0000000000821549
AUTHOR
J. Viitala
Sex and age-specific differences in ultraviolet reflectance of scent marks of bank voles ( Clethrionomys glareolus )
Scent markings of voles are visible via their ultraviolet reflection. Kestrels, and possibly other diurnal raptors, may use this property when hunting. We performed a laboratory study on bank voles to determine whether UV-reflectance of scent marks differs in relation to sex, age and social status. When reflectance spectra of scent marks were measured with a spectro-radiometer, we found UV reflectance to be strongest in mature males. There were no differences between mature females and immature juveniles, nor between sexes in juveniles or mature and immature individuals in females. Moreover, we did not find any difference in UV reflectance between dominant and subordinate mature males. The …
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…
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…