OBSERVATIONS ON THE DIET COMPOSITION OF THE GRAY SHREW NOTIOSOREX CRAWFORDI (INSECTIVORA), INCLUDING INTERACTIONS WITH LARGE ARTHROPODS

摘要

Observations were made on the natural history of the gray shrew, Notiosorex crawfordi, from Big Bend National Park, Brewster County, Texas. Mean weights and ranges recorded for juveniles, adult males and adult females were 0.42g (0.36 - 0.47), 4.83 (4.42 - 5.11), and 5.22 g (4.78 - 5.42), respectively. This nocturnal shrew feeds on a variety of arthropod and vertebrate prey species. Arthropods occurring most frequently in the fecal pellets of this shrew included beetles, grasshoppers and spiders. Vertebrate prey included several species of mice (Peromyscus, Perognathus and Reithrodontomys), lizards and snakes. In staged laboratory encounter trials, these shrews were capable of attacking, killing and feeding on large, formidable arthropods that occur sympatrically with this shrew, including tarantula spiders and scorpions. It also was shown that a bite from the tarantula, Aphonopelma hentzi can be lethal to this shrew. The behavioral interactions between shrews and these large arthropods are discussed.