Carola Haas

Virginia Tech (Virginia Polytechnic Institute and State University) | VT · Department of Fish and Wildlife Conservation

Individual growth rates are intrinsically related to survival and lifetime reproductive success and hence, are key determinants of population growth. Efforts to quantify age-size relationships are hampered by difficulties in aging individuals in wild populations. In addition, species with complex life-histories often show distinct shifts in growth...

Reticulated flatwoods salamander (Ambystoma bishopi) populations began decreasing dramatically in the 1900s. Contemporary populations are small, isolated, and may be susceptible to inbreeding and reduced adaptive potential because of low genetic variation. Genetic variation at immune genes is especially important as it influences disease susceptibi...

Ephemeral wetlands provide breeding habitat for many amphibian species, and wetland hydrology plays a crucial role in determining amphibian breeding success. We discuss the potential influence of recession rates (i.e., rate of water level decline) and empirically evaluate them in wetlands inhabited by the endangered reticulated flatwoods salamander...

Many species of birds that depend on grassland or savanna habitats have shown substantial overall population declines in North America. To understand the causes of these declines, we examined the habitat requirements of birds in six types of grassland in different regions of the continent. Open habitats were originally maintained by ecological driv...

The endangered bog turtle ( Glyptemys muhlenbergii ) exemplifies issues related to rare species conservation; presence surveys have low detection and variables used in habitat models can lack relevance to established biological relationships of the species to its environment. The species' use of groundwater saturated soils and stream networks as co...

Integrated assessments of wetland hydrologic regimes and other environmental factors are key to understanding the ecology of species breeding in ephemerally flooded wetlands, and reproductive success is often directly linked to suitable flooding regimes, both temporally and spatially. We used high-resolution Light Detection and Ranging (LiDAR) data...

Population viability analyses (PVAs) represent a key component of many recovery plans for threatened and endangered species. Demography links the processes that affect individuals to population‐level patterns, and hence projections constructed from demographic data are the most common tools for PVAs. We constructed a size‐structured integral projec...

Virtually all natural community assemblages are dominated by a handful of common species. Dominant species can exert negative impacts on biodiversity through competitive exclusion, and thus there is a strong incentive to understand imbalances in community composition, changes in dominance hierarchies through time, and mechanisms of coexistence. Pon...

Amphibians breeding in ephemeral wetlands within pine-dominated (Pinus spp.) natural communities are less likely to persist in wetlands that have developed high canopy cover and low herbaceous groundcover in the absence of regular plant growing-season wildfires. The reintroduction of historic fire regimes, in conjunction with mechanical or herbicid...

Ephemeral wetlands are globally important systems that are regulated by regular cycles of wetting and drying, which are primarily controlled by responses to relatively short-term weather events ( e.g. , precipitation and evapotranspiration). Climate change is predicted to have significant effects on many ephemeral wetland systems and the organisms...

The field of conservation has seen a shift in focus from monitoring trends in census population size to trends in ‘effective’ population size. Numerous genetic methods exist for estimating effective population size, resulting in uncertainty among conservation practitioners as to which methods are most appropriate when conducting population assessme...

Ephemeral wetlands are commonly embedded within pine uplands of the southeastern United States. These wetlands support diverse communities but have often been degraded by a lack of growing-season fires that historically maintained the vegetation structure. In the absence of fire, wetlands develop a dense mid-story of woody vegetation that increases...

Local extinction and undetected presence are two very different biological phenomena, but they can be challenging to differentiate. Stochastic environments hamper the development of standardized monitoring schemes for wildlife, and make it more challenging to plan and evaluate the success of conservation efforts. To avoid reintroductions of species...

The reticulated flatwoods salamander (Ambystoma bishopi), an endangered species endemic to the longleaf-pine savanna ecosystem of the southeastern U.S., persists in a small number of remnant habitat patches. Breeding ponds and associated populations are threatened by habitat loss, degradation, and fragmentation stemming from fire suppression and la...

A correction to this paper has been published: https://doi.org/10.1007/s10592-021-01367-w

American Shad (Alosa sapidissima), Hickory Shad (A. mediocris), and river herrings (Alewife A. pseudoharengus and Blueback Herring A. aestivalis) are anadromous pelagic fishes, which as adults spend most of the annual cycle at sea, but enter the coastal rivers in spring to spawn. Once as one of the most valuable fisheries along the Atlantic coast,...

