bluuebunny/crossref_metadata_2025_split huggingface dataset:
The density and biomass of large mammals in Lake Nakuru National Park
Authors: KUTILEK M. J. 
Published: April 2008

SummaryOver the past 70 years, human activity has severely limited the diversity and movements of large mammals in the region of Lake Nakuru National Park, Kenya. Game counts were begun in April 1970 to assess the status of those species remaining. The density of large mammals per km2 was found to be 64.20±8.86 (mean ±S.D.) and the biomass density of the six major species in kg/km2 was 6298±801. The biomass was most heavily concentrated in the grassland‐woodland area south of the lake. Defassa water‐buck was the dominant species accounting for 76% of the biomass density. The probable reasons for their dominance are: (1) favourable habitat; (2) decreased competition; (3) reduced predation; (4) control of poaching; and (5) non‐migratory habits. Future management may ultimately depend on the relationship of waterbuck to the food resources available.
The pattern of lion predation in Nairobi Park
Authors: RUDNAI JUDITH 
Published: April 2008

SummaryThe feeding habits of lions in Nairobi National Park have been observed between 1968 and 1972.Nairobi Park is briefly described and the herbivore and predator populations are discussed.The relationship between the changing status of the prey population for the period 1968‐72 and the feeding habits of the lions is examined and compared with data from earlier years.Selection ratio (preference ratio) for three of the most important prey species is more closely adjusted to the abundance of these species in the total ungulate population than was the case prior to 1968. Only warthog and eland form an exception. Predation on wildebeest shows the most marked decrease although this species has been increasing during the last 5 years.Wildebeest, kongoni, zebra and warthog have provided 80% of total kills throughout the study on the basis of numbers killed. On this basis, warthog has the highest preference rating. However, the largest contribution to the lions' diet expressed in kg is by kongoni, followed by zebra, wildebeest, eland and warthog, in that order.Kongoni and wildebeest contribute most during the first half of the year and zebra and eland during the last 6 months.Selection for males is significant in zebra and eland and highly significant in kongoni, whilst only in zebra is selection for juveniles evident.
The savanna ecology of Kidepo Valley National Park: The effects of burning and browsing on the vegetation
Authors: HARRINGTON G. N. , ROSS I. C. 
Published: April 2008

SummaryBetween 1947 and 1967 tree frequency was reduced by 30% in the Narus valley, Kidepo Valley National Park. Between 1967 and 1972 a further 50% reduction took place on experimental plots. Elephants were largely responsible. Despite a regeneration potential of c. 200 young trees per ha, very little tree regeneration was observed. Experimental fire treatments and animal–free exclosures revealed that annual burning and the current browsing pressure were independently capable of preventing tree regeneration.Fire effects were significant in the herb composition of the animal exclosures but less so on the grazed areas. This was attributed to trampling of litter on the grazed areas, which assisted termites in litter removal. Untrampled litter accumulation suppressed Themeda triandra to the benefit of Panicum maximum.Fire effects on the soil were small and impermanent.
The natural regulation of buffalo populations in East Africa: Introduction and resource requirements*
Authors: SINCLAIR A. R. E. 
Published: April 2008

SummaryAlthough it would appear that regulation in animal populations is highly probable, the evidence for it in nature is meagre. The various hypotheses on regulation are outlined in order to point out the critical evidence needed to test them. A population of the East African buffalo has been studied since 1965 with a view to obtaining this information.The ecological requirements including habitat selection and food selection are described. Using Association analysis the ‘best available’ habitat for buffalo was found to be a combination of riverine grassland and forest. This was most pronounced in the dry season when other habitats became less suitable due to the grass drying out and becoming unsuitable food. The movements between vegetation types were correlated with changes in rainfall and with the area of burnt ground after grass fires. Hence the movements could be attributed to changes in the food supply.Within the ‘best available’ habitats the buffalo ate grass exclusively but not all grass was food. The most preferred component was the combined grass leaf and leaf base, this being the most nutritious part of the plant. This component was predominant in the diet during the rains but declined to a minimum by the end of the dry season despite the animals' ability to select for it.
Habitat utilization by hippopotamus in the Mara River*
Authors: OLIVIER R. C. D. , LAURIE W. A. 
Published: April 2008

