A mezei nyúl (Lepus europaeus P.) szaporodásbiológiai mutatóinak vizsgálata kis- és nagyalföldi populációk esetén

Abstract

Background: Despite the dramatic decline in the population of the brown hare, it remains of great importance in the small game management in Hungary. The decline of its populations was caused mainly by drastic changes in the agricultural environment. Breeding biology is a fundamental pillar of the population dynamics of this species, and knowledge of these factors can help to identify and understand the complex causes of population decline. The studies carried out in Hungary provide us with data based on a rather small sample size, mainly due to the old literature data, which are limited to a small area of the country. Objectives: The aim of the present study is to assess the breeding biology and condition of the brown hare populations, to investigate their spatial differences, to study the correlations and interactions of the parameters, and to record the effects of the detected genital changes on reproductive efficiency. Materials and Methods: In the 2023 hunting season, a total of 162 brown hares were bagged and sampled from Little Hungarian Plain (n = 86) and Great Hungarian Plain (n = 76). The focus of our study was on the evolution of reproductive traits (number of placental scars, testicular weight), which we examined in relation to condition parameters (body weight, kidney fat index) and age class traits by area. Pathological changes in the reproductive tract detected during autopsies were identified by laboratory tests. Results and Discussion: Significant differences were found between the body mass data collected from Little and Great Hungarian Plain populations. We could not confirm any differences in the number of placental scars by area and by condition parameters. In the female population, we found significant differences in the number of placental scars only between juvenlie and adult age groups. There were differences in testicular weight both by area and by age group. We also confirmed our hypothesis that the reproductive period of the brown hare was prolonged. Pathological changes in the uterus were found in 5.3% of the examined females, all of which were infertile and all of which were in the highest age group of the adult age group.