Assessing population trends for imperiled species that occur at low densities across large geographic areas can be challenging. Standard sampling techniques are often designed for small areas where target species can be easily observed across most of the study site. We evaluated the use of an occupancy framework for sampling a low-density Gopher To...

McCoy, S.T.S., J. B. Feaga, G.J. Graeter, C.A. Haas 2020. Glyptemys muhlenbergii (Bog Turtle). Predation. Natural History Notes. Herpetological Review 51(4): 828-829. Over the course of several decades of research, we have documented a few instances of Canis familiaris (Domestic Dogs) biting and sometimes killing adult G. muhlenbergii in Virginia a...

We present a joint effort at Virginia Tech between a research group in the Department of Fish and Wildlife Conservation and Data Services in the University Libraries to improve data management for long-term ecological field research projects in the Florida Panhandle. Consultative research data management support from Data Services in the University...

In conservation science, metapopulation models are frequently used to explore the spatial dynamics of organisms, and ultimately guide management decisions for threatened and endangered species. Pond‐breeding amphibians are often touted as a classic example of metapopulation structure. However, empirical assessment of this assumption is lacking for...

The prevalence of studies that discern the drivers of animal migrations is increasing exponentially, in line with raised concerns over climate-driven shifts in phenological patterns. Amphibians that breed in ephemeral wetlands are particularly vulnerable owing to the stochastic nature of their breeding habitat and high survival and reproductive cos...

Changing climate will impact species' ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,00...

Gopherus polyphemus (Gopher Tortoise) populations historically occurred throughout much of the southeastern Coastal Plain, and burrows created by this species provide refugia for a large suite of commensal species. Our objective was to evaluate the physical degradation of Gopher Tortoise burrows over time. We provide burrow-status information from...

Feral swine Sus scrofa have been implicated as a major threat to sensitive habitats and ecosystems as well as threatened wildlife. Nevertheless, direct and indirect impacts on threatened species (especially small, fossorial species) are not well documented. The decline of the U.S. federally endangered reticulated flatwoods salamander Ambystoma bish...

Section 6 funds were used to conduct surveys to determine the status and distribution of three rare and imperiled pond-breeding amphibians: striped newt (Notophthalmus perstriatus), frosted flatwoods salamander (Ambystoma cingulatum), and reticulated flatwoods salamander (A.bishopi). This report summarizes the results of surveys for these species f...

Ephemeral wetlands surrounded by Pinus palustris Mill. (Longleaf Pine) flatwoods support diverse herpetofaunal communities and provide important breeding habitat for many species. We sampled herpetofauna in three pine flatwoods wetlands on Eglin Air Force Base, Okaloosa County, Florida, over two time periods (one wetland [1] from 1993–1995 and two...

Ephemeral wetlands surrounded by Pinus palustris (Longleaf Pine) flatwoods support diverse herpetofaunal communities and provide important breeding habitat for many species. We sampled herpetofauna in 3 pine flatwoods wetlands on Eglin Air Force Base, Okaloosa County, FL, over 2 time periods (1 wetland [1] from 1993 to1995 and 2 wetlands [2 and 3]...

Predator–prey interactions play an important role in structuring larval anuran communities in ephemeral wetlands. The type of interaction often depends on the predator species and the complexity of the aquatic habitat. We experimentally evaluated the effects of Panhandle Crayfish (Procambarus evermanni) predation on larval Southern Leopard Frogs (L...

The hydroperiod of ephemeral wetlands is often the most important characteristic determining amphibian breeding success, especially for species with long development times. In mesic and wet pine flatwoods of the southeastern United States, ephemeral wetlands were a common landscape feature. Reticulated flatwoods salamanders (Ambystoma bishopi), a f...

Area and maximum depth (2005–2014) of 17 pine flatwoods wetlands. (XLSX)

Water depth measurements from 17 pine flatwoods wetlands over a 9-year period. (XLSX)

Natural disturbances play a critical role in structuring many ecosystems. In the southeastern United States, fire suppression and exclusion have removed the natural disturbance regime from many ecosystems, including ephemeral wetlands embedded within longleaf pine forests. We sampled aquatic invertebrate and amphibian communities in 21 pine flatwoo...

