Steven B. Castleberry

University of Georgia | UGA · Warnell School of Forestry and Natural Resources

Private, working forests are a significant component of the landscape in the southeastern United States. Past research has documented diverse bat communities in these areas, but there is limited information on how forest management practices affect bat and insect communities in winter. We applied structural equation modeling to examine relationship...

The tricolored bat (Perimyotis subflavus), once common in the eastern United States, has experienced significant mortality due to white‐nose syndrome (WNS), a fungal disease that primarily affects bats hibernating in caves and mines. In coastal regions of the southeastern United States, where caves and mines are scarce, tricolored bats often use ro...

The potential harm inflicted by forearm bands on bats has been debated for decades. To aid in decision‐making regarding bat marking, we conducted a comprehensive assessment of banding injuries using recapture data from a long‐term overwintering study in Georgia, USA, involving 776 banded tricolored bats (Perimyotis subflavus) with 284 recaptures. M...

Although previously close to extirpation in the southeastern United States, American black bear (Ursus americanus) abundance and distribution have increased with habitat management and harvest regulation. The north Georgia black bear population, the most abundant and widely distributed in the state, is currently being exposed to pressures from incr...

Context Once common, the northern long-eared bat (Myotis septentrionalis) has experienced declines > 90% due to white-nose syndrome (WNS). This severe mortality has resulted in their listing under the Endangered Species Act and made them a conservation priority. However, their broad distribution, variability in habitat use, and population instabili...

Knowledge of the population genetic structure and diversity of at-risk species is essential to accurately evaluate population viability and define units for conservation and management. The southeastern pocket gopher (Geomys pinetis) is a fossorial rodent native to the imperiled longleaf pine savannas of the southeastern United States. Its recent d...

Working forests comprise a large proportion of forested landscapes in the southeastern United States and are important to the conservation of bats, which rely on forests for roosting and foraging. While relationships between bat ecology and forest management are well studied during summer, winter bat ecology remains understudied. Hence, we aimed to...

BioBlitzes, rapid field studies conducted by a collaborative team of scientists and conservation professionals in specific geographic areas, offer an opportunity to enhance research capabilities, foster partnerships, and provide learning opportunities for scientists, conservation professionals, and non-professional volunteers. Since the detection o...

Insectivorous bats in temperate zones have evolved strategies such as migration or hibernation to overcome challenges of reduced resource availability and increased energy demand during winter. In the southeastern United States Coastal Plain, bats are either year‐round residents and remain active during winter or are migrants from colder areas seek...

Long‐term monitoring programs are necessary to assess populations for conservation planning and management decisions. Hibernating bats in North America have declined because of numerous natural and human‐induced disturbances. White‐nose syndrome (WNS) has become the most serious threat to North American cave‐dwelling bats, leading to significant po...

When art meets science, new discoveries and ideas move past tables of data and turn into a visual language that can be effectively interpreted by everyone. Scientific illustrations work in tandem with academic progress in cementing new ideas and acting as a launch point for new discoveries. In this study, describe the research and collaboration to...

The longleaf pine (Pinus palustris Mill.) savanna ecosystem in North America has declined by 97% from its historic range and its restoration is a conservation priority. The southeastern pocket gopher (Geomys pinetis), an ecosystem engineer in longleaf pine savannas, is absent from most of its historic range. Translocation of pocket gophers may be n...

Knowledge and understanding of bat activity and habitat associations are important for effective conservation and management, especially in landscapes undergoing land use changes. Dasypterus intermedius (northern yellow bat), a broadly distributed species in the Coastal Plain of the southeastern United States, is a species of conservation concern d...

Total mercury (THg) concentrations were measured in wild alligators inhabiting a coastal marsh in southern Louisiana, to determine the tissue distribution of THg among various body organs and tissue compartments. Concentrations of THg in claws and dermal tail scutes were compared to those in blood, brain, gonad, heart, kidney, liver, and skeletal m...

White-nose syndrome (WNS) has emerged as the most serious threat to North American cave-dwelling bat species, with estimated mortality of over 6 million. Tri-colored bat Perimyotis subflavus is one of the species most affected, with hibernaculum counts at caves in WNS-positive regions reduced by >90% from previous counts. While declines have been d...

The Allegheny woodrat Neotoma magister, a rock outcrop habitat specialist, has suffered drastic reductions in geographic range over the past 40 years. Previous research has examined habitat characteristics at varying spatial scales, but none have used occupancy modeling to examine trends over time. Therefore, we used presence/absence data from live...

Pocket gophers provide vital ecosystem services; however, species like the southeastern pocket gopher (Geomys pinetis), endemic to the southeastern United States, are declining. Long-term conservation of this species requires greater understanding of its habitat characteristics. Our objective here was to determine habitat features associated with s...

