Bio

Dr. Kinyua BioData

He is a senior lecturer in Rangeland Resource Economics in the Department of Land Resource Management and Agricultural Technology. He holds a PhD in Resource Economics from University of British Columbia, Canada, a Masters in Range Economics from University of Wyoming, U.S.A., B.Sc. degree in Range Management from the University of Nairobi, Kenya. He also holds a Diploma in Agriculture from Egerton College. He has published widely in his area of specialty.

PDF Upload: 

Publications


2012

2006

THEURI, DRNJOKAJESSE, D. DRKINYUAPATRICKI.  2006.  J. T. Njoka and P.I.D. Kinyua, 2006: The Logistic Model-generated carrying capacities, maximum sustained off-take rates and optimal stocking rates for Kenya. Research and Extension Results, Margarini Settlement Scheme Agronomy Programme - Short Rains 1978. Margarine Project Report.. : Heinrich Boll Foundation. Abstract
This paper deals with the derivation of logistic model for cattle, sheep and goats in a commercial ranching system in Machakos District, Kenya, a savannah ecosystem with average annual rainfall of 589.3  159.3mm and an area of 10,117ha. It involves modeling livestock population dynamics as discrete-time logistic equations wiyh fixed carrying capacities. The fixed carrying capacities are generated endogenously using time-series ranch data, covering a period of 15 years, from 1987 to 2001, in a commercial ranching enterprise. The model incorporates interaction parameters, generated endogenously. The estimation of the logistic models involves estimation of econometric models for each livestock species, followed by the recovery of the logistic model mathematically. Optimisation procedures are employed to determine the optimal stocking levels and the optimal off-take levels. The model-generated carrying capacities are 2,985, 791 and 201 animal units (AU) for cattle, sheep and goats, respectively. Optimal stocking levels are 1,369, 154 and 69 Aus for cattle, sheep and goats, respectively, while the optimal off-take levels are 857, 88 and 63 for cattle, sheep and goats, respectively. This shows that the logistic model-based system analysis is applicable to the management of mixed-species commercial ranching enterprises.

2001

THEURI, DRNJOKAJESSE, D. DRKINYUAPATRICKI.  2001.  Kinyua P.I.D and Njoka J. T. 2001: Animal Exchange Ratios: an alternative point of view. African Journal of Ecology Vol.: 39, 59-64. Blackwell. Research and Extension Results, Margarini Settlement Scheme Agronomy Programme - Short Rains 1978. Margarine Project Report.. : Heinrich Boll Foundation. Abstract

An alternative interpretation is provided of the con- cepts of carrying capacity and exchange ratios, particu- larly suitable for game animal species, based on management models for a given area of rangeland or pasture. It involves modelling animal population dynamics as discrete-time logistic equations. Carrying capacity is then generated endogenously using rainfall as a proxy. The model interaction parameters, also gen- erated endogenously, represent the animal exchange ratios. Because these two parameters are generated endogenously, this approach takes into account all the animals' habitat requirements (food, cover, water and space) simultaneously, unlike other approaches that tend to consider food requirements only.Thismakes the approach amenable to multi-species situations. It also captures the ecological de¢nition of population growth models where the realized rather than the theoretical carrying capacity is determined endogenously.

2000

Kinyua, PID, Kooten GC, Bulte EH.  2000.  African wildlife policy: protecting wildlife herbivores on private game ranches. Abstract

In large parts of Africa, wildlife herbivores spill over onto private lands, competing with domestic livestock for forage resources. To encourage private landowners to take into account the externality benefits of wildlife, game cropping is increasingly considered as an important component of conservation policies. In this paper, we employ a bioeconomic model of a private game ranch to examine five potential government policies concerning wildlife conservation, ranging from (strict) preservation to uncontrolled exploitation. 'Intermediate' policies appear to contribute most to wildlife conservation, with costs to landowners of such policies being modest. The model outcomes support recent wildlife policy shifts in Kenya.

1998

D., DRKINYUAPATRICKI.  1998.  Kinyua P.I.D., G.C. Van Kooten and E.H. Bulte, 1998. African Wildlife Policy: Protecting Wildlife Herbivores on Private Game Ranches, European Review of Agricultural Economics 27 (2):227-244. Research and Extension Results, Margarini Settlement Scheme Agronomy Programme - Short Rains 1978. Margarine Project Report.. : Heinrich Boll Foundation.
D., DRKINYUAPATRICKI.  1998.  Kinyua P.I.D., 1998. Game Ranching in Machakos District: An Application of Mathematical Programming to the Study of Wildlife Policy. Ph.D. dissertation, University of British Columbia. Research and Extension Results, Margarini Settlement Scheme Agronomy Programme - Short Rains 1978. Margarine Project Report.. : Heinrich Boll Foundation.

1997

Kooten, C, Bulte E, Kinyua P.  1997.  Game cropping and wildlife conservation in Kenya: A dynamic simulation model with adaptive control. Abstract

We use a dynamic stochastic simulation model of forage, herbivores, predators and domestic livestock in the Machakos District of Kenya to address policies related to the multiple use of rangeland resources. The particular policy examined is that of switching from a traditional system, where commercial ranchers do not harvest wildlife herbivores, to one where ranchers are provided economic incentives to adopt multiple-use management of the range resource. Simulations using an adaptive controller indicate that the effects of the policy change on wildlife populations depend on the conditions of the ecosystem and, importantly, on ranchers' attitudes to risk. When forage is abundant, and game and livestock do not compete for food, the policy change leads to reduced wildlife populations, especially of the relatively more valuable species. This indicates that game cropping may not be more compatible with nature conservation than standard pastoralist practices. However, in periods of drought when competition for forage occurs, the policy change may dampen the decline in game populations, as risk-averse ranchers may decide to sell more cattle and harvest wildlife instead. Game cropping reduces wildlife populations, but increases their stability.

D., DRKINYUAPATRICKI.  1997.  van Kooten, G.C., E.H. Bulte and Patrick Kinyua, 1997. Game Cropping and Wildlife Conservation in Kenya: A Dynamic Simulation Model with Adaptive Control, Agricultural Systems 54 (August): 439-462. Research and Extension Results, Margarini Settlement Scheme Agronomy Programme - Short Rains 1978. Margarine Project Report.. : Heinrich Boll Foundation.

1991

UoN Websites Search