摘要:

SummaryChronological ages have been assigned to the defassa waterbuck of western Uganda using four complementary techniques. These are the “jaw board” method in which collected skulls are sorted into arbitrary groups based upon tooth eruption and attrition; tooth impressions taken from immobilised animals at yearly intervals; counting of cementum lines in sectioned incisor teeth, and growth of horns in young males. Using these methods an animal could be aged to within plus or minus six mon

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00756.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryThe efficacy of censusing black rhinoceros (Diceros bicornisLinnaeus) populations from the air was tested. Repeated aerial counts were made of the black rhinoceros population centered on Qlduvai Gorge, Tanzania, where the number of rhinoceros on the ground is known accurately. Even under the most ideal conditions only 50% of the population was detected by observers in an aircraft, and factors accounting for this are considered. It is concluded that the light aircraft is of limited value in providing estimates of black rhinoceros populations, and estimates based purely on aerial counts are subject to considerable variation.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00757.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryMore than 300 game animals shot in the Grumeti Controlled Area, Tanzania during research into game utilisation were weighed and measured. The results are presented and compared with other available data. Considerable variation is apparent between animals of the same species from different areas.The techniques of linear measurement are fully described in an attempt to standardise measurements for comparative purposes.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00758.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryFifty‐four post‐mortem examinations were carried out on wild animals. A wide range of disease conditions was found and a number of these are discussed in detail. Two conditions of particular importance were parasitic bronchitis and muscular dystrophy; these were found in approximately one third of the antelopes exami

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00759.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryEye lens dry‐weights have been determined for 543 African elephants from three populations in East Africa. When plotted against estimated ages based on tooth replacement and wear criteria they indicate growth curves with rapid initial growth in lens weight, succeeded by a phase of rectilinear growth which apparently persists throughout life.Parameters for the regressions of lens dry weight on age have been calculated by sex and locality. Confidence limits are fitted and no significant difference in the growth rates can be demonstrated, except for a sex difference in the values for the α intercept.Variability at age is slightly greater in males than females, but is little greater than i3 indicated by studies on other species using known‐age animals. This is taken to confirm the accuracy of the age criteria adopted and leads to conclusions on their precision.It is suggested that this method might provide an objective check on the accuracy and precision of age estimates in other spe

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00760.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryThe effects of intensive Tsetse Control hunting operations on a duiker population (Sylvicapra grimmia) were investigated in a 200 sq. mile area in Eastern Zambia. Two years of hunting were insufficient to reduce this population so significantly that a marked shift of its age composition towards the juvenile age classes resulted. There were, however, indications of beginning accelerated population growth through increased breeding and inclusion of more juveniles in the reproduction process, as a first response to the hunting pressure. Although general availability of duiker did not diminish, they became increasingly difficult to shoot because of behavioural adaptation and changing periods of feeding activity. Neither hunting nor various other human disturbances provoked emigration from the area or a change of the seasonal pattern of localised movement.The studied hunting operation failed to remove more than the annual increment to the duiker population and in respect of this species was thus ineffective as a means of Tsetse Control.Implications of the results of this study for the management of duiker for sustained meat production are discussed.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00761.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryThe paper describes observations made over a period of two years on the feeding habits, general ecology and distribution of five species of ants (harvester‐, stink‐, soldier‐, tree‐, and sugar‐ants) in Northern Somalia, p‐incipally in the plains and bushland of the Haud.Harvester and stink ants are discussed in some detail, and some dimensions of excavated nests and runways are given. The occurrence of associated insects is noted and the ecological roles of seed‐eating and predatory ants (particularly in relation to termites) are discussed.There are notes on the climate and topography of the region, and a glossary of vernacular name

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00762.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Summary1. Lake Rudolf, nothern Kenya, has one of the largest undisturbed populations of the Nile Crocodile. In 1965 the Kenya Game Department initiated the Lake Rudolf Crocodile Research Project. Central Island, where the crocodiles live under undisturbed conditions, was chosen for studying breeding behaviour and ecology of the reptile. Eight months were spent on the island.2. On the island most of the crocodile population was confined to a crater lake, Lake C, which supported up to 500 animate at the height of the 1965‐66 breeding season.3. The 1200 m shoreline of Lake C was shared out between about a dozen large males each guarding his territory by patrolling up and down the shore. The territorial shore lengths ranged from 60 to 230 m. The territories extended about 50 m into the water.4. The crocodiles were first seen courting on 10.10.65 in Lake C. The territorial males exhibited a “courtship splash display”. Copulation ranged from 30 to 100 seconds; eleven copulations averaged 58 seconds.5. The factors important in site selection for nesting are shade, suitable soil, proximity to water and the degree of slope of the shore. Because the shores of a second crater lake, Lake A, satisfied these conditions they had the largest number of nests. The fully exposed sites on Lake C, and the Lake Rudolf shores, had very few nests.6. The females dig the nests with their forelimbs, using them in turn. The hind limbs and the belly are used to push away the soil collecting at the mouth of the burrow. The female guards the nest constantly throughout the incubation period of three months against monitor luzards. Laying began in the third week of November, 1965 reaching its peak during the second week of December. The crocodileeggis oblong, measuring 55.5 to 89.0 mm in length and 43.0 to 54.0 mm in width. Mean weights of the eggs from 15 clutches ranged from 83.7 to 126.6 g. Clutch sizes on Central Island varied from 14 to 46 eggs, giving a mean of 33 eggs per clutch.When the young are about to hatch, the mother releases them by digging up the nest. The young when they hatch are about 31.0 cm long and weigh about 76.8 g. They are guarded by the mother for at least six weeks. Infant mortality is probably very conside

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00763.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryWaterbuck were darted with the new “Hypodart” fired from the crossbow, and with the “Cap‐Chur” gun.Eleven waterbuck were successfully immobilised with M.99 alone. The remaining 37 received M.99 in conjunction with an ataractic, acetylpromazine maleate. Hyoscine hydrobromide, a parasympatholytic drug, never formed part of the immobilising dose and was given to only five of the immobilised animals. Not only is this drug unnecessary; its use is a positive disadvantage and was responsible for the death of one waterbuck. Three other waterbuck died, two of these probably from heat stroke, a consequence of using acepromzine on a hot day. The remaining animal damaged a leg when trying to get up and was killed by lion five days later.This paper gives justification for combining M.99 and acepromazine in the approximate ratio of 1:1 for the immobilisation of this species, and suggests that the losses experienced by other workers through torticollis may well have been the result of the ace

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00764.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SummaryA correlation between dissected hind leg weight and Uve weight is demon‐strated for 38 African elephants. Cal‐culated regressions are presented for adult males and for females and immature males. Considered as a per‐centage of Uve weight, hind leg weight varIes between 5.3 and 6.3% according to live weight, and can be used to predict live weight accur

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1967.tb00765.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY