The Nile Monitor (Varanus niloticus), the longest lizard in Africa, was first observed in southwestern peninsular Florida in the Cape Coral area of Lee County ca. 1990. From April 2001 through 7 July 2003, we compiled 146 sightings or captures of this species by local residents or ourselves. Numerous individuals of all size classes have been observed or collected, suggesting the occurrence of a reproducing population. Although our records are mostly confined to Cape Coral, our data indicate that V. niloticus has recently expanded its range northwards and to nearby islands. Because this large lizard has the potential to disperse into nearby ecologically sensitive areas and preserves where it could pose a serious threat to waterbirds, Burrowing Owls (Athene cunicularia), sea turtles, and other native wildlife, population monitoring and eradication are warranted.

American Alligators (Alligator mississippiensis Daudin) are ecological engineers who alter the Everglades landscape through creation and maintenance of small ponds, called alligator holes, that play a key ecological role by providing both drier and wetter habitats for other organisms. The objective of this study was to compare morphology, vegetation, and activity of alligators in twenty natural and nine man-made alligator holes in ridge and slough wetlands of the central Everglades. All alligator holes were circular in shape and excavated to flat limestone substrate. Nine natural alligator holes were associated with tree islands and 11 were surrounded by sawgrass marsh. Man-made alligator holes were adjacent to islands constructed as high water refugia for deer. Marsh alligator holes were smaller and shallower than alligator holes associated with tree islands. Alligator hole size was correlated with water depth. Alligator holes surrounded by marsh had less diversified surroundings and lower species richness than alligator holes associated with tree islands. Alligator holes contained species of vegetation not found in the surrounding marsh. Seventy-nine percent of the alligator holes had signs of recent activity by alligators. Larger alligator holes associated with tree islands had adult and hatchling alligators and smaller marsh alligator holes contained juvenile alligators. Understanding the ecological role of alligator holes will be critical to planning and evaluating restoration of the Everglades ecosystem.

We conducted a 13-year study of a stream community of eight turtle species in a west-central Florida spring-run. A major shift towards smaller species is apparent when this study is compared to another made at the same locality six decades earlier. Over the duration of our study, sizes of Pseudemys concinna and P. floridana populations appeared to increase, though not to the levels of six decades previously. Average adult size for both species also increased significantly; these changes may reflect enhanced levels of protection. Growth rates of P. concinna and P. floridana vary throughout life and appear to be strongly seasonal. In light of constant water temperature and abundant food, we suggest that basking behaviors may limit growth, and the availability of basking sites may be critical to the health of the population. Data on sexual dimorphism in P. concinna and P. floridana are also presented.

Loggerhead sea turtles Caretta caretta (Linnaeus) were sampled (n = 304) for epibionts while nesting in Georgia from 1998–2003. Twelve newly documented epibiont species were observed and represent the first records of a hermit crab and a sea star as sea turtle epibionts. We report some physical, behavioral and ecological characteristics of the newly documented epibionts, particularly because nothing is known of their life history in Georgia as sea turtle epibionts. We also discuss the role of epibiotic crabs as facultative associates of loggerhead turtles.

A hierarchical clustering technique was used to classify sites in the upper Tennessee River basin based on relative abundance of fish species. Five site groups were identified. These groups differed mainly by the occurrence of minnow and darter species. Drainage area and ecoregion were the primary factors explaining the differences among groups; elevation and human influence were of secondary importance. The Blue Ridge site group had the most distinct fish assemblage, large-river sites supported the highest species richness, and the upper Ridge and Valley sites contained the highest percentages of environmentally sensitive species. These results can provide a regional framework for management and conservation activities.

Fish assemblages were sampled from streams in Mississippi (fall 2000–2003) allowing a comparison of fish species diversity across drainages and years. Because species diversity is dependent on sample size, we used rarefaction to compare richness and evenness across drainages at a standardized abundance. Rarefied richness was higher in northern drainages (Tennessee, Tombigbee, Lower Mississippi North) than in southern drainages (Pearl, Pascagoula, Lower Mississippi South). Rarefied evenness did not differ across drainages. Diversity and species composition at localities were relatively similar across time. Local diversity was not associated with regional diversity, supporting the idea that local ecological factors limit the number of coexisting species. Higher diversity of the Lower Mississippi North, Tennessee, and Tombigbee drainages is strongly related to their biogeographical history.

