Wyniki wyszukiwania - Biblioteka Nauki

1

Remarks on body growth and phenotypes in Asian elephant Elephas maximus

100%

Kurt F. , Kumarasinghe J. C.

Acta Theriologica. Supplement

|

1998

|

tom 43

|

nr 5

2

Socio-ethogram of adult males versus biochemical-genetic variation in assessing phylogenetic relationships of the Caprinae

100%

Kurt F. , Hartl G. B.

Acta Theriologica. Supplement

|

1995

|

nr 03

EN

To investigate phylogenetic relationships among 9 genera of the Caprinae (Capra, Ammotragus, Hemitragus, Pseudois, Ovis, Rupicapra, Oreamnos, Nemorhaedus, Capri- cornis) behaviours involved in courtship and mating, aggression, threat, dominance, submission, and marking of adult males were subjected to phylogenetic analysis. Based on all 32 characters and 96 character states investigated, phylogenetic patterns generally were in good agreement with biochemical-genetic data avaliable. Discordance between phylogenetic trees constructed from behavioural and from biochemical-genetic traits as to the position of Ammotragus turned out to be associated with ethological functional categories. Behaviours involved in courtship and mating were identified as the most reliable ones for phylogenetic studies. Courtship displays function as isolation mechanisms among closely related taxa. This is of paramount importance in those forms where secondary sexual characters such as horns are poorly differentiated while in highly evolved taxa size and shape of horns may also trigger readiness for mating in estrous females.

3

A stochastic simulation model for Asian elephant Elephas maximus populations and the inheritance of tusks

100%

Tiedemann R. , Kurt F.

Acta Theriologica. Supplement

|

1995

|

nr 03

EN

In the framework of available historical data on population size and human impact on the Asian elephant Elephas maximus Linnaeus, 1758, we developed a stochastic simulation model for elephant populations, which simulates individual elephants and includes their geno- and phenotype regarding the tusk character. The model omits density dependence of reproduction parameters and mortality rates. The model predicts female mortality and mean calving interval to be the paramount factors determining the long-term population trend. For simulated female mortality rates of 5% and 5.5% a mean calving interval of 5.2 years and 4.4-4.5 years, respectively, leads to stable populations, which is in accordance with values derived from field observations. Taking into account a higher mortality of tuskers due to human impact, frequencies of the tusk allele were simulated both for dominant and recessive inheritance of the tusk character. The best accordance with census data was achieved, when the tusk allele was assumed to be dominant, combined with a slight reproductive advantage for tuskers. Since the model simulates population dynamics and tusk allele frequencies under various mortality schedules, it can be used to predict the effect of conservation efforts on populations of the Asian elephant.

4

Differences in spatial genetic population structure between African and Asian elephant (Loxodonta africana, Elephas maximus) as revealed by sequence analysis of the mitochondrial Cyt b gene

80%

Tiedemann R. , Kurt F. , Haberrhauer A. , Hartl G. B.

Acta Theriologica. Supplement

|

1998

|

tom 43

|

nr 5

5

Breeding strategies and genetic variation in European roe deer Capreolus capreolus populations

80%

Kurt F. , Hartl G. B. , Volk F.

Acta Theriologica. Supplement

|

1993

|

tom 38

|

nr 2

EN

Based on previously published electrophoretic data on genetic variability in 31 roe deer Capreolus capreolus Linnaeus, 1758 populations, the proportion of loci polymorphic (P), average heterozygosity (H), and the inbreeding coefficient (FIS) were examined for relationships with the social structure displayed in the various populations. Our hypothesis was that genetic variability is lower and FIS-values are more positive in populations where males maintain a stable pattern of territories during the rutting season (forest dwelling roe deer) than in those characterized by pronounced fluctuations in population structure, both within and among seasons (field or mountain dwelling roe deer). P and H did not show differences among those two groups. FIS was significantly more positive in the 'forest' roe deer than in the more migratory 'type', but only when populations subjected to high culling rates were excluded from the analysis. Highly negative FIS-values in forest populations with high culling rates suggested that considerable perturbations of population structure may be caused by hunting. In conclusion, the 'forest' roe deer and the 'field' roe deer do not represent two distinct ecotypes with a particular genetic integrity, but rather reflect the considerable behavioural plasticity of the species.

6

Tuskless bulls in Asian elephant Elephas maximus. History and population genetics of a man-made phenomenon

80%

Kurt F. , Hartl G. B. , Tiedemann R.

Acta Theriologica. Supplement

|

1995

|

nr 03

EN

In Asian elephant Elephas maximus Linnaeus, 1758 tuskless bulls or maknas are generally rare. Only in Sri Lanka 93% of subadult and adult bulls have been reported to be maknas. Using historical records and computer simulations we demonstrate that this situation is man-made. The following mechanisms were identified to be associated with a loss of tuskers: (1) When using elephants, man has always preferred tuskers. (2) Selective hunting and capturing frequently led to a decrease of tuskers in wildliving populations. (3) The impact of selective hunting and capturing was highest in isolated populations, such as Sri Lanka. (4) Selective removal of tuskers for protecting a maximum wild-living male population resulted in an increase of maknas. The rate of increase in the frequencies of maknas in particular populations with known history could be best explained by a dominant mode of inheritance of tusks in combination with a slight advantage of tuskers in reproduction. For the mainland populations it can be predicted that even in those where tuskers are already largely lacking the allele responsible for the expression of tusks should often be sufficiently abundant to allow the recovery of tusk bearing males.