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Terrestrial, marine, and freshwater habitats in the South are home to 246 mammalian species (NatureServe 2000). The number of mammals ranges from 176 species in Texas to 62 species in Mississippi. One hundred two species are in Georgia, 101 in South Carolina, 96 in Oklahoma, and 95 in Florida. The total includes rodents, carnivores, bats, whales, dolphins, and other mammals (Figure 6).
This vertebrate group comprises 11 major orders and 26 families (Echternacht and Harris 1993). All but five families have one or more sensitive species (Laerm and others 2000). These families include Didelphidae (opossum), Dasypodidae (armadillo), Castoridae (beaver), Myocastoridae (nutria), and Suidae (wild boar). The order Rodentia dominates the region's mammalian fauna in the number of different species. This order includes chipmunks, squirrels, pocket gophers, mice, rats, voles, muskrats, nutria, and beavers. Examples of carnivores include the Florida panther, red fox, bobcat, river otter, and mink. The category of "other mammals" in Figure 6 includes the Florida manatee, white-tailed deer, eastern cottontail rabbit, opossum, armadillo, shrews, moles, and several other species.
Five mammal species are known or presumed to be extinct or extirpated from the region. These are the jaguar, ocelot, gray wolf, elk, and bison (Echternacht and Harris 1993). Beavers were once extirpated in the South but were reestablished over the past two decades.
Endemic species represent a relatively small percentage of the mammals in the region. Eight rodent species are endemic to the Coastal Plain: the southeastern pocket gopher, colonial pocket gopher, Sherman's pocket gopher, Cumberland Island pocket gopher, oldfield mouse, Florida mouse, Perdido Key beach mouse, and round-tailed muskrat (White and others 1998). The region also has eight species of introduced mammals, including the coyote, wild boar, and nutria.
Thirty-three species of mammals are listed as threatened or endangered (Table 12). These include the Key deer, red wolf, Louisiana black bear, Indiana bat, gray myotis, Virginia northern flying squirrel, and southeastern beach mouse. Ten of the listed rodent species inhabit the Coastal Plain of Florida or Alabama.
In addition, 12 species are classified as imperiled or vulnerable under the Natural Heritage system (CHAPTER TERRA-1). These include the Rafinesque's big-eared bat, gray-footed chipmunk, round-tailed muskrat, Allegheny woodrat, and swift fox. These species are in jeopardy due to habitat loss, land-use change, human disturbance, and coastal development.
The white-tailed deer is the most widespread browsing species represented in the region today. Elk have recently been reintroduced into selected locations. The absence of large carnivores (wolves, jaguar) reflects history since European settlement (CHAPTER TERRA-1). The black bear is the largest carnivore now in the South. Four wild canids occur in the region. The coyote has expanded its range, while the red wolf is critically imperiled due to habitat loss and hybridization with other canids. Red and gray foxes remain relatively common. The Florida panther is in jeopardy, while the bobcat remains widespread throughout the region.
The absence of large predators has encouraged the proliferation of raccoons, opossums, and skunks. These species demonstrate broad ecological tolerance, inhabiting virtually every type of habitat available. They consume a variety of foods: frogs, turtles, snakes, mice, berries, and other vegetation. These mammals are rapidly becoming urban wildlife in many communities of the South.
Rodents are a diverse group that persists in abundance in many areas. They tend to have high birth rates that permit the maintenance of stable populations despite predation pressure and control measures. The rodent species that are most at risk in the South have narrow distributions. In beach habitats, feral cats represent a significant threat. Pesticide residues affect shrews and other insectivores. The fox squirrel that inhabits longleaf pine savannas is threatened by fire suppression and land-use conversion (White and others 1998).
The absence of mountain barriers and other opportunities for isolation and speciation contribute to the lack of species richness among squirrels and burrowing mammals (Echternacht and Harris 1993). The eight species of sciurid rodents in the region include the 13-lined ground squirrel, gray squirrel, fox squirrel, and two flying squirrels. The region's 10 burrowing rodents include the hairy-tailed mole, eastern mole, and star-nosed mole; woodchuck; eastern chipmunk; and five species of pocket gophers. Soil type is the primary factor determining the ranges of pocket gophers.
