The Herpetological Journal

pp.115-121

Authors: R. E. Willemsen, A. Hailey, S. Longepierre And C. Grenot

Abstract: The condition index (Cl) of the tortoises Testudo graeca, T. hermanni hermanni, T. h. boettgeri and T. marginata was examined in captivity in southern and northern Europe. The CI was calculated using mass-length relationships of wild tortoises: log (M/M'), where M is observed mass and M' is mass predicted from length. The mass-length relationships differed slightly between the subspecies of T. hermanni. Captive tortoises at the Centro Carapax ( Italy) and the Oosterbeek Tortoise Study Centre (The Netherlands) had Cl within the same range as wild tortoises, so there was no general effect of captivity on body mass condition even at densities ten times the highest observed in the wild. However, the seasonal pattern of CJ at Oosterbeek differed significantly from that of wild tortoises, with a peak in late summer rather than in spring. Low Cl of tortoises in some enclosures at the Centro Carapax prompted supplementary feeding before their health was affected. Tortoises at SOPTOM (France) during a period of disease had significantly lower Cl than wild tortoises, with mean CJ of -0.04 and mean relative mass (M/M') of 91 %. The Cl offers a useful guide to the health and management of captive Mediterranean tortoises, although further data are required on those kept in different circumstances, such as outdoor-only enclosures in northern Europe.

Keywords: captivity, condition index, management, Testudo, tortoise