No abstract

Like other terrestrial tortoises, the courtship behaviour of Hermann's tortoises (Testudo hermanni Gmelin, 1789) is based on a multiple signalling system that involves visual, olfactory, tactile, and acoustic signals. In this study, we analysed relationships between male morphology, hematological profile, courtship intensity, vocalizations, and mounting success in Hermann's tortoises breeding in semi-natural enclosures to investigate the effects of male condition on signals exhibited during courtship and on their mounting success. Results showed that mounting success of Hermann's tortoise males was positively affected by the number of sexual interactions/h, number of bites given to the female during interactions, and by call rate and frequency-modulation range. Call rate, frequency-modulation range, and number of sexual interaction/h increased with hematocrit value, while number of bites given to females decreased with leukocyte concentration. In conclusion, courtship signals exhibited by Hermann's tortoise males, including vocalizations, reliably reveal different components of male condition, and females may use these multiple traits to choose high-quality partners. This is the first study documenting the condition-dependent nature of tortoise courting signals and their effect on male mounting success.

No abstract

Many animals use chemical and visual cues to obtain reliable information about potential food resources. Most reptiles have evolved highly specialized chemosensory and visual capacities, in particular colour vision, to accomplish this task. By presenting animals with flowers and coloured cardboard discs in two-choice experiments, we examined whether both male and female Hermann's tortoises (Testudo hermanni) were able to distinguish between different colours, and show some preference for certain colours. We found that both sexes responded and discriminated equally between different colours, with some differences between flowers and discs. In particular, the red was preferred in the disc experiment, mainly by males, but was disregarded by both sexes in the flower experiment, where red was represented by poppy, Papaver rhoeas. This suggests that Hermann's tortoise probably relies on a mixed system of olfactory and visual abilities to detect food in order to optimize the intake of essential nutrients as minerals or carotenoids. Our results demonstrate that the most preferred colour by tortoises was the yellow, which might reflect carotenoid content, and we discuss the potential implications of this finding.

Highly repeated nuclear DNA sequences from leaves of Nicotiana plumbaginifolia were cloned in pBR322 and tested for their effect on direct gene transfer in protoplasts of the same organism. Protoplasts were prepared from suspension cultures and were incubated in the presence of the plasmid pHP23 carrying the kanamycin resistance gene APH(3')II and in the presence of the plasmids carrying the cloned sequence. DNA uptake was induced by a polyethyleneglycol (PEG) treatment. Out of the 22 tested clones, 3 significantly stimulated the frequency of appearance of transformed colonies. DNA was extracted from some of the kanamycin-resistant calli obtained by co-transformations. Dot-blots have shown that the stimulatory effect on transformation frequency is often accompanied by a consistent increase in integrated genes sequences.