The following sections discuss the habitat needs for two of the highest profile groups of mammals: bats and carnivores. Additional species are also profiled in the species account section that concludes the segment on mammals.
The 20 species of bats in the South are key components of forested ecosystems. Four bats are listed as endangered: the gray bat, Indiana bat, and Ozark and Virginia big-eared bats (Table 13). The southeastern bat, the eastern small-footed bat, Rafinesque's big-eared bat, and Wagner's mastiff bat are of special concern.
Forest bats depend on forests for shelter, roosting sites, and foraging areas. Bats are in two major classes: cave bats and tree bats. Cave bats inhabit caves during all or part of the year, while noncave species seldom enter caves. Some of their ranges are limited to relatively small geographic areas. Insectivorous bats have tiny eyes and are capable of sight, but most species locate prey by echolocation.
Bats hibernate in a variety of locations including leaf litter, woody debris, caves, hollow trees, and rock crevices. Many species hibernate under exfoliating bark and in tree cavities, mines, and buildings. Roosting sites range from solitary sites to caves containing thousands of individuals. Sites selected for roosting and hibernation meet precise environmental conditions, such as stable temperatures and high relative humidity. Disturbance often results in the abandonment of the site.
Bats have evolved to fill a variety of food niches. These mammals begin foraging at dusk. The diet varies by species, and consists of insects and other arthropods.
Widespread pesticide use caused significant declines in bat populations during the past several decades (Harvey and others 1999). This threat has diminished somewhat with pesticide use regulations. The current threat to bats stems from habitat destruction and cave disturbance. Few caves meet the narrow temperature and humidity requirements for hibernation. The large numbers of bats occupying specific caves make these species vulnerable to disturbance of an individual cave.
Various locations are used as maternity roost sites. Snags are used by Indiana, northern, and evening bats, while hollow trees are important for Rafinesque's and southeastern bats. A particular threat is human disturbance to hibernation and maternity colonies. Hibernating bats wake when disturbed, and expend critical winter stores of fat. Summer maternity colonies have low tolerance of disturbance; disturbed parents will often abandon their offspring. Bats produce an average of one offspring per year, but some species give birth to three or four babies at a time. The low rate of reproduction results in populations that can be quickly destroyed with little opportunity for recovery. Other adverse impacts include habitat destruction, direct killing, vandalism, and predation by raptors, raccoons, skunks, and snakes (Tuttle 1995).
A number of forest management actions can enhance bat habitat. Seedtree and shelterwood harvests open up forest canopies, creating foraging opportunities by reducing branch obstructions (Krusic and others 1996). Retention of cavity trees and snags, creation of large snags, and designation of streamside zones also are beneficial (Kulhavy and Conner 1986, Harvey and Saugey 2001). The creation of ponds can also enhance habitat by providing water, breeding sites, and a source of insect prey (Wilhide and others 1998).
Even-aged poletimber stands often are unsuitable for bole and cavity users, and do not provide the cavities and bark characteristics preferred by bats (Pierson 1998). Clearcutting eliminates roosting opportunities until replacement trees of suitable size become available (Harvey and Saugey 2001). However, the resulting availability of herbaceous growth results in increased insect populations (Barclay and Brigham 1998). Stand rotations long enough to allow for cavity development are important for species that require cavities.
Prescribed burning can enhance invertebrate biomass by reducing midstory trees and shrubs, allowing the regeneration of herbaceous plants. The resulting canopy gaps provide additional foraging opportunities. However, fire may jeopardize bats hibernating on the ground during winter when they are torpid and slow to arouse (Harvey and Saugey 2001). The impact of dormant-season burning on species that roost in ground litter is unclear. Snags used by bats may be felled by fire if their bases burn through, resulting in the loss of cavities or roosting sites under exfoliating bark.
Finally, recreational caving should be minimized to prevent disturbance to maternity and hibernating colonies. Properly designed gates on cave entrances afford the best protection. Other protective measures include limiting the use of pesticides and preventing destruction of habitat.
Carnivores are a viable component of the southern landscape whose management has changed significantly over the last several decades. The perception that carnivores must be eliminated is no longer widely held. These mammals contribute to ecosystem stability by controlling rodent populations.
