Twelve month heart rate and activity data for Bear 1 (female denning with cubs in 2009 and yearlings in 2010) and Bear 2 (female denning with yearlings in 2009 and giving birth to cubs in 2010). Average daytime heart rate (blue; 08:00-20:00), average nightly heart rate (red; 0:00-04:00 AM), and daily activity (black line) are shown. Initiation of denning, elevated heart rates following device implantation and during den visit in mid-December, and a shift towards nocturnal behavior in the fall are evident. An expanded plot of the daily activity during the second winter is included. Bear 2 gave birth to cubs in January 2010 with a reduction in both activity and heart rate seen in subsequent days.
Laske et al. BMC Physiology 2011 11:13 doi:10.1186/1472-6793-11-13