SummaryThe results are presented of a 2‐month study of the Mara River hippopotamus population in the Serengeti National Park and the Maasai Mara Game Reserve. A method for correcting aerial counts of hippos in turbid rivers and based on herd behaviour characteristics is described. There were an estimated 1927 hippos at an average density of 16‐1/km in the area censused. The population became more dispersed and the mean group size decreased from thirty to fifteen after a rise in water level. The value of comparisons between populations in various terms of expression of density, and mean group sizes, are discussed. The amount of day living space, defined as areas preferred or utilizable by hippo during the day, and productivity of the food plants are seen to be very important factors in hippo habitat utilization, and as constraints on population increase.Hippo use of the habitat and the effects of hippo on the vegetation at various distances from the river were quantified, and a cycle of vegetational changes suggested which may be associated with the effects of hippo grazing and fire in other parts of Africa.Groups were found to consist of nearly equal numbers of males and females. There was no evidence of territorial behaviour either on land or in the water. A number of observations on social interactions and defaecating behaviour are described and indicate that olfactory communication is very important in interactions between hippos. Hippo society is unstable due to climatic influences, but a dominance hierarchy including males and females exists in the groups. Males appear less firmly attached to groups than females, but a male is normally the dominant animal in a group.
Diurnal and nocturnal strategies of the bushbuck Tragelaphus scriptus (Pallas)
Authors: WASER PETER 
Published: April 2008

SummaryBushbuck density, activity cycles, and ranging patterns on the Mweya Peninsula have been determined by continuous observation of individually recognizable animals. Individuals were followed for periods of 2 to 12 h, and observations were continued at night with the aid of a Starlight Scope image intensifier.The density of this population of bushbuck is very high compared to those reported using more standard censusing techniques. Home range size is larger (15‐3‐35‐2 ha) for adult and subadult males than for females and immatures. Sex ratios show a preponderance of adult females, as has been reported for other populations.Contrary to most published accounts, these bushbuck are no more active at night than during the day; rather, they exhibit cycles of activity with a periodicity of 2–5 h. A crepuscular peak of movement is, however, apparent. Examination of individual home ranges and of ranging patterns indicates that this crepuscular activity peak is connected with a complete disjunction of areas utilized at night and during the day. Bushbuck move out of thickets into patches of grassland at dusk, returning to thickets before dawn. Other differences between nocturnal and diurnal activity include an increase in the relative amount of grazing at night. Possible reasons for these phenomena, in particular the probable role of predation, are discussed.
The numbers and distribution of large mammals in Ruaha National Park, Tanzania*
Authors: NORTON‐GRIFFITHS M. 
Published: April 2008

SummaryTwo aerial sample counts were carried out in Ruaha National Park, Tanzania, in the dry season of 1972 and the wet season of 1973. Population estimates of elephant, buffalo and other large mammals were made, and trend surface analysis was used to identify the basic gradients and contours of density, diversity and biomass within the Park. A cluster analysis, based on similarities between principal component scores, and validated by a multiple discriminant analysis, produced a classification of the Park into three Regions which differed significantly in densities, diversity and biomass.Ruaha Park carries year round a high density of elephants (1–7 km‐8). Seasonal movements into and out of the Park were not found, although movements within and between Regions could be detected.
Temporal patterns of reproduction in ungulates of Tsavo East National Park, Kenya
Authors: LEUTHOLD WALTER , LEUTHOLD BARBARA M. 
Published: April 2008

