摘要:

SummaryMonthly observations were made of the food habits of tame warthog, reedbuck and kob over a period of a year. Measurements were taken of the shoulder height and size of mouth of the animals at different stages of their growth.Whilst a few species of grass were regularly preferred, the majority showed fluctuations in their preference. Some consistent seasonal differences were apparent. Most herbs were avoided.Large differences in food habits occurred between warthog and antelope; however, there was some overlap during the rains when food was abundant and at the height of the dry season when it was scarce. Some differences were apparent between kob and reedbuck and between individual warthog and reedbuck. Intraspecific differences, however, were less noticeable than interspecific differences.The height of the animal and the size of its mouth were important in determining the portion of the sward available for food and the degree of selection possible within the available food supply.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00825.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryWarthog activity was recorded at 4‐min intervals for continuous periods of 14 h on three consecutive days. The major activities were feeding or lying down and walking. The amount of time spent in feeding is related to the size of the animal and maximum‐intensity feeding occurs in the early morning and in the late afternoon and evening. The animals drank usually only once each day. Adult females urinate much more often than males and this is thought to be a behavioural adaptation whereby the males can tell whether or not a female is in h

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00826.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryA study was conducted of grass selectivity shown by four herbivores on open range lands of Kenya Masailand. At four seasons over one year, wildebeest, zebra and kongoni (Coke's hartebeest) were taken. Stomach materials and faeces were sampled from each animal. Faecal samples were collected from cattle that had been grazing in the same area. Simultaneously, vegetation availability assessments were made.A comparison of techniques for determining the food selectivity indicates that faecal and stomach‐content analyses provide similar results when the diets are almost entirely grass.The selectivity exhibited by the four herbivores was determined by faecal analyses. Three grass species were preponderant in all diets as well as in the available menu. In comparing the selectivity shown for the three dominant grasses there is a high degree of similarity even though statistical differences are demonstrated. All animals favouredThemeda triandraoverPennisetum mezianumandDigitaria macroblephara. Kongoni displayed the highest degree of selectivity and cattle and zebra had the greatest similarity in diets. Each animal species had a wide spectrum of grasses in their diets: these contained a greater number of species during the drier seasons than during the rainy seasons.Wild animals had a greater diet variation between seasons than did cattle, the diet of the latter remaining much more consistent than the combination of available grasse

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00827.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryMaterial from 100 impala from a mainly grazing population in the Kenya Rift Valley was investigated to establish age criteria applicable in both the field and the laboratory. Methods relate to tooth eruption, replacement and attrition; horn development; skull and long bone growth and ossification.Determinations are related to the main calving seasons, which occur with two peaks at the time of the long and short rains. All results are approximations which have an accuracy of ±2 months up to physical maturity at an age of c. 2 y. Age determination in animals from 3–8 y appears to yield reliable results with an accuracy of ±6 months at the lower end of the scale, and ± 1 y or even 2 y in older ani

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00828.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryA description is given of the external features, the muscles moving the rhinarium and lower lip, the jaw muscles and the muscles attached to the occiput in a yearling maleHylochoerus.Rubbing places and scrapes made by the animals in their natural habitat, possibly in search of small invertebrates, are described and certain features of the skull architecture and musculature are considered in relation to the chewing mechanism.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00829.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryThe behaviour of a translocated group of 11 Rothschild's giraffe (Giraffa camelopardalis rothschildiLydekker) was studied for 9 weeks in 1968. A comparison was made between their new and former habitats, the food plants eaten in both places, and behaviour.For 31/2months after release, they appeared to have settled in the area, but they suddenly started extending their range.Possible reasons are suggested for their failure to stay in the release area and their eventual disappearance.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00830.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryThe banded mongoose is a social, diurnal, medium‐sized carnivore classified in the family Viverridae.Packs of up to 32 animals were found to occupy a single, old termite mound for periods in excess of 2 months. Nine out of ten dens were in termite mounds, the other was in a gully. One den was excavated to show structure. The whole pack occupied the central chamber each night.One group of 32 consisted of 17 adults, 7 juveniles, and 8 babies too small to leave the den with the pack during the day.The animals were strictly diurnal, usually leaving the den about one hour after dawn; time of return was more variable, but was usually during the hour before dark.Senses of sight, smell and hearing were found to be very acute.During the day the packs covered large distances, foraging as they went. During the period of study, food (estimated by dung analysis) consisted almost entirely of Coleoptera (mainly dung beetles) and millipedes. The packs followed the trails of elephant and buffalo and obtained most of their food from their dung. Detailed behaviour is described.Mating was seen on three occasions and two males were seen to copulate with the same female. Family size was not determined, but eight young were seen to be suckled by three females indiscriminately. One mother looked after all eight young during the day when the pack was away.The animals used communal defaecating areas on and around the den, the faeces being scattered over the surface of the ground.Reactions to various animals, including predators, are described. When caught in the open the pack tended to bunch together acting as a single unit. If bushes were near they used them for shelter.Adaptations are discusse

