Untitled

Mwangi, Evans Mungai; Western, David

doi:10.1023/a:1008891027230

Cited by 15 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact overlap indices were consistently high during the seasons. This lack of a clear trend in overlap in habitat use and the fact that the overlaps between grazers within the same body weight classes were consistently high suggest that no reasonable change in seasonal habitat use occurred in the Park among the grazers contrary to what [27] found out. The habitats during the time of this study were more compressed with a higher population density of large grazers than when [27] conducted their field work five years earlier.…”

Section: Discussionmentioning

confidence: 59%

Seasonal resource use and niche breadth in an assemblage of coexisting grazers in a fenced Park

Mwasi¹,

Wieren²,

Heitkönig³

et al. 2013

OJE

View full text Add to dashboard Cite

Many small Parks in Kenya are being fenced to control human-wildlife conflict. Some of these Parks have a diversity of large herbivores which might increase in density in the wake of fencing and subsequent compression of their home ranges due to closure of their migratory routes. It is important to understand the consequences of such an increase on the structuring of insularised herbivore assemblages in such Parks. We studied seasonal resource segregation and niche breadth variation as mechanisms of coexistence in a high density grazer assemblage in Lake Nakuru National Park which is small and completely fenced. Diet composition and habitat use were considered as variables of resource use. We predicted that overlap in resource use and niche breadth would be the smallest among grazers with similar body weights in the dry season which is the most resource limiting for grazers in East Africa. Our results were contrary to the predictions because of lack of seasonal differentiation in the overlap of diet composition and habitat use, and in niche breadth. Overlaps in resource use were consistently high during both the wet and dry seasons, and niche breadth contraction during the dry season was not possible probably because of lack of species-specific niches during the dry season. Our results suggest that there might be competitive interactions in this grazer assemblage which is an important parameter to consider in the management of the Park.

show abstract

Section: Discussionmentioning

confidence: 59%

Seasonal resource use and niche breadth in an assemblage of coexisting grazers in a fenced Park

Mwasi¹,

Wieren²,

Heitkönig³

et al. 2013

OJE

View full text Add to dashboard Cite

show abstract

“…There exists a notable correlation between the intensity of livestock grazing and the presence of both native and non-native species of O. stricta (Pemberton and Liu, 2007). The selective consumption of palatable plant species by predominantly grazing herbivores in open grasslands has contributed to the increased spread of O. stricta which is less preferred (Hobbs and Huenneke, 1992;Mwangi and Western, 1998) As an arid-adapted species, it thrives in environments with limited resources enabling it to out compete native species particularly during drought periods. Furthermore, its success is attributed to its dual reproductive modes (Padrón et al, 2011).…”

Section: Distribution and Spread Of Opuntia Stricta In Kenyamentioning

confidence: 99%

The Correlation between Opuntia stricta Distribution and Soil Chemical Composition in Tsavo East National Park

2024

JRIIE

View full text Add to dashboard Cite

Biological invasions have been observed in Kenya some of which are deemed to have significant socio-economic repercussions on affected communities altering the composition and structure of ecosystems. Data from the East African region indicates that Kenya has been invaded by 34 distinct species with notable examples including Opuntia stricta (Haw) and water hyacinth (Eichhornia crassipes). This study aimed to examine the relationship between the distribution of the invasive species O. stricta and the soil chemical composition in Tsavo East National Park, Kenya (TENP). The study area was divided into twelve 2km-long transects with ten 5m by 5m quadrats systematically established along each transect. Data on O. stricta coverage and soil chemical concentration were collected in each quadrat. Analysis of variance (ANOVA) was conducted on O. stricta coverage revealing significant differences in its distribution across the sampled transects. Correlation analysis between O. stricta and soil chemical composition was performed. Among the soil chemical components examined, phosphates exhibited a negative correlation with O. stricta cover at a significance level of p=0.002 for α=5%. Conversely, sodium content and O. stricta cover showed a positive correlation at a significance level of P=0.039 for α=5%. These findings are critical for guiding strategies aimed at controlling the rapid spread of O. stricta in Tsavo East National Park and similar ecosystems.

show abstract

Dynamics of ungulates in relation to climatic and land use changes in an insularized African savanna ecosystem

et al. 2012

View full text Add to dashboard Cite

Land use change and human population growth are accelerating the fragmentation and insularization of wildlife habitats worldwide. The conservation and management of wildlife in the resultant 'island' ecosystems in the context of global warming is challenging due to the isolation and reduced size of the ecosystems and hence the scale over which ecosystem processes can operate. We analyzed trends in numbers of nine large herbivores in Kenya's Lake Nakuru National Park to understand how rainfall and temperature variability, surrounding land use changes, and boundary fencing affected wildlife population dynamics inside the park during 1970-2011. Buffalo, zebra and Thomson's gazelle numbers increased persistently. Grant's gazelle and impala increased initially then gradually declined. Waterbuck and warthog numbers progressively declined to levels that potentially threatened their local population persistence. The total biomass of ungulates tripled from 1970 to 2011, with buffalo replacing waterbuck as the predominant species in biomass. Increased competition from buffalo and zebra, heightened predation and illicit human harvests probably all contributed to the declines by waterbuck and warthog.Density-dependent limitation of population growth within the park confines was evident for buffalo, impala, eland, giraffe, Grant's and Thomson's gazelles. Fluctuations in the lake level related to varying rainfall affected changes in animal abundance through expansion of the lake area and flooding of grasslands bordering the lake. Unusually, the most stressful conditions were associated with high water levels following high rainfall. There was also evidence of carry-over effects from prior habitat conditions affecting all species. The relatively stable populations of all species except warthog and waterbuck demonstrate the remarkable capacity of this small, insularized park to retain viable populations of most of the large herbivores, without much management intervention.

show abstract

Untitled

Cited by 15 publications

References 6 publications

Seasonal resource use and niche breadth in an assemblage of coexisting grazers in a fenced Park

Seasonal resource use and niche breadth in an assemblage of coexisting grazers in a fenced Park

The Correlation between Opuntia stricta Distribution and Soil Chemical Composition in Tsavo East National Park

Dynamics of ungulates in relation to climatic and land use changes in an insularized African savanna ecosystem

Contact Info

Product

Resources

About