The Barbary Ground Squirrel on Fuerteventura Island
Marta López-Darias
The ecology of the invasion of the Barbary Ground Squirrel on Fuerteventura Island (Canary Islands)
Background
In 1965, the Barbary Ground Squirrel (Atlantoxerus getulus), a rodent native to Morocco and small areas of Algeria, was introduced onto Fuerteventura Is. Two squirrels were brought in as pets, but they were soon released and the species successfully colonized the island. Some 40 years after the invasion, few data exist on the ecology of the ground squirrel and its impacts on the native flora and fauna. In 2003 I began a PhD which was focused on the ecology of this invasion.
Objectives
The main objectives pursued in this thesis are: 1) to understand why the species was so successful in colonizing the island; 2) to explore some of the impacts that the species might have.
Objective 1
Four factors have been considered to understand the success of the invasion:
- Climate suitability on the island. To explore this we have used predictive climatic models based on presence data of the ground squirrel in its native range and extrapolated the conditions to Fuerteventura Is. and the whole archipelago.
- Habitat availability on the island. I have studied various habitat variables that are associated with the presence of the ground squirrels.
- Presence of predators in the island vs. in the native distribution area. I study the diets of all the potential predators on the island and compared these with data available from the continent.
- Parasite load. I have explored both the ecto- and endoparasites of the species on the island and in Marocco. There are fewer parastites in the island population than in its native range.
Objective 2
Two potential impacts of this rodent have been explored during this project:
- The impacts on predators populations. One species of raptor, the Common Buzzard (Buteo buteo) appears to have been affected by the presence of this new prey.
- The impacts on disruption on the dispersal mechanisms of native fleshy-fruit plant species.
The project is almost finished and many results are under review by different journals.
Study area
This study was mainly done in Fuerteventura Island, Canarian Archipelago. The Canarian Archipelago consists of seven main volcanic islands situated between 27º-29ºN and 13º-18ºW off the Atlantic coast of north-west Africa. Fuerteventura is the second largest island (1660 km2), the second lowest in altitude (807 m a.s.l.), the oldest and is the nearest to the African continent (approximately 100 km distant).
Financial support and collaborators
This work was mainly financed by La Obra Social de La Caja de Canarias and Cabildo de Fuerteventura, as well as by a fellowship to me supported by the Ministerio de Educación y Ciencia.The study was done with the continuous support of Dr. Fernando Hiraldo. Dr. Manuel Nogales, Dr. Jorge Lobo and Dr. Carlos Feliu collaborated partially with it.
For further details, contact Marta López-Darias, Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología, IPNA-CSIC, 38206-La Laguna, Tenerife, Canary Islands. Email: ,