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00831.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryIn the context of widespread vegetation changes in Tsavo National Park, food habits of gerenuk are being investigated; the present paper gives an account of the results obtained during the first year of the study.Feeding of free‐ranging gerenuk was observed from a landrover in two study areas with different vegetation types. Plant species eaten were determined in the field or collected for identification.Gerenuk feed almost exclusively on leaves, shoots, flowers, and a few fruits of trees and shrubs, as well as some climbers and vines, the latter mainly during the rainy seasons. No small herbs or grass were found to be eaten.The composition of the diet differed considerably between the two study areas, largely as a result of differences in the available vegetation.Seasonal variations in the diet are brought about mainly by variations in the availability of different food plants, notably the ratio between deciduous and evergreen species at different seasons.On the basis of a preliminary quantitative survey of the vegetation in the study areas, actual preferences have been evaluated. Some common plant species were found to be rejected altogether, although they are eaten by other browsing animals.A total of 68 plant species has so far been recorded as food plants, indicating that gerenuk are able to utilize a wide range of plants. In view of this adaptability, and of the abundance of preferred food plants in the study areas, the vegetation changes in Tsavo National Park do not, at present, appear to endanger the continued existence of the gerenu

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00832.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Summary1This report presents the results of a survey into the current status of the Nile crocodile in the major waters of central and western Uganda, made on behalf of the Uganda Fisheries Department and the Trustees of the Uganda National Parks.2The waters covered by the survey are described briefy3Crocodile numbers and distribution were assessed by diurnal aerial counting and nocturnal ground counts as described by Graham (1968). The major sources of error inherent in these techniques are recognised and discussed. Efforts to reduce bias in results included the use of a light helicopter to obtain data for comparison with those obtained from a conventional aircraft. Comparative costs are also presented.4Inaccessible areas of dense papyrus were searched at night from a helicopter equipped with a spotlight.5Information was obtained from fishermen in Lake Albert on the status of crocodile to corroborate other results.6The analysed results of aerial and ground counts give estimates of less than 100 crocodile outside the Murchison Falls National Park, indicating the species' reduction to the status of an ‘occasional’ or ‘rare’ animal. Within the National Park crocodile occur in two populations separated by the Murchison Falls. Below the Falls it is estimated that there are 1064 crocodile, and above 433.7By use of aerial photography 369 crocodile from the larger of the National Park's populations were measured for length. From Graham's (1968) age/length data, age classes are ascribed to those measured. This, together with data from the counts, permitted the computation of a survivorship curve for the population. This is presented with two possible alternatives. From these curves it does not appear that the population is declining through lack of recruitment.8From the aerial photographs river banks are classified into four crude categories. By relating crocodile in the photographs to the nearest bank category, it is shown that they have a marked preference for sandy banks over swampy shores, hard flat earth or cliffs. It is also shown that smaller crocodile make more use of swampy areas than larger specimens.9Biomass densities for both crocodile populations in the National Park are computed. The larger shows a biomass of 347 kg/km of shoreline which compares with 350.2 kg/km for Lake Rudolf (Graham's (1968) data modified), the smaller 75.3 kg/km.10The decline of crocodile in Uganda is attributed to expanding human populations and over‐exploitation for skins.11Recommendations for the future conservation and management of crocodile are presented. These are based on reducing immature mortality rates by hatching eggs and artificially rearing small crocodiles for a period of 6 months after hatching. Some of these should be used to augment recruitment in the National Park populations, and the surplus placed in other waters until of an exploit

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00833.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SummaryTsavo National Park, in Kenya, probably contains the largest population of black rhinoceros (Diceros bicornis(L.)) left in existence. Large‐scale damage of the vegetation initiated by elephants and aggravated by fire has changed considerable areas of the park. The ecology of the black rhinoceros in this changing environment has been studied; the present status and population structure is considered here, including the development of detailed ageing criteria for the species, an analysis of natural mortality and survivorship, and a record of the structure of the living populations within the major habitat types.Crania and mandibles were collected from 506 rhinoceros found dead in all areas of the park. This material was divided into 20 relative age classes based on dental characteristics. Crude chronological ages, based on an estimate of the maximum expectation of life and the examination of seven known‐age dental records of captive animals, were assigned to each age class. These crude ages were then refined by examination of 16 dental records of known‐age wild rhinoceros, and a chronological age scale established.A survivorship curve of the population was thus constructed. Annual mortality during the first and second year of life is about 16%, and the indicated mean annual mortality from 5–25 y is 9.8%. A theoretical model of the population structure is shown, and analysis of the annual mortality and recruitment at birth suggests that the population was stable during the 1960's. Assuming the data represent a stable population the mean expectation of life at birth is 8.4 y.Thirteen major habitat types are described. The characteristics of the rhinoceros population within each habitat type were established both from ground studies and aerial observations. Nearly 700 rhinoceros were identified and catalogued on the ground, in sample areas selected for intensive study. Population structures, cow: calf ratios, and recruitment appear to be average in most habitat types. The analysis of recruitment at birth and mortality during the first year of life, both from computations from the survivorship curve and from the structure of the living populations, support the validity of the ageing criteria, and further suggest that the population was stable during the 1960's.Finally, the relationship between the elephant and the rhinoceros in the changing environment is discussed with reference to recent findings in elephant ecology. In conclusion it is recommended that population reduction of the Tsavo elephants should be in

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1970.tb00834.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY