Changes of body weight during pregnancy and lactation as well as food ingested, assimilated and metabolizable energy were recorded. Pregnancy lasted on an average 19.6 days, mean number of born animals was 9.78, and the mean body weight of newborn mouse was 1.14 g. The total amount of metabolizable energy taken by the female in connection with pregnancy was 82.32 Kcal. Caloric value of litter was 10.704 Kcal, placenta 4.004 Kcal. The body weight increase of female itself was observed during pregnancy and lactation. Caloric value of one gram of wet weight of the placenta was 513.7 cal and dry weight 6,306 cal/g. The total amount of metabolizable energy additionally taken by female during 26 days of lactation amounted to 354.224 Kcal.

Spatial distribution and interactions were analysed for three cooccurring populations of the rodents Clethrionomys glareolus (Schreber, 1780), Microtus agrestis (Linnaeus, 1761) and Apodemus agrarius (Pallas, 1771). The study was conducted in three 1-ha plots located in forests of southern Poland, in an industrial region (Silesia). Rodents were captured by the CMR method from October 1977 to October 1981. The study areas differed in the degradation of plant communities and the degree of industrial pollution. It has been found that C. glareolus showed a higher degree of aggregation, less frequently changed the points of capture, and was most permanently attracted to them, as compared with the other species. All the rodent species tended to avoid one another at trapping points, especially C. glareolus and M.agrestis. There were differences in the values of various indices among particular plots, which can be related to the degree of plant cover degradation.[Department of Vertebrate Ecology, Institute of Ecology P. A. Sci., Dziekanów, 05-092 Łomianki, Poland] INTRODUCTIONSmall rodents living in mixed forests usually form multispecies communities. They have relatively similar food and habitat requirements. The distribution of individual species was analysed by many authors (Turcek, 1960; Koplin & Hoffman, 1968;Chełkowska, 1969;Flint, 1977;Dienske, 1979; Kovalevskij & Korenberg, 1980;Bashenina, 1981;Andrzejewski & Simonides, 1982, and others), but so far it is not clear how individual species occupy the habitat when they co-occur, and how they interact.The purpose of this paper is to analyse differences in the distribution of co-occurring populations of C. glareolus (Schreber, 1780), M. agrestis (Linnaeus, 1761) and A. agrarius (Pallas, 1771), to find whether or not they interact, and to determine the effect of habitat on their spatial structure. (2) Plot S -at Szczygłowice, at a distance of about 10 km from plot A, close to a pit-coal mine, in Tilio-Carpinetum with Carex brizoides and Pteridium aquilinum.This was a fertile, moist site with no heavily submerged areas like those in plot A.(3) Plot P -at Jankowice near Pszczyna, about 60 km distant from the other plots, in a large forest complex. This plot was covered by Tilio-Carpinetum with Carex brizoides and Pteridium aquilinum, and by Calamagrostio villosae-Pinetum. This was the least polluted and least degenerated habitat.The degradation of plant communities on the study plots was estimated by Dr. S. Wika and Dr. S. Cabala using a 5-degree scale of Celiński and Wika (1980). This scale is based on changes in species composition, such as disappearance of characteristic plant species and appearance of non-typical, ruderal forms, and also on dying trees, leaf fall, absence of seeds, etc. Wika and Cabala also prepared a detailed botanical characteristic of the study plot«. On this basis, several) indices characterizing plant cover of the study plots were calculated. Also the coverage of earth surface by fallen trees and dry branches was estimated. The data on industri...

Investigations were made of the caloricity, and water and ash contents of the body in 135 white mice from 1 to 365 days old. The caloric equivalent of 1 g of biomass of the mice depends primarily on the amount of water in the body. Newborn mice are characterised by high water content of the tissues, and in consequence by their low caloricity. The indices examined do not change between the 10th and 30th day of life. Later increase in the caloric value of fresh tissue in white mice is due on the one hand to continued reduction of the water content, and on the other to the gradual accumulation of fat by the animals. The caloric value of 1 g of dry mass without ash and the amount of ash in the body do not alter during the postnatal development of mice.