There are few reliable density estimates for furbearers because they are secretive and difficult to census. Most are territorial. Population density is relatively low, reflecting their position at the top of the food chain. Two carnivores (the bobcat and river otter) are protected under the Convention for the International Trade of Endangered Species of Fauna and Flora (CITES) and are monitored closely by States that allow harvest of these species (Leopold and Chamberlain 2001).
The diet of carnivores is primarily composed of other animals. Bobcats, river otters, weasels, and mink characteristically have diets in which animal material exceeds 95 percent. The amounts of fruits, berries, and seeds vary with seasonal availability. For example, gray and red fox foods change from animal foods in the fall and winter to invertebrates and fruits during spring and summer.
Each species is associated with specific habitats that provide required food, water, and cover. Often, areas that are diverse in vegetative composition, structure, and seral stage are inhabited by a diversity of these mammals. A substantial number of carnivores depend on forested ecosystems to provide one or more habitat requirements. Mosaics of cover types and the ecotones between successional stages enhance prey and other food diversity. The structural components important to many mammals include mature trees, standing dead trees, woody debris, and patchy understories. Structural diversity and decaying trees provide suitable cover and foraging habitat.
Habitat quality determines the stability of these populations, while habitat loss is the primary threat to these species. Habitat modification influences species distribution and abundance. Forest clearing, grassland conversion, irrigation, and wetland drainage have improved habitat for some species and damaged habitat for others. The expanded range of the coyote throughout the South resulted from urbanization and the removal of large predators such as red wolves and Florida panthers.
Species with restrictive habitat requirements are vulnerable to losses of habitat. The swift fox depends on native shortgrass prairie communities; its range has become restricted due to the conversion of prairies into cultivated fields. Mammals associated with wetland habitats are not very resilient to habitat modification. For example, river channelization reduces habitat suitability for river otters (Allen 1988).
Large mammals such as the red wolf, Florida panther, and black bear have extensive home ranges. The maintenance of a mosaic of vegetation types and multiple seral stages supports prey populations and the food-producing plants that comprise the diet of these species. In contrast, the majority of carnivores depend on much smaller geographic areas. These species rely on a diversity of cover types in relatively close proximity to provide seasonal cover and food. Red foxes, gray foxes, and weasels are associated with early to mid-successional vegetation and the ecotones between these communities. Management that maintains fencerows, shelterbelts, and riparian vegetation will benefit these species and enhance their distribution.
The elimination of woody debris influences small mammal populations and makes them easier prey for associated predators. Timber harvest and prescribed burning change vegetation composition and enhances understory growth. However, timber removal may harm other mammals that require mature forest. In some cases, the protection of critical habitat may be the preferred management strategy.
Conservation of wetland carnivores centers on prevention of wetland degradation. Vegetative structure, surrounding land use, water quality, and cover diversity influence habitat quality for these mammals. For example, the manipulation of water levels and the planting of desired vegetation can enhance habitat. The maintenance of water availability and prey species also improves habitat potential. Debris and structural diversity along shorelines enhance prey availability for river otters. The removal of aquatic shoreline vegetation reduces availability of prey for mink.
Important habitat features for carnivores as well as other mammals occurring in the South are summarized in Table 14. Detailed information for selected species in presented in the following section.
Beaver. This species was extirpated from most of its southern range by the 1950s due to extensive trapping that began in the seventeenth century. Restocking programs in Louisiana, Mississippi, Alabama, Florida, Georgia, Oklahoma, Virginia, Arkansas, and North and South Carolina have led to viable populations across most of the South (Jones and Leopold 2001).
Beavers use freshwater habitats such as ponds, small lakes, and streams. Slow-moving streams and creeks with proximity to trees and shrubs that provide a food source are important. Beaver damming can flood forests, causing substantial economic impact from prolonged flooding. However, beavers create a complex successional mosaic of aquatic and terrestrial habitats that enrich landscape diversity. The creation of wetlands positively influences ground water, water quality, structural diversity, and erosion resistance. Beaver impoundments create favorable conditions for fish, birds, and amphibians. Beaver ponds on intermittent streams provide aquatic habitat conducive to the river otter.
