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We characterized the tree community of a mesic hardwood hammock in south-central Georgia as an oak-pine-hickory forest, with Liquidambar styraciflua (Sweetgum), Magnolia grandiflora (Southern Magnolia), and Ilex opaca Ait. (American Holly) as subdominants. We surveyed this forest for colonies of the most northerly distributed epiphytic orchid in the Western Hemisphere, Epidendrum magnoliae (Green Fly Orchid), and recorded the species and trunk diameter of 112 host trees (phorophytes) as well as the height and size of each orchid colony. We calculated a selectivity index (SI) to compare phorophyte frequency with availability, based on a point-transect survey. Green Fly Orchid occurred on 8 species of hardwood trees, but had a strong preference for Southern Magnolia as a host and a moderately strong preference for Quercus virginiana (Live Oak). Host trees were much larger (presumably older) than the average of available trees, and that effect was strongest for the most preferred host. Orchid colonies also occupied significantly greater areas on individual Southern Magnolia than on other phorophytes. It is likely that old-growth Southern Magnolia and Live Oak trees are critical to the viability of this population of Green Fly Orchid, which is rare in inland forests in Georgia. In addition to being the most persistent epiphyte substrates in this environment, their broadleaf evergreen canopies—which would be especially true of Southern Magnolia —may provide the most favorable microclimates in terms of shade, humidity, and frost protection.
This paper reports the results of an inventory of the vascular plants from an Ozark Plateau Site in Ottawa County, northeastern Oklahoma. A total of 318 taxa in 219 genera and 81 families were collected. The families with the greatest number of species were the Asteraceae (with 37 taxa), Poaceae (36), and Fabaceae (31). Ninety-one species were annuals, three were biennials, and 224 were perennials. Fifty-eight species of woody plants were present. Thirty-three non-native species, representing 10.4% of the flora, were collected. Three species tracked by the Oklahoma Natural Heritage Inventory were found.
Body mass and antler development of Odocoileus virginianus (White-tailed Deer) vary by soil resource region in Mississippi, but a causative link from soil to deer morphology has not been established. We investigated crude protein (CP) content of 8 important deer forages in 5 soil-resource regions to determine if regional differences in available nutrition could potentially explain some variation in morphometrics. Crude protein levels of a species composite and all but 1 individual forage species decreased from spring to summer. Every species exhibited regional differences in spring, and only 1 species did not vary by region in summer. Composite CP also differed by region. Differences in potential nutritional planes among regions may be substantial enough to impact lactation success, fawn recruitment, and body growth. Directly sampling seasonal diet quality among regions and comparing nutritional planes among deer herds of different densities may further explain regional morphometric differences.
Although Eptesicus fuscus (Big Brown Bat) has been widely studied, information on tree-roosting in forests by males is rare, and little information is available on tree roosting in the southeastern United States. Our objectives were to characterize diurnal summer roosts, primarily for male Big Brown Bats, and to determine relationships between forest structure and roost selection. We quantified 25 male roosts located via radiotelemetry, and describe an additional 9 maternity roosts for females. All roosts for both sexes were in Pinus echinata (Shortleaf Pine) snags, and 82% of roost snags were 15–25 cm diameter at breast height (dbh). Most (94%) roosts for both sexes were under loose bark. A logistic regression model differentiating male roost sites from random locations indicated males were more likely to roost in recently thinned, open-forest conditions (less canopy cover, more cut stumps, and fewer under-story stems) that contained abundant overstory pines ≥25 cm dbh and abundant snags. Males roosted primarily (84%) in stands that had recently undergone partial harvesting. Maintaining a supply of pine snags ≥15 cm dbh in relatively open forest habitats, including areas undergoing partial harvest, would provide roosting habitat for male Big Brown Bats in the Ouachita Mountains.
On the basis of published records, 16 bat species occur in Georgia. Of these, only one species is documented from Baldwin County in central Georgia, but records from surrounding counties suggest the likelihood of additional species inhabiting the county. On the basis of museum specimens in the mammal collection of Georgia College and State University, we report seven species of bats inhabiting the county: Perimyotis subflavus (Eastern Pipistrelle), Nycticeius humeralis (Evening Bat), Lasiurus borealis (Red Bat), Lasiurus seminolus (Seminole Bat), Eptesicus fuscus (Big Brown Bat), Myotis austroriparius (Southeastern Myotis), and Tadarida brasiliensis (Brazilian Free-tailed Bat). With the exception of the Brazilian Free-tailed Bat, the specimens represent first records from Baldwin County. Moreover, the records significantly add to the general baseline information of species richness and distribution of bats in central Georgia, and they help fill distribution gaps in this part of the southeastern United States.
