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The radiation of cichlid ¢shes in the African great lakes is often described as adaptive, because, at a super¢cial level, cichlid ¢shes seem adapted to the ecological niches they occupy. However, adaptiveness has rarely been studied. We investigated to what extent island populations of three species of the rockdwelling genus Neochromis, endemic to Lake Victoria, are adapted anatomically to exploit locally abundant resources. Speci¢cally, we asked whether di¡erent resource environments were re£ected in di¡erences in the feeding apparatus, both within species and between species. In populations of two specialized biters, the algae scrapers N. rufocaudalis and N. omnicaeruleus, the biting force of the lower jaw increased with increasing amount of items that require biting in the diet. N. greenwoodi is a less specialized biter; we found di¡erences between two populations in the hyoid position and in the premaxilla that enhance suction feeding. These adaptations were related to the amount of items requiring suction. Comparing across three sympatric pairs of species, in each case di¡erent diets were re£ected in di¡erences in anatomy.

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The degree of philopatry exhibited by females in an unhunted black bear (Ursus americanus) population occupying the Chapleau Crown Game Preserve in northern Ontario was examined. A truncated kernel estimator was used to identify home-range use. Pairs of adult females were categorized as having home ranges that had moderate overlap or low overlap or were adjacent and non-overlapping or non-adjacent and non-overlapping. Females had low overlap with 6.4 other females, on average, and moderate overlap with 1.5 females. The degree of philopatry was assessed using two methods, each of which was used in an attempt to examine home-range overlap and average genetic relatedness. Relatedness among bears was determined from DNA fingerprints, using an alkaline phosphatase labelled multilocus probe and chemiluminescence detection. The first method involved choosing the 3 oldest females in the region to represent potential matriarchs, and all neighbouring females were identified (n = 8, 8, and 11). DNA fingerprints from each matriarch were compared with those of her neighbours. Average band-sharing coefficients and relatedness estimates within the groups did not reveal patterns of close kinship. The second method involved band-sharing comparisons among pairs of females from each of the 4 home-range categories (n = 12, 57, 80, and 21). Again, no relationship between spatial proximity and average genetic relatedness (range 0.032-0.120) was suggested. The extensive home-range overlap exhibited by this population is not a consequence of natal philopatric tendencies.