Eric Britzke

Engineer Research and Development Center - U.S. Army | ERDC US Army · Environmental Laboratory

The Tricolored Bat (Perimyotis subflavus) has suffered significant population declines in much of its geographic range due to white-nose syndrome (WNS). Our aim was to describe the torpor patterns of tricolored bats within the southeastern United States to further our understanding of their winter ecology and potential susceptibility to WNS in curr...

This special report reviews current scientific literature to identify the most commonly cited metrics used to describe the macrohabitat criteria important for Chiroptera presence in the United States. The review evaluates 69 scientific articles from 1994 to 2018. The most commonly cited metrics were divided into four main categories: tree-species-l...

DNA contained in animal scat provides a wealth of information about the animal, and DNA metabarcoding of scat collections can provide key information about animal populations and communities. Next‐generation DNA sequencing technologies and DNA metabarcoding provide an efficient means for obtaining information available in scat samples. We used Mult...

This special report provides a selection process for choosing priority species using the specific focus of high-elevation, forested habitats in the North Atlantic to demonstrate the process. This process includes criteria for choosing invasive species to incorporate into models, given the predicted spread of invasive plant species because of climat...

The Handbook summarizes all the key steps in conducting an acoustic survey of a bat community, including project planning, strategies for data collection, approaches to analysis and interpretation, a guide to purchasing a bat detector, and a series of case studies. Chapter 1 (“Introduction to bat echolocation”) provides a broad introduction to the...

Bat guano is a noninvasive, data-rich genetic resource. However, the constituent bat DNA is relatively scant, degraded, and complexed with polymerase chain reaction inhibitors. It also is comingled with a rich pool of nontarget DNA from microbes, parasites, and dietary items. We designed and tested new DNA assays for bat species identification (COX...

This study surveyed and mapped shale barren habitats, and documented associated plant communities, at Raystown Lake, Pennsylvania. Additional surveys were conducted on Noctuid moth communities on the shale barrens, plus further surveys on bats and aquatic invertebrates were performed. These surveys serve to update and document the current presence...

We assessed parentage within and among maternity colonies of northern long-eared bats (Myotis septentrionalis (Trouessart, 1897)) in north-central Kentucky, USA, from 2011 to 2013 to examine colony social structure, formation, and membership dynamics. We intensively sampled colonies in close and remote (>10 km) proximity before and after targeted d...

The North American Bat Monitoring Program (NABat) is a multi-national, multi-agency coordinated monitoring program designed to assess the status and trends of North American bats at local, state, and range-wide scales. NABat monitoring efforts focus on the 47 species of bats shared by Canada, the United States, and Mexico. NABat is composed of a ne...

As multiple species of bats are currently experiencing dramatic declines in populations due to White‐Nose Syndrome (WNS) and other factors, conservation managers have an urgent need for data on the ecology and overall status of populations of once‐common bat species. Standard approaches to obtain data on bat populations often involve capture and ha...

Fission–fusion dynamics appear common among temperate bats where females form roost groups that change in size and composition, as females switch roosts almost daily. One hypothesis for frequent roost switching is that females move to find suitable thermal conditions as ambient conditions change. Tests of this hypothesis have, however, been conduct...

Though characterization of, and understanding determinants of, social structure in bats is increasing, little is known about how bat social groups respond to disturbance resulting in roost loss. Given that many species of bats roost in ephemeral or transitory resources such as plants, it is clear that bat social groups can tolerate some level of ro...

Bat day-roost selection often is described through comparisons of day-roosts with randomly selected, and assumed unused, trees. Relatively few studies, however, look at patterns of multi-year selection or compare day-roosts used across years. We explored day-roost selection using 2 years of roost selection data for female northern long-eared bats (...

INTRODUCTION: The objective of this work was to develop a series of conceptual models (CMs) that illustrate how various aspects of climate change can impact contaminant availability and threatened, endangered, and at-risk species (TER-S) of terrestrial habitats on military installations. The goal was to develop tools that aid installation managers...

Forest roosting bats use a variety of ephemeral roosts such as snags and declining live trees. Although conservation of summer maternity habitat is considered critical for forest-roosting bats, bat response to roost loss still is poorly understood. To address this, we monitored 3 northern long-eared bat (Myotis septentrionalis) maternity colonies o...

