Research

I am generally interested in various research questions related to eco-physiology of mammals, in particular thermoregulation and energy expenditure. This includes (but is not limited to) energy saving adaptations such as torpor use, heat production mechanisms such as nonshivering thermogenesis in brown adipose tissue or muscle or individual differences in physiological and  behavioural traits that influence survival.

More functions of torpor

I am fascinated by the ability of  heterothermic species to undergo torpor, thereby reducing body temperature and metabolic rate, enabling individuals to reduce energy demands and outlast energetic bottlenecks.

Interestingly, torpor is not only used by mammals to survive the cold and unproductive winter season, but has many more functions. For example, many species use torpor rather flexible in response to emergency situations, such as fires or storms. Furthermore, animals that are able to use torpor (flexibly) are likely to cope better with the challenges of climate change.

Figure1
Sugar gliders reducing body temperature in response to rainfall and high wind speeds (Nowack et al. 2015. Sci Rep)

Muscle NST

I recently also started to look into the mechanisms of heat production in mammals (non-shivering thermogenesis; NST). While heat production during cold exposure via UCP1 in the brown adipose tissue (BAT) is well understood, only about 20% of all endotherms possess BAT. Species lacking this mechanism are for example birds, marsupials, monotremes or domestic pigs and wild boar. One possible alternative mechanism of NST is heat production in muscle via Ca2+-cycling. The sarcoplasmatic reticulum Ca2+- ATPase 1a (SERCA1a) can produce heat without muscle contraction under the involvement of the protein sarcolipin. Me and my colleagues are currently investigating whether muscle NST is of significance for thermoregulation of new born wild boar.

FLIR0449
Thermal camera image of huddling piglets (picture: J.Nowack)

Personality

Individuals of one population are assumed to adopt different ‘pace of life syndromes’, which represent combinations of traits that together provide optimal ‘solutions’ to cope with different environmental challenges. E.g., Individuals with a high resting metabolic rate (energy expenditure) also tend to have bold and active ‘personalities’, and because they find more food, those ‘fast’ syndromes in turn grow faster and produce more offspring (and vice versa for individuals adopting ‘slow’ syndromes). On the other hand, this ‘fast’ syndrome is predicted to be costly in terms of accelerated physiological ageing.

Please get in touch if you are interested to find out more about currently running projects.