Mebrate, Assefa (PhD)Tsegaye, Bekele2018-06-252023-11-082018-06-252023-11-081999-09http://etd.aau.edu.et/handle/123456789/3032An ecological study or rodents was carried out in the different habitat patches of Entoto Natural Park, northern outskirts of Addis Ababa, from February 1998 to January 1999. Twelve species were found comprising the rodent fauna of the park. A total of 572 individual rodents belonging to nine species werc captured li'OI11 two 0.36 ha grids using a mark-release-recapture technique. The species werc Arl'icall/liis abyssinicus (57%), Myomys albipes (15.73%), Lophuromys .flavopunc/alus (7.17%), Mus mahomel (5.8%), Olomys 1)'lJUS (5.24%), Muriculus imberbis (4.9%), De.\•IIIOIIIYS Ii({rrillglolli (2.27%), Delldmlllus IOl'ali (1.75%) and D. mystaca/is (0.17%) together with the subterranean mole rat (TachyOl)'clcs .\jJlendel1.\). Presence of two other rodent species (RollllS mIlliS and l-lys/rix crista/a) was confirmed from survey trapping and indices like droppings and spines. Both temporal and spatial differences in species number were apparent. Species number on the two grids fluctuated between five in the wet season and eight during the dry season and 'small rains'. Disappearance or the small-sized and rarc specics of rodents accounts for the lower number of species in the wet season and subsequent months. The number of species of rodents sampled using survey trapping was half of that obtained on the grids. Monthly numbers of small rodents that are known to be alive on both grids varied between 93 at the end or the wet season (October) and 172 during the 'small rains' (April). Population size peaks on both grids appeared during the 'small rains' and in the middle part of the first half of the dry scason. Reproductive peaks occurred mainly during and immediately after both the 'small and big rains'. A. ohyssinicl/s, M. o/hipes, and M. illlbcrbis had their reproductive peaks after the 'big' and 'small rains'. Loplilll'OIIIYS jlavoplIJ1c/a/lis and o./)11I1S on the other hand had their reproductive peaks during the 'big rains'. Hence, reproductive peaks were associated with precipitation be it 'big' or •small'. Adults dominated monthly population structures. Juveniles and subadults were better represented in captures made after the main breeding season of each species. More juvenile L. f1avojJIIIICi((l/Is and 0. i.l'jJlIS were seen just after the end of the wet season while those of A. AbyssilliclI.1 and M. iI/hipes were seen two months later. Thc wet season survival rate was thc lowest for most of the species. Very few members of some populations survived for II months and the more common species had about 37% survival probability for three months. Distribution of small rodents in habitats and microhabitats of the mountain was patchy and related to occupation of suitable places. Shrubby grasslands, bushes on brook bank and sloppy hillsides were places of high species number. Swampy grasslands, eucalyptus plantation and grazed woodlands had none or the least species number of small rodents. Man-made microhabitats like stone fcnce line and hcaped stones together with bushy fragments and herbaccous grassland hosted the greatest number of spccies and individuals on the grids. Trap stations with very short grass and located on sloppy hillsides, rocky out crops and adjacent eucalyptus plantations had the least species number and capture success.enBiologyThesis