Timothy C. Carter

Effects of group selection silviculture in bottomland hardwoods on the spatial activity patterns of bats

Abstract The effects of forest management practices on the spatial activity patterns of bats are poorly understood. We determined the effect of group selection timber harvests on the spatial activity patterns of bats below the forest canopy at the Savannah River Site, Aiken, SC, using the Anabat system. We monitored the effect of group selection timber harvests on feeding and foraging activity of bats at three spatial scales: among habitats within a landscape, among harvested and unharvested areas in the stand where patches were harvested, and within an individual gap. Habitats examined included Carolina bays, unharvested bottomland hardwoods, bottomland hardwoods in which a group selection harvest occurred, and upland stands containing a hardwood/pine mix. Within the harvested stand, we compared the level of foraging and feeding activity among large patch cuts (gaps), small gaps, skidder trails, and forested areas. Within the large gaps, we compared activity among the center of the gap, the edge of the gap, and the forest surrounding the gap. Levels of bat activity differed among stands. More activity occurred in the bottomland stand in which patches had been harvested and around Carolina bays than in unharvested stands of bottomland hardwoods and upland hardwoods and pines. Levels of bat activity also differed among harvested and unharvested areas within the stand and among different positions within gaps and the surrounding forest. Activity was concentrated in forest gaps and along skidder trails. Within gaps, activity was concentrated along the edge between the gap and forest. Spatial activity patterns also depended on the species of bat. These results suggest that the inclusion of gaps in bottomland hardwoods increases the total level of foraging and feeding activity of bats below the canopy. They also suggest differences in the size and shape of the harvest affect the total amount of bat activity recorded in the gap and that these effects may be species specific.

Summer habitat use and home-range analysis of the endangered Indiana bat

JENNIFER M. MENZEL,1 U.S. Forest Service, Northeastern Research Station, Parsons, WV 26287, USA W. MARK FORD, U.S. Forest Service, Northeastern Research Station, Parsons, WV 26287, USA MICHAEL A. MENZEL, Alston & Bird, LLP, Atlanta, GA 30309, USA TIMOTHY C. CARTER, Southern Illinois University, Carbondale, IL 62966, USA JAMES E. GARDNER, Missouri Department of Conservation, Jefferson City, MO 65102, USA JAMES D. GARNER, Illinois Department of Natural Resources, Springfield, IL 62702, USA JOYCE E. HOFMANN, University of Illinois Museum of Natural History, Champaign, IL 61820, USA

Tree-roost Characteristics of Subadult and Female Adult Evening Bats (Nycticeius humeralis) in the Upper Coastal Plain of South Carolina

Abstract We radio-tracked 4 solitary subadult (2 male and 2 females) and 3 adult female evening bats (Nycticeius humeralis) to 7 and 14 roost trees, respectively, during the summer of 1997 on the Upper Coastal Plain of South Carolina. Roosts for both age-classes were located in cavities and under exfoliating bark in live trees and dead snags. Based on nightly exit counts, adult female evening bats roosted communally. Some roosts were presumed to be active maternity colonies. Five of six subadult roosts and one adult female roost were located under exfoliating bark on dead snags in beaver (Castor canadensis) ponds. Thirteen of 14 adult female evening bat roosts were located in cavities in live longleaf pines (Pinus palustris) in stands of relatively mature, park-like, pine plantations. One subadult roost was located under exfoliating bark in a live longleaf pine. No evening bats roosted in the more densely canopied, nearby bottomland hardwood stands, mixed pine-hardwood stands or loblolly pine (P. taeda) stands. Roost fidelity by individual evening bats was short (2.3 roost-days per bat) and did not differ between subadults and adult females. Although average daily maximum roost temperature was higher in subadult roosts than in adult female roosts, internal average temperature, daily minimum temperature and daily temperature range did not differ significantly between the two roost categories. Overstory height surrounding roost trees, canopy density and basal area of pine in the surrounding stand were greater at roosts within longleaf pine stands than those in beaver ponds. Conversely, stand basal area, overstory tree species richness, abundance of Spanish moss (Tillandsia usneoides) and basal area of hardwood trees were greater at roost sites within beaver ponds than those same measures in longleaf pine stands.

