Mixed Species Game Ranching in Kenya, East Africa
Ecological and production relationships were explored on an experimental game ranchin Kenya. The goals of Wildlife Ranching and Research Ltd. (WRR) are to demonstrate the environmetnal and economic wisdom of land-use systems based on commercial consumptive use of native ungulates.
A harvest technology emphasizing night-lighting of free rnaching wildilfe and on-Ranch processing of carcases proved effective. Following government inspection, carcasses were sold to a strong domestic market. Dressing percentage, carctass shrink, body composition and external measurements were quantified to estimate potential revenue and determine the effects of a cropping p;rogram on morphometrics. Favorable growth in unulate populations (12%/yr), despite an annual harvest of 40%, was attributed to a a game proffe fencing preventing emigration, reduced cattle numbers, predator control and a skewed sex ration favoring females.
Resource availability and utilitzation studies identied occupationsl patterns of native ungulates. Topograhic relief and seasonal rainfall emerged as primary determinants of resource use large through their affects on forage quality and quantity, although ungulate mobility and thermoregulation may have been important. Distinctive resource use patterns of Thomson's gazelle, Grant's gazelle, Coke's hartebeest and wildebeest ensured a level of ecological separationa nd enourage blanced utilization of forages.
Prescribed burns improved rangeland quality in valleys for grazers by removing moribund vegeation and discouraging tree growth. High unulate densities were recorded on all topographic levels of recently burned areas, presumably in response to a unifgorm sward of rapidly growing grasses.
Although comprising am small proportion of WRR, rangleand proximal to livestock enclosures (bomas) signifiantly affected distribution of native ungulates. Enriched by excreta, these biophsycially distinct areas were characterized by increased grass productivity, utilization and quality. Relocation of bomas could be used by management to attrack herbivores to under-utilized rangelands.
Body condition of grazelles, measured by perinephric fat, flucatuated seasonally in response to forage quality. Dissimilar occupational patterns of Thomson's and Grant's grazeele accounted for their non-syndhronic changes in body fat. Knowledge of weight gaina nd attribution would allow harvestors to concentrate on species with most ravorable carcass characteristics.
Comparisons of morphometrics measurements indicated that territorieal males gazelles wer older, heavier and possessed longer horns than bachelor conspecifics. Selective harvest of males on WRR has reeuced compeition among males for breeding females. To minimize inbreeding, a maximal sex ratio limit should be recognized and males from surrounding rangelands hould be periodically introduced into the resident population.
As a management strategy, fenced game ranching appears practical and economic under current conditions. However, the high capital investment required by this production system may preclude its development in other semi-arid regions. Another system of cropping wildlife is proposed as a practical and cost-effective alternative.