Aquatic and semiaquatic turtles use wetlands and thermally buffered soils to thermoregulate during the active season and to sustain body temperatures above freezing during overwintering. We deployed temperature data loggers during wintertime and summertime in wetlands occupied by Bog Turtles (Glyptemys muhlenbergii) in southwestern Virginia, United...

The Reticulated Flatwoods Salamander (Ambystoma bishopi) is one of three southeastern U.S. ambystomatid salamanders that deposit eggs in ephemeral wetlands without standing water. Eggs typically hatch from inundation by rising water levels during the late fall or early winter. We described microhabitat characteristics of A. bishopi egg deposition s...

Ambystoma bishopi (reticulated flatwoods salamander) is federally endangered and one of two flatwoods salamanders that occur in the longleaf pine ecosystem. Both species are experiencing population declines attributed to habitat loss and degradation. Flatwoods salamanders are fossorial for much of the year. Little information is available on habita...

Eglin Air Force Base (Eglin) in Florida is one of few remaining public lands where the Reticulated Flatwoods Salamander (Ambystoma bishopi) occurs, and it represents the only remaining location within the entire range of this endangered species to have two populations that both occur in wetland complexes with >2 occupied wetlands (Gorman et al., 20...

Conservation of a target species is often hindered by the absence of basic demographic information. Lithobates [Rana] okaloosae (Florida Bog Frog) was discovered in 1982 and occupies only three counties in northwest Florida, with its geographic range occurring almost exclusively on Eglin Air Force Base. This limited distribution has led to the list...

In recent years, silivicultural methods have shifted away from clearcut harvesting towards greater retention of version: trees through part or all of a rotation. However, little is known about the effects of partial harvesting on wildlife populations. Thus, we examined effects of high-leave shelterwood management on terrestrial salamanders prior to...

Bog turtles (Glyptemys muhlenbergii) access saturated wetland soils and move through them to thermoregulate, find cover, and hibernate. Variability in the physical properties of the soil that affects suitability for turtle use is little understood. We identified dominant soil series and measured soil organic carbon (SOC) content and particle size i...

Rana okaloosae is endemic to northwestern Florida and is sympatric with R. clamitans clamitans, its closest relative and possibly its main interspecific competitor. We evaluated the movements, dynamic interactions, and nearest neighbor distances of male R. okaloosae and R. c. clamitans in Okaloosa County, Florida. Mean minimum daily distances moved...

Although fire is recognized as an important disturbance in longleaf pine uplands of the southeastern US, less is known about the importance of fire or other disturbances in the wetlands embedded within this ecosystem. The reticulated flatwoods salamander (Ambystoma bishopi), a federally endangered species, and other rare and declining amphibians, a...

The bog turtle (Glyptemys muhlenbergii) is known to select wetland areas that are near water with deep mud, but water table dynamics in their habitats have not been well described. We installed and monitored shallow groundwater wells to evaluate hydrology over a continuous 28-month period on six wetlands known to be frequently used by bog turtles a...

As a result of declining populations and reduced availability of suitable habitat, Ambystoma bishopi (Reticulated Flatwoods Salamander) and A. cingulatum (Frosted Flatwoods Salamander) are federally listed as endangered and threatened, respectively, by the United States Fish and Wildlife Service under the Endangered Species Act. Recovery efforts ar...

We investigated the behavioral response of Florida bog frog (Lithobates [Rana] okaloosae), bronze frog (L. clamitans), and southern leopard frog (L. sphenocephala) tadpoles to chemical cues from two predators, the banded water snake (Colubridae: Nerodia fasciata) and the red fin pickerel (Esocidae: Esox americanus). Bog and bronze frogs are close r...

Competition is an ecological process that may play a role in the structuring of communities. Understanding the effect of competition on rare species may be particularly important for amphibian conservation, because amphibians are experiencing global declines. We experimentally evaluated the effects of Lithobates [Rana] clamitans (Bronze Frog) tadpo...

Quantifying and comparing habitat selection of related, syntopic species may help elucidate how species partition resources and compete. The Florida Bog Frog (Lithobates okaloosae) is endemic to northwestern Florida and is syntopic with the more widely distributed Bronze Frog (Lithobates clamitans clamitans). Our objective was to determine whether...

Environmental temperatures affect nearly all aspects of ectotherm physiology, including terrestrial salamanders. Therefore, habitat disturbances that alter temperature regimes may interact with physiological processes to affect energy budgets of salamanders or constrain surface activity and possibly lead to changes in population-level parameters. W...

