It is generally accepted that predation by wolves Canis lupus is one of the major factors limiting densities of woodland caribou Rangifer tarandus caribou in North America. Conversely, little is known about the role of European wild forest reindeer R. t. fennicus as wolf prey, or about the influence of wolf predation on populations of this rare subspecies. This relationship was examined in east-central Finland, where wild forest reindeer coexist with moose Alces alces at a numerical ratio of c. 1 reindeer to 1.5 moose. During the study, moose were clearly the primary prey of wolves. Reindeer were, however, an important part of wolf diet in summer, autumn and early winter, when their remains comprised roughly 20-50% of all food items identified in wolf scats. Wolves exhibited a slight preference for reindeer over moose as prey during early winter (November-December) when the reindeer were moving towards their wintering ranges. Virtually no reindeer were killed by wolves during midwinter (JanuaryMarch). This held also for a pack whose territory was located in the middle of the wintering range of reindeer, where reindeer outnumbered moose during the winter months. After the approximate ratio of wolves to reindeer increased from 0.004 (1998) to 0.02 (2000), wolf predation became the most common source of mortality (50%) for reindeer. The annual net increase in the reindeer population decreased from 13% to 7% because of increased wolf predation.The results indicate that wolf predation was an important factor limiting reindeer population growth. Wolves were, however, unable to prevent entirely the number of reindeer from increasing, partly owing to behavioural traits used by reindeer during winter and calving times.
The relevance of the familiar area hypothesis to the behaviour of the wild forest reindeer (Rangifer tarandus fennicus Lönnb.) was studied in a Fenno-Soviet project by radio and field tracking of these ungulates in Karelia, Northern Europe, in 1978 - 1985. This subpopulation (500 - 600 exx.) has a tradition of overwintering in a restricted area around Lake Lentua (ca. 1000 km2). The spring migration period is shorter in length than the autumn migration. The migration routes are generally the same in autumn and spring, although exceptions occur, indicating exploratory behaviour. The large winter herds disband into small groups or lone individuals for the summertime, when this subpopulation is spread over a much wider area (ca. 5400 km2). It is concluded that the observations made support the familiar area hypothesis in all essential points
The intensity of growth of Sorex araneus L. and Clethrionomys glareolus Schreb. in the Oulu district of Finland is studied as a function of age and seasonal rhythm, and compared with the results of growth‐rate measurements of Sorex araneus L., Clethrionomys rufocanus Sund. and Clethrionomys rutilus Pall. in Kirkenes, Norway. It is assumed that the postnatal development of the Common shrew with its growth and regression phases is to some extent controlled by an endogenous seasonal rhythm. The growth of the voles is not as clearly controlled by these rhythms as that of the Common shrew although the growth of the Bank vole and Northern red‐backed vole is obviously considerably retarded in autumn and in winter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.