Please login to bookmark

Cave Conundrum: Is White-Nose Syndrome Responsible for All Declining Bat Populations?

Hibernating bat populations across the Eastern United States have suffered declines since the 2000s. Little brown bat populations have declined 70 percent or more. Populations of the northern long-eared bat and tricolored bat have declined by 30 percent. The scientists studied these three bat species in their research.

The cause of bat population declines is often assumed to be white-nose syndrome (WNS), a deadly disease caused by a fungal pathogen. Evidence suggests WNS is a serious threat to bat populations. However, research has not yet supported WNS as the only cause of bat population declines. Therefore, the scientists in this study asked: Is WNS the sole cause of these bat population declines, or is there something else causing bat populations to decline?

Cave Conundrum: Is White-Nose Syndrome Responsible for All Declining Bat Populations?

Meet the Scientists

Sybill Amelon

Wildlife Ecologist

Brent Sewall

Biologist

What Kinds of Scientists Did This Research?

Wildlife ecologist: This scientist studies the relationship of different kind of wildlife with each other and with their living and nonliving environment.
Biologist: This scientist studies living organisms and living systems.

Thinking About Science

Research questions in science often require a large amount of information to get an accurate answer. Sometimes, scientists discover that there is not enough information to get an accurate answer to a research question. To solve this problem, some scientists begin long-term research studies. For instance, scientists may want to know how drought affects pine tree growth.

First, they would want to know how pine trees grow in both non-drought years and drought years. They would need many years’ worth of data to understand normal pine tree growth before determining how drought might change that growth.

In 1908, the Forest Service recognized the need for long-term research sites. The Forest Service established a system of Experimental Forests and Ranges (EFRs) (figure 1). At these sites, scientists regularly collect information about the rainfall, soil, plant and animal populations, and other environmental conditions of the area. By recording these data over many years, EFRs provide a broad range of information that can help scientists answer complex, long-term research questions. Similarly, in this research about white nose syndrome, scientists needed to gather research over a longer period of time.

A map of the United States with dots on all the Experimental Forest and Ranges — **Figure 1**. Today, 80 experimental forests and ranges are spread across the United States. FIND Outdoors map by Carey Burda and Stephanie Pfeiffer.

Thinking About the Environment

White-nose syndrome (WNS) is a disease affecting hibernating bat populations. The disease is named for the white fungus that collects on the muzzle and other parts of infected bats (figure 2).

A close up of a bat with white fungus growing on it's nose — **Figure 2**. Scientists can identify WNS on bats from the white fungus that develops on the bat’s nose and damaged skin on the bat’s
body. U. S. Fish and Wildlife Service photo by of Jonathan Mays.

The disease was first introduced in New York in winter of 2006. Since the time WNS was first introduced, the disease has spread to caves and mines across 33 States and 7 Canadian provinces. WNS has killed an estimated 6 million bats in the Eastern United States and Canada (figure 3). At some sites, 90 to 100 percent of bats have died from WNS infection.

Scientists are dedicated to understanding and combatting WNS because bats are important to the ecosystems in which they live. In some ecosystems, plants rely on bats to pollinate flowers or spread seeds. Bats, the only free flying mammal, are also an important indicator species that signal changing conditions in an ecosystem. Some bat species are insectivores, and act as a natural method of pest control in their environment.

A map of the United States showing white nose syndrome occurence in different counties by year — **Figure 3**. Since its introduction in New York in 2006, WNS has spread across the Eastern United States as well as other areas. U. S. Fish and Wildlife Service map by https://www.whitenosesyndrome.org.

Number Crunch

Introduction

Hibernating bat populations across the Eastern United States have suffered declines since the 2000s. Little brown bat populations have declined 70 percent or more. Populations of the northern long-eared bat and tricolored bat have declined by 30 percent (figures 4, 5, and 6). The scientists studied these three bat species in their research.

A small brown bat hanging upside down in a cave — **Figure 4**. The little brown bat is small, usually weighing less than half an ounce.

U.S. Fish and Wildlife Service photo by Marvin Moriarty

Northern long-eared bat hanging upside down in a cave — **Figure 5**. Northern long-eared bats are known for their especially long ears.

U.S. Fish and Wildlife Service photo

A bat resting in a cave — **Figure 6**. Tricolored bats, like the one pictured, rest in dead leaves or the needles of trees.

