Clutch, egg and hatchling characteristics in the Souss Valley tortoises, Testudo graeca soussensis Pieh, 2001 (Testudines: Testudinidae) from an arid steppe-land of west-central Morocco

Abstract

Clutch, egg and hatchling characteristics in the Souss Valley tortoises Testudo graeca soussensis (Testudinidae) from an arid steppe area of west-central Morocco were investigated in semi captivity in spring–early summer 2011. Mating activity occurs twice in the year, mainly in early spring and for a short period in mid-autumn. The egg laying period lasts from late May to early July. The mean clutch size, based on the first clutches, is 3.44±1.33 eggs per clutch (range: 1–5 eggs); the eggs are elongated in shape. The mean relative egg mass and relative clutch mass are 1.70±0.28% and 4.06±1.32%, respectively. No egg variable was significantly correlated with the female body size (carapace length and body weight). The mean incubation duration of artificially incubated eggs (at 31°C) is 70±5.7 days. The body mass at hatching is 12.8±0.6 g. The carapace is sub-circular and more domed than that of adults. The obtained data are compared to those reported for other populations and subspecies of T. graeca across its distribution range. The present study would, hopefully, help to assess the potential for tortoise captive breeding in the eco-climatic conditions of Marrakech, west-central Morocco, for the reinforcement of local declining populations.