Mortality from white-nose syndrome has made management and recovery of the northern long-eared bat (Myotis septentrionalis) a priority. Ensuring availability of diurnal summer roosts, where gestation and rearing of young occurs, is a critical component of successful recovery. However, observed variation in roost selection across the species’ range...

Abstract - Peromyscus gossypinus allapaticola (Key Largo Cotton Mouse) is a federally endangered subspecies of Cotton Mouse endemic to the island of Key Largo, FL. While conducting a live-trapping session to estimate Key Largo Cotton Mouse population size, we were scheduled to survey at 1 of our trapping grids on 02 November 2007, a week after a pe...

Animals living underground deal with multiple physiological challenges, such as hypoxia and hypercarbia, but may have reduced thermoregulation demands because of the more stable underground microclimate. Southeastern pocket gophers (Geomys pinetis Rafinesque) occur in the fire-adapted, open-pine forests of the southeastern Atlantic Coastal Plain wh...

Insectivorous bats in temperate zones have evolved strategies, including migration or hibernation, to face the challenges of reduced resource availability and increased energy demand during winter. However, in the southeastern U.S. Coastal Plain, many bats are year-round residents and remain active throughout the year. Some species (e.g., Lasiurus...

Site-occupancy of bats in forested landscapes has been linked to vegetation clutter, but clutter alone may not sufficiently explain observed site-occupancy. Abundance of prey likely has a strong influence on habitat use in forest landscapes as well. Therefore, we simultaneously examined influence of insect abundance and vegetation characteristics o...

In the fire maintained longleaf pine (Pinus palustris) ecosystem, underground refugia such as gopher tortoise (Gopherus polyphemus) burrows and stump holes may be important for animals to escape fire and extreme temperatures. Despite being documented as refugia for several species of concern including the black pine snake (Pituophis melanoleucus lo...

Pocket gophers (Geomyidae) require soils amenable to burrowing and vegetation communities that provide adequate foods. We examined the interplay of soil texture and vegetation structure in determining site occupancy of the southeastern pocket gopher (Geomys pinetis), a species of conservation concern throughout its range. Using a case-control sampl...

Knowledge of roost selection by northern yellow bats (Lasiurus intermedius) is limited to a small number of known roost locations. Yet knowledge of basic life history is fundamental to understanding past response to anthropogenic change and to predict how species will respond to future environmental change. Therefore, we examined male northern yell...

Many sympatric species use Gopherus polyphemus (Gopher Tortoise) burrows as refugia from predators, extreme temperatures, and fire. As part of an ongoing project involving trail-camera monitoring at Gopher Tortoise burrows, we observed a Sciurus niger (Eastern Fox Squirrel) sheltering in an occupied burrow twice in a single day. Eastern Fox Squirre...

Geomys pinetis (Southeastern Pocket Gopher) is absent from much of its historic distribution due to reductions in suitable habitat, which consists largely of open Pinus (pine) systems. Restored open pine habitat represents an opportunity to reestablish Southeastern Pocket Gophers into areas within their historic distribution through translocation....

Live-trapping is important for studying wildlife. In 2016 at Ordway-Swisher Biological Station in Melrose, Florida, USA, we tested the efficacy of a modified pitfall trap designed to safely and effectively capture southeastern pocket gophers (Geomys pinetis). When compared with the commonly used Hart trap, the new design captured 92% of all live ca...

Allegheny woodrats (Neotoma magister) exist as groups of metapopulations due to their dependence on naturally disjunct rocky outcrops in the eastern United States. Severe demographic declines of Allegheny woodrats have occurred in many parts of the range due to a myriad of interacting processes, therefore identifying factors that help maintain the...

Increased market viability of harvest residues as forest bioenergy feedstock may escalate removal of coarse woody debris in managed forests. Meanwhile, many forest invertebrates use coarse woody debris for cover, food, and reproduction. Few studies have explicitly addressed effects of operational-scale woody biomass harvesting on invertebrates foll...

Geomys pinetis (Southeastern pocket gopher) is a fossorial rodent historically associated with Pinus palustris (longleaf pine) communities. Conversion and fragmentation of longleaf pine communities have reduced quality and quantity of southeastern pocket gopher habitat. It is therefore important to determine characteristics of suitable habitat for...

Montane rock outcrops are a sensitive habitat type throughout the Appalachian Mountains. These areas provide habitat for a variety of endemic or rare fauna and flora species assemblages. Our objective was to conduct a status survey of focal mammal species considered rare in the Appalachian region, including Allegheny woodrat (Neotoma magister), eas...

The southeastern pocket gopher Geomys pinetis is absent from a large portion of its historical range. Translocation may represent a viable management technique to reestablish populations into suitable habitat. However, several aspects of the species’ ecology are poorly understood, making development of an effective translocation approach challengin...