U.S. Fish and Wildlife Service photo by Pete Pattavina

The cause of bat population declines is often assumed to be WNS, a deadly disease caused by a fungal pathogen. Evidence suggests WNS is a serious threat to bat populations. However, research has not yet supported WNS as the only cause of bat population declines. Therefore, the scientists in this study asked: Is WNS the sole cause of these bat population declines, or is there something else causing bat populations to decline?

The scientists hypothesized that if WNS is the sole cause of decline in bat populations, then the following conditions will be true:

Only bat populations infected with WNS will experience declines;
Declines in bat populations will happen later at caves farther from where WNS was discovered; and
Bat populations will begin declining shortly
after WNS infects a colony.

Reflection Section

Methods

To test their ideas, the scientists needed to know how bat populations have changed before and after WNS was introduced. They needed a large amount of information about bat populations over a period of many years to understand population trends. They used data collected by State wildlife agencies in New York, Pennsylvania, West Virginia, and Tennessee. These data were gathered during regular surveys of bat hibernacula during winter every 2 years between 1999 and 2011 (figure 7).

Many pats piled up together hibernating in a cave in the winter. — **Figure 7**. Many species of bats hibernate throughout winter in caves, mines, and other cold, dark places. These sites are called **hibernacula** (hī bər na kyə lə).
U.S. Fish and Wildlife photo by Keith Shannon.

Biologists visited the same hibernacula to collect data on the location of caves, the number of bats, and presence or absence of WNS (figure 8).

A scientist holding a bat's wings open. — **Figure 8**. During the surveys, biologists found
WNS present in approximately 44-48 percent
of the routes they surveyed for all three species.
U.S. Fish and Wildlife Service photo by Gary Peeples.

The scientists graphed the population trends of each bat species in each State using the data. They also graphed the expected scenarios, or models. These models illustrated how the bat populations would change over time if all three of the hypothesized WNS conditions were present. By comparing the results of the models with the graphs of actual population trends, the scientists were able to evaluate whether the hypothesized conditions were true.

Reflection Section

How Do Scientists Detect WNS?

When scientists survey caves, they look for signs of WNS. Visible signs of WNS include skin damage, white fungus on the bats’ noses, and the number of dead bats in the cave. However, these visual methods are not always an accurate way to detect WNS. New research has found a way to detect a WNS infection using a certain range of light. Ultraviolet light, which is invisible to the human eye, makes the skin damage caused by WNS glow an orange-yellow color. A study showed this method was 98.8 percent effective at positively detecting WNS, and it provides a new, reliable way to identify WNS on bats.

Source: “Black-Light Detects White Nose Syndrome in Bats,” by U.S. Geological Survey.

How Do Scientists Make Models?

You probably have seen toy cars and airplanes that look just like the real thing, only smaller. These toys are actually models, or simplified representations of a larger item. Models are used frequently in our day-to-day lives to help people see and understand large objects, concepts, and processes.

Scientists also use models when a scientific research question is too big or too complicated to answer. In these situations, scientists may use scientific modeling. A scientific model uses data to represent complex scientific concepts in a simpler way. In the case of this study, the scientists used models to better understand how a disease, like WNS, affects bat populations.

Models are useful tools for scientists, but they are only as good as the data that are put into them. The scientists in this study used data taken from four States across 11 years. Using this quantity of data helped the scientists increase the likelihood that their model would give them an accurate representation of the bat populations they were studying. In the table below, the total numbers of surveys conducted, routes traveled, and individual bats counted are shown. The scientists used this information to build their model (table 1).

A graphic of a table used in the study — **Table 1**. This table shows the set of data the scientists in this study used to make their model.

Findings

The scientists compared the modeled and real population patterns. The data showed all three of the bat species met at least one of the three hypothesized conditions. However, none of the species met all three conditions (table 2). Results indicate that certain bat populations were declining before WNS was discovered in those populations. Other bat populations were experiencing a population increase that continued despite WNS infection.

Table 2. This table shows whether or not the modeled bat populations met the three hypothesized conditions.
Hypothesized Condition	Little Brown Bat	Nothern long-eared bat	Tricolored bat
1. Only bat populations infected with WNS will experience declines	No; Bat colonies with and without WNS experiences similar population changes	No; Bat colonies with and without WNS experiences similar population changes	Yes; Bat colonies with WNS declined more severely than bat colonies without WNS
2. Declines in bat populations will happen later at caves farther from where WNS was discovered	No; Patterns varied greatly by region, though most areas experienced declines	Yes; Declines were slower and less severe further from the point of WNS introduction	No; Declines did not vary with distance from the point of WNS introduction
3. Bat populations will begin declining shortly after WNS infects a colony	Yes; Onset of bat population declines matched local detection of WNS within 1 year	No; Bat population declines began before local detection of WNS by 10+ years	No; Bat population declines began before local detection of WNS by 3-7 years

Reflection Section

Discussion

The results of the study support the idea that WNS is an important cause of decline of bat populations in the Eastern United States. However, the results indicate that WNS is not the only cause of decline. Most efforts to aid bat populations have focused on preventing transmission of WNS by humans (figure 9). However, WNS also is often transmitted through non-human means, like one bat contacting and infecting another bat.