Planimetric comparisons of home range sizes of white-tailed deer (Odocoileus virginianus Zimmermann) from across their range may not be appropriate due to regional differences in topography. We compare seasonal topographic diversity between male and female white-tailed deer home ranges in the central Appalachians using percent increase from planimetric to topographic areas as a measure. Mean percent increase in home range size for all deer-seasons combined was 3.1 (range = 1.3–6.4). No differences in percent increase in home range areas occurred between sexes or among seasons. The relatively low percent increase in home range area and lack of variation between sexes and among seasons validates the common practice of comparing planimetric home range sizes from different geographic areas.

We report a sighting, supported by DNA evidence from a scat, of a cougar (Puma concolor) in southeastern Louisiana. The 16S-rRNA genotype obtained from mtDNA is one that is common throughout North America, making it difficult to determine the origin of the individual. Based on DNA and hair scale analysis, the scat contained the partially digested remains of a dog (Canis familiaris) and an eastern cottontail (Sylvilagus floridanus), indicating that the individual was successfully foraging on locally occurring prey.

Proper den sites are crucial to the reproduction of female black bears (Ursus americanus). We monitored 31 bears for 39 bear winters in the Southern Appalachians with 95% of the bears confirmed to have denned. Bears denned in trees (41%), rock cavities (32%), excavations (14%), snags (8%), and ground nests (5%). Chestnut oak (Quercus prinus; n = 9), red oak (Q. rubra; n = 8), and tulip-poplar (Liriodendron tulipifera; n = 1) were used as tree dens. Habitat characteristics did not differ between ground dens and tree dens; however, older bears used ground dens more frequently than tree dens (Z = −2.484, P = 0.013). We documented one instance of den reuse. Our results provide managers with more accurate information about black bear dens.

We evaluated breeding bird communities in forested streamside zones in eastern Texas to determine threshold widths of riparian forest that were associated with the addition of mature-forest-breeding birds and loss of shrub-breeding birds. We observed an association of shrub-breeding birds with narrow streamside zones and an increasing number of mature forest species within wider streamside zones. Streamside zones also provided song perches for many shrub breeding species. Although many bird species increased or decreased in a generally linear pattern as streamside zone width increased, some species appeared to have threshold widths associated with their presence. The Acadian Flycatcher (Empidonax virescens), Yellow-throated Vireo (Vireo flavifrons), and Yellow-billed Cuckoo (Coccyzus americanus) seemed to require at least 70 m of forest width before their abundance increased. In contrast, the Blue Grosbeak (Passerina caerulea), Painted Bunting (Passerina ciris), and Prairie Warbler (Dendroica discolor) decreased markedly at widths greater than 20 m and were absent after streamside zone widths increased beyond 70 m. We were unable to detect a relationship between streamside zone width and abundance of 11 species of birds. Uncut forested streamside zones within pine plantations provided a variety of habitat for forest-breeding and shrub-breeding birds that would not have been present had streamside zones been cut during harvesting operations. Our results provide important information to help forest managers balance the habitat requirements of both shrub-breeding and forest-breeding birds when they harvest timber in southern pine forests.

Habitat use and reproductive success of the Brown-headed Nuthatch (Sitta pusilla Latham) were studied in East Texas during the 2001–2002 breeding seasons. We compared nest cavity selection at used and randomly selected non-used areas. Height of nest trees, midstory density, and percent leaf litter were negatively correlated with nest site selection. Brown-headed Nuthatches showed a strong preference for short snags; yet placed their nest cavity entrances near the top of the snags. While nuthatches may be selecting for habitats with little or no midstory density, percent of leaf litter in the nest sites is most likely the consequence of frequent burning. No significant differences among habitat variables and snag characteristics were found between successful and failed nest cavities. Additionally, no habitat variables were correlated with the number of chicks fledged per nest. Predation was the major cause of nest failure in this study.