Introduced plants and animals have been a prominent worldwide environmental issue for decades; however, considerable debate and confusion remain over how to list and otherwise categorize these species. This paper describes a process for categorizing exotic freshwater fishes that have been found in public waters. The basis of this process has been used by the Florida Fish and Wildlife Conservation Commission for nearly 30 years. Reproducing exotic fishes are grouped into three subcategories (established, possibly established, and localized) using species-specific biological and population characteristics resulting in a list that is helpful for prioritizing research and management activities. The purpose of this paper is to stimulate interest in standardizing processes for categorizing introduced species based on how well they adapt to new environments.
Cyprinella caerulea (Blue Shiner) is a federally threatened minnow endemic to the Mobile Basin that is currently restricted to four disjunct populations. We examined the population structure in the Blue Shiner by sequencing the mitochondrial ND2 gene in 37 individuals. We recovered eleven haplotypes, with only one shared between populations, for an overall haplotype diversity of 0.768. Genetic differentiation between populations was significant, accounting for 26% of the variability found within the species. One individual morphologically identified as a Blue Shiner had a haplotype resolved with the sympatric Cyprinella trichroistia (Tricolor Shiner) in our phylogenetic analysis. Long-term management of the Blue Shiner should focus on restoring connectivity between populations in order to restore natural patterns of gene flow.
Epinephelus morio (Red Grouper) is an important component of commercial fisheries for the United States and Mexico. Fishery-independent long-line surveys that utilized standardized sampling designs were conducted along the west Florida shelf, Florida and Campeche Bank, Mexico (2001–2002). Detecting true differences in abundance and sizes are difficult, but by using standard collection and aging methodologies, the level of bias was kept at a minimum. Relative abundance was higher in the Campeche Bank compared to the west Florida shelf (1.74 and 0.63 Red Grouper/100 hook hr, respectively). Fish from the Campeche Bank were also significantly smaller at length and weight. Differences in length, weight, and relative abundance of Red Grouper may be because of historical fishing pressure and management regulations, or the available carrying capacity of each area for Red Grouper. These differences have a substantial impact on how an overfished population can recover and be sustained.
Etheostoma moorei (Yellowcheek Darter), a candidate species for federal listing, is endemic and obligate to headwater riffles of the upper Little Red River drainage in north central Arkansas. Downstream segments of these tributaries were inundated in 1964 as a result of filling of Greers Ferry Reservoir. We compared riffle densities during drought (1999–2001) and non-drought periods (2003–2004), and to historic data (1979–1980). Upstream sites dried periodically during the drought of 1999–2001, and Yellowcheek Darters occupying those sites were extirpated; even at downstream sites, densities were significantly lower than historical levels. During normal precipitation levels during 2003–2004, densities increased significantly, yet several upstream sites and one complete stream remained extirpated. The loss of downstream refugia as a result of the construction of Greers Ferry Dam in 1964 may exacerbate natural climatic cycles, which include drought, resulting in stream-wide extirpations.
Cyprinella venusta (Blacktail Shiner) were studied at four sites to investigate life-history parameter variation in Alabama streams. Consistent with life-history theory, fish from a perceived degraded site were significantly smaller than fish from sites that had less apparent environmental disturbance. Fish from the degraded site had the smallest size at maturity and the smallest propagule size. Egg diameters were not related to standard length of fish among sites. There was no significant difference in mature egg diameters; however, ripening egg diameters differed among sites. Clutch sizes adjusted for standard length varied among sites. There was no difference in gonad mass in females for all spawning months; however, there were differences in gonad mass in males in July. The gonadosomatic index peaked in July for both males and females. Reproductive males were still present in September for three sites, but all females from all sites had become latent by September, indicating that the spawning season had ended. The results of this study suggest that Cyprinella venusta has the ability to alter life-history parameters and this may be a factor contributing to its persistence in habitats where other species are declining.