River channelization significantly affects habitat quality by reducing amounts of riparian vegetation, macroinvertebrates, and fish biomass. The modification of river flow rates also reduces the number of islands occurring in the channel, impacting potential den habitat.
Black bear. Black bears historically ranged over most of the South. Habitat loss, fragmentation, and unrestricted harvest have significantly changed their distribution and abundance.
Their current distribution is restricted to relatively undisturbed forests in the Appalachian Mountains and the Interior Highlands of Arkansas, and in scattered coastal areas from Virginia to Louisiana (Vaughn and Pelton 1995). Populations appear to be secure and increasing in parts of Virginia, Tennessee, North Carolina, northern Georgia and northern South Carolina, where they support regulated hunting seasons. In Tennessee, the species is known only from the mountains in the eastern part of the State (Chapman and Laerm in press). In Kentucky, the black bear is designated as a Species of Special Concern. Texas biologists indicate there is no resident breeding population there.
Two subspecies are of special concern. The Louisiana black bear is designated as threatened on the Federal species list and as endangered by the States of Mississippi, Louisiana and Texas. The Florida subspecies is listed as threatened by the Florida Game and Fresh Water Fish Commission. Until recently, this subspecies was considered for protection under the Federal Endangered Species Act. Both subspecies populations are restricted to islands of public land and inaccessible areas of bottomland forest.
Black bears inhabit diverse forest habitats, and are often found in oak-hickory and mixed mesophytic forests. Forested areas of 150 to 300 square miles with limited human intrusion are needed to sustain viable populations. In coastal areas, the species occupies pocosins, hardwood bottomlands, Carolina bays, mixed hardwood hammocks, cypress swamps, pine flatwoods, and sand pine scrub. Black bears need dense understory cover, such as laurel thickets and greenbriar, to provide refuge cover in the Coastal Plain.
Adequate denning cover is a necessary component of black bear habitat in the South. Such cover includes cavities in large trees, logs, stumps, rock outcroppings, and impenetrable thickets. Females and cubs are very susceptible to disturbance. Black bears need secure corridors to make seasonal movements for food, for dispersal of younger animals, and for movement by males during the breeding season (Pelton 2001).
The diet of black bears is primarily hard and soft mast, including berries, nuts, acorns, wild cherries, and grapes, as well as invertebrates. In some areas, bears feed on agricultural crops such as corn, wheat or soybeans. Black bears will occasionally eat opossums, armadillos, feral pigs, raccoons, and young white-tailed deer.
The seasonal variations in availability of soft and hard mast influence shifts in home range to locate these foods. During periods of drought and food scarcity, bears further disperse and become victims of vehicular accidents, nuisance control, and illegal hunting.
Bear populations in the Southern Appalachians have been monitored since the 1960s. Although bear populations have increased during this period, the illegal trade in bear gall bladders has raised concerns about the effect of poaching. Because bears have low reproductive rates, their populations recover slowly from losses.
Habitat degradation continues to threaten black bears in the South. Forest fragmentation and the conversion of forests to agriculture, urban development, and pine monocultures restricts available habitat (Pelton 2001). The fragmented nature of black bear populations in the Coastal Plain may contribute to a loss of genetic diversity. As the human population in the South continues to expand into bear habitat, increased incidents of road kills are being reported in North Carolina, Tennessee, and Florida. As people settle into established bear ranges, increased human-bear interactions are inevitable. Poaching and increased access capabilities can result in over-exploitation.
Components of black bear management include hunting access, habitat, protection, nuisance control, education, and research (Pelton 2001). Access can be restricted through road gating, designation of no-hunting zones, and provision of escape cover. Habitat management includes oak enhancement, protection of old growth (for den trees), and management of forest openings for soft mast production. The establishment of black bear sanctuaries and viable corridors on public land has protected bears in the region (Vaughn and Pelton 1995). Texas has proposed the establishment of bear "recovery zones" through a partnership among Federal and State agencies, forest industry, and other owners of large parcels of timberland. Stringent law enforcement also is required to reduce illegal hunting. Finally, State biologists suggest that education of the general public is critical to increase awareness and acceptance of regulations such as those that discourage feeding of bears.
