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Mara National Reserve (mara + national_reserve)

Distribution by Scientific Domains

Life Sciences	83%

Selected Abstracts

Expansion of human settlement in Kenya's Maasai Mara: what future for pastoralism and wildlife?

JOURNAL OF BIOGEOGRAPHY, Issue 6 2004
Richard H. Lamprey
Abstract Aim, Wildlife and pastoral peoples have lived side-by-side in the Mara ecosystem of south-western Kenya for at least 2000 years. Recent changes in human population and landuse are jeopardizing this co-existence. The aim of the study is to determine the viability of pastoralism and wildlife conservation in Maasai ranches around the Maasai Mara National Reserve (MMNR). Location, A study area of 2250 km2 was selected in the northern part of the Serengeti-Mara ecosystem, encompassing group ranches adjoining the MMNR. Emphasis is placed on Koyake Group Ranch, a rangeland area owned by Maasai pastoralists, and one of Kenya's major wildlife tourism areas. Methods, Maasai settlement patterns, vegetation, livestock numbers and wildlife numbers were analysed over a 50-year period. Settlement distributions and vegetation changes were determined from aerial photography and aerial surveys of 1950, 1961, 1967, 1974, 1983 and 1999. Livestock and wildlife numbers were determined from re-analysis of systematic reconnaissance flights conducted by the Kenya Government from 1977 to 2000, and from ground counts in 2002. Corroborating data on livestock numbers were obtained from aerial photography of Maasai settlements in 2001. Trends in livestock were related to rainfall, and to vegetation production as indicated by the seasonal Normalized Difference Vegetation Index. With these data sets, per capita livestock holdings were determined for the period 1980,2000, a period of fluctuating rainfall and primary production. Results, For the first half of the twentieth century, the Mara was infested with tsetse-flies, and the Maasai were confined to the Lemek Valley area to the north of the MMNR. During the early 1960s, active tsetse-control measures by both government and the Maasai led to the destruction of woodlands across the Mara and the retreat of tsetse flies. The Maasai were then able to expand their settlement area south towards MMNR. Meanwhile, wildebeest (Connochaetes taurinus) from the increasing Serengeti population began to spill into the Mara rangelands each dry season, leading to direct competition between livestock and wildlife. Group ranches were established in the area in 1970 to formalize land tenure for the Maasai. By the late 1980s, with rapid population growth, new settlement areas had been established at Talek and other parts adjacent to the MMNR. Over the period 1983,99, the number of Maasai bomas in Koyake has increased at 6.4% per annum (pa), and the human population at 4.4% pa. Over the same period, cattle numbers on Koyake varied from 20,000 to 45,000 (average 25,000), in relation to total rainfall received over the previous 2 years. The rangelands of the Mara cannot support a greater cattle population under current pastoral practices. Conclusions, With the rapid increase in human settlement in the Mara, and with imminent land privatization, it is probable that wildlife populations on Koyake will decline significantly in the next 3,5 years. Per capita livestock holdings on the ranch have now fallen to three livestock units/reference adult, well below minimum pastoral subsistence requirements. During the 1980s and 90s the Maasai diversified their livelihoods to generate revenues from tourism, small-scale agriculture and land-leases for mechanized cultivation. However, there is a massive imbalance in tourism incomes in favour of a small elite. In 1999 the membership of Koyake voted to subdivide the ranch into individual holdings. In 2003 the subdivision survey allocated plots of 60 ha average size to 1020 ranch members. This land privatization may result in increased cultivation and fencing, the exclusion of wildlife, and the decline of tourism as a revenue generator. This unique pastoral/wildlife system will shortly be lost unless land holdings can be managed to maintain the free movement of livestock and wildlife. [source]

Status of the Mara Woodlands in Kenya

AFRICAN JOURNAL OF ECOLOGY, Issue 3 2004
Matthew J. Walpole
Abstract The woodlands of the Masai Mara National Reserve in Kenya have suffered dramatic declines over four decades as a result of elephant and fire pressure. This study examined the current status of woody resources in the Reserve and browse pressure thereon, using both classification (TWINSPAN) and ordination (DCA) techniques. From 333 widespread regular plots used to survey the vegetation, a total of 62 woody species were identified. Thirteen woody habitats were identified on the basis of species composition, varying from species-rich closed thickets and forest to less diverse open grasslands. A NW/SE stratification of the more open habitats was observed, possibly as a result of differences in soils, rainfall and drainage. Both plant density and diversity were lower than in communal and privately managed areas outside the Reserve. Moreover, browser pressure was substantially higher than that observed previously in the ecosystem, and suggests increased competition for scarcer woody resources within the Reserve. This has implications for the management of the ecosystem as a whole. As woodland and thickets continue to decline, long-term monitoring should expand to encompass the wider habitat diversity of the open grasslands and unprotected areas where much of the regeneration potential resides. Résumé Les forêts de la Réserve Nationale de Masai Mara, au Kenya, ont subi des réductions dramatiques depuis quatre décennies, suite à la pression des éléphants et des feux. Cette étude a examiné le statut actuel des ressources en bois dans la Réserve et la pression du pâturage qui s'y ajoute, en utilisant les techniques de classification (TWINSPAN) et d'ordination (DCA). Dans 333 plots régulièrement dispersés, utilisés pour étudier la végétation, on a identifié 62 espèces ligneuses. On a identifié aussi 13 habitats forestiers sur la base de la composition des espèces, depuis les buissons et les forêts fermés riches en espèces jusqu'aux prairies ouvertes moins diverses. On a observé une stratification NO/SE dans les habitats plus ouverts, résultat peut-être de différences de sols, de chutes de pluies et de drainage. La densité et la diversité des plantes étaient plus faibles que dans les aires gérées en commun ou de façon privée en dehors de la Réserve. Qui plus est, la pression des animaux qui mangent les buissons y était substantiellement plus élevée que celle qu'on observait jadis dans cet écosystème, et elle laisse penser qu'il y a une compétition plus forte pour des ressources ligneuses plus rares dans la Réserve. Ceci a des implications pour la gestion de l'écosystème dans son ensemble. Si les forêts et les buissons continuent à se rèduire, le monitoring à long terme devrait s'élargir pour englober la plus grande diversité d,habitat des prairies ouvertes et des aires non protégées où réside l'essentiel du potentiel de régénération. [source]

Demography of lions in relation to prey and habitat in the Maasai Mara National Reserve, Kenya

AFRICAN JOURNAL OF ECOLOGY, Issue 2 2002
J. O. Ogutu
Abstract We studied lion demography in the Maasai Mara National Reserve between September 1990 and April 1992, with a special emphasis on the spatial and seasonal variation in demographic characteristics. Lion density (0.2,0.4 lions km,2) and pride size (range 8,48) were high because of a high resident prey biomass (10 335 kg km,2) augmented by migrant prey to 26 092 kg km,2 in the dry season. Overall, their sex ratio was almost at parity and varied neither spatially nor seasonally. Sex ratio was even among subadults but skewed toward males and females among cubs and adults, respectively. This implies an increasing differential mortality of males with age through subadulthood. The age ratio varied seasonally because of a birth peak in March,June and an influx of subadults into the reserve during July,August, coincident with increases in migrant prey. The birth peak was apparently preceded by another peak in mating activity falling between November and May. Further research should investigate the precise causes of the biased cub sex ratio, low lion density in the Mara Triangle and the higher ratio of subadults in Musiara than in the Mara Triangle or Sekenani. Résumé Nous avons étudié la démographie des lions dans la Réserve Nationale de Masai Mara entre septembre 1990 et avril 1992, en insistant particulièrement sur les variations spatiales et saisonnières des caractéristiques démographiques. La densité des lions (0.2,;0.4 lions/km2) et la taille des troupes (de 8 à 48) étaient élevées en raison de la forte biomasse des proies résidentes (10 335 kg/km2), portée à 26 092 kg/km2 en saison sèche par les proies migratrices. En général, le sex-ratio était à peu près égal et ne variait ni selon les saisons, ni selon les endroits. Les sex-ratio était égal parmi les sub-adultes, mais il déviait en faveur des mâles et des femelles chez les petits et les adultes, respectivement. Ceci implique une mortalité de plus en plus différentielle des mâles à l'âge sub-adulte. L'âge-ratio variait avec les saisons en raison d'un pic de natalité de mars à juin et d'une arrivée de sub-adultes dans la réserve en juillet-août, coïncidant avec l'augmentation des proies migratrices. Le pic des naissances était apparemment précédé par un autre pic des activités d'accouplement, entre novembre et mai. De nouvelles recherches devraient étudier les raisons précises du sex-ratio biaisé chez les lionceaux, de la faible densité des lions dans le Mara Triangle et du taux de sub-adultes plus élevéà Musiara que dans le Mara Triangle ou à Sekenani. [source]

