Influence of Vegetation on Bat Use of Riparian Areas at Multiple Spatial Scales

Abstract

ABSTRACT Research on habitat use by bats typically occurs at a single fine spatial scale, despite recent work demonstrating the importance of considering multiple spatial scales when investigating vertebrate habitat selection. We assessed bat use of 118 stream reaches located throughout the Oregon Coast Range, USA, and measured vegetation characteristics at 3 spatial scales surrounding each of these locations. We used an information‐theoretic approach to determine vegetation characteristics most closely related to bat activity and a multilevel modeling approach to evaluate variation in bat activity at different spatial scales. Characteristics of vegetation at the finest spatial scale explained more variation in bat activity than did characteristics of vegetation at broader spatial scales, suggesting that fine‐scale anthropogenic or natural disturbance events that alter cover of shrubs or trees in riparian areas are likely to influence bat habitat use. The influence of vegetation on activity varied by species of bat and appeared to operate more strongly through constraints imposed by vegetation architecture than through influences on abundance of insect prey. This diversity of responses to vegetation characteristics among bat species suggests that the best strategy for biodiversity conservation over broad spatial scales is maintenance or creation of a diversity of riparian vegetation conditions. We recommend that land managers planning to manipulate riparian vegetation strive to create diversity in shrub coverage, canopy coverage, and open space above the stream channel to promote foraging habitat for all species.