Bobcat. Bobcats are found throughout the South with the exception of northcentral Kentucky, coastal Louisiana, and eastern Virginia (Leopold and Chamberlain 2001). Population density varies according to habitat type and prey density.
Bobcats use several habitats, preferring areas with dense understory vegetation that supports prey populations. A mixture of mature and early-successional forest habitats is best. Other habitats include agricultural fields and pastures. Home ranges of bobcats throughout the Southeastern United States range from less than 740 acres to 17,830 acres. Home ranges may reflect road avoidance. Important prey species include rabbits and various rodents, opossum, game birds, and snakes (Chapman and Laerm in press).
There are no major threats to bobcats in the South due to their wide distribution and ecological tolerance. Potential risks include overharvest by trapping, forest fragmentation, and road construction.
Carolina Northern Flying Squirrel and Virginia Northern Flying Squirrel. These two endangered subspecies inhabit high-elevation sites in the Southern Appalachians. The Carolina squirrel occurs in isolated locations in North Carolina and Tennessee, while the Virginia subspecies is in Virginia and West Virginia. The disjunct distribution of these subspecies in the Southern Appalachians suggests they are relicts that have become isolated in small patches of suitable habitat by changing climatic and vegetation conditions since the last Ice Age (U. S. Fish and Wildlife Service 1990b).
Flying squirrels are associated with high-elevation boreal habitats, especially spruce-fir and northern hardwood forests (Fridell and Litvaitis 1991). They occur in conifer-hardwood ecotones consisting of red spruce and fir associated with mature beech, yellow birch, maple, and several other species. Widely spaced, mature trees and snags provide cavities for nesting. Understory components do not appear to be important habitat components of northern flying squirrel habitat (U. S. Fish and Wildlife Service 1990b).
Their diet consists of lichens, fungi, seeds, fruit, staminate cones, and insects. Periodic dependence on certain species of fungi may be a factor in restricting the species to high-elevation, mesic habitats (U. S. Fish and Wildlife Service 1990b).
The limited range of this species makes it vulnerable to natural and human-related impacts. Isolated populations suffer from insufficient gene pools. Other concerns include habitat destruction, insect pests such as the balsam wooly adelgid and the gypsy moth, recreational use, acid rain (which contaminates their mycorrhizal food source), and heavy metals (lead, copper, nickel, zinc, and manganese) in forest litter and soil (U. S. Fish and Wildlife Service 1990b).
Conservation strategies include determination of species distributions, protection of occupied sites from human-related disturbance, and implementation of habitat management guidelines on national forests and parks.
Coyote. The distribution of coyotes has extended into the South during the past few decades in response to the elimination of gray and red wolves from their former ranges. Prior to 1970, red wolves were common throughout the South, but trapping and poisoning eliminated free-ranging populations. Gray wolves also once inhabited Kentucky, Tennessee, Virginia, and North Carolina. Removal of these two species contributed to coyote expansion. Leopold and Chamberlain (2001) indicate that coyote populations have expanded throughout the South, with the exception of southern peninsular Florida. The current population density of coyotes is unknown.
Coyotes occupy a broad range of habitats and occur in grassland, forest, agricultural fields, and urban areas. In the South, this species has been observed in open fields, brushlands, thickets, young forest, and forest-edge habitats. Habitat use by coyotes in the South is diverse, and reflects their opportunistic feeding habits.
Their diet includes rabbits, small mammals, ground-nesting birds and their eggs, amphibians, lizards, fish, snails, crustaceans, insects, carrion, fruits, and plant roots (Chapman and Laerm in press).
There are no known threats to coyote survival in the region. Animal damage control programs in the Western United States have been unsuccessful.
Florida Panther. The Florida panther, one of 30 subspecies presently recognized, is the only subspecies of mountain lion remaining in the South. The species originally ranged from eastern Texas eastward through Arkansas, Louisiana, Mississippi, Alabama, Florida, Georgia, and portions of Tennessee and South Carolina. Due to large-scale habitat destruction and indiscriminant shooting, panthers were extirpated throughout most of their range by the early 1900s. Although periodic sightings are reported in remote areas of selected States, it is unlikely that viable populations exist outside of Florida. Currently, the population is estimated at between 20 and 5O animals.
