Dynamics of space use and male vigour amongst wood mice, Apodemus sylvaticus, in the cereal ecosystem

Abstract

Abstract. The spatial organisation of male and female wood mice, Apodemus sylvaticus, was investigated in a large-scale radio-tracking study on arable farmland near Oxford, United Kingdom, during the breeding season. Both sexes had significantly larger home ranges in the breeding season than at other times, and the breeding season home ranges of male (X = 1.44 ha) were significantly larger than those of females (X = 0.49 ha). Home range overlap was significantly greater between males, and between males and females, than it was between females. Overlap between males tended to be greatest in heavily utilised areas. Except during sexual consortship, there was minimal evidence of dynamic interaction among individuals. Home range sizes of breeding males varied widely, as did their body weights. There was no relationship between male body weight and home range size or any other movement parameter. However, males with the largest home ranges had the highest scores on all other movement parameters, indicating that they expended more energy in movement. These more 'vigorous' males had access to the home ranges of more females than did males with small home ranges.

Differentiation of tundra/taiga and boreal coniferous forest wolves: genetics, coat colour and association with migratory caribou

“…The spatial overlap of two home ranges and congruence in at least part of the utiHzation distributions is termed 'static interaction' (Macdonald et al 1980;Doncaster 1990). Following Tew & Macdonald (1994), we used nonparametric utilization distribution analyses to measure static interactions between wolves and caribou. In ARCVIEW, we divided the area encompassing all wolf and caribou locations into a grid.…”

The wild life of tick-borne pathogens

“…First, an increase of rodent density could result in the dilution of the available nymphs and larvae over more rodents. Secondly, the day range -the product of activity level and movement speed -of rodents could decrease with rodent density 213 , resulting in a lower encounter rate of rodents and ticks, hence a lower prevalence and intensity of infestation. Studies investigating behavioural responses of rodents to crowding in relation to tick burdens are needed to determine which mechanism is more important.…”

“…The day range of the host relative to the presence of parasites is determined by many factors. Large host species tend to move over larger distances than small host species 67,212 and males often have larger home and day ranges than females 213 . In addition, predation risk can decrease the distance travelled by prey species 214 .…”

“…In addition, predation risk can decrease the distance travelled by prey species 214 . Finally, day range and home range size often decline with conspecific density 213 . The likelihood of a host individual encountering a parasite thus depends on intrinsic factors (individual characteristics of the host; e.g., species, size and sex) as well as extrinsic factors (abundance of other animals in the community).…”

“…N. mikurensis 50 -between twenty forest plots that differed in their vertebrate assemblage composition. Based on the theoretical mechanisms of Keesing et al 31 and the empirical evidence of Cagnacci et al 32, and Kiffner et al 95 , we propose six relationships between predator, deer and rodent density, tick burden on rodents and DIN for rodent-transmitted tick-borne pathogens ( Figure 6.1): 1) tick burden on rodents increases with the density of deer, important maintenance hosts for adult female I. ricinus that can therefore increase the number of immature ticks in the environment 32,190 (vector augmentation); 2) tick burden on rodents decreases with rodent density because ticks are distributed over more individuals and because rodents decrease their spatial activity, decreasing encounter rate 95,213 (encounter reduction); 3) tick burden on rodents decreases with predator density because rodents decrease their activity in response to predation risk, decreasing encounter rate 214 (encounter reduction); 4) rodent density decreases with predator density (reservoir host regulation) 31,160 ; 5) the DIN of rodent-transmitted tick-borne pathogens increases with per-capita tick burden on rodents, because the chance of individuals becoming infected with a pathogen by feeding an infected nymph increases with tick burden, and each infected individual will infect more larvae, resulting in a higher DIN irrespective of rodent density; and 6) for a given per-capita tick burden, the DIN of rodenttransmitted tick-borne pathogens increases with rodent density 33 .…”