In the summers of 2011 and 2012, we compared passive and active acoustic sampling for bats at 31 sites at Fort Drum Military Installation, New York. We defined active sampling as acoustic sampling that occurred in 30-min intervals between the hours of sunset and 0200 with a user present to manipulate the directionality of the microphone. We defined...

Introduction Many species of ambystomatid salamanders are dependent upon highly variable temporary wetlands for larval development. High larval densities may prompt the expression of a distinct head morphology that may facilitate cannibalism. However, few studies have characterized structural cannibalism within natural populations of larval salaman...

With dramatic declines of bat populations due to mortality caused by Pseudogymnoascus destructans (White-nose Syndrome), assessing habitat preferences of bats in the northeastern US is now critical to guide the development of regional conservation efforts. In the summer of 2012, we conducted fixed-station simultaneous telemetry to determine nocturn...

Understanding population trends of any species is essential for conservation and management. However, due to difficulty in sampling some species, population status of many bat species is poorly understood. In an effort to resolve this issue, especially in light of emerging threats (e.g., white-nose syndrome and wind energy), a national mobile acous...

AimEmerging infectious diseases present a major perturbation with apparent direct effects such as reduced population density, extirpation and/or extinction. Comparatively less is known about the potential indirect effects of disease that likely alter community structure and larger ecosystem function. Since 2006, white-nose syndrome (WNS) has result...

Concomitant with the emergence and spread of white-nose syndrome (WNS) and precipitous decline of many bat species in North America, natural resource managers need modified and/or new techniques for bat inventory and monitoring that provide robust occupancy estimates. We used Anabat acoustic detectors to determine the most efficient passive acousti...

An increasingly popular mark-recapture method to study the ecology of bats is the use of passive integrated transponder (PIT) tags. Deployment of PIT reader arrays at entrances to caves and mines can yield insight into bat behavior during swarming, winter activity, and emergence. This application has the potential to address questions about bat act...

The Holdridge Life Zone system was used to map the extent of present and future climatic envelopes that influence the distribution of forest tree species and cover types in the continental United States. The Holdridge system integrates mean annual temperature, mean annual precipitation and mean annual potential evapotranspiration (PET) to define cl...

Ultrasonic detectors have become a mainstay for studying the ecology of bats throughout the world. Despite their enormous utility to address a wide variety of research and management issues, many factors that impact the applicability of collected data for answering desired questions are often ignored. Here, we review our current understanding of th...

Understanding seasonal movements of bats is important for effective conservation efforts. Although female Indiana bats (Myotis sodalis Miller and Allen, 1928) have been documented to migrate >500 km, knowledge of their migratory patterns is still extremely limited. We used the relationship between latitude and stable hydrogen isotope ratio in bat h...

White-nose syndrome (WNS), an emerging infectious disease that has killed over 5.5 million hibernating bats, is named for the causative agent, a white fungus (Geomyces destructans (Gd)) that invades the skin of torpid bats. During hibernation, arousals to warm (euthermic) body temperatures are normal but deplete fat stores. Temperature-sensitive da...

Instructions for producing temperature sensitive dataloggers for attachment to bats, including figures. (PDF)

Description of WNS histopathology and assignment of wing damage severity scores (SS), including figures. (PDF)

Vertebrate insectivores such as bats are a pervasive top-down force on prey populations in forest ecosystems. Conservation focusing on forest-dwelling bats requires understanding of community-level interactions between these predators and their insect prey. Our study assessed bat activity and insect occurrence (abundance and diversity) across a gra...

Conservation of summer maternity roosts is considered critical for bat management in North America, yet many aspects of the physical and environmental factors that drive roost selection are poorly understood. We tracked 58 female northern bats ( Myotis septentrionalis ) to 105 roost trees of 21 species on the Fort Knox military reservation in north...

White-nose Syndrome (WNS), a wildlife health concern that has decimated cave-hibernating bat populations in eastern North America since 2006, began affecting source-caves for summer bat populations at Fort Drum, a U.S. Army installation in New York in the winter of 2007–2008. As regional die-offs of bats became evident, and Fort Drum's known popula...