Panthers prefer large remote tracts that are typically heavily vegetated and have minimal human disturbance. These animals use highly diverse habitats including hardwood hammocks, saw-palmetto woodlands, sawgrass prairies, cypress strands, and oak-pine woodlands. Home ranges average 200 square miles for males and 75 square miles for females.
Panthers subsist on a variety of mammalian prey, particularly white-tailed deer and feral hogs. In the northern portion of its range, feral hogs constitute the bulk of the diet, whereas white-tailed deer are more important in the southern portion. Panthers also readily take raccoons, armadillos, rabbits, and other small animals (Clark 2001).
Loss of habitat is the greatest threat to viable panther populations, but illegal shooting and highway collisions also are major problems. Off-road vehicle traffic has increased, making accessible large areas that formerly had been isolated wilderness. Intolerant of human disturbance, panthers are sensitive to habitat fragmentation stemming from road construction, agricultural development, and urban expansion. Other threats include parasites, diseases such as feline distemper and upper respiratory infections, and inbreeding depression. Panther populations are losing genetic diversity by 3-7 percent per generation; at this rate, extinction is probable in the next few decades (Clark 2001). Reduced prey base also is a concern. Panthers consume up to one deer or hog weekly. Due to habitat alteration, these prey animals may not be sufficiently abundant in Florida to meet this need.
Since panther habitat includes public and private land, management efforts must be coordinated. The key to panther conservation is habitat protection and acquisition of large, interconnected blocks of woodland. The recovery plan recommends: (1) enhancing existing populations through genetic management including captive breeding programs and genetic restoration; (2) protecting and managing existing habitat, including prescribed burning and exotic plant control); (3) establishing public support by educating private landowners; and (4) reintroducing panthers into areas of suitable habitat (U. S. Fish and Wildlife Service 1995). Potential release sites include the lower coastal plain of Alabama, Mississippi, Arkansas, and Louisiana, and the lower Apalachicola River in Florida.
Gray fox and Red fox. Foxes occur throughout Virginia, North Carolina, South Carolina, Georgia, Alabama, Mississippi, Louisiana and eastern Texas. The gray fox does not occur in coastal Louisiana or the Florida Keys, while the red fox does not inhabit the southern Florida peninsula. The population density of red and gray foxes in the South is not known.
Foxes occur in a variety of habitats. The red fox prefers open habitats including old fields, shrublands, pastures, and mixed hardwood forests; the gray fox is more of a woodland-edge species. Both prefer areas supporting an interspersion of different vegetative communities. Hollow logs, trees, brush piles, and rock outcrops are often used as dens. Patterns of habitat use change seasonally with food availability.
Foxes are opportunistic feeders. During the fall and winter, small animals comprise the bulk of their diet. Common prey includes rabbits, voles, mice, wood rats, and various birds (Fritzell 1987). Fruits, berries, arthropods, and amphibians are added to the diet during the summer and fall.
The planting of blackberry, honeysuckle, and other soft mast enhances fox habitat. Prescribed burning maintains old fields and forests in desirable condition. Cultivation of trees that produce hard mast also is important.
Trapping, hunting, road kills, and rabies are the major causes of fox mortality. The decline in red fox populations in some areas of the South has been attributed to interspecific interaction with coyotes.
Gray Bat. The U.S. Fish and Wildlife Service lists this species as endangered. The species distribution in the South includes the cave regions of Alabama, Arkansas, Kentucky, and Tennessee, but a few occur in Florida, Georgia, northeastern Oklahoma, Mississippi, Virginia, and North Carolina. Bat populations have become fragmented during the past few decades (Harvey and Saugey 2001). Ninety-five percent of gray bats hibernate in 10 caves.
Gray bats are year-round cave residents, but usually occupy different caves in summer and winter. During the winter, they hibernate primarily in deep vertical caves with large rooms acting as cold-air traps (42-52oF). Maternity roosts are established in warm, humid caves that provide domed ceilings capable of trapping body heat from bat clusters. Less than 5 percent of available caves in the South have the right properties of temperature, humidity, and structure to make them suitable for gray bat occupation (Harvey and Saugey 2001).
