Abstract:
We studied the foraging ecology of Xerus rutilus (the African unstriped
ground squirrel), Grammomys dolichurus (African tree rat), Acomys sp. (the
spiny mouse), and (bush rat) on and around the base of a kopje,
Mlima Chui (Leopard Mountain), Rhino Sanctuary, Tsavo West National Park,
Kenya. We employed giving-up densities in experimental food
patches. We analyzed for the effects of habitat selection (on-kopje
or off- kopje/ surrounding savanna), microhabitat (bush and open), food
preference (raw peanuts, cooked sunflower seeds, white maize, and yellow
corn), and plant toxins (oxalates and tannins). The nocturnal rodents exhibited
higher GUDs for bush microhabitat… Preference for bush microhabitat
probably results from higher perceived predation risk in open areas, the
higher risk due to owls. For X. rutilus, no significant difference
between bush and open or kopje habitat and savanna habitat was found.
Either X. rutilus perceives both microhabitats and habitats as equivalent
in predation risk, or the high foraging efficiency of X. rutilus in these
resource patches may have prevented accurate results. For diet choice
cooked sunflower seeds and raw peanuts were preferred to dried white and
yellow corns. We believe that this is the result of sunflowers and
peanuts contain higher lipid content and lower handling time than the corns.
G. dolichurus showed a tolerance for seeds soaked in tannic acid, whereas
X. rutilus showed no significant difference between water-treated seeds
and tannic-treated seeds. However, oxalates raised the GUDs for both
species, suggesting oxalates are a toxin for both species.