Diet, population density, dispersion, and productivity of red foxes were investigated in an 11 km² area of mixed agriculture representative of much of lowland rural Britain, where medium-sized animals (adult weight 0.3–3.5 kg) were abundant. Four small game species within this size range - brown hare Lepus europaeus, pheasant Phasianus colchicus, grey partridge Perdix perdix, and redleg partridge Alectoris rufa - were also censussed twice a year throughout the study. Fox diet was determined by analysis of faecal material, with diet of cubs at breeding dens analysed separately. Two-thirds of fox diet consisted of vertebrate prey in the range 0.3–3.0 kg. Prey types of overwhelming importance for foxes in other environments - such as small rodents, fruit and invertebrates - each contributed 10% or less to fox diet. Fox territory size was determined by radio-tracking eight adult foxes during a three-year period in spring, summer and autumn. Details of family group size, number of litters per group, and litter size were determined through field observation. Adjacent fox territories (mean size 2.7 km²) formed a contiguous mosaic with individual foxes spending less than 10% of their active time on ground shared with neighbouring groups. Typically each territorial group held an adult pair and had one litter of four cubs. Half of these groups had an additional, non-breeding vixen. Most known fox deaths were the result of deliberate control by man. Control on a central 4.75 km² farm reduced adult fox density and eliminated cub production there, and for the whole 11 km² study site deliberate control was almost sufficient in itself to negate annual numerical increase in fox numbers. The food requirements of foxes living at this density was estimated, and from this the biomass of lagomorphs and gamebirds consumed. Even assuming early dispersal of juvenile foxes, the biomass of these species consumed annually was substantial relative to that available at the onset of breeding. It is suggested that hare and rabbit populations were able to survive this heavy depredation because they have a long breeding season and foxes exploited annual production of young prior to maturity; by contrast, the pheasant population was supported artificially by release of hand-reared birds.

The effects of necklace radio transmitters on survival and breeding success of red grouse Lagopus lagopus scoticus in southern and central Scotland during 1991–1994 were assessed. Recovery rates of birds with 15-g dummy radio transmitters did not differ from those of control birds marked with wing tags only. Clutch size and hatching success did not differ between female grouse equipped with functioning radio transmitters and an independent sample of control birds. It appears that necklace radio transmitters had no measurable effect on survival and breeding success of red grouse in our study areas, although the power of the statistical tests was low.

We analysed harvest data for gyrfalcon Falco rusticolus and rock ptarmigan Lagopus mutus from Iceland with respect to regularity in fluctuations of numbers. The gyrfalcon data concerned live trapped birds exported to Denmark between 1731 and 1793, and totalled 4,848 falcons, including 4,318 grey, 156 half-white and 374 white colour morphs. According to contemporary sources grey birds were part of the local breeding population (islandus-type birds) but the other morphs represented mainly visitors from Greenland. This is also the current situation but some of the lightest Icelandic breeders could be classified as half-white. The rock ptarmigan harvest data concerned birds exported to Europe in the period 1864–1919, in total ca 3.3 million birds. The data series for white and half-white gyrfalcons were significantly correlated (r = 0.501, p < 0.001). The data series for grey and white morphs (r = -0.099, P = 0.445) and grey and the half-white morphs (r = -0.1183, P = 0.360), showed no correlation. Time series analysis showed that the white (candicans-type) morph fluctuated irregularly. The half-white morph behaved similarly but also showed some affinity with the grey morph, and could have represented a mixture of local breeders and Greenlandic winter visitors. Grey morph gyrfalcons and rock ptarmigan showed regular fluctuations in numbers with a 10-year periodicity. The reliance of Icelandic gyrfalcons on rock ptarmigan during the early part of the breeding season and in all phases of the ptarmigan cycle is well established and may offer a case for causal connections between the two cyclic populations.

Scale-dependent effects of landscape heterogeneity on predation of artificial ground nests were studied. Two spatial scales were selected: landscape grain size and single stand size. The landscape types did not differ from each other in their total predation intensity. Depredation was highest in larger stands in all the landscape types studied and the highest predation rate was detected in the largest stands within the most fragmented landscapes. This is possibly due to concentration of rodent-eating predators from surrounding open areas into large stands in the study year when their main prey, voles, crashed. In crash years, alternative predation on e.g. forest bird nests may play an important role for these predators. The influence of predators concentrating into forest stands is expected to be especially strong in landscapes of fine grain size because such a landscape contains relatively more open areas. The predation rate was independent of the distance of nests from the edges of forestry roads. Direct cover (a branch) placed above dummy nests improved the survival rate of these nests. However, tree canopy cover only had a slight effect on the predation rate. The lacking impact of canopy cover on nest predation may be due to the openness of the northern pine forests which makes it particularly easy for predators to discover dummy nests on the ground.

The main habitat for wild boar in the Netherlands consists of a forest/heathland ecosystem. In this ecosystem we found an exclusive correlation between mast availability and nutritional condition in winter and reproduction of wild boar in the succeeding spring. This correlation was used to model carrying capacity in terms of a threshold density in winter, above which the average body weight is density-dependently reduced. The results of modelling carrying capacity of an area of forests and heathlands on poor, sandy soils, for wild boar are presented. The model is based on available mast and broadleaved grasses, the latter being the main substitute for mast during winter.

Diurnal variation in the number of mallards Anas platyrhynchos shot by hunters at Long Point, Ontario, was assessed during the 1989 hunting season to determine peak periods of harvest and to test the prediction that ducks shot during non-peak periods would be in poor relative condition. In addition, attempts were made to determine whether lone mallards are disproportionately vulnerable to hunting and whether ducks shot as singles are in poor condition relative to those shot from flocks. Diurnal variation in size of the harvest was pronounced, with peak harvest occurring during the first third of the day. Relatively few ducks were shot at mid-day, suggesting that mallards were largely inactive at this time. Analysis of abdominal fat masses, however, revealed no relationship between individual condition and time shot. Single mallards were apparently more vulnerable to hunting than were those occurring in flocks, as the hunter-shot sample contained a high proportion of lone birds relative to an expected frequency based on observational data. However, no evidence of a relationship between individual condition and status (i.e. alone vs. in a flock) at the time of harvest was found. Our results, in conjunction with previous work, suggest that flocking behaviour may be a general component of hunting mortality in waterfowl and furthermore that increased vulnerability of lone birds can occur independently of variation in individual condition.

On the basis of questionnaires to moose hunters the colonisation pattern of reintroduced beaver in the province of Värmland was mapped. The beaver spread rapidly within water drainage systems resulting initially in scattered colonisation and very low population densities in relation to range. Spread was slowed by watershed divides. Illustrating the shape of the expansion wave front by plotting the relative increase of the population and range against time, shows a very flat front characterised by long dispersal distances.