Wildlife Dynamics : an Analysis of Change in the Masai Mara
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Wildlife Dynamics AnAnalysi s of Change inth eMasa iMar a Ecosystem ofKeny a Wilber Khasilwa Ottichilo 0000 0807 2106 WILDLIFEDYNAMIC S AnAnalysi so f Changei nth eMasa iMar aEcosyste m Promotores: Dr. H.H.T. Prins Hoogleraar in het Natuurbeheer ind eTrope n en deEcologi e van Vertebraten Dr. A.K. Skidmore Hoogleraar Vegetation and Agricultural Land Survey Co-promotor: Dr. J. de Leeuw Universitair hoofd docent Environmental Systems Analysis and Monitoring, ITC, Enschede II ^*W>\ ^ WILDLIFE DYNAMICS AnAnalysi s of Change inth eMasa iMar a Ecosystem ofKeny a Wilber Khasilwa Ottichilo Thesis to fulfill the requirements for the degree of doctor on the authority of therecto r magnificus of Wageningen University, dr. C. M. Karssen to be publicly defended on Wednesday 22Marc h 2000 at three o'clock in the Auditorium of ITC at Enschede. Ill lF>\r\ oryzbbS IV WBLIOTHEEK LANDBOUWUNIVERSITTrr WAGENTMGI-N To my mother and father, who supported and encouraged me to pursue education Doctoral thesis (2000) ISBN 90-5808-197- 4 Wageningen University and Research Centre, The Nethelands. © 2000 Ottichilo, W.K. ITC Publication Series No. 76 This study was carried out at the International Institute for Aerospace Survey and Earth Sciences (ITC), P.O. Box 6 7500A A Enschede, The Netherlands. Cover design: Febodruk BV, Postbus 40100, 7504 RC, Enschede. Cover photos: Jan de Leeuw and H.N. Koster. VI jjMOlZO/,£?*)<- Prepositions (Stellingen) Wilber K. Ottichilo Wildlife Dynamics:A nAnalysi so fChang ei nth eMasa i Mara Ecosystemo f Kenya (PhD dissertation) 1. Proper planning andmanagemen t of wildlife requires reliable andconsisten t data and infor mation onthei r abundance anddistribution . 2. Toge ta ninsigh t into population size trends oflarg e wildlife herbivores, collectionan d analysis oflong-ter m population estimate orabundanc e data isnecessary . Therefore, iti s necessary toestablis h long-term wildlife monitoring programmes inwildlif e conservation areas. 3. Development of systems andanalytica l approaches inecologica l work hasbee n slow.Th e current interest inthes e approaches andparticularl y theus eo f geo-statistics and modelling techniques inecologica l research should beencourage d and supported. 4. Development of new technologies like remote sensing, GIS, GPS, videography etcwil l certainly enhance collection of useful anddetaile d data on wildlife andthei r environments in thenea r future butthe y will notreplac e expert knowledge of ecologists. 5. Wildlife ecologists arenotoriousl y known tostud y wildlife species toextinctio n without getting involved orparticipatin g inth especie s recovery programmes. They always claim that more data andinformatio n isrequire d even incase s where there arewallowin gi n abundant data. Future ecologists must beproactiv e andmus t identify their research priorities incollaboratio n with wildlife managers butmus t notlos s their search for novel creativity. 6. There appear tob ea genera l consensus among most wildlife ecologists thatth e unprecedented worldwide decline of wildlife species (plants andanimals ) ismainl y due to the increasing loss ofthei r habitats toothe r human activities, pollution andthei r over- exploitation byman . Torevers e this declining trend, wildlife and environmental conservation strategy for the21 st century must focus onhabita t restoration and wildlife recovery programmes. This calls for increased scientific research inrestoratio n ecologyan d ecological engineering. 7. Toachiev e sustainable wildlife andenvironmenta l conservation, itmus t berealize d that conservation anddevelopmen t areinterdependen t andtherefor e theintegratio n ofth e two is necessary for sustainable development. Although theconcept s of sustainable development are newan dno teas y to implement, mankind must strive toachiev e sustainable development if we have tomaintai n live supporting systems andprocesse s onou rplanet . 8. Science being a creative activity it is impossible to predict a head of time where a particular line of inquiry will lead. This makes science a very wasteful activity, in that most scientists spend most of their time travelling down paths that leal nowhere (Jonfairall, editor,GIS User(Vol. 13,February-March 2000). 9. Increasing demand of modern age for accountability and productivity is stifling development of future scientists. More prospective scientists are increasingly becoming technologists for fear of taking the wrong road. This trend is a threat to science and must be reversed if science has to remain the main foundation of human development. 10. Embarking on PhD study is like embarking on ajourne y whose route is undefined but is known to berock y and full of potholes. Therefore, to succeed one must clearly map out an achievable route at the onset and be ready to weather the hard struggle. 