Chapter 5: Maintaining Species in the South 113 Chapter 5
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TERRE Chapter 5: Maintaining Species in the South 113 Chapter 5: S What conditions will be Maintaining Species TRIAL needed to maintain animal species associations in the South? in the South Margaret Katherine Trani (Griep) Southern Region, USDA Forest Service mammals of concern include the ■ Many reptiles and amphibians Key Findings Carolina and Virginia northern are long-lived and late maturing, flying squirrels, the river otter, and have restricted geographic ■ Geographic patterns of diversity and several rodents. ranges. Managing for these species in the South indicate that species ■ Twenty species of bats inhabit will require different strategies than richness is highest in Texas, Florida, the South. Four are listed as those in place for birds and mammals. North Carolina, and Georgia. Texas endangered: the gray bat, Indiana The paucity of monitoring data leads in the richness of mammals, bat, and Ozark and Virginia big- further inhibits their management. birds, and reptiles; North Carolina eared bats. Human disturbance leads in amphibian diversity. Texas to hibernation and maternity colonies dominates vertebrate richness by Introduction is a major factor in their decline. virtue of its large size and the variety of its ecosystems. ■ The South is the center of The biodiversity of the South is amphibian biodiversity in the ■ Loss of habitat is the primary impressive. Factors contributing to Nation. However, there are growing cause of endangerment of terrestrial that diversity include regional gradients concerns about amphibian declines. vertebrates. Forests, grasslands, in climate, geologic and edaphic site Potential causes include habitat shrublands, and wetlands have conditions, topographic variation, destruction, exotic species, water been converted to urban, industrial, natural disturbance processes, and pollution, ozone depletion leading and agricultural uses. Other factors the activities of Native Americans to excessive ultraviolet radiation, include environmental contaminants, and European settlers (Boyce and acid deposition, synthetic chemicals, commercial exploitation, coastal Martin 1993, Delcourt and others and prolonged drought conditions. development, fire suppression, 1993, Healy 1985). These factors river and stream modification, ■ Seven species of amphibians are have contributed to the diversity of and wetland degradation. listed as threatened or endangered several species groups: salamanders, by the U.S. Fish and Wildlife snakes, and turtles (White and others ■ Species that are federally listed as Service: the Houston toad, Flatwoods 1998). The evolution of plants and threatened or endangered consist of salamander, San Marcos salamander, animals, combined with the isolation 22 birds, 33 mammals, 7 amphibians, Barton Springs salamander, Red that characterizes some habitats, and 17 reptiles. Florida leads with Hills salamander, Shenandoah produced remarkable levels of the number of threatened (16) and Mountain salamander, and Texas endemism—species that are endangered (26) vertebrates; Texas blind salamander. These species restricted to special habitats. is second in endangered species (23); are imperiled due to physiological while Mississippi is second in the The terrestrial vertebrate fauna of constraints that limit them to moist number of threatened species (11). the South, including the entire States habitats, relatively small ranges, of Texas and Oklahoma, consists ■ Birds of high concern include and highly specific sites. of 1,208 species. This total includes the red-cockaded woodpecker, ■ Reptile species of concern include 170 amphibians, 197 reptiles, 595 bald eagle, piping plover, whooping the Louisiana pine snake, eastern birds, and 246 mammals (NatureServe crane, wood stork, black-capped indigo snake, crocodile, glass lizard, 2000). Species richness is highest in vireo, Florida scrub jay, and the bluetail mole skink, gopher tortoise, Texas, Florida, North Carolina, and roseate and least terns. and bog turtle. General problems Georgia (fig. 5.1). North Carolina ■ Habitat destruction and the paucity faced by reptiles include habitat leads in amphibian diversity, of large tracts of undisturbed land destruction, pet trade, negative public while Texas leads in the richness threaten far-ranging mammals such attitudes, degradation of aquatic of mammals, birds, and reptiles. as the Florida panther, red wolf, and habitats, and fire suppression or the The variation in species richness the Louisiana black bear. Other lack of sufficient prescribed burning. among States is influenced by TERRESTRIAL 114 Southern Forest Resource Assessment Amphibians Reptiles Mammals Birds South. Scientific names are provided in the chapter tables and the master Kentucky species list in the Assessment appendix; Tennessee therefore, only common names are Arkansas provided in the text. Louisiana Mississippi Methods and South Carolina Virginia Data Sources Alabama Oklahoma Data on the status of threatened or Georgia endangered vertebrate species of the North Carolina South were compiled from the U.S. Florida Department of the Interior (2000). That Texas agency provided information on the distribution of listed species by State. 