We sampled five stream reaches within an agricultural landscape in southwestern Georgia for benthic macroinvertebrates and larval amphibians from 2002 to 2003 to determine whether cattle grazing impacts these faunal components. Two of the stream reaches had been fenced to exclude cattle (buffered), whereas the other three were not, allowing cattle access to the streams (unbuffered). We captured larval Eurycea cirrgera (Southern Two-lined Salamanders) incidentally in our benthic samples and compared salamander capture rates between buffered versus unbuffered streams. We also examined salamander stomach contents relative to the composition and abundance of benthic macroinvertebrates, comparing these data by stream type as well. Overall, capture success for larval salamanders was higher at buffered sites. Midge larvae (family Chironomidae) were the most frequent invertebrate taxon detected, both in the benthic and stomach content samples; however, we also observed cladocerans, copepods, and ostracods in each sampling regime. A linear electivity index revealed that larval Southern Two-lined Salamanders showed slight dietary selection for midge larvae in the subfamily Tanypodinae. This finding, coupled with the observation that chironomid larvae composed over half of Southern Two-lined Salamanders stomach contents, suggests some preference or selection for this benthic group. However, larval Tanypodinae were found at all sites, suggesting that their identification to species level may be necessary to determine whether differences in the prey base explained differences in salamander selectivity between buffered versus unbuffered streams. Factors other than prey selectivity, such as instream habitat quality, may also have influenced larval salamander abundance.
The plethodontid salamanders Stereochilus marginatus (Many-lined Salamander) and Pseudotriton montanus (Mud Salamander) have overlapping distributions in the southeastern Atlantic Coastal Plain, where they often co-occur in low, swampy habitats. The main objective of this study was to document life-history traits of S. marginatus at Cool Springs in eastern North Carolina, and compare these findings with life-history parameters of a population surveyed in the late 1960s at a nearby locality (Croatan Forest). A second objective was to compare larval development of S. marginatus and P. montanus at Cool Springs. I found that S. marginatus has a larval period of 13–14 months, hatching in early spring and undergoing metamorphosis late in the second spring. Males may breed initially as early as the autumn following metamorphosis, at 19–21 months of age; females probably require an additional year to attain maturity, ovipositing initially at 3 years. Clutch sizes, based on counts of yolked ovarian follicles of dissected females, ranged from 42 to 60. Compared to S. marginatus, the larval period of P. montanus is slightly longer (14–17 months), extending from hatching in winter to metamorphosis in the second spring. Although larval body sizes of S. marginatus and P. montanus overlap considerably, larvae of the latter species tend to grow larger and metamorphose at slightly larger sizes. The phenologies of the life cycles of both species corroborate earlier studies, both across years and across southeastern localities. However, growth and developmental rates of S. marginatus at Cool Springs appear to be accelerated relative to those reported previously for the Croatan Forest population.
Populations of hydrobiid snails and their larval trematode parasites in salt marsh along the Skidaway River were studied to determine their distribution. Additionally, the prevalence of larval trematodes infecting the snails was examined to investigate definitive host distribution patterns on the Skidaway River and to identify sites for future studies on second intermediate host susceptibility to trematode infection. To do so, surface sediment and vegetation were collected at low tide from 0.5-m2 quadrats along 20 vertical transects beginning in high marsh at the forest edge and salt meadow, passing through high, medium, and low Spartina alterniflora zones, and ending in the low marsh at creekbed level. Samples were filtered through sieves to concentrate snails, which were then counted and identified. Two species of hydrobiid snails, Spurwinkia salsa (4201 specimens) and Onobops jacksoni (136 specimens) were collected. Hydrobiid snails were found in sediments and on plant stems throughout the S. alterniflora zones, and snail density was greatest in the higher Spartina zones. Sediments from the 3 Spartina zones differed with respect to percent sand, but not percent silt or clay. Salinity and chlorophyll-a levels did not differ between the 3 Spartina zones, and there was no relationship between hydrobiid abundance and the abundance of other snail species. The mean prevalence of trematode infection in S. salsa and O. jacksoni snails was 5.5% and 7.5%, respectively. Snails were infected most commonly with either an oculate monostome, possibly the heterophyid Phagicola diminuta, or 2 types of xiphidiocercariae, one of which likely includes the microphallid Microphallus turgidus. No infected snails were found in over half of the collection sites, and the distribution of infected snails was patchy and unpredictable.