SummaryTemporal patterns of reproduction in nine species of ungulates were studied by means of repeated road strip counts and through observation of individually known females. Zebra and oryx show one distinct peak of births annually, Coke's hartebeest two peaks per year, but all these species may give birth throughout the year. In waterbuck, impala, Grant's gazelle, gerenuk, lesser kudu and giraffe no marked peaks were evident, i.e. reproduction is largely non‐seasonal. Only the warthog (though not studied in detail) has a short, distinct reproductive season. While mean rainfall and temperatures follow a well‐defined seasonal pattern, rainfall is often irregularly distributed, both in time and in space, and varies considerably from year to year. For most species, more or less continuous reproduction may therefore be more advantageous than a seasonal pattern related to average climatic conditions. Other factors influencing the temporal pattern of reproduction include phylogenetic relationships and food habits. Seasonal reproduction is more marked in grazers than in browsers, and this difference is probably related to seasonal changes in food quality.
Rainfall, primary production and ‘carrying capacity’ of Tsavo National Park (East), Kenya
Authors: PHILLIPSON JOHN 
Published: April 2008

SummaryAnnual and monthly rainfall records (1969‐72) for the southern section of Tsavo National Park (East) were used to estimate net primary production above ground. Annual estimates of mean primary production varied between 210 g nr‐2 a‐1 (1971) and 545 g nr‐2 a‐1 (1969). The distribution limits of elephant deaths during 1970‐71 showed good correlation with the annual 200 g nr‐2 a‐1 contours.The calculated food consumption of the elephant population indicated txhat 4–7% of the primary production was eaten in years of good rainfall and 8–12% in drought years. Monthly food consumption was used to demonstrate that in a year where 4 to 5 consecutive months fell below the large mammal food requirement some mortality occurred.Maps showing the probability of a given level of primary production occurring in a specific region in any one month related very well to recorded elephant distributions. Further maps showing the probability with time of 4 and 5 consecutive months with primary production below the food requirements of the large mammals predicted 5 and 10 year and 43–50 year periodicities in primary production. The influence of the annual and longer term periodicities is discussed, and illustrated by generalized models which predict the ‘carrying capacities’ of the habitat for the different faunal categories.The potential of the probability maps for management purposes was demonstrated by reference to the ‘elephant problem’ and the much discussed recommendations of culling and non‐interference. On the available evidence it is believed that, in Tsavo (East), non‐interference is the better management policy.
Reproduction in the giraffe in relation to some environmental factors
Authors: HALL‐MARTIN A. J. , SKINNER J. D. , DYK J. M. VAN 
Published: April 2008

SummaryEnvironmental influences on reproduction in female giraffe were investigated by calculating conception dates for 123 calves and twenty foetal giraffe from the eastern Transvaal, South Africa. Of these, 60% occurred during the 4 months December to March. This period is the peak of the austral summer when plant leaf production is at a maximum, the preferred food species of the giraffe are abundant and the protein and energy content of these are high. Rainfall is also highest at this time. Conceptions also occurred in all other months of the year. Data on calving from captive animals in Australia, and from wild giraffe elsewhere in South and East Africa were also included in the study. Nineteen adult male giraffe collected over a period of 1 year from the eastern Transvaal were also investigated. Seminiferous tubule diameter fluctuated with age but regular seasonal fluctuation was not apparent. Testicular testosterone concentration varied from trace amounts to 10.1 μg/g. Testes mass and epididymes mass were closely correlated with age but no seasonal effects were apparent.
The feeding ecology of wildebeest and zebra in Athi‐Kaputei plains
Authors: OWAGA MARY L. 
Published: April 2008

SummaryFood habit studies on wildebeest (Connochaetes taurinus Burchell) and plains zebra (Equus burchelli Gray), using stomach contents analysis, were carried out between April 1972 and October 1973 in the Athi‐Kaputei plains and Nguruman in Kajiado district. Both areas fall within the semi‐arid region of Kenya and are grazed by both Masai stock and wildlife.Wildebeest was highly selective for grass leaves, while zebra took more of the coarse plant materials, viz. sheath and stem. Zebra is more suited to coarse feeding, which enables it to survive the droughts better than wildebeest. The latter is usually hit harder at such times, as it cannot maintain itself on the fibrous materials which can constitute a maintenance diet for zebra.
Breeding of the lappet‐faced and white‐headed vultures (Torgos tracheliotus Forster and Trigonoceps occipitalis Burchell) on the Serengeti Plains, Tanzania
Authors: PENNYCUICK C. J. 
Published: April 2008

