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Jose Daniel Anadon Herrera

Population dynamics and connectivity of population of spur-thighed tortoise (Testudo graeca) in fragmented landscapes in southeast Spain

Jimi is field ecologist and studied in his PhD thesis at the University of Murcia the distribution and abundance of the spur-thighed tortoise (Testudo graeca) in southeast Spain. However, he recognized that many aspects of the dynamics of the population, especially those related to habitat loss and fragmentation, require adoption of a dynamic modelling perspective. This is why Jimi is here; he wants to apply spatially-explicit population models using individual-based and pattern-oriented modelling techniques to study population viability of the spur-thighed tortoise.

Postdoc project in Leipzig

The aim of his project is to study the spatial and temporal dynamics of populations of the terrestrial spur-thighed tortoise (Testudo graeca) at the landscape scale. This species is a characteristic element of the fauna in semiarid ecosystems of southeast Spain. It is mainly associated with traditional agricultural landscapes with intermediate disturbance levels. However, due to changes in land use practise which result in habitat and loss and fragmentation the populations of the spur-thighed tortoise are severely threatened.

To study the population viability we will develop an individual-based spatially-explicit population model. This general aim can be broken down into several steps. In a first step we study the habitat use of the tortoise during movement; in a second step we take advantage of telemetric data to develop a movement model using the pattern-oriented modelling strategy, and in a third step the movement model is integrated into a demographic population model. In a fourth step the population model will be applied to study the effects of different scenarios of landscape change on population viability. The scenarios of land use changes include the main processes affecting the habitat of the species: land intensification due to new irrigated lands and tourism development, and rural abandonment. Finally we will tackle more specific objectives such as the connectivity between protected areas and concrete.