Rychlik, LeszekJancewicz, Elżbieta2011-10-192011-10-192002Behavioral Ecology vol. 13 no. 2, 2002, pp. 216–223http://hdl.handle.net/10593/1307Some predictions relating metabolic constraints of foraging behavior and prey selection were tested by comparison of food handling and utilization in four sympatric shrew species: Sorex minutus (mean body mass=3.0 g), S. araneus (8.0 g), Neomys anomalus (10.0 g), and N. fodiens (14.4 g). Live fly larvae, mealworm larvae and aquatic arthropods were offered to shrews as small prey (body mass <0.1 g). Live earthworms, snails and small fish were large prey (>0.3 g). The larvae were the highly nutritious food (>8 kJ/g) and the other prey were the low nutritious food (<4 kJ/g). The smallest S. minutus utilized (ate+hoarded) <30% of offered food, and the other species utilized >48% of food. The larger the shrew, the more prey it ate per capita. However, highly energetic insect larvae composed 75% of food utilized by S. minutus and only >40% by the other species. Thus, inverse relationships appeared between shrew body mass and mass-specific food mass utilization and between shrew body mass and mass-specific food energy utilization: the largest N. fodiens utilized the least food mass and the least energy quantity per 1 g of its body. Also, the proportion of food hoarded by shrews decreased with an increase in size. With the exception of S. araneus, the size of prey hoarded by the shrews was significantly larger than the size of prey eaten. Tiny S. minutus hoarded and ate smaller prey items than the other shrews, and large N. fodiens hoarded larger prey than the other shrews.enEnergy requirementsFood hoardingOptimal foragingStrategyPrey energetic valuePrey size preferencesArtykuł