Michael A. Menzel

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.

Roost tree selection by northern long-eared bat (Myotis septentrionalis) maternity colonies in an industrial forest of the central Appalachian mountains

As part of a bat ecology research effort in managed forests, we tracked seven lactating northern long-eared bats (Myotis septentrionalis Trouessart) to 12 roost trees used by maternity colonies ranging in size from 11 to 65 individuals in the central Appalachians of West Virginia. Lactating females switched among roosts on average every 5 days. Roosts were located in nine tree species, with 11 roosts in tree cavities and 1 under exfoliating bark. Eight of the roosts were located in snags; the other four were located in cavities in living trees. Black locust (Robinia pseudo-acacia L.) snags were selected as a roost sites more than expected based on their occurrence in the forests we surveyed. Only 3 of the 24 habitat characteristics differed between actual roost trees and randomly located cavity trees. Structurally, actual roosts tended to be closer to neighboring trees than did suitable roosts in randomly located cavity trees. Tree species was an important factor that influenced roost tree selection, with black locusts being used significantly more than expected based on their abundance across the managed forest landscape we studied. All northern long-eared bat roosts were located in or below the forest canopy which suggests that solar exposure may not be as critical for selection of roost trees by maternity colonies of this species as opposed to other species of tree-roosting bat at more northern latitudes in North America. Although many previous studies have demonstrated the importance of old-growth habitat in providing roosting habitat for tree-roosting bats, use of roosting habitat and characteristics of roost sites have been little documented within intensively managed forests. Our research indicates that in managed, Allegheny hardwood-northern hardwood forests of the central Appalachians, short-lived, early successional species such as black locust may provide suitable roosting habitat for northern long-eared bats, as well as other species of bats. Published by Elsevier Science B.V.

Presence and absence of bats across habitat scales in the upper Coastal Plain of South Carolina

Abstract During 2001, we used active acoustical sampling (Anabat II) to survey foraging habitat relationships of bats on the Savannah River Site (SRS) in the upper Coastal Plain of South Carolina. Using an a priori information-theoretic approach, we conducted logistic regression analysis to examine presence of individual bat species relative to a suite of microhabitat, stand, and landscape-level features such as forest structural metrics, forest type, proximity to riparian zones and Carolina bay wetlands, insect abundance, and weather. There was considerable empirical support to suggest that the majority of the activity of bats across most of the 6 species occurred at smaller, stand-level habitat scales that combine measures of habitat clutter (e.g., declining forest canopy cover and basal area), proximity to riparian zones, and insect abundance. Accordingly, we hypothesized that most foraging habitat relationships were more local than landscape across this relatively large area for generalist species of bats. The southeastern myotis (Myotis austroriparius) was the partial exception, as its presence was linked to proximity of Carolina bays (best-approximating model) and bottomland hardwood communities (other models with empirical support). Efforts at SRS to promote open longleaf pine (Pinus palustris) and loblolly pine (P. taeda) savanna conditions and to actively restore degraded Carolina bay wetlands will be beneficial to bats. Accordingly, our results should provide managers better insight for crafting guidelines for bat habitat conservation that could be linked to widely accepted land management and environmental restoration practices for the region.

Stand age and habitat influences on salamanders in Appalachian cove hardwood forests

We surveyed cove hardwood stands aged 15, 25, 50, and ≥85 years following clearcutting in the southern Appalachian Mountains of northern Georgia to assess the effects of stand age and stand habitat characteristics on salamander communities using drift-fence array and pitfall methodologies from May 1994 to April 1995. Over a 60,060 pitfall trapnight effort, we collected 3937 salamanders represented by Desmognathus aeneus, Desmognathus monticola, Desmognathus ocoee, Desmognathus quadramaculatus, Eurycea bislineata, Gyrinophilus porphyriticus, Pseudotriton ruber, Plethodon glutinosus, Plethodon serratus, and Notophthalmus viridescens. Analysis of covariance with pitfall array to stream distance as the covariate showed that salamander species richness and diversity measures and numbers of Desmognathus aeneus and Desmognathus ocoee were highest in stands ≥85 years. Eurycea bislineata and Plethodon glutinosus were more abundant in stands ≤50 years old than in stands ≥85 years. Within cove hardwood stands, species richness and diversity measures and relative abundances of Desmognathus spp. and Gyrinophilus porphyriticus were negatively correlated with distance to stream. Species richness and diversity were positively correlated to amounts of emergent rock. Species richness, diversity and relative abundances of Desmognathus spp. were correlated with basal area within stands and extent of connected mesic, cove hardwood habitat and amount of cove habitat within 1 km radius among stands. Eurycea bislineata was negatively correlated with landform index, a measure of surrounding landform sheltering, and Plethodon glutinosus was positively correlated with elevation in cove hardwood stands. Our research indicates stand age is an important factor in explaining the abundance and community composition of salamanders in southern Appalachian cove hardwood communities. Because southern Appalachian woodland salamander communities are slow to recover and are substantially changed following disturbances such as clearcutting, populations in small, isolated cove hardwood stands might be more vulnerable to extirpation or may require longer recovery times than those in larger coves. Managers may need to assess habitat features such as cove extent and habitat connectivity to minimize impacts on these taxa by forest management activities in southern Appalachian cove hardwood communities.

Home-range Size and Habitat Used by the Northern Myotis (Myotis septentrionalis)

Abstract We examined home range size and habitat use of nine female northern myotis (Myotis septentrionalis) within an intensively managed forest in the central Appalachians of West Virginia. Using the 95% adaptive kernel method, we calculated a mean home range of 65 ha. Northern myotis used recent diameter-limit harvests and road corridors more than expected based on availability of these habitats. Intact forest stands and more open deferment harvested stands were used less than expected based on the availability of these habitats, although intact forest stands still constituted the overall majority of habitat used. Partial timber harvests that leave a relatively closed canopy appear to promote or improve northern myotis foraging habitat in heavily forested landscapes. However, the long-term ecological impacts on bats and other biota from this silviculturally unacceptable practice are unclear.

Forest to wildlife opening: habitat gradient analysis among small mammals in the southern Appalachians

Abstract We examined relative abundance as well as richness, diversity, and evenness values of shrews and rodents along habitat gradients associated with fescue (Festuca spp.)-dominated wildlife opening/forest ecotones in five high elevation, northern hardwood communities in western North Carolina. During 12 000 trap-nights, we collected 831 small mammals. Smoky shrews (Sorex fumeus), pine voles (Microtus pinetorum), white-footed mice (Peromyscus leucopus), and woodland jumping mice (Napaeozapus insignis) exhibited no significant differences along the wildlife opening/forest gradient. The relative abundances of masked shrews (S. cinereus) and red-backed voles (Clethrionomys gapperi) were highest along the edge ecotone between wildlife openings and the forest gradient. Relative abundance of deer mice (Peromyscus maniculatus) increased with increasing distance from the wildlife opening/forest edge. Measures of coarse woody debris (CWD), an important habitat component for many small mammal species, showed a strong gradient for increased loading from the wildlife openings to the forest interior. Abundance of deer mice was strongly positively correlated with CWD loadings. Our results show that habitat generalists such as the masked shrew respond favorably to the microhabitat heterogeneity produced along an edge.

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.

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.