0000000001323821
AUTHOR
T. Mappes
How much do avian predators influence cyclic bank vole populations? An experiment during a peak year
The influence of avian predators on bank vole (Clethrionomys glareolus) populations in four 0.5-ha enclosures was studied in central Finland in 1988. Two of the enclosures were covered with nets to keep out birds of prey, and two were left open to avian predation. A fence of metal sheet and continuous trapping kept out small mustelids during the breeding season. The only avian predators observed in the area throughout the year were the Ural owl (Strix uralensis) and the tawny owl (Strix aluco) and during summer the common buzzard (Buteo buteo). During autumn and winter pygmy owls (Glaucidium passerinum) was present in the study area. No Tengmalm's owls (Aegolius funereus) were observed arou…
Kestrel hunting behaviour towards solitary and grouped Microtus agrestis and M. epiroticus — a laboratory experiment
Extensive field data show that avian and mammalian predators take more Microtus epiroticus than coexisting Microtus agrestis voles. The different vulnerability of these vole species may arise from prey selection or susceptibility differences between the two vole species. We studied the prey selection and hunting behaviour of the kestrel Falco tinnunculus on two Microtus voles, in addition to how behaviour and group structure in voles affect their vulnerability. The main results were that 1) kestrels do not select either of these species, but 2) susceptibility of the vole species deviates significantly. Falcons were more successful in catching M. epiroticus than M. agrestis, indicating that …
Infanticide in the bank vole (Clethrionomys glareolus): Occurrence and the effect of familiarity on female infanticide
We studied infanticide in the bank vole (Clethrionomys glareolus), in a species whose social organization is characterized by strict female territoriality during the breeding season. One possible origin of female territoriality could be to protect the nest site and pups from potentially infanticidal conspecifics. However, direct evidence of the occurrence of infanticide, and thus of its possible role in territorial behaviour of the bank vole females, is totally lacking. Observations in the laboratory, but also in the field and small enclosures yielded a proportion of 30% or more of infanticidal cases of both females and males intruding a strange nest. If an individual of either sex was infa…
Female relatedness and microtine population dynamics: experience from cyclic populations
Charnov & Finerty's (1980) hypothesis of the impact of relatedness between individuals on the multiannual fluctuations of microtine populations (cyclicity) has initiated a number of field experiments in the Holarctic region (Kawata 1987; Boonstra & Hogg 1988, Ylönen, et al. 1990). During recent years, the Charnov-Finerty hypothesis has been shown to be insufficient in explaining population cycles (e.g. Kawata 1990, Pugh & Tamarin 1990, Stenseth & Lomnicki 1990). Lambin & Krebs (1991) presented a new general model for all microtines of the impact of relatedness on the population fluctuations. In the present paper we go through some of the assumptions of the Lambin-Krebs model about the forma…