November 12th 2019 13h: international seminar


Kevin UNO

Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10025, USA.


Isotopes & Ivory: Geochemical approaches to elephant ecology, paleoclimate, and wildlife forensics

An elephant tusk is a geochemical treasure trove that contains decades of life history and climate information. A stable isotope profile along the growth axis of a tusk yields a time series of elephant diet and body water. From this, temporal (i.e., seasonal) changes in vegetation and rainfall can also be reconstructed. In this talk, I will present multi-year tusk profiles from wild and zoo elephants that demonstrate the fidelity of tusks as recorders of elephant life history and their environments. I will also describe how my initial interest in stable isotopes as diet and climate proxies led to the development of radiocarbon as a wildlife forensics tool. Initially, we turned to bomb-curve radiocarbon dating to determine how fast tusks and teeth grow. From this, it was realized that the year of death of an elephant could be established with high precision. Since the age of ivory determines its trade legality, I now use radiocarbon to fight the illegal trade in ivory. I will present radiocarbon results from fourteen large ivory seizures that show ca. 90% comes from elephants killed within three years of the seizure date. The results confirm the recent rapid decline of African elephant populations and provide actionable intelligence for guiding policy and law enforcement efforts to save the elephant.

Kevin Uno is internationally renowned through his contributions using biogeochemistry and aiming at reconstructing past and extant terrestrial ecosystems. He is involved in numerous research projects, notably in Africa. He has collaborated with PALEVOPRIM since 2013.


Room 410, build. B35 (3rd floor, north wing), University of Poitiers.

Find out more

Consult all the news


Tél. : +33 (0)5 49 45 37 53

Guylaine REYNAUD

Tél. : +33 (0)5 49 45 37 26

Fax : +33.(0)5 49 45 40 17


Université de Poitiers – UFR SFA


Bât B35 – TSA 51106

6 rue Michel Brunet

86073 POITIERS Cedex 9