Presented here are the results of research on spatial organisation among hares originating from enclosure-type rearing but released into a natural environment for them. The fates of the 60 animals were traced by radiotelemetry in the course of four successive years of research. The mean annual home range size was found to be 1.68 km 2 in males, significantly greater than that noted for females (0.43 km 2). Similar relationships were observed in the case of seasonal ranges. The mean distance of movements noted for hares between successive radio-locations in the first month after release (at 239 m) was significantly greater than that noted for the second month (103 m) or the third (116 m). The mean distance of movement within individual annual home range for the males hares was 335 m and was significantly greater than that for females (226 m). Similar findings were obtained for seasonal ranges.
The main reason for reitroducing beavers (Castor fiber) to the Raifa part of the Voga-Kama National Nature Zapovednik (VKNNZ) was to utilise their habitat-changing activities - primarily the use of their ability to build dams - to stop the degradation of the Zapovednik hydrosystem (Gorshkov et al. 1999). Today there are seven beaver dams on the rivers that run through the Zapovednik. We studied the movements of the beavers by locating new cuts, dens, trails, dams, etc. and by radiotelemetry. We assumed that in the first phase of reintroduction the spatial structure of the beaver subpopulation consisted of four permanent and five temporary settlements. We determined the home ranges of the reintroduced beavers as being approximately seven ha, plus smaller additional patches of habitat that were used during the witner. Another object of our investigation - the feeding behaviour of reintroduced beavers - showed that the most preferred tree genera were aspen and willows, followed by alder and birch. The wolume of trees cut by beavers between autumn 1996 and spring 1999 in the Volga-kama National Nature Zapovednik was 11.69 m3
Disturbed circadian activity of the sympathetic system may be involved in negative consequences of chronodisruption on the cardiovascular system. We studied daily changes in pressure response to adrenergic stimulation in rats exposed to repeated phase advance shifts (PAS) of light/dark (LD) regimen. Blood pressure (BP), heart rate (HR) and locomotor activity was measured by radiotelemetry in normotensive Wistar rats exposed to repeated PAS (three 8-h shifts per week) lasting for 12 weeks. Norepinephrine was administered subcutaneously in the middle of L and D during week 12 of PAS exposure. In the control LD cycle, cardiovascular parameters exhibited significant daily rhythms with expected higher values during D than L phase. Rats exposed to PAS showed disturbed rhythms without a BP and HR increase. Administration of norepinephrine to control rats revealed daily variability in the cardiovascular response with higher stimulation of BP during L than D. This daily pattern of BP response to norepinephrine was diminished in the PAS group. The damped daily variability in pressure response to norepinephrine and augmented response during the light phase of the day suggest that the increased and desynchronized activity of the sympathetic system may worsen responses of the cardiovascular system to load in individuals exposed to irregular LD conditions., L. Molcan, A. Vesela, M. Zeman., and Obsahuje bibliografii