Harvest of low value trees and logging residues for bioenergy reduces downed wood post-harvest with potential indirect negative effects on ground-dwelling wildlife such as rodents. We assessed the influence of woody biomass harvests on rodent abundances using an operational-scale, randomized complete block experimental design study in North Carolin...

Forest regeneration following timber harvest is a principal source of habitat for early-successional birds and characterized by influxes of early-successional vegetation and residual downed woody material. Early-successional birds may use harvest residues for communication, cover, foraging, and nesting. Yet, increased market viability of woody biom...

Total counts of breeding birds detected near (within 1 m of windrow), in, or on branches of windrows in regenerating stands (n = 4), 15 April– 15 July, 2012–2014, Glynn and Chatham counties, Georgia. (PDF)

Number and location of breeding birds observed in regenerating stands (n = 4) and surrounding edge, 15 April– 15 July, 2012–2014, Beaufort County, North Carolina. Regenerating stands and treatments therein were bordered by drainage ditches (~1 m wide) containing vegetation which was unaffected by site preparation and thus more developed than vegeta...

Number and location of breeding birds observed in regenerating stands (n = 4) and surrounding edge, 15 April– 15 July, 2012–2014, Glynn and Chatham counties, Georgia. Regenerating stands and treatments therein were bordered by drainage ditches (~1 m wide) containing vegetation which was unaffected by site preparation and thus more developed than ve...

Total counts of breeding birds detected near (within 1 m of pile), in, or on branches of piles of downed wood in regenerating stands (n = 4), 15 April– 15 July, 2012–2014, Beaufort County, North Carolina. (PDF)

Though abundant throughout much of its range, the ecology and local geographic distribution of Mustela frenata (Long-tailed Weasel) is not well-known, especially in the central Appalachian Mountains. In 2015, we conducted a camera study in rock outcrop habitats within Shenandoah National Park, Virginia. Our objective was to determine the presence o...

Gopher tortoise (Gopherus polyphemus) populations are declining range-wide primarily because of habitat loss, fragmentation, and degradation, but low recruitment due to nest predation also may be contributing to this decline. The relationship of nest location and nest survival is unknown. Therefore, our objective was to determine whether nest locat...

Little is known about common bottlenose dolphin (Tursiops truncatus) seasonal migration along the United States southeastern Atlantic coast, or what factors influence migratory patterns. Therefore, our objectives were to: 1) document evidence for seasonal movement of dolphins in this region (that would indicate migratory behavior) and 2) determine...

Forests are a major supplier of renewable energy; however, gleaning logging residues for use as woody biomass feedstock could negatively alter habitat for species dependent on downed wood. Biomass Harvesting Guidelines (BHGs) recommend retaining a portion of woody biomass on the forest floor following harvest. Despite BHGs being developed to help e...

Forests are a major supplier of renewable energy; however, gleaning logging residues for use as woody biomass feedstock could negatively alter habitat for species dependent on downed wood. Biomass Harvesting Guidelines (BHGs) recommend retaining a portion of woody biomass on the forest floor following harvest. Despite BHGs being developed to help e...

Red imported fire ants (Solenopsis invicta; fire ants) are predators of turtle (Testudine) eggs and hatchlings, but little information is available indicating how and when fire ants detect turtle nests during incubation. Therefore, during 2014, we compared fire ant presence at gopher tortoise (Gopherus polyphemus) nests in burrow aprons in early an...

Invasive species, such as the Red Imported Fire Ant (Solenopsis invicta, hereafter, Fire Ant), impact native species via predation, competition for resources, and modifying prey behavior. However, relatively little is known about the effects of Fire Ants on oviparous reptiles. Therefore, we quantified nestling and hatchling survival and examined in...

The Allegheny woodrat has experienced sharp declines along the perimeter of its historic range and is now extirpated from several states along the range exterior. The goals of the study were to survey Allegheny woodrats at historic and potential sites and determine the genetic status and landscape features that influence the Allegheny woodrat in Vi...

Loggerhead sea turtle (Caretta caretta) nesting-beach management is an integral component of population recovery efforts for this internationally threatened species. In Georgia, nests threatened by tidal inundation are commonly relocated to elevated dunes, and screens are placed over nests to prevent depredation. The objective of this study was to...

Abstract - Neotoma floridana smalli (Key Largo Woodrat) is currently at high risk of extinction from anthropogenic disturbances, including loss and degradation of habitat and non-native predators. Habitat degradation may affect food-resource availability, yet food habits are poorly understood. Therefore, we examined seasonal diets of Key Largo Wood...

Neotoma floridana smalli (Key Largo Woodrat) is currently at high risk of extinction from anthropogenic disturbances, including loss and degradation of habitat and non-native predators. Habitat degradation may affect food-resource availability, yet food habits are poorly understood. Therefore, we examined seasonal diets of Key Largo Wood-rats using...