11. Successful completion of PhD sets you free the way truth liberates you. 12. Success is like science, that if you have the conditions, you have the results. 13. It's great nuisance that knowledge can only be acquired by hard work- Somerset Maugham, English Writer(1874-1965). 14. Knowledge comes, but wisdom lingers-Lord Alfred,English poet (1809-1892). 15. An idea that is not dangerous is unworthy of being called an idea at all- Oscar Wilde, Irish Writer(1854-1990). 16. The further backward you look the further forward you see- Sir WinstonChurchill, Prime minister of Britain (1874-1965). 17. Happiness lies not in the mere possession of money; it lies in thejo y of achievement, in the thrill of creative effort- Franklin Roosevelt, President ofU.S.A. Tableo f contents Contents i Abstract iii Acknowledgements v Chapter 1 1 General introduction Chapter 2 19 Validation of observer and aircraft calibration for aerial animal surveys: A case of the Department of Resource Surveys and Remote Sensing (DRSRS), Kenya W.K. Ottichilo & W.M.Khaemba (in press, African Journal of Ecology) Chapter 3 35 Comparison of the Sample and total counts of elephant and buffalo in Masai Mara Ecosystem, Kenya W.K.Ottichilo ( African Journal ofEcology: 37/4 (1999),p. 435-438) Chapter 4 43 Population trends of large non-migratory wild herbivores and livestock in the Masai Mara Ecosystem, Kenya, between 1977 and 1997 W.K.Ottichilo, J.de Leeuw,A.K. Skidmore, H.H.T. Prins & M.Said (inpress, African Journal of Ecology) Chapter 5 71 Population trend and seasonal distribution of Burchell's zebra in the Masai Mara Ecosystem, Kenya W.K.Ottichilo (submitted, Journal ofAnimal Ecology) Chapter 6 91 Population trends of resident wildebeest (Connchaetes taurinus) and factors influencing them in Masai Mara Ecosystem, Kenya W.K.Ottichilo, J.de Leeuw & H.H.T. Prins (inpress, Biological Conservation) Chapter 7 123 The dynamics of migratory wildebeest in the Masai Mara Ecosystem, Kenya: 1977 - 1997 W.K.Ottichilo, M. Y. Said, H.N. Koster, H.H.T. Prins, J.de Leeuwand LM.A. Heikonig(s\xbmi\ted, Oecologia) Chapter 8 159 Synthesis: Wildlife population size changes and factors influencing them in Masai Mara Ecosystem Summary 167 Samenvatting 169 Resume 171 Curriculum Vitae 173 Abstract W. K. Ottichilo. Wildlife Dynamics: An Analysis of Change in the Masai Mara Ecosystem of Kenya. Doctoral thesis: ISBN 90- 5808- 197-4 . This thesis deals with the analysis of change in populations of large wild herbivore species in the Masai Mara ecosystem of Kenya. The total population size of all non-migratory wildlife was found to have declined by 58% in the past 20 years. Nine out of twelve species revealed significant decline. There was no significant decline in population sizes of elephant, impala and ostrich. The population sizes of livestock species did not also significantly change during theentir e analysis period except for the donkey, which declined by 67%. There was surprisingly no significant difference in the decline of wildlife species and groups inside and outside the Masai Mara National Reserve except for Thomson's gazelle and warthog. For migratory species, resident wildebeest declined by 81% while resident zebra population declined by 50%. The recorded decline of resident wildebeest population was attributed to agricultural encroachment in their former wet season grazing and breeding areas. Apart from habitat loss to agriculture, occurrence of droughts, poaching and possible competition between wildlife and livestock for scarce food may have further contributed to their decline through reduced reproduction and survival rates. These same factors are postulated here to have been responsible for thedeclin e of other wildlife species. The number of wildebeest migrating into the Masai Mara ecosystem from Serengeti fluctuated between years while those of the zebra increased during the analysis period. The migration of wildebeest and zebra from Serengeti to Masai Mara ecosystem was found to be related to wet season rainfall and the availability of green biomass during the dry season in the Masai Mara ecosystem. There was a strong relationship between the migrant wildebeest population size and the Normalized Difference Vegetation Index (NDVI) of NOAA-AVHRR imagery in the Masai Mara ecosystem during the migratory period (June to October). Therefore, it was concluded that NDVI could be used for monitoring and predicting the movements of migratory wildebeest populations in the Serengeti-Mara ecosystem. ill Lastly, in this thesis an alarming decline of most wildlife populations in the Masai Mara ecosystem over the past 20 years is reported. This decline is mainly attributed to habitat loss, due to agricultural encroachment. Therefore,