Zoe Simmons
Research Mentor: Ethan Shirley
Mentor Department: Earth and Environmental Sciences / Museum of Paleontology, LSA
Author(s): Zoë Simmons, Ethan Shirley
Session: Session 6 (3:00 PM – 3:50 PM)
Presentation Type: Poster 26
Abstract
Well-preserved mammoth tusks from high latitudes of North America and Eurasia can provide a window through which to study the reproductive life history of woolly mammoths. Male woolly mammoth tusks from Siberia contain traces of testosterone that is higher in certain parts of the tusk than others (i.e., during different times in the animal’s life). These higher testosterone spikes likely correspond to episodes of “musth”, which in living elephants are violent phases of reproductive heat. However, we have not yet been able to show testosterone spikes in North American male specimens or measure the length of time between oscillations in growth rates. Here we present preliminary findings from three North American mammoths, one male specimen from the permafrost of Yukon and two female specimens from upstate New York. We used a micro-mill to drill along growth increments in tusk material to obtain fine tusk powder from specific times of the animals’ lives. We then measured the relative amounts of progesterone and testosterone in the powder samples using two methods: mass-spectrometry and enzyme-linked immunosorbent assays (ELISAs). Progesterone levels in one New York state mammoth were unusually high, likely indicating contamination. Testosterone levels in the male were within the range of those expected in permafrost specimens, and show spikes akin to those likely representing musth in Siberian mammoths. Growth increment measures in the female mammoth tusks show variability, but desiccation fractures render precise measurements difficult. North American mammoths likely show similar reproductive behaviors as those in Siberia, and more work will help clarify the similarities and differences in regional behavioral ecology of these species.