Indiana bats in the Midwest: The importance of hydric habitats

Abstract The endangered Indiana bat (Myotis sodalis) requires very specific habitats to provide necessary day-roosting and foraging resources during the spring and summer months throughout its distribution in the eastern United States. Maternity colonies of Indiana bats are almost always found under the exfoliating bark of dead or dying trees. Furthermore, they switch frequently among multiple roosts within large but still somewhat local areas. Therefore, habitats with large numbers of snags or decadent trees are needed to support Indiana bat maternity colonies. These habitats arise naturally and anthropogenically in a variety of ways. However, these conditions often are rare relative to other forest conditions. In the Midwest, such as southern and central Illinois, USA, maternity colonies are more commonly associated with bottomland, riparian, wetland, or other hydric forest types. It is unclear if this occurs because areas with large numbers of snags are more common in these habitats, if maternity colonies prefer these habitats for their foraging resources, or if decades of intensive agriculture have restricted colonies to these habitats. Because many large maternity colonies have been observed in hydric habitats of the Midwest, I hypothesize that these are preferred maternity habitats. Moreover, very few large maternity colonies have been located using upland forest habitats within the region. Elsewhere, such as in the central and southern Appalachians, maternity colonies have been located in upland areas where bottomland habitats are less extensive. However, these colonies are usually characterized by small numbers of bats and ephemeral persistence. Future conservation efforts for the Indiana bat should focus on protecting and regenerating bottomland habitats along the major river systems of the midwestern United States. It is within these bottomland and riparian habitats that future large and long-term maternity colonies will be established.

Review of the forest habitat relationships of the Indiana bat (Myotis sodalis)

Reviews the available literature on the ecology of the endangered Indiana bat (Myotis sodalis), including its selection and use of hibernacula, roost trees, and foraging habitat. An extensive list of published references related to the Indiana bat is included.

FOOD HABITS OF SEVEN SPECIES OF BATS IN THE ALLEGHENY PLATEAU AND RIDGE AND VALLEY OF WEST VIRGINIA

Abstract We captured 159 bats in the Allegheny Plateau and Ridge and Valley physiographic provinces of West Virginia during summer 1998, including the northern long-eared myotis (Myotis septentrionalis; n = 40), little brown myotis (M. lucifugus; n = 34), big brown bat (Eptesicus fuscus; n = 29), eastern pipistrelle (Pipistrellus subflavus; n = 27), eastern red bat (Lasiurus borealis; n = 22), hoary bat (L. cinereus; n = 5), and silver-haired bat (Lasionycteris noctivagans; n = 2). We analyzed fecal pellets of each bat to determine food habits. Diets of northern long-eared myotis and eastern red bats were dominated by Coleoptera (42.3 and 24.5%, respectively) and Lepidoptera (31.1 and 47.0%, respectively). Diet of big brown bats primarily consisted of Coleoptera (67.5%). Diet of hoary bats was dominated by Lepidoptera (98%). Diet of silver-haired bats was moderately diverse, but primarily composed of Lepidoptera (47.5%) and Diptera (20.0%). Diets of little brown myotis and eastern pipistrelles were highly diverse, consuming an even proportion of six orders of insects including Coleoptera, Hemiptera, Lepidoptera, Homoptera, Diptera, Hymenoptera, and Tricoptera. Diets of these seven species of bats did not differ notably from diet of each species reported from other regions of the eastern United States. Our results provide information about food habits of bats that are common throughout the central Appalachian Mountains.

Home Range and Habitat Use of Male Rafinesque's Big-eared Bats (Corynorhinus rafinesquii)

Abstract We examined home range size and habitat use of four reproductively active male Rafinesques big-eared bats (Corynorhinus rafinesquii) in an area of the Upper Coastal Plain of South Carolina during August and September 1999. Corynorhinus rafinesquii had biphasic activity patterns, with most foraging activity occurring during the first 4 h after sunset and 2 h before sunrise. Mean home range size calculated using the adaptive kernel method with a 95% use distribution was 93.1 ha. Although large contiguous tracts of mature bottomland hardwoods were common in the study area, most foraging activity occurred in young pine stands. Only 9% of foraging areas were in bottomland hardwoods.

