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

Abstract

Patterns of rodent species abundance and diversity were examined over a 5 months period in two areas of a Kenyan relict tropical rainforest. The two areas are subjected to different administrations which lead to various levels of anthropogenic disturbance: one can be considered relatively disturbed and one relatively undisturbed. Anthropogenic disturbance causes a reduction in woody stem density between 0 and 1.5 m and reduced understory tree canopy cover. Rodent abundance was estimated using the program CAPTURE and compared with the number of individuals actually captured. Density was estimated with three different methods, two of these utilised a boundary strip to estimate effective size of the area trapped. Density resulted in being relatively high in both areas, so population might have been at a peak. Species richness was higher in the disturbed forest, while species diversity and evenness was higher in the undisturbed forest. We suggest that in the disturbed forest the increase in number of species might be due to sporadical entrance in the forest by non-forest species, while the decrease in diversity might be due to the decrease of lower strata vegetation that occurs in the disturbed forest, hence this factor might affect species equitability. Bibliographic data supports this hypothesis as rodent species diversity and ground vegetation cover have been found to be correlated.

Terrestrial small mammal diversity and abundance in Taï National Park, Côte d'Ivoire

“…The type of traps used and the great heterogeneity of habitats of the TNP (Adou Yao & N'Guessan, 2005) could justify this great diversity of terrestrial small mammals. Indeed, habitat heterogeneity is recognised as an important environmental parameter capable to influence the diversity and distribution of terrestrial small mammals on a given site (Caro, 2002;Magige & Senzota, 2006;Mortelliti & Boitani, 2006). This is due to the colonisation capacity of different habitats by terrestrial small mammals (Caro, 2001;Fitzherbert et al, 2006).…”

Consistent pattern of habitat and species selection by post-dispersal seed predators in a Mediterranean mosaic landscape

“…This was in part explained by the abundance of shrubs, although the effect did not explain much variance in the model (Table 2). Presumably, shrubs offer shelter and food to rodents, the main predators, thereby increasing their abundance and activity (Simonetti 1989;Fedriani and Manzaneda 2005;Muñoz 2005;Mortelliti and Biotani 2006). Following this trend, the native forest (the least-degraded landscape unit) as well as shrubland showed heavy predation pressure (Fig.…”

Ectoparasites of wild rodents in forest sites invaded and uninvaded by Maesopsis eminii in Amani nature forest reserve, Tanzania

“…Trapping stations were then marked with unique codes written on ribbons for easy identification. Traps were hidden with dry leaf litter to protect them from rain and direct sunlight, and were set for three consecutive nights at each site per month, for 24 months from April 2020 through March 2022 and inspected once per day between 7:00 a.m. and 11:00 a.m. Mortelliti and Boitani (2006) and Musese et al (2023) have also found success in inspecting traps once a day, with no heat or cold deaths reported. The Capture- Mark Recapture (CMR) technique was used to capture rodents and each rodent captured was permanently marked with the unique number codes generated by the CMR software MARK as explained by Borremans et al (2015) .…”