Like many bats, this species hunts for insects above forested rivers and streams. Moths, beetles, flies, mosquitoes, mayflies, and other insects are important in the diet.
The primary reasons for population declines include disturbance, vandalism, cave destruction, and pollution. Disturbance during hibernation depletes energy reserves and increases mortality. Conservation actions focus on the protection of occupied caves and appropriate management of the surrounding forest and aquatic foraging sites. Cave gates and fences must be properly designed to allow bat movement. This species is recovering due to the protection of four critical caves (Harvey and Saugey 2001).
Indiana Bat. The Indiana bat is listed as endangered by the U.S. Fish and Wildlife Service. This species is known to occur throughout much of the Midwestern and Eastern United States; however, it has been virtually eliminated from much of its former range. The bat occurs in the northern portions of the South, including Tennessee, Virginia, and Kentucky. Isolated sightings have been made in the Carolinas, Alabama, and Mississippi. The current population of the species nationwide is estimated at 400,000 individuals; approximately 85 percent of the population is limited to seven caves (Harvey and Saugey 2001).
During the summer, maternity roosts are established between exfoliating bark and the bole of snags, in hollow trees, or in live trees. Male bats often use pitch pine and shortleaf pines. These bats need winter caves or mines retaining stable temperatures of 39-46oF, and standing water that maintains relative humidity. The bats forage above streams, water bodies, and open areas. Riparian, upland, and floodplain forests are also used.
During hibernation, the Indiana bat is extremely vulnerable to any type of disturbance. Factors contributing to its decline include cave disturbance, improperly designed cave gates, and intentional killing. Habitat loss stemming from deforestation and stream channelization is another concern. Natural elements that imperil the species include flooding of occupied caves, exposure to freezing temperatures, and cave ceiling collapse. Forest management centers on the provision of summer roost sites and foraging habitat.
Mink. Mink occur throughout the South, with the exception of central Florida and western Texas. They are common in the marshes along the Atlantic and Gulf Coasts and are widespread in Virginia, North Carolina, and South Carolina (Chapman and Laerm in press). Population densities vary with the type and permanence of aquatic habitat, and are influenced by climate, trapping, and intraspecific interaction.
Mink require wetland habitats, such as marshes, swamps, riverbanks, and streams. Habitat use varies by geographic area and season. There are no published data on mink home ranges or habitat use patterns in the South. Muskrats, mice, and lagomorphs are the preferred prey; mink diets also include birds, amphibians, crawfish, and fish.
Habitat degradation as a result of wetland alteration is a concern in the South. Mink are vulnerable to environmental contaminants, particularly mercury and pesticide residues, concentrated in prey foods. The prevention of high levels of environmental contaminants is needed to ensure habitat quality for this species.
Ozark Big-eared Bat and Virginia Big-eared Bat. These two subspecies are endangered and are Federally protected throughout their respective ranges. Only a few caves in eastern Oklahoma, Arkansas, and Missouri are known habitats for the Ozark subspecies. The Virginia bat inhabits eastern Kentucky, Virginia, North Carolina, and West Virginia, but fewer than five caves are known to contain nursery colonies of this subspecies (Harvey and Saugey 2001).
The bats inhabit caves in limestone and schist formations throughout the year. Adjacent land-use does not appear to influence cave selection. Roosting sites are often near mature bottomland and upland hardwood forests adjacent to water. Important habitat features include hollow trees, loose bark, and rock shelters. The bats prefer relatively cold, well-ventilated locations and are often found near cave entrances when hibernating. Big-eared bats forage in forested areas among the canopies of large trees, consuming beetles, flies, mosquitoes, gnats, moths, and many other insects.
The species is vulnerable to pesticides and human disturbance of their caves. They are easily disturbed and quick to take flight. Conservation actions center on the protection of roosting sites and the retention of hollow trees.
Red Wolf. The red wolf is an endangered species. The original distribution of the wolf included southern Illinois, Indiana, and Pennsylvania south to Florida and west to southern Texas. Indiscriminate trapping, hunting, and poisoning, loss of habitat, and expansion of urban and agricultural areas contributed to the demise of this species. The last remnant populations in the wild were verified in southern Louisiana and Texas in the 1970s.