Partitioning of Food Resources by Syntopic Eastern Red (Lasiurus borealis), Seminole (L. seminolus) and Evening (Nycticeius humeralis) Bats

Abstract We evaluated partitioning of food resources among syntopic eastern red (Lasiurus borealis), Seminole (L. seminolus) and evening (Nycticeius humeralis) bats at the Savannah River Site, South Carolina, from June through August of 1996 and 1997. We compared diets to indices of relative prey availability, which were based on samples of the insect communities in bat foraging habitats and the amounts of time the bats foraged in each habitat. The relative proportions of insect orders consumed differed among the species. We recorded only minor differences between insect consumption and indices of prey availability, as assessed by insect light traps placed within foraging habitats. Our data suggest that Eastern red bats and evening bats altered their prey selection late in the summer.

Prey Consumed by Eight Species of Insectivorous Bats from Southern Illinois

Abstract We collected data on the diet of eight species of insectivorous bats (Chiroptera, Vespertilionidae): big brown bats (Eptesicus fuscus), red bats (Lasiurus borealis), evening bats (Nycticeius humeralis), northern myotis (Myotis septentrionalis), little brown myotis (M. lucifugus), Indiana myotis (M. sodalis), southeastern myotis (M. austroriparius) and eastern pipistrelles (Perimyotis subflavus). Bats were mist netted during the summers of 1999 and 2000 at 41 forest sites throughout southern Illinois. We analyzed prey remains in fecal pellets of 305 individuals to assess diet similarity among species and relationships between bat body mass and prey diversity and hardness. Larger species included big brown bats and evening bats that ate primarily hard-bodied beetles (Coleoptera). These bats had the greatest dietary similarity index value compared with the other chiropterans in the community, and the highest hardness indices of prey consumed. Red bats, second only to E. fuscus in mean body mass, ate more soft bodied moths (Lepidoptera) and leaf hoppers (Homoptera) than beetles. Smaller bats, including three species of Myotis, consumed the greatest diversity of prey and were generally grouped together in diet similarity indices. Little brown myotis, northern myotis and Indiana myotis fed primarily on moths and beetles. Northern myotis and little brown myotis also fed extensively on spiders, suggesting significant gleaning behavior. Unlike other Myotis, the southeastern myotis had a low dietary diversity index and fed primarily on caddisflies (Trichoptera), as did eastern pipistrelles. Pipistrelles and myotines had the lowest hardness indices of prey consumed. Bats in southern Illinois exhibited landscape level (macroscale) feeding patterns consistent with the predicted relationship between body size and hardness of prey consumed, while at the local, site-specific level (microscale) they foraged with extensive overlap among similar-sized species, especially most Myotis. Regional differences in diets were minimal within the same assemblage of bat species in southern Indiana.

PLACEMENT OF NETS FOR BATS: EFFECTS ON PERCEIVED FAUNA

Abstract We used mistnets to survey bats at 41 sites throughout the Shawnee National Forest in southern Illinois during the summers of 1999 and 2000. Unlike most previous studies, we placed nets in the interior of forest stands as well as the more typical placement along edge habitats associated with water. We captured 417 individual bats representing 10 species. Of these, 168 individuals (40.3%) and 8 species were collected in interior forest. Northern long-eared bats (Myotis septentrionalis) were caught significantly more often in interior forest, whereas red bats (Lasiurus borealis), eastern pipistrelles (Pipistrellus subflavus), and big brown bats (Eptesicus fuscus) were netted more often in edge habitats. In contiguous forest, especially within the geographic range of M. septentrionalis, a more accurate measure of bat diversity and relative abundance is obtained by placing nets in interior forest as well as edge habitats.