Vertical lines show the 95% SB-715992 pointwise confidence limits whereas SAR302503 cell line stars indicate that the mean densities differed significantly between the reserve and Koyiaki Large sized herbivores Buffalo and elephant were consistently more abundant in the reserve than in the ranches in both seasons (Fig. 4b, d; Tables S1, S2). Eland had higher densities in the

ranches than in the reserve in the wet season but lower densities in the ranches than in the reserve in the dry season (Fig. 4a). Giraffe did not show significant differences between the reserve and the ranches during the dry season, but were somewhat more abundant in the reserve. However, they were consistently more abundant in the ranches than the reserve in the wet season (Fig. 4c; Tables S1, S2). Fig. 4 Comparative changes in densities

(number/km2) of large pure grazers and mixed grazer/browsers, a eland, b buffalo, c giraffe and d elephant between the Mara Reserve (light bars) and the adjoining Koyiaki pastoral ranch (dark bars) during the dry and wet seasons based on the DRSRS aerial surveys from 1977 to 2010. Vertical lines show the 95% pointwise confidence limits whereas stars indicate that the mean densities differed significantly between the reserve and Koyiaki The ground counts conducted Natural Product Library in vitro in 1999 and 2002 confirmed that both gazelles, impala and giraffe were indeed more abundant in the ranches and that topi, hartebeest, wildebeest, zebra, eland, buffalo and elephant were more abundant in the reserve second than in the ranches in the dry season, as revealed by the aerial survey data. High variance in herd sizes rendered the apparently large differences in wildebeest densities between landscapes statistically insignificant. The ground counts also confirmed the greater abundance of livestock in the ranches than

in the reserve shown by the aerial survey data (Table 2). Table 2 Comparisons of mean herbivore densities between the Mara Reserve (808 km2) and Koyiaki pastoral ranch (649 km2) based on ground mapping censuses conducted in November 1999 and 2002 Species November 1999 November 2002 Ranches Reserve Ranches Reserve Thomson’s gazelle 15.97 16.70 28.13 21.30 Sheep + goats 31.28 2.02 61.96 9.19 Impala 9.24 4.49 12.22 6.08 Warthog 0.50 0.83 0.74 1.38 Grant’s gazelle 1.68 1.52 1.96 2.72 Topi 2.68 4.38 3.79 4.21 Wildebeest 12.75 79.21 25.58 108.35 Hartebeest 0.14 0.38 0.16 0.42 Waterbuck 0.25 0.34 0.35 0.27 Cattle 16.84 4.08 34.30 15.98 Zebra 7.90 11.95 15.80 21.01 Eland 0.20 1.00 0.15 1.37 Buffalo 0.50 1.27 0.08 1.31 Giraffe 0.59 0.24 0.65 0.25 Elephant 0.07 0.56 0.09 0.55 Densities that differ significantly (P < 0.