Rafinesque's Big-eared Bat Research Articles

Development and characterization of 15 polymorphic microsatellite loci isolated from Rafinesque's big‐eared bat, Corynorhinus rafinesquii

We developed and characterized 15 microsatellite markers for Rafinesque's big-eared bat, Corynorhinus rafinesquii. In a population from Tennessee, the number of alleles per locus ranged from three to 13 and observed heterozygosities were 0.35 to 0.97 per locus. These loci will provide appropriate variability for estimation of population connectivity, demographic parameters, and genetic diversity for this species of concern.

Use and Selection of Bridges as Day Roosts by Rafinesque's Big-Eared Bats

Rafinesque's big-eared bats (Corynorhinus rafinesquii) use bridges as day roosts in parts of their range, but information on bridge use across their range is lacking. From May to Aug. 2002 we surveyed 1129 bridges (12.5%) within all 46 counties of South Carolina to determine use and selection of bridges as day roosts by big-eared bats and to document their distribution across the state. During summer 2003, we visited 235 bridges in previously occupied areas of the state to evaluate short-term fidelity to bridge roosts. We found colonies and solitary big-eared bats beneath 38 bridges in 2002 and 54 bridges in 2003. Construction type and size of bridges strongly influenced use in both years; bats selected large, concrete girder bridges and avoided flat-bottomed slab bridges. The majority of occupied bridges (94.7%) were in the Upper and Lower Coastal Plains, but a few bridges (5.3%) were located in the Piedmont. Rafinesque's big-eared bats were absent beneath bridges in the Blue Ridge Mountains. We established new records of occurrence for 10 counties. In the Coastal Plains, big-eared bats exhibited a high degree of short-term fidelity to roosts in highway bridges. For bridges that were occupied at least once, mean frequency of use was 65.9%. Probability of finding bats under a bridge ranged from 0.46 to 0.73 depending on whether the bridge was occupied in the previous year. Thus, bridges should be inspected three to five times in a given year to determine whether they are being used. Regional bridge roost surveys may be a good method for determining the distribution of C. rafinesquii, particularly in the Coastal Plains, and protection of suitable bridges may be a viable conservation strategy where natural roost sites are limited.

Roost Tree Use by Sympatric Rafinesque's Big-Eared Bats (Corynorhinus Rafinesquii) and Southeastern Myotis (Myotis Austroriparius)

Rafinesque's big-eared bats (Corynorhinus rafinesquii) and southeastern myotis (Myotis austroriparius) are uncommon throughout their range and are listed (informally) by the U.S. Fish and Wildlife Service as species of management concern. Much of the decline in numbers of these species can be linked to a loss of bottomland hardwood forests throughout their range, resulting in a loss of natural roost structures in many areas. We characterized day roosts of both species and determined differences in characteristics of roost trees in western Tennessee. Radio transmitters were attached to adult females of both species to aid in locating new roosts. Thirty-one roost trees were identified, with most (93.5%) being large hollow water tupelos (Nyssa aquatica). Only two roost trees were used by both species during the survey period and no simultaneous roosting was documented. Roost trees in our study typically had triangular-shaped basal openings and large diameters (129.2 ± 7.3 cm). A significant difference (P < 0.05) in roost-tree diameter was observed between trees used by the two bat species. Our study is the first to compare characteristics of tree roosts of sympatric populations of Rafinesque's big-eared bats and southeastern myotis. Results suggest that these species may have different preferences for roost trees.

Habitat Associations of Bottomland Bats, With Focus on Rafinesque's Big-Eared Bat and Southeastern Myotis

ABSTRACT Bottomland forests in the eastern United States are used by bat populations for both roosting and foraging. To quantify habitat characteristics important to bat presence in the Mississippi River alluvial valley, we measured forest habitat variables and related them to bat captures obtained in six management areas located near Jonesboro, Arkansas. Forest measurements included species composition, stem count, canopy height, basal area, canopy coverage and percent vegetative ground coverage for trees found in 120 0.03-ha circular plots from 12 bat capture sites. Principal component analysis was conducted on habitat data, and compared to bat captures by use of multiple regression analysis. Interaction effects due to the nested structure of the sampling design were measured with mixed linear models. We found significant correlations between total bat captures, composed of all captures for eight species and forests of high stem count and vegetative ground cover. Mixed model analysis revealed that Rafin...

Short-term Roost Fidelity of Rafinesque's Big-eared Bat (Corynorhinus rafinesquii) Varies with Habitat

Abstract Conservation of cavity-roosting bats must take into account their frequent movements among multiple roosts within a forest. One such species, Rafinesque's big-eared bat (Corynorhinus rafinesquii) is apparently rare or declining or both over its range. From 2001 through 2004 we captured C. rafinesquii at roosts located under bridges and used radiotelemetry to monitor movements of bats among roosts in southeastern Mississippi. We calculated an index of roost fidelity for individuals and compared indices based on sex, age-class, and location of capture (2 different sites). Of 25 different roost structures that we located, 14 were hollow trees and 11 were human-made (bridges, abandoned houses, and an oil tank). Overall, bats switched roosts every 2.1 days, changed roosts 2.6 ± 2.0 times (mean ± SD) per tracking period, and used 2.5 ± 1.2 roosts per tracking period. Bats that were captured together sometimes reunited at subsequent roosts. Dissimilarity in roosting opportunities between the 2 localitie...

Characteristics of Tree Roosts of Rafinesque's Big-eared Bat (Corynorhinus rafinesquii) in Southeastern Mississippi

Cavity-roosting species of bats generally require patches of forest containing older timber, but such habitats have been reduced in the southeastern United States. Rafinesque's big-eared bat, Corynorhinus rafinesquii, is a rare species for which data on natural roosts in the Gulf Coastal Plain (where caves are largely absent) are scant. We used radiotelemetry to locate tree roosts of C. rafinesquii in southeastern Mississippi from August 2001 until August 2004. We captured and radiotagged 25 bats that led us to 14 trees. Corynorhinus rafinesquii used hollow Nyssa spp. and Magnolia grandiflora. Most of these trees were still alive, relatively large (mean DBH = 79.4 cm, mean height = 18.5 m), possessed cavities with openings not located at their bases and were located adjacent to streams or other bodies of water. When bats shifted roosts among different trees, these sites were usually located nearby (mean distance ≅ 360 m). Tree roosts were apparently rare within the study area, and C. rafinesquii showed roost fidelity to particular areas of forest. Six tree roosts were used by multiple individuals and several trees were reused within tracking sessions and among years.

Influence of investigator disturbance and temporal variation on surveys of bats roosting under bridges

Given the importance of roost sites to bats, monitoring roost use is an important tool for assessing the local status of some species. We surveyed bridges for day-roosting bats in the Kisatchie National Forest of Louisiana to assess how temporal patterns of bridge use and disturbance from surveyors might affect survey results. We found no support for the hypothesis that surveys of day-roosts affected bat use of bridges. The 3 most common species roosting under bridges, Rafinesque's big-eared bats (Corynorhinus rafinesquii), eastern pipistrelles (Pipistrellus subflavus), and big brown bats (Eptesicus fuscus), exhibited strikingly different patterns of seasonal use. Because of seasonal variation in bridge use, a monitoring program would need to involve a minimum of a summer and a winter survey to document all common species that use bridges. Surveys during the day detected many more bats than surveys conducted at night. Although individuals tended to return to the same roosts over long periods of time, tagged bats often were absent during intervening surveys. Because individuals used multiple roosts, at least 3 surveys within a season will be necessary if an objective is to determine which specific bridges are used as roosts by locally abundant species.

Gastrointestinal Helminths of Rafinesque's Big-Eared Bat, Corynorhinus rafinesquii (Chiroptera: Vespertilionidae), from Southwestern Arkansas, U.S.A.

Three new host records and a new locality record are reported for helminth parasites of Rafinesque's big-eared bat, Corynorhinus rafinesquii, from Little River County, Arkansas, U.S.A. Nine of 10 (90%) of the bats harbored 1 or more of 3 parasites, including 1 (10%) with an immature Vampirolepis sp., 1 (10%) with a third-stage larva of Physaloptera sp., and 9 (90%) with female or ova of Capillaria palmata. All represent new host records for these helminths. Capillaria palmata is reported from Arkansas for the first time.

SEASONAL USE OF BRIDGES BY RAFINESQUE'S BIG-EARED BAT, CORYNORHINUS RAFINESQUII, IN SOUTHERN MISSISSIPPI

We conducted surveys of concrete bridges in southern Mississippi from 2000–2002 to determine the phenological pattern of use by Rafinesque's big-eared bat, Corynorhinus rafinesquii. The earliest dates on which we located maternity colonies were 9 March 2000, 20 April 2001, and 15 May 2002. Maternity colonies increased in size and abundance as spring progressed. Pups were born in mid- to late May (first observed 12 May 2000, 15 May 2001, 27 May 2002) and nursed through midsummer (lactating females last captured 14 July 2000, 25 July 2001, 16 July 2002). Colony size and percentage of bridges occupied by bats declined in late summer. Colonies were absent during fall and winter, although we occasionally found solitary individuals during these seasons. Number of bats present under an occupied bridge ranged from 1 to 25. The mean number of individuals per occupied bridge was 4.6 (SD = 5.8) in 2000, 3.9 (SD = 5.0) in 2001, and 3.0 (SD = 4.4) in 2002. The mean number of adult females per maternity colony was 5.6 (SD = 3.1). Although we found males throughout the study period, females were largely absent from bridges outside of the maternity season, suggesting that much of the population used alternate roosts during this time.

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 Rafinesque's 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.

Day-Roost Selection by Rafinesque's Big-Eared Bats (Corynorhinus rafinesquii) in Louisiana Forests

Day-Roost Selection by Rafinesque's Big-Eared Bats (Corynorhinus rafinesquii) in Louisiana Forests

Seasonal Use of Lepidopteran Prey by Rafinesque's Big-eared Bats (Corynorhinus rafinesquii)

We examined seasonal patterns in lepidopteran prey of Rafinesque's big-eared bat (Corynorhinus rafinesquii) by collecting culled moth wings from March to September 1998 from the floor of the entrance room to a sandstone cave used as a roosting site by a maternity colony. We identified 22 species and 6 families (Arctiidae, Geometridae, Megalopygidae, Noctuidae, Notodontidae and Sphingidae) in the diet of C. rafinesquii from 135 identifiable wings recovered from the cave floor. Twelve wings comprising >2 species of moths of the family Arctiidae were recovered, indicating that C. rafinesquii periodically preys on arctiids. Abundance of culled wings was highest from 24 May to 25 July. Mean wingspan of moth prey did not vary across seasons. We observed C. rafinesquii feeding at the entrance to the roost by gleaning moths from the walls and ceiling of the cave and by capturing moths directly in flight, confirming that this species does use more than one foraging strategy in capturing moth prey.

Roost Selection, Population Size and Habitat Use by a Colony of Rafinesque's Big-eared Bats (Corynorhinus rafinesquii)

Abstract Rafinesque's big-eared bat (Corynorhinus rafinesquii) is a species of concern throughout much of its range, with limited information available on the life history of this rare bat. We tracked patterns of population size, measured roost temperatures and used radiotelemetry to locate foraging areas of C. rafinesquii inhabiting a sandstone cave, which these bats used as both a hibernaculum and a maternity site. Counts of hibernating C. rafinesquii ranged from 14–49, with summer colony size reaching a maximum of 118 bats. Bats roosted in different rooms of the cave in winter and summer. Temperatures in a room used in winter were consistently cooler and less stable than temperatures in the room used as the maternity site. Size of foraging areas ranged from 61.6–225.3 ha, and distance of foraging areas from the roost varied from 0.12–1.22 km. We detected no bat >2.5 km from the roost of capture. Bats foraged along ridgelines supporting upland oak-hickory forest.

Food Habits of Rafinesque's Big-Eared Bat in Southeastern Kentucky

The diet of Rafinesque's big-eared bat ( Corynorhinus rafinesquii ) was determined from 94 fecal pellets and 86 culled wings of moths collected from four roosts and five feeding shelters in southeastern Kentucky. Seven orders of insects were consumed, with Lepidoptera occurring at >90% volume and 100% frequency in all samples, suggesting that C. rafinesquii is a moth-specialist. Five families and seven species of moths were identified from culled wings. The average wingspan for the species of moths was 45.4 mm ( SD = 8.4). This and other studies suggest that Corynorhinus preys primarily upon moths ranging in size from 31 to 57 mm.

First Record of Plecotus rafinesquii in Central Arkansas

A specimen of Rafinesque's big-eared bat, Plecotus rafinesquii macrotis, was collected at Camp Robinson, Pulaski Co., Arkansas. The specimen, a male, was taken on 23 March 1986 inside an abandoned building. The bat is deposited in the Tarleton State University mammal collection, Stephenville, Texas. In Arkansas, P. r. macrotis is only known to occur in the western and southern counties (Barbour and Davis, 1969; Jones, 1977; Sealander, 1979; Hall, 1981). This record from Pluaski County, Arkansas, is noteworthy, as it fills in the gap between Crawford and Drew Counties extending Rafinesque's big-eared bat into central Arkansas (Sealander, 1979).