With 4 plates and 12 figures)The burrowing behaviour and burrow patterns of the mole-rats Tachyoryctes (Family Rhizomyidae), Heliophobius and Heterocephalus (Family Bathyergidae) were compared. Remarkable similarities were found both in the method of digging and the basic burrow pattern of the three genera. Dissimilarities in burrow length can be attributed to the availability of food and the number of animals occupying one burrow system. Thus, the solitary Tachyoryctes, which eats a wide range of foods, has the shortest burrow system; while the colonial Heterocephalus, which eat a limited range of foods and live in arid regions, have very extensive burrow systems.All the mole-rats bite at the earth face with well developed incisors; collect the excavated soil with their fore and hind feet and push it behind them. Tachyoryctes differs from the bathyergids in then turning round and using one side of its face and one fore foot to push the excavated soil along the burrow and out onto the surface. The bathyergids back up to the soil and push with their hind feet. Tachyoryctes has a multi-purpose nest chamber used for sleeping, food storage and sanitary purposes; the bathyergids have a simple nest chamber used solely for sleeping, they do not store food but instead partly expose tubers in the foraging burrows and eat pieces from them when hungry.Differences between the bathyergids are largely attributable to their social structure; Heliophobius is solitary and Heterocephalus colonial. Digging and soil disposal are essentially similar but in Heterocephalus the various stages are taken by different members of the colony and a digging chain is established. Soil type and moisture content influence mound formation; Heterocephalus kicks out a spray of fine dry soil through an open hole.The other two mole-rats live in areas with higher soil moisture content and push out solid cores of soil.

Summary Following the 1970‐71 drought, which resulted in heavy elephant mortality, a long‐term study was initiated in Tsavo National Park to determine movements and home ranges of individual elephants and their relations to overall distribution patterns and environmental factors such as rainfall. The preliminary results presented show the post‐drought situation but it is recognized that they may not represent normality. Methods used were radio‐tracking and observations of visually identifiable individuals. Two aerial counts provided data on overall distribution. Two bulls and two cows were radio‐tagged in Tsavo West and two bulls and four cows in Tsavo East, providing home range and movement data. Home ranges in Tsavo West (mean = 350 km2) were considerably smaller than in Tsavo East (mean = 1580 km2). The differences between Tsavo West and Tsavo East are probably related to habitat quality, Tsavo East receiving less rainfall than Tsavo West. This view is supported by the fact that the 1970‐71 mortality was largely confined to Tsavo East. The movements of individuals were useful in interpreting relatively major shifts in elephant distribution that occurred within a 4‐month period. The following preliminary conclusions emerge from the results obtained so far: (1) Elephants in the Tsavo area, particularly Tsavo East, were more mobile during the study period than was assumed from earlier studies, undertaking long‐distance movements in fairly direct response to localized rainfall. (2) A subdivision of the overall population into locally distinct units may exist during the dry season but did not obtain after significant rainfall, when the elephants ranged over wide areas and came into contact with animals from other dry‐season units. (3) Circumstantial evidence suggests that food is the primary proximal factor governing movements and distribution of elephants in the area. Food availability, in turn, is determined largely by the spatial and temporal pattern of rainfall.

Samples from 69 British red deer Cervus elaphus scoticus from seven populations in Scotland and England were analysed with respect to variability within and differentiation among stocks using 11 polymorphic microsatellite loci and 439 bp of the mitochondrial control region. The results clearly showed the effects of anthropogenic factors on British red deer. On the whole, variability values were within the species' reported range. The island population of Islay, Scotland, however, while showing average microsatellite variability, exhibited no mitochondrial variation at all. One microsatellite locus was monomorphic in three Scottish populations (Islay, Dunachton and Achnacarry). Overall and pairwise F ST values indicate considerable differentiation among the populations studied, but Dunachton and Achnacarry, two adjacent populations free from recorded introductions, showed only a little differentiation and were paired in trees based on genetic distances. In terms of variability, no statistically significant differences were observed between island and mainland populations and the overall test of isolation by distance was negative. Possible reasons for the genetic patterns observed, such as differences in human impact on the populations, are discussed.

The paper is based on field observations and studies of a captive colony.

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