devices. Maps by: Stephen Blake, CDF.

We now know the movements of newborn tortoises in El Chato area on Santa Cruz Island. Our data show how baby tortoises move a relatively long distance from their nest, walking up to half a kilometer away until they find a place where they can feed and survive during the upcoming years.

Left: Newborn tortoise with tracking device (VHF radio). © Ainoa Nieto. Right: Map of baby tortoise movements right after leaving the nest. Each color represents a specific tortoise; the dark large points indicate the nests
Left: Newborn tortoise with tracking device (VHF radio). Photo by: Ainoa Nieto, CDF. Right: Chart of baby tortoise movements right after leaving the nest. Each color represents a specific tortoise; the dark large points indicate the nests. Map by: Stephen Blake, CDF.

We know that the incubation temperature determines tortoise sex; warmer temperatures will result in more females whereas colder temperatures will deliver more males. In Western Santa Cruz (C. porteri), most  of the males are born in colder and more humid areas where young tortoise survival is lower because of environmental conditions. 

Our Programme also has a strong education and outreach component. Anne, our local coordinator, leads numerous activities all year round to translate our science results to the local community and disseminate our results to visitors and international students. Our education projects are based on experiential learning, giving the local students the opportunity to actively participate in field and laboratory activities, and experience the challenges of working with and for wildlife species in the Galapagos Islands.

High school students in the lab
High school students in the lab with our coordinator Anne. Photo by: Juan Manuel García, CDF.

Keywords: Galapagos tortoise, Galapagos, One Health, migration

Bibliographical References

  • Bastille-Rousseau, G., Potts, J., Yackulic, C., Frair, J., Ellington, E., & Blake, S. (2016). Flexible characterization of animal movement pattern using net squared displacement and a latent state model. Movement Ecology, 4(1), 15.
  • Bastille-Rousseau, G., Gibbs, J. P., Campbell, K., Yackulic, C. B., & Blake, S. (2017). Ecosystem implications of conserving endemic versus eradicating introduced large herbivores in the Galapagos Archipelago. Biological Conservation, 209, 1–10.
  • Bastille-Rousseau, G., Yackulic, C. B., Frair, J. L., Cabrera, F., & Blake, S. (2016). Allometric and temporal scaling of movement characteristics in Galapagos tortoises. Journal of Animal Ecology, 85(5), 1171–1181.
  • Benitez-Capistros, F., Nieto Claudin, A.,Cabrera, F., Couenberg, P., and Blake, S. 2019. Identifying shared strategies and solutions to the Human-Giant Tortoise conflict in Santa Cruz, Galapagos. Sustainability (Accepted).
  • Benitez-Capistros, F., Hugé, J., Dahdouh-Guebas, F., & Koedam, N. (2016) Exploring conservation discourses in the Galapagos Islands: A case study of the Galapagos giant tortoises. Ambio, 45 (6), 706-724.
  • Benitez-Capistros, F., Camperio-Ciani, G., Hugé, J., Dahdouh-Guebas, F., & Koedam, N. Emergent conflicts in conservation: The case of giant tortoises and farmers in the rural area of Santa Cruz Island, Galapagos, Ecuador. PLoS ONE. Submitted.
  • Blake, S., Guézou, A., Deem, S. L., Yackulic, C., & Cabrera, F. (2015). The Dominance of Introduced Plant Species in the Diets of Migratory Galapagos Tortoises Increases with Elevation on a Human-Occupied Island, 47(2), 246–258.
  • Blake, S., C. B. Yackulic, F. Cabrera, W. Tapia, J. P. Gibbs, F. Kummeth, and M. Wikelski. 2013. Vegetation dynamics drive segregation by body size in Galapagos tortoises migrating across altitudinal gradients. Journal of Animal Ecology 82:310-321.
  • Blake, S., Wikelski, M., Cabrera, F., Guezou, A., Silva, M., Sadeghayobi, E., Jaramillo, P. (2012). Seed dispersal by Galapagos tortoises. Journal of Biogeography, 39(11), 1961–1972.
  • Gibbs, J. P., Sterling, E. J., & Zabala, F. J. (2010). Giant tortoises as ecological engineers: A long-term quasi-experiment in the Galapagos Islands. Biotropica, 42(2), 208–214.
  • Nieto Claudin, A., Esperón, F., and Deem, S.L. 2019. Antimicrobial resistance genes present in the microbiomes of free-living Galapagos tortoises (Chelonoidis porteri). Zoonoses and Public Health (submitted).
  • Sadeghayobi, E., S. Blake, M. Wikelski, J. Gibbs, R. Mackie, and F. Cabrera. 2011. Digesta retention time in the Galápagos tortoise (Chelonoidis nigra). Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology 160:493-497.
  • Sheldon, J. D., Stacy, N. I., Blake, S., Cabrera, F., & Deem, S. L. (2016). Comparison of Total Leukocyte Quantification Methods in free-living Galapagos tortoises (Chelonoidis Spp.). Journal of Zoo and Wildlife Medicine, 47(1), 196–205.

The “Charles Darwin Foundation for the Galapagos Islands”, in French “Fondation Charles Darwin pour les îles Galapagos”, Association International sans but lucratif (“AISBL”), has its registered office located at Chaussée de la Hulpe 177 Bte 20 (rez) - 1170, Brussels, and is registered under the trade registry of Brussels under the number 0409.359.103.

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