Birth rate and offspring survival in a free-ranging wild boar Sus scrofa population

© WILDLIFE BIOLOGY · 9:Suppl. 1 (2003) In the course of planning the population number of big game, such as wild boar Sus scrofa, we generally start from the estimated economic carrying capacity, the estimated number of individuals and the recruitment to the female population. Partly due to the unreliability of data on population parameters, e.g. density, birth rate and recruitment, planning is extremely simplified in the overwhelming majority of cases. Usually, an empirical population growth index is used to calculate the recruitment to the population. However, differences in litter size are too large to neglect in the course of planning. Large differences exist not only on a large scale, varying along a latitudinal gradient throughout Europe (Saez-Royuela & Telleria 1987), but also on a nationwide scale (Andrzejewski & Jezierski 1978, Heltay, Matrai, Sugar & Kovacs 1981, Kohalmy 1979). On the other hand, as pregnancy and birth rates vary according to age (von de Vos & Sassani 1977, Pedone, Mattioli, Mattioli, Siemoni, Lovari & Mazzarone 1991), the age structure of the population cannot be neglected. Furthermore, it is well known that the annual fluctuation in survival of the offspring is high and depends on mast availability (Briedermann 1971, Ahrens 1984, Aumaitre, Quere & Peiniau 1984, Groot Bruinderink & Hazebroek 1994). All the above statements suggest, that annual data on birth and mortality rates cannot be ignored, especially in cases where offspring are more heavily influenced by early destruction (Martys 1982, Boisaubert & Klein 1984). We aimed at finding applicable methods for game management practice in estimating the birth rate. We also aimed at determining the scale of neonatal mortality and summer survival of the offspring. Birth rate and offspring survival in a free-ranging wild boar Sus scrofa population