Energetics and Activity Patterns of Short‐Tailed Shrews (Blarina) on Restricted Diets

Several short—tailed shrews were maintained from December 1967 through March 1968 on mealworms in amounts equivalent to one—tenth of their body weight per day. Others lived during the same interval eating only cracked corn. Minimum resting metabolic rates of shrews on restricted diets averaged 2.18 cc ) 2 /g per hr; much less than rates previously reported for this species. Oxygen uptake of shrews while engaged in other behavior patterns was (in cc/g per hr): exploring 4.56; feeding, 6.22; hyperactivity, 11.63. Blarina demonstrated a short, continual activity pattern, and were active for only 16% of each day. The two factors most fundamental to the success of the species in cold—temperate climates are 1) its proclivity to eat almost anything of energy value, and 2) an activity pattern in which the overwhelming majority of time is spent inactive, at low, resting metabolism.