In Africa, no other nonhuman animal fulfils the role of ecosystem engineers to the extent of the elephant. However, little is known about the relationship between elephant modified habitats and species composition of other animals. Our objective was to sample the herpetofauna within an Acacia habitat that varied in the degree of elephant impact. If elephant foraging was only modifying but not degrading or enriching the habitat, then herpetofauna species abundance and richness were predicted to be similar in elephant damaged and elephant excluded areas. We conducted this study at Endarakwai Ranch in northeastern Tanzania for 6 months in 2007 and 2008. We sampled herpetofaunal species richness and abundance within high, medium and low elephant damaged areas and in a plot that excluded elephants. Areas of heavy damage yielded higher species richness than the exclusion plot. Species diversity did not differ between the damaged areas and the exclusion plot. Frogs were more abundant in areas of high damage; in contrast, toads were found the least in high damage areas. The results support the notion that free ranging elephants influence herpetofaunal species distribution by creating habitat complexity through modifying the woodland area.

No abstract

No abstract

In ant-hemipteran mutualisms, ‘tending’ ants indiscriminately defend hemipterans from other arthropods, protecting mutualism-hosting plants from defoliating herbivores in some cases. Censuses of a treehopper, Publilia concava, observations of tending ants, and measurements of leaf area were conducted on tall goldenrod, Solidago altissima, over the course of a summer at a field site in central Vermont. Hosting ant-tended treehopper aggregations had no effect on leaf area or the ability for goldenrod to flower, suggesting that in the absence of an herbivore outbreak this mutualism is neither necessary nor inherently detrimental for goldenrod. These findings support the hypothesis that the net consequence of the ant-hemipteran mutualism for its host plant depends on the costs of hemipteran damage, and the benefits of ant defense from other arthropods.