Reproductive biology of the Nile Soft-Shell Turtle, Trionyx triunguis, at the Seyhan River, Turkey (Testudines: Trionychidae)

Abstract

Several populations of the Nile Soft-shelled Turtle, Trionyx triunguis, are found along the Levantine and Turkish Mediterranean coast. The riverbanks of the Seyhan River hold one of the largest nesting populations. In a survey carried out between 2009 and 2018, a total of 209 nests were recorded (20.9 nests per season). Ninety-four percent of the nests were concentrated at one specific site where the nesting density was 4.18 nest/metre, but where most of the nests were predated by Red Fox (Vulpes vulpes) or Golden Jackal (Canus aureus). 137 nests (65.5%) with altogether 5,716 eggs were therefore transferred to a safe place, where 1,811 hatchlings emerged and were released at the nesting site at the Seyhan River. The average clutch size was 40.8±0.89 eggs. The mean hatching success in relocated nests was 34.6%. A total of 1,718 eggs (23.0%) were predated by mammalian predators. The remainder were developmentally interrupted eggs of early (37.9%), middle (4.3%), and late (6.5%) stages. It is discussed whether the high rate of loss of early stage eggs is related to the translocation process.

Keywords:

• Hatching success
• clutch size
• predation
• Mediterranean Sea

View correction statement:

Correction

Acknowledgements

The authors would like to thank all the volunteers, especially students from Adnan Menderes University, Department of Biology. The authors also would like thank James Parham (Cal State Fullerton, California) for improving the English language of the text.

Disclosure Statement

No potential conflict of interest was reported by the authors.