White-nose syndrome (WNS) is a disease responsible for unprecedented mortality in hibernating bats in the northeastern U.S. This previously unrecognized disease has spread very rapidly since its discovery in January 2007, and poses a considerable threat to hibernating bats throughout North America. As WNS spreads, the challenges for understanding a...

Ultrasonic detectors are widely used to survey bats in ecological studies. To evaluate efficacy of acoustic identification, we compiled a library of search phase calls from across the eastern United States using the Anabat system. The call library included 1,846 call sequences of 12 species recorded from 14 states. We determined accuracy rates usin...

Ultrasonic detectors are powerful tools for the study of bat ecology. Many options are available for deploying acoustic detectors including various weatherproofing designs and microphone orientations, but the impacts of these options on the quantity and quality of the bat calls that are recorded are unknown. We compared the impacts of three microph...

In temperate ecosystems, hibernation allows bats to survive long periods of limited prey and water availability during colder months. Despite the extended amount of time some bats spend in hibernation, researchers have only recently been able to study the hibernation ecology of bats under natural conditions. With the emergence of white-nose syndrom...

On 6 May 2003, a tornado severely damaged 284 ha of Mermet Lake State Forest and Wildlife Area in southern Illinois. We used mist nets and Anabat ultrasonic detectors to determine if community composition and habitat use of bats differed between the tornado-disturbed forest and surrounding undisturbed forest during the summers of 2004 and 2005. Ten...

Stable hydrogen isotopes (dDs) in metabolically inert tissues such as feathers and hair provide a set of endogenous markers that may be useful for establishing migratory connectivity in animals. We tested the assumption of a clear relationship between dD values of growing-season–weighted average precipitation (dD p) derived from 2 geographic inform...

We characterized Indiana bat (Myotis sodalis) roosting habitat at three maternity colony sites in western North Carolina and eastern Tennessee. Using radio telemetry, we tracked six bats a total of 40 bat days (range 4–9 days/bat). In 1999, we located a primary roost in an eastern hemlock (Tsuga canadensis) snag (109 cm DBH) in the Nantahala Nation...

Extensive effort has been directed at the roosting ecology of the federally endangered Indiana bat (Myotis sodalis) during the maternity season; however, spring roosting ecology has received much less attention. In April 2002, radio transmitters were attached to the back of 19 female Indiana bats as they emerged from a hibernaculum in northeastern...

Doctor of Philosophy in Environmental Sciences Bats in the eastern United States use echolocation to locate prey and navigate in their surroundings. Recent advances in technology have enhanced use of ultrasonic detectors in field studies. Data recorded using ultrasonic detectors have been used to investigate a wide variety of questions involving ec...

Although echolocation calls of most bats exhibit species-specific characteristics, intraspecific variation can obscure differences among species and make reliable acoustic identification difficult. We examined levels of intraspecific variation in search-phase calls of 7 species of vespertilionid bats from several locations in the eastern and centra...

Among the myriad of recent studies on endocrine-disrupting chemicals, relatively few involve thyroid disruption, and most of these address exposure/disruption during embryonic life. Of those involving adult vertebrates, the endpoints examined are thyroid measurements. Even though thyroid disruption could potentially interfere with energy metabolism...

When animals differ visibly in competitive ability, contests are predicted to be settled quickly. We tested the hypotheses that body size and experience influence agonistic displays in contests between adult male zigzag salamanders, Plethodon angusticlavius. We paired males of either the same size (±1 mm SVL length) or of different sizes (≥4 mm dif...

A survey of bat communities was conducted in Missouri during the summer of 1998 using both mist nets and Anabat. Mist nets provide valuable information about population demographics and species diversity within bat communities. However, they can yield biased samples of bat community activity and may cause undue stress to captured bats. The use of u...

Ultrasonic detectors have been employed to study a variety of different aspects of bat ecology. Common studies involve using detectors to quantify bat activity in an area or to identify bats using their echolocation calls. Bat activity is compared across habitat treatments to investigate factors influencing bat use. While quantification of bat acti...

"August 1998." Thesis (M.S.)--Southwest Missouri State University, 1998. Includes bibliographical references (leaves 63-70).