Qualitative sampling for Marstonia pachyta (Armored Snail) and Campeloma decampi (Slender Campeloma), two federally endangered species, was conducted at road crossings on Limestone (n = 13), Piney (n = 10), and Round Island (n = 7) creeks, AL, to determine their distribution. Marstonia pachyta was observed at 9 sites on Limestone Creek and 3 sites on Piney Creek. The species extended upstream to river mile 31 on Limestone Creek and river mile 15 on Piney Creek. Haphazard sampling also yielded a greater overall number of individuals from Limestone Creek than Piney Creek. Marstonia pachyta was not found in Round Island Creek, where it is replaced by M. arga (Ghost Marstonia). Live C. decampi were observed at 12 of the sampled sites (n = 30) in the three streams. Round Island Creek had the greatest percentage of sites with the species (4 of 7) and the highest catch per unit effort. Campeloma decampi extended up to river mile 14.5, 19.3, and 7.8 on Limestone, Piney, and Round Island creeks, respectively. Results extended the known occurrence of M. pachyta and C. decampi upstream of their previously known ranges. However, careful monitoring and more in-depth studies seem warranted considering the rapid urban and industrial growth within the watersheds of the three streams that they inhabit.
Little is known about nest-site fidelity in wild Alligator mississippiensis (American Alligator). As part of a long-term study on multiple paternity and mate fidelity that required capture and marking of nesting female alligators, we documented several instances of nest-site reuse by individual females. In one case, the female nested at the same site seven years after initial capture, demonstrating long-term nest-site fidelity. Another female used one nest site in 2000, 2002, and 2004. Herein, we provide data on minimum nesting intervals for recaptured alligators, including three cases of females nesting in two consecutive years. Despite tremendous habitat alteration and storm surge from Hurricane Rita in 2005 and a catastrophic drought precluding nesting in 2006, we found female alligators in 2007 at nests within 20 m and 170 m of their nest sites from seven years and three years, respectively, prior to those events.
Larvae of Hydropsyche carolina were collected from Doe Creek, Johnson County, TN in 2005 during a qualitative benthic survey conducted by the Tennessee Wildlife Resources Agency. This finding represents a new distribution record for this species, and its first reported collection in Tennessee. A revised distribution for H. carolina is presented.
I describe terrestrial foraging behavior in Trachemys scripta elegans (Red-eared Slider) and Graptemys pseudogeographica kohnii (Mississippi Map Turtle), two species of semiaquatic turtles. I observed specimens of Red-eared Slider on two occasions in two different locations climbing onto the bank of a stream and consuming grass blades (Luziola fluitans [Southern Watergrass] and Eragrostis hypnoides [Teal Lovegrass]), which were swallowed when the turtles returned to the water. These observations included both adult males and females. In addition, I observed on one occasion two juvenile Mississippi Map Turtles leave the water and forage on plants on a stream bank also used by Red-eared Sliders. Individuals of Mississippi Map Turtles passed by grass and consumed the sprouts of a dicot (Ludwigia decurrens [Wingleaf Waterprimrose] and/or Pentodon pentandrus [Hale s Pentodon]).
We report the depredation of a Picoides borealis (Red-cockaded Woodpecker) nest by an Elaphe alleghaniensis (Eastern Rat Snake). Of 38 banded woodpecker groups monitored by video surveillance during 1998–2000, we documented one nest depredation by an Eastern Rat Snake. Woodpecker visitation to the nest area during the depredation event increased substantially compared with pre-depredation nesting behavior. Woodpecker visitation to the nest cavity was minimal during the first six hours after the snake was discovered by the adult woodpeckers. Visitation levels by woodpeckers remained higher than pre-depredation levels while the snake remained in the nest cavity. After the snake's departure from the nest, visitation rates dropped below pre-depredation levels. Woodpeckers continued to visit the cavity during the day and roost in the cavity at night for the remaining seven days of surveillance post-depredation. This same banded woodpecker pair nested in the same cavity in 1999 and fledged 1 female. Overall, we observed a low rate of nest depredation by rat snakes during this study; only one instance was recorded during more than 15,000 hours of video surveillance. Based on the proclivity of Red-cockaded Woodpeckers to re-nest in previous nest cavities, and the potential for snakes to re-climb trees based on past successes, resource managers may want to prioritize placement of snake excluder devices or use of bark-shaving at active cavity trees where snake depredation has occurred, especially if funding is limited. We urge ornithologists to continue to incorporate snake research into their avian research to achieve a greater understanding of predator-prey relationships that impact cavity-nesting birds, especially threatened and endangered species such as Red-cockaded Woodpeckers.
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