ABSTRACT:
While most studies of the impacts of climate change have investigated shifts in the spatial distribution of organisms, temporal shifts in the time of activity are another important adjustment made by animals in a changing world. The most important environmental cycles that shape temporal activity patterns are temperature and light/dark cycles. Therefore, studies of subterranean organisms, which are not directly exposed to these cycles, have the potential to provide important insights into the interrelationships among abiotic variables, behaviour and physiology. In this work, we aimed to characterize underground and surface activity of Argentinean tuco-tucos from the Monte desert (Ctenomys aff. knighti) in semi-natural enclosures using bio-logging devices for individual, long-term recording of daily activity/rest (accelerometry) and time on surface (light-loggers). We verified the occurrence of modulation of time on surface by environmental variables, which were measured simultaneously to the experiment, in winter season. Activity bouts were detected both during day and night but majority of the highest values happened during daytime. The average total duration that these subterranean animals spent on surface was 3 h per day. Time on surface was modulated mainly by underground temperature, increasing when underground temperature was lowest. Finally, transport of these animals to the indoor laboratory and assessment of their activity rhythms under constant darkness revealed a switch in the timing of activity. Plasticity of activity timing is not uncommon among desert rodents and may be adaptive in changing environments, such as the Monte desert where these tuco-tucos live.
Link to the article: https://academic.oup.