SummaryThe lappet‐faced and white‐headed vulture nests in a 1636 km2 study area on the Serengeti Plains were kept under observation from June 1972 to August 1973. Active nests were inspected from a light aircraft at intervals of approximately 2 weeks.The inverse nesting densities were estimated as 43 km2/pair for the lappet‐faced vulture and 409 km2/pair for the white‐headed vulture. Nests were built of sticks in exposed sites on the crowns of trees, Acacia tortilis being the most popular species. Where the previous history was known, 44% of lappet‐faced vulture nests were newly constructed, and the rest re‐used from the previous year.The incubation period was about 55 days and the fledging period about 100 days in both species. Juveniles continued to frequent their nests after they could fly, sometimes for several months.Most lappet‐faced vultures laid their eggs in April‐May, the white‐headed vultures in June‐August. This means that the lappet‐faced vultures raised their young during the dry season, when Grant's and Thomson's gazelles were the only animals present in any numbers on the plains. By contrast, the Ruppell's griffons nesting in the nearby Gol Escarpment colony raise their young during February‐May, when the wildebeest and zebra herds are normally on the plains.The survival rate of lappet‐faced vultures from laying to fledging was about 40%. The chicks are thought to be vulnerable to predation by tawny eagles, and one was known to have been killed by a leopard. Three adult vultures were killed on their nests, from unknown causes.Food remains from lappet‐faced vulture nests showed a heavy preponderance of Grant's and Thomson's gazelles in all cases, with golden jackal the next most commonly occurring species. No food remains were obtained from white‐headed vulture nests.The possibility of using aerial counts of vulture nests as an indicator of productivity is discussed.
Immobilization of African buffaloes (Syncerus caffer coffer) in large numbers for veterinary research
Authors: DRÄGER N. , PATTERSON L. , BRETON D. 
Published: April 2008

SummaryFour hundred and eleven African buffaloes were immobilized with etorphine hydrochloride (M99, Reckitts) and sampled under difficult conditions in North Western Botswana. The buffaloes were darted from a helicopter in 36 days. 584 darts were fired giving a success rate of 70‐5%. Various age groups in three separate buffalo populations were included.The technique and difficulties encountered when working from a helicopter are described. Mechanical failure of the darting equipment was negligible.A breakdown of the costs involved is given and a comparison made with similar work carried out solely from land vehicles.
Palatability factors and nutritive values of the food of buffaloes (Syncerus caffer) in Uganda
Authors: FIELD C. R. 
Published: April 2008

SummaryThe food preferences of tame buffaloes grazing different vegetation types were recorded. The effects of fire and rainfall were investigated. By initiating a new growth cycle, fire altered the food habits of large herbivores and also the distribution of small mammals. Seasonal variations in the effect of rainfall on plant growth explains why preferences did not change in proportion to precipitation.The more important grasses were collected and their parts analysed physically and chemically. Their stem to leaf ratio is considered to have influenced the species eaten by coarse grazers such as buffalo. A broad correlation was obtained between buffalo preferences and the percentage green leaf of Hyparrhenia filipendula and Themeda triandra. This correlation was improved when preferences were compared with the number of grams green leaf carbohydrate per 100 g dry grass. There was a negative response to the silica present in dead leaves, but stem fibre appeared to have little effect on preferences. A grazing animal experiences a combination of attractants and repellants, i.e. green leaf carbohydrate and protein less stem fibre and dead leaf silica.Other palatability factors were noted, in particular tannins and oils in grasses of the tribe Andropogoneae. These may act as repellants, possibly only when the grazing animal has alternative vegetation from which to choose.The mineral content of grasses appeared to be adequate and calcium and phosphorus were present in about the required proportions.The observations support the belief that selective grazing enables a herbivore to consume a diet of significantly higher nutritive value than that of the average sward. Browsing and new growth after fire help compensate for the low nutritive value of pasture during the dry season. The nutritive value of the diet is considered to be the proximal factor in the seasonal cycle of reproduction of the buffalo and probably the ultimate factor in the reproduction of certain other ungulates and rodents.
The frequency and extent of uncontrolled grass fires in the Rwenzori National Park, Uganda
Authors: ELTRINGHAM S. K. 
Published: April 2008

