Relation between physical condition and reproductive activity in a population of Iberian hares, Lepus granatensis in northern Iberian peninsula

Abstract

The aim of this study was to analyze the relation between physical condition, measured as the Kidney Fat Index (KFI), and some reproductive parameters of Lepus granatensis in Navarra province, Spain. Samples were collected between October 2001 and January 2003, totaling 174 hares (87 males and 87 females). All the hares were sexed and classified in three age categories (immature, young and adult). Fertile males and females were present in all monthly samples. Kidney weight was greater in females than in males for all the age classes and kidney weight variation along the year was not significant. Ranges of perirenal fat accumulated were larger in females but mean weight of fat for all hares was similar in males and females. Body weight and kidney fat weight was directly related both for males and females. Global pattern of fat deposition along the year was similar for both sexes. The amount of perirenal fat in adult fertile hares reaches maximum values just before the main reproduction period and reproductive state conditioned kidney fat levels. Pregnancy induces fat deposition in females and factors such as the number of embryos and the stage of gestation influence kidney fat levels.