Search

Extensive radiotracking of adult Testudo hermanni for 1 year, and regular inspections for 5 years, in a coastal area of central Italy, allowed us to assess the seasonal variation in mobility and home range size of both sexes, and their use of the different parts of home range. Males are more mobile than the females but, due to a different long-term movement pattern, they have a generally smaller home range. Both sexes show a marked seasonal variation in home range size, but no seasonal migrations. Wild rabbits burrows, and simple pallets under dense vegetation are repeatedly used as shelters by the same individual. The animals show a certain preference for specific basking areas in the midst of dense shrubbery. They feed mainly on vegetation common throughout the study area but special displacements in order to forage also occur. Mating encounters are based on home range overlapping between mates and high male mobility. Our findings and those of other authors on different populations of the same species suggest that these activities act together to produce the long-term home range stability observed in wild T. hermanni even though none of them is performed at a constant site. [ABSTRACT FROM PUBLISHER]

Experimental control of eutrophication in a small coastal lagoon was attempted by means of sediment disturbance. A specially designed boat was used to resuspend the top 3 cm of sediment by a jets of air-water directed towards the bottom. This disturbance was carried out for 3 months in each of two areas with a surface area of 24 and 20 hectares respectively. In a total of 80 stations in these two areas and in two undisturbed areas of 16 and 20 ha, organic matter, porosity, density and redox potential were monitored in sediment bimonthly and free sulphides were monitored in water close to the bottom. Before, during and after disturbance, the impact of daily sediment resuspension on the water column was monitored monthly, as ammonium nitrogen (N-NH4), soluble reactive phosphorus (SRP), dissolved oxygen (DO) and pH. In the whole lagoon, sediment texture was determined at the start and at the end of the experiment in 120 stations, and seaweed (mainly Chaetomorpha linum and Lophosiphonia subadunca) and seagrass (Ruppia cirrhosa) biomasses were estimated in 42 stations every month. The results showed a stable organic matter content in disturbed areas and an increase in undisturbed areas, as well as an increase in seaweed in areas distant from disturbed areas. No significant effect of sediment resuspension on water column N-NH4, SRP, DO or pH was found., (Copyright 2010 Elsevier Ltd. All rights reserved.)

The tortoise Testudo hermanni Gmelin is non-territorial, frequents non-personal shelters and is generalist in diet, but stays within a home range very stable in time. Analysis of shell temperatures obtained at set intervals by radiothermometers showed that while tortoises resident in the study area behave as homoiotherms, animals imported from a similar environment appear relatively poikilotherms. Moreover, residents are more efficient in basking, reaching the daily thermal maxima systematically earlier than the unfamiliar animals. These observations support the hypothesis that its home range stability and the associated familiarity with the microenvironment facilitates the behavioural thermoregulation in T. hermanni.