Ecology of small rodents in Africa

Abstract

This account considers progress in research on small rodent ecology since about 1970. While some ecological survey has been undertaken throughout much of the continent, the main research thrust has involved the detailed examination of population processes in a range of habitats from deserts to tropical rain forests. The deserts and semi‐arid regions support a range of species with some better adapted to these harsh conditions than others. The adaptations manifest themselves in different life history strategies e.g., opportunistic with high turnover species, or low turnover‐low reproduction species, in their physiology e.g., adaption to water retention, and in their behaviour e.g., avoiding heat of day. Long term studies show large numerical fluctuations with a quick response by some species to favourable conditions caused by relatively high precipitation. In the savanna and grasslands, studies have centred on population dynamics, the relationship between food and breeding, reproductive and life history strategies and the determination of niche. These have been approached through the study of groups of species in particular localities as well as by the examination of individual species. In these habitats populations are more stable and less erratic than in semi‐arid regions. Perturbations, particularly fire, can have various effects on the numbers and species composition of the disturbed area. In the tropical rain forest population fluctuations are modest and may take up to 2–3 years to pass from a peak to a trough and back again. Breeding typically extends over much of the year with, apparently, the greatest number of rodents occurring on the ground surface. Bush and temporary farms derived as a result of forest modification support more animals (and often more species) than forest. The niches occupied by forest rodents are poorly understood and very little is known of the ecology within the canopy. In most localities a small number of species are abundant and the remainder much less frequent.

A quantitative study of diet in three species of rodents in natural and irrigated savanna fields

“…In addition, much of the research involving seasonal changes of diets of small mammals in Africa has been on the influence and regulatory role of diet in reproduction (Sheppe 1972, Neal 1977, Ghobrial and Hodieb 1982, Neal 1982, Delany 1986, Delany and Monro 1986, Leirs et al 1989.…”

Small mammal species diversity in brazilian tropical primary and secondary forests of different sizes

“…Other studies have provided data on small mammal ecology of~~veral tropical ecosystems, from savanna type vegetation to evergreeu forests (FLEMING, 1971;1975a;ALHO, 1981;FONSECA & REDFORD, 1984;ALHO et aI., 1986;EMMONS et al, 1983;AUGUST 1983AUGUST , 1984DELANY, 1986;NITIKMA & MARES, 1987;ISABIRYE-BASUTA & KASENENE, 1987;LACHER & ALHO, in press;LACHER et al, in press). These areas, however, were mostly characterized by comparatively lower small mammal diversity.…”

Patterns of Rodent Species Diversity and Abundance in a Kenyan Relict Tropical Rainforest

“…According to Jefferey (1977), Delany (1986), Isabyrie-Basuta and Kasenene (1987) and Sthruhsaker (1997), rodent abundance, as well as species richness (sensu number of species in the community -Krebs (1999)) and diversity indices (Shannon-Wiener and Simpson indices), increase with logging. Isabirye-Basuta and Kasenene (1987) in the Kibale Forest found a positive correlation between rodent species richness and diversity with ground vegetation cover (0-1.2 m).…”

“…Modification of natural habitat types can have quite marked effects on the rodent fauna (Delany 1986). According to Jefferey (1977), Delany (1986), Isabyrie-Basuta and Kasenene (1987) and Sthruhsaker (1997), rodent abundance, as well as species richness (sensu number of species in the community -Krebs (1999)) and diversity indices (Shannon-Wiener and Simpson indices), increase with logging.…”

“…Most studies on the ecology of African rodents have focused on communities in savanna, secondary bush, or formerly cultivated land, hence tropical rainforests are the most understudied of major habitat types (Delany 1986;Isabyrie-Basuta and Kasenene 1987).…”