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Influence of individual traits on locomotor abilities of Hermann's tortoise

Nikola Bajler

nbajler@hotmail.com

Introduction proportional to the length of shell bridges, and positively
correlated with the space for extremities. Factors that
Tortoises (Testudines) are animals specific of their osseous- influence ability of righting indicate to antagonism of
tegument complex of armour that surely enables advantages morpho-functional traits i. e. the so-called trade-off
of vital importance, reffering to protection from negative between characteristics (e.g. relation mobility-protection).
influences of environment and predators. However, armour The righting ability can be considered as an indicator of
can be the cause of potential problems in everyday life of fitness index. Actually, in locomotor abilities the individual
individual. fitness index is reflected, and it corresponds to specific
behaviour. Also, in all three tests, the success depends on
Materials and methodes habitat type of examined individuals. It can be recognized
that the demanding topography causes greater mobility of
In this paper connection between morphology, age, individual.
characteristics of habitat and behaviour are deliberated in
three locomotor aspects. Different populations of Conclusions
Hermann's tortoise (Testudo hermanni) were the subject of
several researches. This paper appears as a sum of previous It is possible that mentioned differences in behaviour are
studies and represents the comprehensive insight into the more a result of the onthogenetic changes arising from the
multiple correlations between ethology and locomotion experience rather than variation in morphological traits. In
with different individual traits. As the basis of the research, addition to these examined correlations, this research
three problems that individuals of species T. hermanni presents an insight into the types of overlapping of morpho-
surely face in their natural environment were taken: locomotor skills and sexual selection. This study has
overcoming of height obstacles by taking a plunge (aware conservation significance, since the type of habitat for the
fall) [1], righting after overturn on carapace [2] and translocation of the part of the population and restoring the
releasing from vegetation hooked on their armour [3]. areal of distribution must be taken into account.

Results Literature
1. A
P O V . Golubović et al, Moving in the real world:
sex - + - tortoises take plunge to cross steep steps, 2012
body size - + - 2. . Golubović et al, Variations in righting A

habitat type + + + behavior across Hermanns tortoise, 2013
morphological + + - 3. . Golubović et al, Skills or strength- how A
traits tortoises cope with dense vegetation? 2013
age of + - - 4. V
individual . Demals et al, The righting response as a
Tab. 1- Assessment of influence of some traits on three fitness index in freshwater turtles, 2007
types of locomotor and ethological activities was given 5. X
( where P- taking a plunge, O- overturning and V- coping . Bonnet et all, Sexual dimorphism in steppe
with dense vegetation). In cases marked with -, influence of tortoises (T. horsfieldii): influence of the
specific trait on concrete problem does not exist or it is not enviroment and sexual selection on body
shape and mobility, 2000
significant.
6. R
. E. Willemsen and A. Hailey, Sexual
It is remarkable that sexual dimorphism in the agility can be
ascertained only by overturning. Certain trends in variation dimorphism of body soze and shell shape in
of behaviour can be recognised. The length of bridge is European tortoise, 2003.
inversely proportional to the degree of mobility. The second
principle shows that the ability of righting is inversly