Temporal niche switching and reduced nest attendance in response to heat dissipation limits in lactating common voles (Microtus arvalis)

Reducing the time attending the nest can reduce the risk of hyperthermia, and may be the behavioral component resulting in lower milk production and hence reproductive output. Becoming more day active allows feeding and nursing of the pups during the rest phase to occur during the night at which lower ambient temperatures are expected in the field. In natural situations this strategy will increase heat dissipation and lactation capacity. Whether there are similar benefits associated with a longer ultradian period is currently unknown, but these are likely to result from decreased energy turnover at 30 °C. In conclusion, our study shows that lactating common voles facing heat dissipation problems re-organize their behavior in a way that can maximize heat dissipation capabilities and thereby optimize lactation capacity.