Identifying the species of bats roosting in redwood basal hollows using genetic methods

Abstract

Bats frequently use basal hollows in trees to gain access to interior roost sites but it has been challenging to verify which species do so because it is difficult to capture bats or identify bats using acoustic methods at these locations. We employed noninvasive genetic sampling of guano to identify the species of bats that use basal hollows in redwood (Sequoia sempervirens) trees in coastal northern California. Guano was collected using screen traps suspended within the hollows of trees in the northern and central range of the redwood, in Del Norte and Mendocino County, California, respectively. A representative sample of 231 guano pellets from 104 trees was selected for analysis; 149 pellets from 63 trees amplified sufficiently for genetic sequencing. Species identification is possible for 8 of the 11 species that were assumed to occur in the study area, based on previous studies using two 190 bp regions of the 16S ribosomal subunit gene. Seven distinct species, subspecies or species groups were identified; all 7 were represented from samples in the northern study area whereas only 5 of these occurred within the central study area. The long-legged bat (Myotis volans) was the most frequent taxa identified. Genetic sampling to identify the species using roosts will be an important contribution to the conservation of bats. This method is noninvasive and appears more efficient than other methods, such as following radio-marked bats to basal hollows or attempting to capture bats as they enter or leave a hollow. New laboratory developments in this field, such as microarrays, when combined with sequencing, will open up domains of research on individual species and species composition at various temporal and geographic scales.

Citation

Zielinski, William J.; Mazurek, Mary Jo; Zinck, Jan. 2007. Identifying the species of bats roosting in redwood basal hollows using genetic methods. Northwest Science 81(2): 155-162