摘要:

SummaryThe three‐stage desk calculation of the von Bertalanffy equation to describe growth in height and weight with age in the elephant is compared with a new approach to calculating the three coefficients in the function by a computer. The two methods give different results with respect to the weight/age calculations. Theoretical von Bertalanffy equations calculated by both methods to describe growth in height and weight with age in the African elephant in Zambia are compared with previously published equations for the elephant in East Africa.Details are given of growth in height in two known‐age African elephants, a female ‘Diksie’ and a male ‘Kartoum’. Theoretical growth in height curves for the female African and Asiatic elephant are compared. The coefficientsKand / for growth in height are not transferable to the growth in weight equations.Inherent inaccuracies in the calculation of the coefficients in the von Bertalanffy equation are discussed, and it is concluded that in animals which have a long life‐span such as the elephant, the equation serves as a purely empirical representation of weight‐at‐age data and that there is little biological significance in the parameters it contains. The computer‐calculated curves give the best fit to the data. The regression of log age on log shoulder height from 2–20 years of age provides a more realistic approach to comparative growth studies.The increase in adrenal weight with age is linear.Tusk growth in relation to age and sex in Zambia is compared with East Africa. It is concluded that the tusks in Zambia are smaller and are more difficult to sex correctly than their East African counterparts, possibly a consequence of the Zambian elephant having a greater degree of tusk wear.Allometric growth is described with emphasis on the estimation of body weight from shoulder height. The most reliable estimates are obtained from a purely empirical representation of the data, a semilog plot of log body weig

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00870.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SummaryA method of zebra age determination, using the decreasing height of Ml in a wear model, was compared with the method of visual assessment of incisor changes as used by Klingel&Klingel (1966). Good agreement between the methods was found.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00871.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SummaryThe failure and success achieved while attempting to immobilize sixty‐two elephants (Loxodonta africana) and twenty‐five African buffalo{Syncerus coffer) with etorphine hydrochloride administered by syringe projectile are described.Failures due to mechanical causes are divided into those occurring before and those occurring after injection.In the elephant series the most frequent cause of mechanical failure before injection was due to the dart bouncing off the target animal often coupled with bending or breaking of the needle. In the buffalo series, misfires due to faulty cartridges were responsible for most of the failures before injection, but bounce‐offs were common, too. Failure to immobilize or inadequate immobilization following apparently successful darting of both elephant and buffalo was most often due to the penetration of the plunger by the detonator.A breakdown of the cost of immobilizing forty elephant and twenty buffalo is given. Total costs for each animal successfully immobilized were U. Shs. 323.0 and U. Shs. 359.9 for elephant and buffalo respect

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00872.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SummaryLong term parallel studies on animal populations can give information on problems concerning population regulation, competition and predation. So far only two populations in the Serengeti have been studied in this way. To initiate long term studies on several ungulate species an aerial transect census was carried out in 1971. The methods of counting and the statistical analysis are described in detail so that future workers can repeat the census. The results are presented for impala, topi, kongoni, giraffe, waterbuck, eland and buffalo male groups. Based upon the confidence limits of the samples, it is suggested that the next census be carried out in June 1974.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00873.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SummaryAerial counts of elephants made three times a day over the same region tended to be consistent if due allowance is made for observed movements to and from the area. There was little difference between observers when two were present. Ground counts made on the same day as the aerial counts tended to return lower totals, due probably to elephants in dense vegetation being hidden from the ground observer but visible from the air. It is concluded that aerial survey is the most efficient way of counting elephants, at least in the Queen Elizabeth National Park.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1972.tb00874.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.tb00875.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.tb00876.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.tb00877.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY