Chapter 3: Species Accounts In this chapter are individual accounts of the 14 species commonly found in South Carolina. They are arranged in alphabetical order by common name and provide information on identification, taxonomy, distribution, population status, habitat, behavior, reproduction, food habits, seasonal movements, longevity, survival, threats, and conservation measures. The current known distribution of each species is shown in the range maps and indicated by shaded South Carolina counties. Additionally, a summer and winter range are provided for the migratory silver-haired bat, a suspected range for the little brown bat is shown with crosshatching, and an asterisk indicates incidental records for the southeastern bat. This range map information is based on museum records, capture records maintained by the SCDNR, records from rabies testing maintained by the state’s epidemiology lab, and captures recorded in published and unpublished literature such as reports and scientific literature (Menzel et al. 2003a, Mary Bunch, SCDNR, pers. comm.). Size measurements based off of Menzel et al. (2003b) are shown in Table 5. Incidental records exist of the big free-tailed bat (Nyctinomops macrotis) and the federally endangered Indiana bat (Myotis sodalis) (DiSalvo et al. 1992, NatureServe 2017). However, these species are not addressed in this document due to their rarity in the state. Table 5: Size measurements of bat species in the southeastern US. Modified from Menzel et al. (2003b). SC Bat Conservation Plan CH 3: Species Accounts 49 Big Brown Bat (Eptesicus fuscus) head with a broad nose and powerful jaw. The pelage is dark above and light below and varies from glossy dark brown to pale. The ears and tragus are short and rounded. Taxonomy Currently there are 12 recognized subspecies (Wilson and Reeder 2005) of the big brown bat, and only Eptesicus fuscus fuscus has been confirmed in South Carolina (Kurta and Baker 1990). Distribution Big brown bats range from southern Canada © MerlinTuttle.org through southern North America into South Description America, and are present on islands of the One of the most widespread and abundant bat Caribbean (Harvey et al. 2011). In South species in North America, the big brown bat Carolina, they are distributed statewide and is ubiquitous in South Carolina. This species found in all four physiographic provinces (M. is the third largest bat in the state, and like A. Menzel et al. 2003). most bats is extremely beneficial ecologically. According to Whitaker (1995), in one summer Population Status a colony of 150 big brown bats consumes Considered the most common bat species enough adult spotted cucumber beetles to through most of its range, the big brown bat is prevent the production of 33 million of their ranked as Globally Secure (G5), Nationally larvae, a major pest of corn. This species is Secure (N5) and Subnationally Secure (S5) closely associated with humans, often (NatureServe 2017). It is currently classified roosting in human-made structures and as Least Concern (LC) on the IUCN Red List commonly using buildings as hibernacula. (Miller et al. 2008). However, this species is Because of this, wildlife control operators are listed as a Highest Priority species in the frequently hired to exclude them from homes. South Carolina 2015 SWAP (SCDNR 2015) Big brown bats are also known for their due to severe WNS-related mortality homing ability, though the release direction occurring in the northeast. from their roost played a large factor in the return rate. General Habitat The big brown bat is a habitat generalist Identification found in a wide variety of habitats, ranging The big brown bat is a medium sized bat, with from lowland deserts to timberline meadows males slightly smaller than females (Burnett (Furlonger et al. 1987). The abundance of this 1983). This species weighs 0.5 to 0.7 ounces species increases as one moves from the (14 to 21 gr) and has a wingspan of 13 to 15 Coniferous Forest Biome to the Deciduous inches (32 to 39 cm) (Harvey et al. 2011). Big Forest Biome of eastern North America brown bats have a relatively heavy body, (Kurta et al. 1989b), and is also abundant in black ears and wing membranes, and a large urban areas. In mountainous regions of south- SC Bat Conservation Plan CH 3: Species Accounts - Big Brown Bat 50 Colony size may depend partially on roost size as larger cavities of roost trees have been found to be correlated with larger numbers of reproductive female big brown bats (Willis et al. 2006). About 72% of adult females have strong maternity roost site or area fidelity and return to the natal roost in successive years, but only 10 to 30% of immature females do the same (Davis 1967, Brenner 1968, Mills et al. 1975). Males may roost with central British Columbia, males are known to females or in all-male occur at higher elevations than females colonies, but are most often solitary during (Fenton et al. 1980). In South Carolina, sparse summer (Davis et al. 1968, Barbour and vegetation was found to be the best predictor Davis 1969). Generally, summer roost sites of habitat use by big brown bats (Loeb and are located in buildings, hollow trees, rock O’Keefe 2006). crevices, tunnels, and even cliff swallow nests (Christian 1956, Barbour and Davis 1969, Roosts and Roosting Behavior Kurta 1980, Kurta and Baker 1990). Males During summer, big brown bat summer roosts may join nursery groups to form large late- can be found in hollow oak (Quercus) and summer colonies when young are able to fly American beech (Fagus grandifolia) (Barbour and Davis 1969). Torpor is regularly (Christian 1956, Kurta 1980). Maternity used during summer while day roosting by colonies were traditionally found beneath females. Males also use torpor, but they enter loose bark and in small cavities of pine, oak, it more deeply and use it more often than beech, bald cypress and other trees (Bat reproductive females (Hamilton and Barclay Conservation International 2015), but now 1994, Lausen and Barclay 2003). Night roosts often roost in human-made structures such as may include garages, breezeways, and house houses, barns, churches, attics, bridges, porches (Harvey et al. 2011). By August, behind chimneys, in hollow walls and in summer colonies begin to disperse (Barbour enclosed eaves (Barbour and Davis 1969, and Davis 1969). Kurta and Baker 1990). In South Carolina, two individuals in a bottomland hardwood During winter when the weather is extremely swamp were tracked to a maternity colony in cold, this species can be found hibernating in a hollow bald cypress (Carter 1998, Menzel caves, mines, rock crevices, storm sewers, 1998). Maternity colony size in the eastern and in attics, basements, and wall spaces of US ranges from 25 to 75 adults, but can vary buildings (Goehring 1954, Barbour and Davis from five to 700 individuals elsewhere (Davis 1969, Vonhof 1995, M. A. Menzel et al. et al. 1968, Kurta 1980, Mills et al. 1975). 2003). SC Bat Conservation Plan CH 3: Species Accounts - Big Brown Bat 51 In fact, buildings are considered the most roost (Brigham 1991). This species flies for important hibernacula for big brown bats in an average of one hour and 40 minutes each northwestern US, who may lose 25% of their night, with the majority of foraging activity pre-hibernation body weight by the end of the happening within the second hour after sunset hibernation period (Nagorsen and Brigham (Kurta and Baker 1990). Each night a few 1993, Maser 1998). They are known to enter foraging bouts are made, interspersed with and leave their hibernacula throughout the night roosting. Some individuals may even winter (Mumford 1958). Winter colonies follow the same feeding pattern on different rarely include more than a few hundred nights, and use the same feeding ground each individuals, but usually they are solitary or night (Harvey et al. 2011). found in small groups. Both sexes have been known to hibernate together (Whitaker and Big brown bats are known to forage in a wide Gummer 2000). However, not much is known variety of habitats including open areas such about the roost habits of big brown bats as fields or large gaps within forests, over during winter in South Carolina. water and lake edges, and foraging around lights in rural areas (Geggie and Fenton 1985, Reproduction Kurta and Baker 1990, Menzel et al. 2001b). Mating occurs between September and March Females are known to use an average foraging (Mumford 1958, Phillips 1966), and sperm is area of 1 mi2 (2.7 km2) compared to 2 mi2 (5 stored in the female’s uterus until spring when km2) for males (Wilkinson and Barclay 1997). fertilization takes place. Twins are usually When comparing activity in National Parks, born from May through July (usually early big brown bat activity was found to be lowest June) in the eastern US (Christian 1956, in fragmented rural parks and greatest in Barbour and Davis 1969). Gestation lasts 60 urban forest parks (J. B. Johnson et al. 2008). days, lactation lasts 32 to 40 days and young Additionally, within urban habitats foraging begin to fly at four to five weeks (Kunz 1974, activity was found to be lowest in commercial Kurta and Baker 1990). Only some females of areas and greatest in parkland and residential this species reproduce at the end of their first areas (Geggie and Fenton 1985). This species year (Schowalter and Gunson 1979), but may prefer foraging among tree foliage rather males reach sexual maturity by autumn of the than above or below the forest canopy first year (Christian 1956). The reproductive (Schmidly 1991), but in South Carolina has habits of this species are unknown in South been known to forage above the forest canopy Carolina.