Seasonal survival in a non-hibernating Mediterranean garden dormouse population

Abstract

The seasonal survival pattern of a garden dormouse Eliomys quercinus population was studied in a Mediterranean agricultural field area from East Spain, a geographical location in which this species does exhibit no hibernation. Individuals were captured from nest—boxes checked monthly during a 4-year period. Data were analysed using an open population Cormack–Jolly–Seber model including sex, age class and season as factors. Best models included the effect of age and differences in survival between adult males and females. Survival rate was more variable between seasons in males than in females or juveniles. Maximum adult male survival was reached in autumn, decreased in winter and dropped to very low values in spring and summer. Survival of adult females was higher and presented a less marked seasonal pattern. Seasonal survival of juveniles was fairly constant along the year. Recapture probability also varied seasonally and was twice in winter than in the rest of the year. The local annual survival rate obtained in adult females exceeded the survival rate observed in some garden dormouse populations from Italy, but it was considerably lower in comparison to the values obtained in South Spain and France. The possible energetic consequences of the constant sexual activity exhibited by this garden dormouse population and the effect of other factors, such as the availability of food and social interactions between individuals, seem to influence in the seasonal variations in survival rate for this rodent species in this agricultural habitat.