Travis Brown

Travis Brown
Department of Biological Sciences
Murray State University

Mentor: Terry L. Derting

Title of Presentation: Effects of stream channelization and dechannelization on mammalian species and habitat in riparian corridors.

Presented at: Kentucky Chapter of the Wildlife Society

ABSTRACT
Stream channelization reduces the diversity and abundance of many taxa. Some channelized streams have been recently restored or "dechannelized" in order to reverse the negative effects of channelization. I investigated differences in habitat characteristics, mammal richness, and mammal activity among three stream types: channelized, unchannelized, and dechannelized. I measured mammal activity and richness at each stream type during four seasons (spring-winter 2005/06), and sampled physical and vegetative aspects of each stream during the summer of 2005. Riparian plant species richness was significantly higher at the unchannelized stream than the other two streams. The Kentucky Macroinvertebrate Bioassessment Index was highest at the unchannelized stream, slightly lower at the channelized stream, and much lower at the dechannelized stream. Mouse (Peromyscus, Ochrotomys, and Reithrodontomys spp.), vole (Microtus spp.), and short-tail shrew (Blarina spp.) activity did not differ among stream types. Richness of terrestrial mammals, as determined by motion-sensitive cameras, did not differ significantly among streams. Track plot surveys showed, however, that unchannelized and dechannelized streams had significantly more terrestrial mammal species richness than the channelized stream. Likewise, track transect surveys, conducted in snow, showed that species richness at the unchannelized stream was significantly higher than the channelized stream and that the dechannelized stream did not differ from the other two. There was some indication that bat activity was affected by an interaction between month and stream type. Although this interaction was not significant, post hoc tests revealed month-specific differences in bat activity among stream types. These results suggested that channelization and dechannelization affect habitat characteristics, mammal richness and mammal activity; however, dechannelized streams have potential to recover many of the characteristics of an unchannelized stream.