GS2 - Population ecology and dynamics P33

Population trends of two hare species (Lepus granatensis and Lepus europaeus) present in Navarra province (northern Iberian Peninsula) over the last decade A. FERNANDEZ', R. SORIGUER 2 , E CARRO 2 and E. CASTIEN 3 Instituto de Agrobiotecnologia y Recursos Naturales (Universidad Ptiblica de Navarra CSIC). Campus A rrosadia sn. 2 Estacion Biologica de Doñana (CSIC). A v. Maria Luisa sn - Sevilla, Spain. 3 Servicio de Conservacion de la Biodiversidad. Gobierno de Navarra, Spain. e-mail: [email protected] Two hare species are present in Navarra; the wide-spread European hare (Lepus europaeus Pallas, 1778) and the Iberian hare (Lepus granatensis Rosenhauer, 1856) endemic to the Iberian Peninsula and one of the main game species. They coexists in parapatry; L. europaeus in the north, and L. granatensis occupying the south of the region. For both species this supposes the limit of their natural distribution range and abundances are considered to be low with respect to other areas of their distribution range, principally for European hare. We have analyzed abundances (number hares/km of transect) for both species over the last decade (1991-2003). Data considered are: (i) those collected by government rangers in spring (480 yearly kilometers for L. europaeus and 280 kms for L. granatensis) and (ii) data collected by hunters associations in their respective game areas during summer (3450 yearly kilometers for L. europaeus and 2120 kms for L. granatensis). Statistical analyses were carried out to detect significant changes in population trends employing non-linear regression models (Jointpoint Regression Analysis). At the same time, in order to test the capacity of this abundance-monitoring program to detect trends in hare populations, a power analysis was employed. Models obtained from both data indicate that L. granatensis trends are slightly positive (1.8% and 4.2% per year respectively). Nevertheless, within this global tendency, a significant period of increase in populations can be observed from 1991 to 1998 and a significant tendency to decrease thereafter (1998-2003). On the other hand L. europaeus populations show a global negative tendency (-1% and -1.9% respectively) but no significant model could be fitted to data. Moreover, very low numbers of hares are observed each year, confirming the dangerous situation of the species in Navarra.