GELIFES Seminars - Claudia Bieber

Claudia Bieber (University of Veterinary Medicine, Vienna)

How a small mammal can live a long life

The life history strategy of edible dormice (Glis glis)

Mammals show huge variation in life history strategies, with body mass seen as a primary axis in the evolution of the slow-fast life history continuum. Edible dormice (Glis glis), however, are small mammals with a long life and seem to contradict this general rule. In the talk I aim to explain the impact of pulsed resources and hibernation on the life history strategy in dormice. Dormice are pulsed resource consumers that are strongly adapted to the availability of beech seeds. They only reproduce in so called mast years and skip reproduction in mast failure years. In mast failure years, however, we observe extremely high survival rates but low recapture probabilities. With the help of implanted data loggers, we found that dormice can spend over 11 months in hibernation in these years. It seems that dormice have found a strategy to decrease the risk of predation by hiding in hibernacula deep below ground.

By decreasing external mortality, it pays to invest in somatic maintenance and to increase cellular repair mechanisms. Since cell replication is arrested during hibernation, we investigated the impact of hibernation on telomers in dormice. Interestingly, telomers are negatively affected and shorten during hibernation, due to the negative impact of periodic arousals. However, dormice are able to prolong telomers during the last part of the hibernation and during the active season. Finally, I will address effects of age on hibernation patterns and life history decisions. Since dormice can “switch” between a state of high survival (hibernation) and lower survival (active season), is seems likely that, with increasing age and less opportunities for further reproduction, older dormice should extend their active season. Whether this is the case, and further details (i.e., effects of age on telomers), will be explained in the talk.

Biosketch
Claudia studied Biology in Marburg, Germany. After her PhD and a lecturer position in animal ecology in Marburg, she moved to Vienna in 1996 and became a research assistant at the Research Institute of Wildlife Ecology (FIWI) at the Veterinary University Vienna. Already during her PhD project Claudia worked on population ecology in edible dormic. At FIWI she got the opportunity to broaden her research aspects on effects of hibernation on survival and aging in this species. In a long-term field project on edible dormice in the Vienna woods, as well as with an enclosure-housed colony, Claudia is still busy with her research on dormice. The finding that hibernation has to be seen as a flexible life-history tool is one of the most important outcomes of these projects. During her research on dormice, Claudia became fascinated by the strong impact of pulsed resources on life history strategies and started to investigate population dynamics and impact of climate change in another pulsed resource consumer, the wild boar (Sus scrofa). Claudia received her habilitation in 2015 and is now co-leader of the ecophysiology group at FIWI. She is an Associate Editor of the Journal of Applied Ecology.

Link to seminar