The Cuban Treefrog, Osteopilus septentrionalis, is an invasive, non-native species whose range is rapidly expanding throughout Florida and may be a significant predator of native treefrogs. To investigate the attractiveness of various sized native Green Treefrogs as prey to Cuban Treefrogs, we conducted laboratory experiments where we offered very large Cuban Treefrogs the choice of arthropods (crickets), conspecifics, and Green Treefrogs. We found that all prey types were consumed by the very large Cuban Treefrogs over the course of the feeding trials. When given the choice of crickets or treefrogs as prey, more of the very large treefrogs ate just crickets and crickets were usually consumed before treefrogs. While not indicating a selection or preference for predation on other treefrogs, our trials did show that Cuban Treefrogs will eat both Green Treefrogs and conspecifics and could have a negative impact on native hylids by removing reproductively mature individuals from the population.

This paper reports the results of an inventory of the vascular plants at the Hugo Wildlife Management Area in southeastern Oklahoma. A total of 573 specific and interspecific taxa of vascular plants in 359 genera and 113 families were collected. The most commonly collected were of the families Poaceae (75), Asteraceae (76), Fabaceae (40), and Cyperaceae (38). One hundred sixty-four species were annuals or biennials, and 409 were perennials. Ninety-seven species of woody plants were present. Fifty-one exotic species were collected representing 9% of the flora. Fourteen species tracked by the Oklahoma Natural Heritage Inventory were found. This study reports 256 species previously not documented in Choctaw County.

We used drift fences with pitfall traps to compare soricid abundance, richness, and demographic parameters among intact multiple-tree windthrow gaps, salvaged gaps, and mature forest in a xeric southern Appalachian forest type during 1997–1999. We also tested whether capture rates were correlated with rainfall, and whether similar-sized species did not co-occur as predicted by multi-species assemblage rules. We captured six species: Blarina brevicauda (Say) (northern short-tailed shrew), Cryptotis parva (Say) (least shrew), Sorex cinereus Kerr (masked shrew), S. fumeus G.M. Miller (smoky shrew), S. hoyi Baird (pygmy shrew), and S. longirostris Bachman (southeastern shrew). Tree basal area, forest structural features, and arthropod abundance differed among treatments, but species richness and abundance of most shrews did not. Captures during June–October were higher in 1998 than in 1997, although 1998 summer rainfall was low. Rainfall was correlated with shrew activity, but explained little of the variability in capture rates (r² = 0.05). The sex ratio within each species was similar among gap treatments and controls, but differed from 1:1 for S. hoyi, S. longirostris, and S. fumeus. The soricid assemblage did not conform to multi-species assemblage rules; three small-bodied species co-occurred in similar numbers at all study sites. Our results suggest that forest management that mimics conditions created by multiple windthrows in xeric forest of the southern Appalachians is unlikely to affect shrew communities adversely, at least in the short-term.

Gray's Post Oak Woodland is an open wooded community located on the western edge of the Wabash Border Natural Division about 9 km southeast of Harrisburg, Saline County, IL. Associated with a clayey soil missing most of the surface layer, the trees were stunted and gnarled. Quercus stellata dominated the canopy, accounting for nearly all of the importance value. Although six other tree species were present, few individuads exceeded 15 cm dbh. The open understory contained few saplings, averaged 1520 stems/ha, with young post oaks common. The herbaceous layer was sparse with a bare ground and litter cover of 48.90%. Danthonia spicata dominated, along with various moss and lichen species, some tree seedlings, and Carex spp.

Walleye (Sander vitreus [Mitchill]) are native to rivers and streams in the Mobile River basin in Mississippi and Alabama. These populations comprise a genetically unique strain (Gulf coast walleye, GCW) and represent the southern-most distribution of walleye in the United States. Luxapallila Creek was considered an important spawning site for GCW prior to and shortly after impoundment of the Tombigbee River in 1980. Extensive sampling in Luxapallila Creek in 2001 and 2002 collected only one larval walleye. Microsatellite DNA analysis suggested 14 of 16 adult walleye from Luxapallila Creek were hatchery-produced fish or their progeny. Controlled angling catch rates of adult walleye have declined since 1997. The scarcity of wild-spawned walleye and the similarity of wild-caught and hatchery broodstock walleye indicates that the GCW population in, or spawning in, Luxapallila Creek is sustained by stocking and recruitment from these stocked fish may be diminishing.