The variability in the mandible dimensions has been investigated in bats of the genus Plecotus Geoffroy, 1818 from Central Europe. The material consisted of 100 individuals of P. auritus and 100 individuals of P. austriacus. The variability in the mandible length appeared to be relatively low in both species (Cv = 3.41-3.99), whereas that in the height of the ramus mandibulae was slightly higher (Cu = 4.93-8.62). For both species the common values of the measurements of the mandible length are found in 10.8-11.0 mm classes, which contain 4 per cent of P. auritus and 18 per cent of P. austriacus. As to the height of the ramus mandibulae, the common range for both species falls to the 3.2 mm class (3 per cent of P. auritus and 4 per cent of P. austriacus). A complete separation of both species can be done by simultaneous comparison of two dimensions using the diagram of their correlation considering morphological characteristics of the mandible. This method may find practical application in indentifying fossil materials or those in owl pellets.

IntroductionThe house mouse is an ubiquitous species which forms many subspecies by crossing synanthropic forms with the original wild ones. U nder favourable climatic conditions, the house mouse may return to the wild, away from hum an settlements (particularly on islands where predators are lacking) (Pucek 1984).In Central Europe, two synanthropic subspecies of the house mouse occur. In the western part of the range M. musculus domesticus Rutty, 1772 is found whereas in Eastern Europe, up to Scandinavia to the north, and Elbe river to the west -M. musculus musculus Linnaeus, 1758. The latter is less associated with hum an settlements and moves easily into natural locations. The two subspecies form hybrids in the border zone o f their ranges (Pucek 1984).The mice of M us musculus musculus from Poland and Bulgaria were obtained from similar habitats (cultivated fields close to hum an settlements), although still different in respect to climatic conditions e.g. average annual air tem perature. In Poland it was lower (7.7°C) than in Bulgaria (9.7°C).M us spretus (Lataste, 1883) is distributed throughout Portugal and M editerranean region (Spain, southern France, northern Africa) (Orsini et al. 1982). In southern [209] France M us spretus occurs in dry warm locations (average annual tem perature 14.7°C) close to salt lakes and unwatered vineyards.The inform ation about physiological param eters is available mainly for laborato ry strains of Mus musculus (Bratke and Górecki 1968, Górecki and Krzanowska 1970, 1971. The data on wild populations of M. musculus are patchy (Pearson 1947, M okriyevich 1966, Bashenina 1977.The aim of this study was to determine basic physiological param eters (m etabo lism rate and therm oregulation) in wild representatives of genus M us and to find if there is any geographical variation between animals living in natural habitats under rem arkably different climatic conditions. Material and methodsThe ResultsThe body weight in mice used in experiments differed significantly. The lowest body weights were noted in M. musculus from Dziekanów (average 13.2 g ± 2.9 SD), the highest -in M. spretus (21.8 g ± 1 .8 SD) while average body weights in Mus musculus from K ostinbrod was 18.6 g ± 3 .0 SD (/?<0.01 and /?<0.05).The lowest value of metabolism rate in therm oneutral zone was assumed to approxim ate the basal metabolism rate (BMR). In M. musculus from Dziekanów such value was obtained at 32°C (Fig. 2).The intensity of therm oregulation was calculated in % per °C. It was lowest in M. spretus (4.0% per °C) while the values for two groups of M. musculus were 6.3 and 7.2% per °C (Dziekanów, Kostinbrod).The param eters o f regression equations of therm oregulation are given in Table 1. The slope coefficients for the range of ambients used in this study differed statistically significantly from each other. The "a " coefficients in these equations differed between two groups of M. musculus and between M. spretus and M. musculus from Dziekanów. Am bient tem p eratu re /°C / Thermoregulation i...