摘要:

SummaryDuring a 3‐year study in Nairobi National Park, 1965–1968, 250 giraffe were identified by their neck markings. The herd structure of these animals was studied, including the relationships between particular individuals. Population information collected included the times of calving, the growth and longevity of giraffe, their reproductive potential, the age structure of the population and its density. Immigration, emigration and home range studies were completed with the help of radio telemetry equipment. The effect of giraffe on the vegetation and the possibility of giraffe surviving without free water are discus

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00855.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SummaryFood eaten by six species of ungulates was studied by analysing stomach contents, using the method developed for faecal analyses.Frequency analyses showed that some herbivore species tend to be selective in their feeding. This suggested that availability and growth form of plants may be important in this respect. The observations agreed with those of other workers, which shows that feeding habits are consistent over large areas.In general, herbivores were classified in three groups with regard to preferences; namely pigs, certain antelope, and buffalo and waterbuck.Comparison of the proportions of epidermal fragments of particular grass species present in stomachs in wet and dry seasons showed that significant seasonal differences exist in the diet of most herbivores. Annuals and most members of the Andropogoneae were present in stomachs in larger proportions during the rains for reasons of availability and palatability.Chloris gayanaandSporobolus pyramidaliswere usually present in greater proportions in dry seasons.Differences in the proportions of epidermal fragments of particular plant species present within wet or dry seasons were usually insignificant. A few herbivores, however, showed significant differences within seasons. This indicates that they are sensitive to small changes in plants and that they may have a feeding cycle involving a gradual and regular alternation of plant species.A comparison of the proportions of fragments of the same plant species in different herbivores showed that animal species usually avoided competition by their specialized food habits. There was greater separation in the longer dry season, but competition may have occurred when food supplies were reduced by large herbivores such as buffalo and hippopotamus.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00856.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SummaryThe status of the Amboseli rhino population has given rise to particular concern, due to an apparently rapid decline since the 1950s.Information on the causes of death is available over the last 3‐3 years and ground counts give a reasonable picture of the gross population structure of the rhinos. Aerial counts indicate a significant decline and provide population estimates on which a reconstruction of changes is possible. It is shown that the population has been declining at an average of about 12% per annum over the last 4 years at least. Seventy‐five per cent of mortality results from spear wounds inflicted by Maasai. Natality is dropping rapidly, while the level of spearing is increasing. Spearing is possibly nonselective, so that the age‐distribution may be similar to previous periods when the population was more stable. As a result, natality is probably not responding to increasing mortality.It is concluded that the rhino population is unable to effectively alter the magnitude of decline through intrinsic factors, or immigration. It would take a population over twice its present size to offset the impact of spearing.The effect of a rapidly changing environment is considered, but although it may result in slightly less favourable conditions for the rhinos, any decline is completely masked by spearing.The reasons for spearing and the recent increases are discussed, as well as the future prospects and implica

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00857.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SummaryAn identification system based on the individual stripe patterns, has been developed for zebra (Equus burchelli, Gray). A taxonomic nomenclature facilitates easy field classification into a number of classes, which form the basis for a photo‐filing system, and thus quick identification of individual animal

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00858.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00859.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00860.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00861.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY