Analyses of predation behavior of the desert shrew Notiosorex crawfordi

The desert shrew Notiosorex crawfordi is the smallest mammal in the arid and semiarid areas of North America. It displays ecological adaptations that allow it to colonize environments inhospitable for other species in the Order Soricomorpha. Little is known about the natural history of this species; hence, this work reports the characteristics of foraging behavior, prey items, prey size and bite effectiveness on prey items of similar or larger size than these shrews. The behavior in captivity of two individuals of N. crawfordi captured in Baja California Sur was analyzed in glass terrariums, recording the locomotion, posture, food preferences, prey manipulation and bite effectiveness. Preference for prey items collected from the same transects/habitat as the shrews and differing in size and belonging to different groups of Arthropoda was evaluated, revealing a greater preference for scorpions, which were attacked within 1 min of being placed in the terrarium. Observations of foraging behavior of captive desert shrews show that prey items from the different arthropod groups and lizards become paralyzed at the first bite. The behavior displayed by the prey suggested the potential presence of toxins in the saliva of N. crawfordi.