Abstract
We conipared bat activity levels in the Coaslal Plain of South Carolina atnong 5 habitat types: forested riparian areas, clearcuts, young pine plantations, ature pine plantations, and pine savannas. We used time-expansion radio-microphones and integrated detectors to simultaneously monitor bat activity at 3 heights (30, 10, 2 mj in each habitat type. Variation in vegetative clutter among sanipling heights and arnttng habitat types allowed us to examine the differential effect of forest vegetation on the spatial activity patterns of clutter-adapted and openadapted bat species. Moreover, monitoring activitation 30, 10, and 2 m permitted us to also compare bat activity above and below the forest canopy. We detected calls of 5 species 01- species groups: eastern red/Seminole bats (
Lasiurus borealis/L.
seminolus) , eastern pipistrelles (
Pipistrellus subflavus), evening bats (
Nycticeius humeralis), big brown bats (
Eptesicus fuscus), and hoary bats (
Lasiurus cinerius). At 2 and 10 m, bat activity was concentrated in iparian areas, whereas we detected relatively low levels of bat activity in pland habitats at those heights. Activity was more evenly distributed across the landscape at 30 m. Bat activity levels above the forest canopy were almost 3 times greater than within or below the canopy. We detected significantly greater activity levels of 2 open-adapted species (hoary and big brown bats) above rather than within or below the forest canopy. However, activity levels of 2 clutter- adapted species (eastern red,'Seminole bats and eastern pipistrelles) did not differ above, within, or below the forest canopy Despite classification as a clutter-adapted species, evening bat activity was greater above rather than within or below he forest canopy. We believe our results highlight the importance of riparian areas as foraging habitat for bats in pine-dominated landscapes in the southeastern United Slates. Although acoustical surveys conducted below forest canopies can provide useful intitmiation about species composition and relative activity levels of bats that forage in cluttered environments, our results sl~owinga ctivity above canopy suggest that such data may not accurately reflect relative activity of bats adapted to forage in more open conditions, and therefore may provide an inaccurate picture of bat community assemblage and foraging habitat use.
Keywords
bat echolocation,
call structure,
pine plantations,
riparian area,
South Carolina,
souteast United States,
time expansion,
wing morphology
Citation
Menzel, Jennifer M.; Menzel, Michael A.; Kilgo, John C.; Ford, W. Mark; Edwards, John w.; McCracken, Gary F. 2005. Effect of habitat and foraging height on bat activity in the coastal plain of South Carolina. Journal of Wildlife Management. 69(1): 235-245.
