Plasticity of physiological parameters and adaptations to extreme seasonality in Galago moholi (Galagidae), a South African primate.

• Applicant: Professorin Dr. Kathrin Dausmann
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2009 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 126647649

• Final Report Year: 2014

Final Report Abstract

The results of our study present the first confirmation of heterothermy in G. moholi, and thus on a primate outside Madagascar. Moreover, our finding is yet another example of the flexibility of physiological parameters within animal populations, as earlier studies on the physiological strategies of G. moholi did not find any evidence of torpid states. Furthermore, our study highlights the potential of how flexible physiological responses can be employed for different ecological conditions and constraints. Although the general underlying physiological parameters seem to be comparable between G. moholi and other heterotherms in general or to Malagasy lemurs in particular, the underlying causes which elicit this physiological response, and thus the extent of expression and timing of heterothermy, have evolved very differently in the different groups, depending on body mass and the specific habitat and lifestyle of the species. The reluctance of G. moholi to enter torpid states, utilizing it only as a last resort in emergency situations, suggests that the underlying trigger of heterothermy varies from other heterotherms. Torpid states in a mainland strepsirrhine makes the plesiomorphic character of heterothermy more likely, with the possible implication that more primate species than previously thought have the potential to use heterothermy to reduce energy and water expenditure. This trait might also have helped for the colonization of Madagascar by mainland strepsirrhines, enabling them to survive long passages through unhospitable landscapes and better cope with the especially challenging and unpredictable habitat conditions of Madagascar. As it is unlikely that this trait evolved more than once in the evolution of strepsirrhine primates, this also suggests that heterothermy may have at least evolved in the primates before the division of African and Malagasy strepsirrhines, and might even be a plesiomorphic characteristic shared in all mammalian species.

Publications

• (2010) Torpor on demand: heterothermy in the non-lemur primate Galago moholi. PLoS ONE 5(5): e10797
  Nowack J, Mzilikazi N and Dausmann KH
  
• (2012) Afrotropical heterothermy: a continuum of possibilities. In: Living in a seasonal world. T. Ruf, C. Bieber, W. Arnold & E. Millesi (Eds.). Springer Berlin, Heidelberg, pp 13-27
  Dausmann KH, Nowack J, Kobbe S and Mzilikazi N
  
• (2013) Nonshivering thermogenesis in the African lesser bushbaby, Galago moholi. Journal of Experimental Biology 216: 3811-3817
  Nowack J, Dausmann KH and Mzilikazi N
  
• (2013) Surviving the cold, dry period in Africa: behavioral adjustments as an alternative to heterothermy in Galago moholi. International Journal of Primatology 34: 49-64
  Nowack J, Wippich M, Mzilikazi N and Dausmann KH
  
• (2013) Torpor as an emergency solution in Galago moholi: heterothermy is triggered by different constraints. Journal of Comparative Physiology B 83: 547-556
  Nowack J, Mzilikazi N and Dausmann KH
  
• (2014) Flexible patterns in energy savings: heterothermy in primates. Journal of Zoology 292: 101-111
  Dausmann KH
  
• (2014) Spicing up the menu: evidence of fruit-feeding in Galago moholi. Primates 55: 359-63
  Scheun J, Bennett NC, Ganswindt A and Nowack J
  
• Can heterothermy facilitate the colonization of new habitats? Mammalian review, Vol 45 Issue 2, April 2015, Pages 117-127
  Nowack J and Dausmann KH