Conservation of terrestrial salamanders requires consideration for landscape-level features and processes; and, therefore, tools are needed to support planning at large spatial scales. We assessed terrestrial salamander distribution patterns using an existing salamander data set and two previously developed landscape-level spatial tools, a landscap...

Conservation of terrestrial salamanders requires consideration for landscape-level features and processes; and, therefore, tools are needed to support planning at large spatial scales. We assessed terrestrial salamander distribution patterns using an existing salamander data set and two previously developed landscape-level spatial tools, a landscap...

Although investigators have determined that some anurans can influence nutrient availability in terrestrial systems, ecological interactions among salamanders, invertebrates, and leaf litter decomposition in the detrital ecosystem are poorly understood. We examined the effects of the Eastern Red-Backed Salamander (Plethodon cinereus) on leaf litter...

(1) We estimated the standard metabolic rate (SMR) of wild-caught Plethodon cinereus across a range of body masses and ecologically relevant temperatures.(2) We collected 16 salamanders, ranging 0.06–1.11 g and quantified oxygen consumption at 10, 15, 20, 25, and 30 °C with a computer-controlled, closed-circuit, indirect respirometer. The multiple...

The flatwoods salamander (Ambystoma cingulatum) was listed as federally threatened in 1999. Alteration of habitat was considered the main threat to the species, especially the loss of habitat for larval flatwoods salamanders that develop in isolated, seasonally flooded wetlands. Our objectives were to evaluate a suite of within-pool factors (i.e.,...

Both observational and experimental studies have documented drastic reductions in salamanders after forest harvesting. Yet, the amount of time until salamander populations rebound and the factors limiting recovery after harvesting are unknown. We compared the effects of six oak regeneration practices to a control, representing a disturbance gradien...

Many species of birds that depend on grassland or savanna habitats have shown substantial overall population declines in North America. To understand the causes of these declines, we examined the habitat requirements of birds in six types of grassland in different regions of the continent. Open habitats were originally maintained by ecological driv...

Increasing demands for timber and non-timber forest products often conflict with demands to maintain biodiversity and ecosystem processes. To examine tradeoffs between these goals, we implemented six alternative management systems using a stand-level, replicated experiment. The treatments included four silvicultural regeneration methods designed to...

This report describes research conducted on vertebrate species of concern inhabiting the longleaf pine ecosystem on Eglin Air Force Base, Florida, during January 2001 through December 2005. This work was conducted first through Research Work Order Number 68 of the USGS-BRD Virginia Cooperative Fish and Wildlife Research Unit at Virginia Tech, and s...

The federally threatened flatwoods salamander (Ambystoma cingulatum Cope) inhabits fire-adapted longleaf pine (Pinus palustris Miller) flatwoods and savannas in the southeastern coastal plain. It breeds in ephemeral wetlands that typically dry during summer and refill in fall and winter. We collected data on burning trends of A. cingulatum habitat...

Little is known about the breeding biology of Bridled White-eyes (Zosterops conspicillatus), especially the federally endangered Rota Bridled White-eye (Z. c. rotensis). Here, we report on the breeding behavior, nest-site characteristics, and nest dimensions of Rota Bridled White-eyes. From 1997 to 1999, we found 20 Rota Bridled White-eye nests in...

Little is known about the breeding biology of Bridled White-eyes (Zosterops conspicillatus), especially the federally endangered Rota Bridled White-eye (Z. c. rotensis). Here, we report on the breeding behavior, nest-site characteristics, and nest dimensions of Rota Bridled White-eyes. From 1997 to 1999, we found 20 Rota Bridled White-eye nests in...

Several studies have demonstrated the negative effects of clearcutting on terrestrial plethodontid salamander populations. However, none has experimentally compared clearcutting with multiple alternative timber-harvest methods. Using a randomized, replicated design, we compared the short-term effects ( 1–4 years after harvest ) of clearcutting to e...

From March 1999 to August 2000, we used mist-netting, point counts, and radio-tracking to study habitat use, area requirements, and breeding of the Ivory-billed Woodcreeper Xiphorhynchus flavigaster in the tropical deciduous and semi-deciduous forest (arroyo forest) of the Chamela-Cuixmala Biosphere Reserve, western Mexico. The Ivory-billed Woodcre...