Records of bountied brown bears Ursus arctos in Norway and Sweden were analysed to estimate population size in the mid-1800's, and changes in population size and distribution in relation to the bear management policies of both countries. In the mid-1800's about 65% of the bears in Scandinavia were in Norway (perhaps 3,100 in Norway and 1,650 in Sweden). Both countries tried to eliminate the bear in the 1800's; Sweden was more effective. By the turn of the century, the numbers of bears were low in both countries. The lowest population level in the population remnants that have subsequently survived occurred around 1930 and was estimated at 130 bears. Sweden's policy was changed at the turn of the century to save the bear from extinction. This policy was successful, and the population is now large and expanding. Norway did not change its policy and bears were virtually eliminated by 1920–30. Since 1975, bear observations increased in Norway. This coincided temporally with an abrupt increase in the Swedish bear population, and bears reappeared sooner in areas closer to the remnant Swedish populations. Both conditions support our conclusion that the bear was virtually exterminated in Norway and suggest that bears observed now are primarily immigrants from Sweden, except for far northern Norway, which was recolonised from Russia and Finland. Today, we estimate that the Scandinavian bear population numbers about 700, with about 2% in Norway (on average about 14 in Norway, 650–700 in Sweden). This is a drastic reduction in the estimate of bears in Norway, compared with earlier studies. The trends in bear numbers responded to the policies in effect. The most effective measures used in Scandinavia to conserve bears were those that reduced or eliminated the economic incentive for people to kill them. Our analysis also suggests that population estimates based on reports from observations made by the general public can be greatly inflated.

Artificial rearing may result in changes in the physiology and anatomy of gallinaceous birds. This may partially explain the poor survival of released birds. To study the effects of hand-rearing on grey partridges Perdix perdix, we measured the anatomical and physiological characteristics of 14 wild and 15 hand-reared partridges. Captive partridges were heavier, had relatively larger breast muscles but relatively lighter hearts and livers than wild birds. Wild birds had longer small intestines, longer caeca and relatively heavier gizzards than hand-reared birds. They also had higher glycogen content and cytochrome-c oxidase activity in the pectoral muscles, indicating their better flying endurance compared to hand-reared birds. The results suggest that captivity results in altered anatomical and physiological characteristics, and hand-reared partridges may therefore be poorly predisposed for an abrupt release into the wild.

The population ecology of the raccoon dog Nyctereutes procyonoides was investigated in Finland from 1973 to 1992. Annual mean temperature explained most of the regional variation in the growth rate and present density of the population. Climate explained most of the regional variation in the productivity of the raccoon dog population; the length of the annual snow-free period accounted for most of the regional variation in the weight and fat reserves of young females in late autumn which, in turn, affected the proportion of reproducing females in the population the following spring. Of the independent variables examined, the abundance of wild berries is the dominating factor in explaining the annual variation in density; mortality is highest during the first year of life and the availability of berries probably affects the mortality of juveniles during autumn and winter. The abundance of voles and the population density of raccoon dogs in spring affects the fat reserves of adult females which, in turn, affect their litter size. The productivity of adult females is density dependent, and, thus, regulates population density to some extent. Changes in population size seem to be density dependent after the population peaked around the mid-1980s.

Winter food supply very likely influences the life history of reindeer Rangifer t. tarandus. We therefore examined how lichen biomass affects winter diet composition, body mass and reproduction in 14 herds of semi-domesticated reindeer in northern Finland. Diet composition was assessed microhistologically on faeces collected from the actual winter feeding sites of reindeer. When lichen was scarce at these sites reindeer included vascular plants and mosses in their diet. Calf dressed weight depended on both ground lichen biomass and the intensity of supplemental feeding, doe dressed weight depended on lichen biomass alone. One explanation for this difference between calves and does is the connection between food supply and calf mortality: low lichen biomass may promote newborn mortality, which, in turn, frees breeding females from investing further in current reproductive investment. Relative offspring weight (calf/female weight ratio) depended on both lichen biomass and supplemental feeding. Low lichen availability appeared to enhance the impact of density-independent factors on reproduction, because the annual variation in reproductive rate increased with decreasing lichen biomass.

The development of temperature regulation in grey partridge Perdix perdix, Galliformes chicks at the age of 0–40 days was studied using three different approaches: 1) heat production was measured by indirect calorimetry of chicks subjected to various ambient temperatures; 2) the ability to resist cooling was studied by subjecting chicks to an ambient temperature of 0°C with either dry or wetted plumage; 3) behavioural responses were studied in a thermal gradient using a video camera and an image processing system. The development of homeothermy was not linear. Absolute metabolic rates increased with age at all temperatures, while the maximal mass-specific heat production (W×kg ^-0.75) doubled between days 1-2 and day 5, but remained unchanged after that. Assuming that the allometric exponent accounts for mass-induced changes in the metabolic rate, this suggests that the increase in maximal heat production before the age of five days can be attributed to both maturation and growth, while the increase after five days can be explained by growth only. At the age of 1–2 days, the chicks' capacity to increase heat production in cold was negligible. In five and 10-11-day-old chicks the capacity was markedly higher, but the maximal heat production occurred already at 25°C. A quantum leap occurred between 10–11 and 15–16 days, when the point of maximal heat production shifted from 25°C to 5°C, which indicates a significant improvement of insulation. Wetted chicks cooled faster than dry chicks until 21 days of age. The relative effect of wetting was maximal at 10–11 days. Behavioural observations suggest a drop in the time spent in the warmest section of the thermal gradient after five days and that the coldest part of the gradient (5°C) was hardly visited before 25 days of age. The sequence for attaining homeothermia in the partridge is thus comprised of an early development of significant thermogenesis from day 5 onwards, followed by a rapid increase in insulation around two weeks of age. Despite this fact, especially wet chicks strongly depend on parental heat in cold spells during the first three weeks of their life. The increase in body mass and the development of a water-impermeable plumage enhance the cold resistance in older chicks.

The bite diameter selection by moose in relation to twig quality on four phenotypes of Scots pine was studied on the basis of a field cafeteria experiment. Comparison of twig quality was made among: 1) phenotypes, 2) different twig diameters, and 3) mean moose bite diameters. Chemical and morphological analyses of the trees indicated that twig fibre and tree/shoot size strongly affected moose bite diameter choice. Sight and chewing sensation are suggested to be the main browsing strategies used by moose. Moose adjusted the bite diameter among phenotypes on the criterion of similar food quality. The factors involved may play a multiple role in affecting moose foraging. Quantitative features of trees had no significant effects on moose bite diameter selection.

Observations of capercaillie, Tetrao urogallus, males that do not mate with soliciting females are rather common. Here I present circumstantial evidence that the delaying of copulation is voluntary and propose a hypothesis to explain it. Males of lekking species may delay copulation voluntarily if females copy the mate choice of others, i.e. females around a male may attract females arriving later at the lek. The benefits of delayed copulation depend on the tendency of females to copy each other and the males' risk of losing copulations. Widely scattered display territories in dense forests and longevity are factors that may promote the delaying behaviour of capercaillie and other species with similar characteristics.