Record of Nile seasonality in Nubian neonates

ABSTRACT

The oxygen isotope compositions of bones (n = 11) and teeth (n = 20) from 12 Sudanese individuals buried on Sai Island (Nubia) were analysed to investigate the registration of the evolution of the Nile environment from 3700 to 500 years BP and the potential effects of ontogeny on the oxygen isotope ratios. The isotopic compositions were converted into the composition of drinking water, ultimately originating from the Nile. δ¹⁸O values decrease during ontogeny; this is mainly related to breastfeeding and physiology. Those of neonates present very large variations. Neonates have a very high bone turnover and are thus able to record seasonal δ¹⁸O variations of the Nile waters. These variations followed a pattern very similar to the present one. Nile δ¹⁸O values increased from 1.4 to 4.4 ‰ (Vienna Standard Mean Ocean Water) from the Classic Kerma (∼3500 BP) through the Christian period (∼1000 BP), traducing a progressive drying of Northeast Africa.

KEYWORDS:

• Aridity
• bones
• isotope ecology
• Nubia
• oxygen-18
• Sudan
• paleoanthropology
• paleoenvironment
• seasonality
• teeth
• weaning

Acknowledgements

The authors thank the archaeological mission of Sai Island, and also G. Escarguel and S. Legendre for help with statistical calculations. We thank T. Tütken and an anonymous reviewer for their constructive remarks and improvements of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by funding provided by the Institut Universitaire de France (CL).