Search results for "free-ranging"
showing 2 items of 2 documents
Survival cost of an early immune soliciting in nature.
2009
8 pages; International audience; If immune functions confer obvious benefits to hosts, life-history theory assumes that they also induce costs, leading to trade-offs between immunity and other fitness components. However, whether substantial fitness costs are associated with immune systems in the wild is debatable, as numerous factors may influence the costs and benefits associated with immune activation. Here, we explore the survival cost of immune deployment in postfledging birds. We injected Eurasian collared dove nestlings (Streptopelia decaocto) with antigens from Escherichia coli, and examined whether this immune challenge affected survival after fledging. To assess survival, birds we…
Transitions in herd management of semi-domesticated reindeer in northern Finland. 45
2008
In northern Finland, reindeer-herd management has experienced two major transitions: extensification of intensive herding, and development of supplementary/corral feeding in winter. The transistions were studied in six herding associations in different parts of the Finnish reindeer management area. It was suggested that intensive herding turns into more extensive forms as the reasons for intensive herding (predation, reindeer disappearing to foreign areas, protection of agricultural fields) gradually ceased to exist. The results of the study, based on interviews of elderly reindeer herders, were variable. In the three southern areas intensive herding changed to the free ranging system at th…