Declines in Allegheny woodrat (Neotoma magister) distribution and numbers have been documented in the northern and western portions of the range for >30 years. Population trends in other parts of the range are uncertain, largely due to a lack of, or inconsistent, survey effort. We examined the efficacy of the trapping protocol currently used by man...

Recovery of loggerhead turtle Caretta caretta populations depends on many factors, including reducing anthropogenic mortality of adult turtles. Shrimp trawls are considered a major source of mortality for adult loggerhead turtles despite the mandatory use of turtle excluder devices. We modeled scenarios for reducing the likelihood of interaction be...

Small mammals are ecologically important and should be considered as part of the sustainable management of pine (Pinus spp.) plantations, a common forest type within the southeastern United States. Few studies, however, have described how combinations of mechanical and chemical site preparation and herbaceous weed control (HWC) used in pine plantat...

Despite the importance of winter roosts to bat ecology, much less is known about tree roosts used by bats in winter than in summer. Rafinesque’s big-eared bat (Corynorhinus rafinesquii) and southeastern myotis (Myotis austroriparius) are species of concern whose winter tree roost selection may be constrained by seasonal flooding in cypressgum swamp...

The Key Largo cotton mouse (Peromyscus gossypinus allapaticola) was federally listed as Endangered in 1984 due to habitat loss and subsequent population decline, but because of infrequent monitoring, the extent of decline and long-term population trends are unknown. We modeled population abundance under a variety of trapping scenarios to develop a...

Roost characteristics have been described for most North American bats, but debate continues over the ultimate mechanisms behind roost selection. Hypotheses include the need for a stable microclimate, protection from predators, proximity to foraging habitat, and availability of alternative roosts, among others. Our objective was to weigh evidence f...

Declines of imperiled small mammals are often attributed to predation without investigating the relative influence of survival and reproductive parameters on population growth. Accordingly, declines in the endangered Key Largo woodrat Neotoma floridana smalli (KLWR) population have been attributed to predation by feral cats Felis catus, Burmese pytho...

Roost requirements of most North American forest bats are well-documented, but questions remain regarding the ultimate mechanisms underlying roost selection. Hypotheses regarding roost selection include provision of a stable microclimate, space for large colonies, protection from predators, and proximity to foraging habitat, among others. Although...

Data on species distribution and abundance are the foundation of population ecology. However, due to difficulties in surveying bats, abundance estimates for tree-roosting microchiropterans are non-existent. Therefore, our objective was to develop methods for estimating colony abundance and density, taking as our model Rafinesque’s big-eared bat Cor...

Loblolly pine (Pinus taeda) plantations are established using various treatments to manage competing vegetation and increase pine production. Although young pine plantations historically supported early successional vegetation communities that contained abundant wildlife forage, increasing intensity of stand-establishment treatments, particularly h...

We radio-tracked 3 male and 1 female Lasiurus intermedius (Northern Yellow Bat) to 16 unique roosts on Sapelo Island, GA in summer 2010. All bats roosted in Tillandsia usneoides (Spanish Moss) hanging in hardwood trees. Trees used as roosts were similar in height as surrounding trees but were larger in diameter. Mature hardwood stands appear to be...

It is widely assumed that tree cavity structure and microclimate affect cavity selection and use in cavity-dwelling bats and birds. Despite the interest in tree structure and microclimate, the relationship between the two has rarely been quantified. Currently available data often comes from artificial structures that may not accurately represent co...

Intensively managed loblolly pine (Pinus taeda) forests are common in the southeastern United States and offer opportunities for conservation of biologic diversity. Within intensively managed landscapes, stand establishment relies on combinations of mechanical and chemical site preparation and herbaceous weed control (HWC) to manage competing veget...

Control of mid-sized mammalian predators (hereafter, mesopredators) is sometimes advocated in an attempt to reduce their impact on wildlife populations, particularly economically important (i.e., game) or endangered species. However, mesopredators may play a role in regulating small mammal populations; thus, lethal control of mesopredators may have...

An understanding of children’s environmental orientations is of critical importance as opportunities for authentic contact with nature diminish. Current instruments for measuring children’s environmental attitudes are complex, and few have been tested across diverse audiences. This study employed a mixed-methods approach that included pilot tests,...

Abstract: Reductions in habitat quantity and quality have contributed to precipitous declines in the Key Largo woodrat (Neotoma floridana smalli) population over the last 30 years. Additional information on microhabitat and nest site selection is needed to increase quality of the remaining habitat and increase the population. In 2005–2006, we evalu...

Understanding year-round roost-site selection is essential for managing forest bat populations. From January to March, 2004 to 2006, we used radiotelemetry to investigate winter roost-site selection by Seminole bats (Lasiurus seminolus) on an intensively managed landscape with forested corridors in southeastern South Carolina, USA. We modeled roost...