In the late 1980s, efforts were made to translocate wolves to five locations: Alligator River National Wildlife Refuge; Bull's Island, South Carolina; St. Vincent Island, Florida; Horn Island, Mississippi; and the Great Smoky Mountains National Park. Recent threats center on genetic dilution due to hybridization with wild dogs and coyotes.
Historically, the wolf was found in old-growth forests, pine forests, bottomland hardwood forests, coastal prairies, and marshes. Current information on wolf ecology is limited to studies in the coastal marshes of Texas and Louisiana during the 1960s and 1970s and to observations at restoration sites (Crawford and others 2001). Heavy vegetative cover along bayous and fallow fields is ideal habitat. Home ranges vary from 17 to 38 square miles, depending upon habitat and prey density. Red wolves require large tracts of land relatively free of human development, paved roads, and livestock.
Red wolves are opportunistic predators, preying upon feral pigs, white-tailed deer, nutria, eastern cottontails, swamp rabbits, marsh rice rats, and fox squirrels. They will also eat birds, rodents, frogs, and turtles. A diversity of prey is necessary for sustaining population levels.
The recovery plan objectives center on the achievement of population levels large enough to ensure genetic integrity (U.S. Fish and Wildlife Service 1989). Potential reintroduction sites are examined for biological factors (prey abundance, habitat types) and socioeconomic factors (agricultural practices, land ownership patterns, proximity of towns). Areas of at least 170,000 acres are required by this species. The absence of coyotes is preferable to avoid hybridization. Site considerations include the potential for wolf/livestock interaction and human disturbance. Public attitudes about wolves are significant factors in their recovery.
River otter. The river otter is listed as a threatened species in Tennessee and as a species of concern in Oklahoma and Virginia. Otters occur regionally in many habitats associated with waterways, and their numbers are increasing in some parts of the region. The species is increasing in abundance throughout Virginia, where it is most common in the Coastal Plain and Piedmont. It also is relatively common in western Tennessee. Reliable census procedures for the river otter have not been developed, and few researchers have attempted to estimate population levels.
River otters use a variety of aquatic habitats including coastal estuaries, marshes, and streams. Riparian and shoreline vegetation bordering waterways is an important component of river otter habitat. Beaver impoundments, submerged trees, and logjams provide shelter and foraging areas for otters. Otters feed primarily on fish; other foods include aquatic insects, birds, small mammals, snakes, and amphibians.
Threats to otter populations include the clearing of bottomland forests, wetland modification, and pollution of aquatic environments. Otters are frequently caught in traps intended for beaver; the low reproductive potential of the otter and the restricted nature of its habitat make the species susceptible to overharvest. As a result of trapping pressure, the otter was given protection under the Convention on International Trade in Wild Species of Endangered Flora and Fauna.
Strict population monitoring is needed. Continued management includes the restoration of otter populations in Kentucky, Oklahoma, Tennessee, and North Carolina. Reintroduction in the Great Smoky Mountains National Park began in the 1980s, where otter populations were once extirpated.
White-Tailed Deer. Deer are widespread and relatively abundant throughout the Southern United States. Populations on some islands have declined. Deer populations have fluctuated dramatically since European settlement of the South. Populations in the past declined to critical levels because of intensive hunting, widespread agricultural clearing, and other habitat alteration. Populations have rebounded during the last several decades due to farm abandonment, lower hunting pressure, and the extirpation of large predators. In some locations, populations are increasing to levels that make the species a pest.
The endangered Key deer is restricted to the lower Florida Keys. Four other subspecies of concern occur on Sapelo and Blackbeard Islands in Georgia; and on Hilton Head Island, Bulls Island, and Hunting Island in South Carolina.
White-tailed deer use a wide range of habitat types, and benefit from a mosaic of wetlands, forests, farmland, and early-successional habitats. Preferred foods are acorns, blueberries, sumac, grapes, hawthorns, common persimmons, dwarf palmettos, and blackberries.
There are no threats to the survival of the white-tailed deer in the region. However, coastal development has contributed to the decline of the island subspecies. Key deer are threatened by habitat loss, poaching, vehicular accidents, and attacks by feral dogs (White and others 1998).
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