Variations in home ranges (HR) size have been attributed to body size, sex, age, reproductive status, season, food and water availability. Reptiles are an ideal group for HR studies due to their low mobility and strong correlation with environmental conditions. However, little is known about the HR of small lizards, especially in the Iberian Peninsula. Geographical Information Systems (GIS) are a powerful analytical tool to perform spatial analyses of HR characteristics, such as size, shape, habitat dominance and distribution, better than other non-spatial software. However, few studies have analysed spatially the factors limiting HRs, as this requires recording them over the whole surface of the study area. Remote Sensing (RS) can supply a strong support together with radio-transmitter devices, which can record larger quantities of data along the whole species activity day . Social status and familiar structure among individuals are factors related with HR size, as well as with position and access to food sources. Also, juveniles and sub-adults dispersion affect HRs of established adults. Therefore, the aim of the project is to analyse the HR of several lacertids in the National Park of Doñana, in order to determine and compare the degree of territoriality of different species, limiting factors, activity sites and main paths, proportion of sedentary and dispersal individuals, as well as the influence of morphology, social position, reproduction and spatial cohesion of family groups. The main integrating component of the study will be the use of GIS and Ecological Modelling (EM) to analyse HR characteristics at a micro-scale and infer their dependence on environmental (both biotic and abiotic) factors, individual lizard traits (morphology, social status, familiar relationships) and inter- and intraspecific variation. First, habitat structure and temperature variation will be captured with a very high resolution using aerial photographs and a portable infrared camera respectively; lizard movements will be tracked with implanted micro-transmitters, which will for the first time give a very detailed description of the lizards? daily activity patterns. Finally, analysis of micro-satellite markers will be used to infer individual characteristics relevant for HR variation.