SummaryThe area of grassland affected by uncontrolled fires was recorded in the Rwenzori National Park for each dry season between July 1970 and July 1973 with the exception of the January 1973 season. The seasonal total of burnt grassland rose to a peak of 32 7% in January 1971 but there was then a marked decline to a negligible level in July 1971. This was followed by a further steady rise which by July 1973 had reached to within 3% of the previous peak. 13 4% of the park was burnt at least once a year on average, and 55 3% was burnt at some time or other during the 3 years. Burning was not uniformly distributed throughout the park and four regions at high risk from fire are identified for particular attention should a fire control policy be introduced. The need for a controlled burning policy is emphasized particularly in view of the destruction of trees which is taking place through the agency of elephants.
Diurnal activity patterns of elephant in the Sengwa Area, Rhodesia
Authors: GUY P. R. 
Published: April 2008

SummaryNine different diurnal activities of elephant—grazing, browsing, debarking, drinking, wallowing, resting in the shade, resting in the open or sun, certain social activities and walking—were monitored during the day. Possible reasons for seasonal differences in time spent per hour engaged in each of these activities are given.
The numbers and distribution of elephant Loxodonta africana in the Rwenzori National Park and Chambura Game Reserve, Uganda
Authors: ELTRINGHAM S. K. 
Published: April 2008

SummaryA series of aerial counts of elephant made between 1968 and 1972 in the Rwenzori National Park and Chambura Game Reserve, Uganda, is described. A summary is included of all previous aerial counts made in the region. Numbers present in the park since 1963 averaged 1752 during the dry seasons, some 3/5 of the wet season mean of 2896. Corresponding figures for the reserve are 325 and 501. The distribution was very significantly aggregated for each count and remained so when the totals for all counts were lumped. The distribution tended to be more aggregated in dry than in wet seasons. The overall density in the park was 1.43 elephant km‐2 with wet and dry season means of 1.74 and 1.05 respectively. Corresponding figures for the reserve are 2.06, 2.42 and 1.57 km‐2. The mean group size in the park was 6.3 elephant but there were significant variations over the whole range of observations although not between wet and dry season means. The elephant in the reserve were highly aggregated with a mean group size of 28.8. It is concluded that there was a significant rise in the wet season population of the park between 1963 and 1968 but that subsequently, numbers remained fairly stable. Numbers in the dry season and in the reserve at all seasons have not varied significantly since 1963. It is suggested that the wet season rise has been due to a reduction in the area of grazing land available outside the park at this time of year. It is concluded that vegetational differences are responsible for the un even distribution of elephant with human disturbance having an effect in some areas. It is believed that in the region censused, there are at least three distinct populations of elephant of which only that in the reserve is showing signs of stress.
Comparison of voluntary food and water consumption and digestion in Kirk's dikdik and suni
Authors: HOPPE PETER P. 
Published: April 2008

SummaryVoluntary food and water consumption of Kirk's dikdik (Madoqua kirki) and suni (Nesotragus moschatus) was determined under controlled laboratory conditions. Both species consumed large amounts of dried matter (lucerne hay leaves) per day. Dry matter consumption of dikdik accounted for 3.8 ± 0.5% and of suni for 3.5 ± 0.2% of body weight. Dry matter intake in one immature dikdik and one female dikdik during late pregnancy and lactation was considerably higher.Dikdik drank very little water (278 ml/day, equalling 83 ml/kg0.82) which is further proof of their adaptation to arid environment. Suni drank about twice as much (401 ml/day, equalling 155 ml/kg0.82), but individual variation of water con sumption was high. Thus, the forest‐dwelling suni seems to be less adapted to de hydration than the dikdik.There was no difference in the digestibility of dry matter and gross energy of lucerne hay leaves for dikdik and suni. The fraction of N‐free extracts which consists mainly of soluble carbohydrates was digested very well (84% and 81%, respectively), whereas fibre and cellulose digestibility was poor. Suni digested crude protein, minerals and cellulose significantly better than dikdik.