Factors affecting black rhino monitoring in Masai Mara National Reserve, Kenya

AFRICAN JOURNAL OF ECOLOGY, Issue 1 2002
Matthew J. Walpole
Abstract The black rhino in Africa is slowly recovering from poaching. This has been achieved in part by maintaining ongoing monitoring as part of intensive protection and biological management. However, the efficacy of population monitoring methods has not been assessed. Rhino surveillance records and rainfall data were used to determine which ecological and operational factors affected monthly rhino sightings by vehicle patrols in Masai Mara, Kenya. Comparisons of sightings capture rates using different ground-based and aerial methods were also conducted. Stepwise multiple regression revealed a model (adjusted R2 = 0.66) predicting monthly rhino sightings with four significant factors; number of patrols, rhino population size, rainfall over the previous 2 months and a dummy variable for the month of August. The latter two variables represent the negative effects of long grass growth and the annual wildebeest migration on rhino sightings, and result in seasonal deficiencies in monitoring. During vehicle patrols, 51% of sightings were made whilst moving, and 49% were made whilst stationary and scanning with binoculars, although sightings capture rate was an order of magnitude higher when stationary. Equally, sightings capture rate from hot air balloons was twice that during vehicle-based patrols, although with less accuracy of identification. The introduction of foot patrols would increase patrol cost-effectiveness and fill seasonal troughs, thereby providing better all-round surveillance. Résumé Le rhino noir d'Afrique récupère peu à peu des méfaits du braconnage. Ceci est le résultat, en partie, de la poursuite des contrôles constants visant une protection intensive et une gestion biologique. Pourtant, on n'a pas évalué l'efficacité des méthodes de surveillance de la population. On a utilisé les rapports de surveillance des rhinos et les données sur les chutes de pluie pour déterminer quels facteurs écologiques et opérationnels influençaient le nombre de fois que les véhicules des patrouilles apercevaient des rhinos chaque mois dans le Masai Mara, au Kenya. On a aussi fait des comparaisons des taux de captures visuelles selon différentes méthodes, au sol et aériennes. La méthode de régression multiple a fait apparaître un modèle (R2 ajusté= 0,66) pour prédire les observations mensuelles de rhinos avec quatre facteurs significatifs; le nombre de patrouilles, la taille de la population de rhinos, les chutes de pluie au cours des deux mois précédents et une variable factice pour le mois d'août. Les deux dernières variables représentent les effets négatifs de la croissance de longues herbes et de la migration annuelle des gnous sur l'observation des rhinos et leurs résultats sur les faiblesses saisonnières des contrôles. Pendant les patrouilles motorisées, 51% des observations se sont faites en mouvement et 41% à l'arrêt, en observant aux jumelles, mais le taux de captures visuelles était un ordre de grandeur supérieur à l'arrêt. De même, le taux de captures visuelles obtenu à partir d'une mongolfière était le double de celui obtenu lors des patrouilles motorisées, mais la précision des identifications était plus faible. L'introduction de patrouilles à pied augmenterait la rentabilité des patrouilles et permettrait de combler les lacunes saisonnières et d'assurer une meilleure continuité de la surveillance. [source]

Effects of food availability on serum insulin and lipid concentrations in free-ranging baboons

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2002
Joseph W. Kemnitz
Abstract The relationship between food availability and metabolic physiology was studied in groups of free-ranging baboons (Papio spp.) living in the Amboseli National Park and the Masai Mara National Reserve of Kenya. Three groups subsisted entirely on natural forage, while two other groups lived near tourist facilities and often consumed food wastes from these lodges. The refuse provided a very accessible food source with relatively high caloric density. Consumption of the refuse was associated with reduced locomotion. Sexually mature individuals from all five groups were sedated surreptitiously in the early morning and blood samples were collected. Compared to animals foraging exclusively in the wild, animals that supplemented their diet with the refuse items had two- to threefold elevations in serum insulin concentrations, as well as increased total cholesterol (C), HDL-C, and VLDL+LDL-C levels. No sex differences in physiological measures were observed except in body mass. Elevated serum insulin, and cholesterol and lipoprotein concentrations influence the development of cardiovascular disease and have been shown to be subject to dietary manipulation and exercise under controlled conditions. The present results suggest potentially deleterious effects of a highly accessible, calorically dense food source, and associated reduction of physical activity for baboons living in an otherwise natural environment. Am. J. Primatol. 57:13,19, 2002. © 2002 Wiley-Liss, Inc. [source]