1Anthropology and Geology, University of Cincinnati, 2Anthropology, University of Massachusetts, Amherst
April 17, 2020 9:30AM, Diamond 3
Among mammals, including anthropoid primates, the primary factors that affect mobility are body size (larger-bodied species move more than smaller ones), diet (frugivores and trophic omnivores are more mobile than folivores), and habit (terrestrial taxa have larger home ranges than arboreal ones). If similar factors hold for lemurs, we would expect the large-bodied (particularly frugivorous) extinct species to have been more mobile than smaller-bodied (particularly folivorous) extant ones. Yet multiple lines of evidence (e.g., low Retzius Periodicities, small semicircular canal size, small relative brain size) suggest that extinct lemurs were relatively inactive. If so, they may have had relatively small home-ranges, perhaps on par with smaller-bodied extant lemurs. We used strontium isotopes (87Sr/86Sr), which vary primarily as a function of geology, to compare mobility for four extant and four extinct lemur genera at two sites, Ankilitelo/Mikoboka and Ampasambazimba. Within each, we expected more mobile taxa to have more variable 87Sr/86Sr. We found no differences in median 87Sr/86Sr or variance between extinct and extant lemurs at either site (Wilcoxon and Bartlett p>0.05 for all comparisons). There were apparent but insignificant differences among individual genera (Kruskal-Wallis and Bartlett p>0.05). These results support low mobility for extinct lemurs, and suggest that extinct as well as extant Lemuriformes differ from anthropoids in having reduced activity levels. Unfortunately, small home ranges also make lemurs more vulnerable to extinction. It is imperative that remaining cover be protected and that connectivity among fragments be improved.
This project was supported by the National Science Foundation [BCS-1750598 to LRG and BCS-1749676 to BEC].