Oral Presentation- Symposium 12th International Mammalogical Congress

Dietary ecology and consequences of drought events on extant macropods: Implications for conservation and palaeoecological reconstructions (#234)

Larisa DeSantis 1 , Graeme Coulson 2 , Eva Biedron 1 , Lindsey Yann 1 3 , Gregory Smith 1 , Clare Death 2 4 , Sarah Garnick 2 , Amishi Kumar 1 , Ellen Reat 1 5 , Anna Reside 1 , Elinor Scholtz 1 , Michelle Wilson 2
  1. Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, United States
  2. School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
  3. Oklahoma State University Center for Health Sciences, Tulsa, OK, USA
  4. Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, VIC, Australia
  5. Geology and Geophysics, University of Utah, Salt Lake City, UT, USA

As Australia is projected to experience more extreme droughts and ~0.8 to 2.8ºC temperature increases by 2050, it is critical to assess the effects of climate change on extant marsupials. Furthermore, our understanding of extant marsupials can help clarify the palaeoecology of extinct taxa, elucidating the consequences of climate change over longer time periods than are accessible to neontologists.  Dental microwear texture analysis (DMTA), the analysis of tooth wear surfaces in three-dimensions, records the dietary textures of consumed foods over the last few days to weeks of an animal's life - an effective tool for assessing diets just prior to the death of organisms, both today and in the past. We developed a DMTA baseline of extant macropods, including Dorcopsulus vanheurniMacropus fuliginosus, Macropus giganteusNotamacropus rufogriseus, Osphranter robustusOsphranter rufusPetrogale lateralisSetonix brachyurus, and Wallabia bicolor. Results demonstrate the ability of DMTA variables (e.g. anisotropy and complexity) to differentiate between tough and hard food consumers, i.e. extant grazers and woody browsers, respectively.  Further, when comparing M. giganteus and M. fuliginosus individuals that were killed during "normal" conditions to those killed during extreme droughts, DMTA reveals dramatic dietary shifts in both taxa to include more woody material, as inferred from significantly greater complexity, during periods of extreme aridity. These data reveal that mammalian dietary niches are not static, but change in response to extreme droughts, and DMTA is useful for identifying dietary ecology of extant and extinct macropods shortly before their death.