0 100 200 300 400 500 600 700 800 900 1000 Its recovery plans and other agency publications were used to compile Figure 5.1—Geographic patterns of diversity by State within information on life history, ecology, the South (NatureServe 2000). and management of individual species. differences in size, geographic location, growth of the human population has Regional species richness in each and environmental complexity (Stein resulted in land use conversion, urban vertebrate taxon was compiled and others 2000). Texas leads the sprawl, and habitat fragmentation from State Natural Heritage offices region with 911 vertebrate species; (White and others 1998). Landscape (NatureServe 2000). This database is diversity there is influenced by the modification has been accompanied an inventory of all known occurrences State’s large size and its diversity of by habitat isolation, water and air for species of conservation concern. habitats (NatureServe 2000). Florida, pollution, and altered disturbance Information was derived from the North Carolina, and Georgia each regimes (Lorimer 2001, Trani and database to determine geographic support over 600 vertebrate species. others 2001). In addition, southern patterns of diversity by State in the The smallest number of species (487) wildlife has been influenced by the South. The system was also used to occurs in Kentucky. Texas and Florida introduction of exotic species and verify the status and distribution of support species typical of Latin America the overexploitation of native species. species included in the fauna accounts. and the Caribbean that reach their Of particular concern is collection Information on bird habitat northern limits there (Stein and others of species for the pet trade and associations was obtained from Partners 2000). For example, the northern limit overharvest of commercial species in Flight (2000) conservation plans. for the American crocodile is in the (Flather and others 1998). These These plans highlight the factors that Florida Keys and south Florida. factors have influenced species and imperil bird species in physiographic This diverse array of vertebrate their habitats in different ways. areas and recommend management species is found in a variety of habitats. This chapter provides an overview actions. The conservation plans were A habitat is comprised of the physical of the habitat associations of birds, used to identify species of conservation and biological resources that allow a mammals, reptiles, and amphibians in concern (Pashley and others 2000). species to survive and reproduce. The the South. The focus is on vertebrates Habitat associations for herpe- habitat requirements for some species because information on the regional tofauna (reptiles and amphibians) may be quite narrow, while those for biogeography of many terrestrial were summarized from the com- another may be rather broad. invertebrate groups is lacking prehensive review conducted by A species may require a certain (Echternacht and Harris 1993). Wilson (1995). Additional literature habitat structure such as vegetation Additional information on plant reviews and reference materials height, percent canopy cover, floristics, and animal associations is provided supplied information on reptile seral stage, patch size, or diversity and in chapters 1, 2, and 23. and amphibian ecology. interspersion of plant communities. Taxa groups are described, and State agency bear biologists were Some species are constrained by general habitat associations for each surveyed for information about the abiotic factors such as the precise are summarized. The status, distri- current status, habitat needs, and cave temperatures required by bution, and habitat requirements management concerns about black many bat species. These features of are provided for selected species of bears. Nine States responded with habitat influence the distribution and concern. Finally, conservation and information: Alabama, Arkansas, abundance of species (Dickson 2001). management actions are suggested Florida, Kentucky, Mississippi, The habitat conditions for southern for enhancing habitat associations North Carolina, Oklahoma, Texas, species have been modified by several and mitigating known threats. and Virginia. factors (Buckner 1989). Habitat loss The following sections discuss the Information on mammal habitat