The aims of the study were to: 1) determine the wildlife population trends in the Mara Enoonkishu Conservancy from the eyes and minds of the public, 2) assess the recent trends in wildlife populations based on actual scientific counts, and 3) compare the two patterns and establish whether they are similar or not. The solicitation of public views was based on household surveys using a standard questionnaire which was administered to 115 randomly selected respondents. The dominant wildlife species according to 39% of the respondents was the elephant followed by the zebra with 35%. 40% of the respondents indicated that the rhino population had declined followed by wild dogs (7%) and cheetah (6%). The actual counts showed that the herbivores with increasing populations included the rhino (r 2 = 0.9992), impala (r 2 = 0.9824), Thomson's gazelle (r 2 = 0.6965), Grant's gazelle (r 2 = 0.7052), elephant (r 2 = 0.5798), and topi (r 2 = 0.4426) while the increasing predators included the lion (r 2 = 1.000), cheetah (r 2 = 0.9093) and hyena (r 2 = 0.8462). The actual wildlife counts appeared to tally with the public views only for the elephant and zebra. The actual counts contradicted the public views in terms of the rhino, lion and gazelles whose numbers were on the increase but the people did not appear to notice. Based on this, it was concluded that the public view on the wildlife population trend was not similar to the actual wildlife population status on the ground based on scientific monitoring.

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Gullies in semi-arid region are important in landscape modification, degradation and increased overland flow affecting geomorphic thresholds of an area. Gullies generate about 95% of global sediment load, important in landscape modification, degradation and increased overland flow in semi-arid regions, but little is known on geomorphic factors that increase ecological fragility increasing gully initiation. To address the problem, landscape regions of accelerated geomorphic processes must be determined. The study aimed to establish topographical thresholds and geomorphic factors which increase landscape fragility in gully head positions in different geographical regions. Gully heads were analyzed by detailed field surveys from 10 m up and down-slope position. Drainage area contributing to gully was demarcated from the point overland flow was assumed to reach the gully head based on water visible flow-lines while gully head slopes were determined by use of clinometers. Gully threshold concept was applied to identify the critical slope (S) and drainage area (A), using appropriate S − A relation (S = aA b ) and verified using ANOVA. The empirical S − A threshold relation S = 0.383A −0.397 , R 2 = 0.0321 (upper-segment), S = 0.174A −0.032 , R 2 = 0.498 (mid-segment), S = 0.23A −0.020 , R 2 = 0.088 (lower segment), represented approximate critical slope-drainage area for gully initiation and regions of dominant geomorphic processes, above which gully initiation was likely to occur. Negative b values represent an areas more dominated by overland flow over sub-surface processes. Coefficient of correlation multiple R = 0.7055 (70.55%) Mid-segment indicated strong relation slope-drainage area for gully initiation. ANOVA analysis p = 0.01, 0.004 and 0.4498 for upper, mid and lower segment respectively revealed stronger relation between independent and dependent variables. p > 0.05 indicated regions influenced by more factors than slope and drainage area. Thus, slope-drainage threshold relation line can be applied in the How to cite this paper: Ireri, C., Krhoda, G.O. and Mukhovi, M.S. (2021) Geomorphic Threshold for Gully Initiation in Different Geographical Environments of Wanjoga River Catchment, Tana Basin, Kenya.