METHODS USED TO SURVEY SHREWS (INSECTIVORA, SORICIDAE) AND THE IMPORTANCE OF FOREST-FLOOR STRUCTURE

We examined shrew (Insectivora: Soricidae) capture rates using selecti ve (best-site) transects, linear transects, and drift-fence arrays to better understand how pitfall trap arrangement might affect our percep tion of shrew assemblages in the southern Appalachian mountains. Also, we studied the use of microhabitat structure (coarse woody or rocky d ebris) by shrews to determine how microhabitat selection might affect capture probabilities. The distributions of shrew captures were simila r at selective and linear transects, but different between either tran sect type and the drift-fence arrays (P < 0.05). Differences in the ef fectiveness of trap arrangements were apparently related to microhabit at use. We found a gradient of selection for habitat structure among S orex fumeus, S, cinereus, and Blarina brevicauda, although relationshi ps were weak. Captures of S. fumeus were most closely associated with the abundance of and distance to woody or rocky debris, and those of B . brevicauda were independent of these microhabitat factors. Caution s hould be used when comparing the results of surveys using different pi tfall trap arrangements.