A sign on a tree designating the area as restricted due to hibernating bats — **Figure 9**. Federal and State agencies close caves where endangered bats hibernate to prevent disturbance from human visitors. U.S. Fish and Wildlife photo by of Ann Froschauer.

The findings in this research also suggest that there are other important causes of decline that may be overlooked. Other potential sources of mortality include agricultural pesticides and chemicals, climate change, collisions with human-built structures and vehicles, and habitat loss or degradation of habitat. These results suggest that scientists should continue to combat WNS while also addressing other threats to bat populations.

Reflection Section

Adapted from Ingersoll, Thomas E.; Sewall, Brent J.; Amelon, Sybill K. 2016. Effects of white-nose syndrome on regional population patterns of 3 hibernating bat species. Conservation Biology. 30(5):1048-1059

Part Of

Caves and Karst Natural Inquirer - Vol. 20 No. 1

Explore Full Journal

ESS3.C-M1
ETS1.B-M4
ETS1.C-M2
LS2.A-M1
LS2.A-M4
LS2.C-M1
LS4.D-M1

What Is a Natural Inquirer Journal?

Three Natural Inquirer journal covers with NI bee

A Natural Inquirer journal is a collection of 4-8 articles on a related science topic. Journals are written for a middle school audience, but they can also be adapted for both high school students and advanced upper elementary students. Some journals are particularly suited to high school students; you can find our grade level recommendations in the tags on the product page or by filtering journals by grade level.

Journals include:

Four to eight articles based on published, peer-reviewed research papers; the articles keep the research paper format (see more below) but are written in language students can understand.
A FACTivity for each article, which is an activity to complete after reading the article. The FACTivity helps reinforce major science concepts from the article. These activities are designed to be easy to implement, with few material requirements and options for adapting them for your audience or available resources. Some articles in a journal may have two FACTivities.
A short “Welcome to the journal” article about key background information and science concepts that unify the articles included in the journal
A glossary of new terms for each article and the introductory materials.
A list of related Natural Inquirer publications for each article as well as outside references.
Standards correlations, including Next Generation Science Standards, addressed in the articles and the FACTivities.

Journals may also include additional essays (called spotlights), other activities (like crossword puzzles or vocabulary challenges), and more.

A screenshot of the article resource tile for "A Flame Changer" showing the three different format option buttons.

Reading Modes

Journals are available in three different formats:

Hard copies can be ordered from the website and shipped, all free of charge.
PDF versions of the printed journal can be downloaded free on the website. The PDF version directly replicates the content and layout of the printed version. You can also download individual articles as pdfs.
The “Read Distraction Free” option allows the individual articles to open in their own window, without the rest of the website being visible. These articles can be found under the “Articles” tab. This version allows readers to scroll to particular sections of the article using the sidebar menu on the left side of the screen. This version also has interactive Reflection Sections and Number Crunches. Students can enter their answers, submit them, and then receive the correct answers to double-check their work. Submitted answers are not saved on the website and will disappear once the window is closed.

What's in a Natural Inquirer Article?

Here, we'll go into more detail about the parts of a Natural Inquirer article and give you some ideas about how they can be used.

Meet the Scientists
This section introduces the scientists (and others) who worked on the study. In their own words, they each share a memorable science experience, a favorite research project, or something they learned during the course of their education or research.

Use this section to:
- Introduce kids to the variety of people who work in science
- Introduce kids to the variety of scientific fields and give brief descriptions of science-related jobs
- Explore ways that people interact with science every day
Next Generation Science Standards (NGSS) applications:
- Science and Engineering Practices
- Crosscutting Concepts: Influence of Science, Engineering, and Technology on Society and the Natural World
Note that specific standards for this particular journal are linked on this educator guide tab.

Other resources:

Many of the scientists and engineers featured in this section are also featured on our collector cards. Learn more about their work, how they got interested in their fields, and interesting projects they worked on. Cards can be printed as posters, too.
Thinking About Science
This section briefly describes a concept about science or scientific research. This overview can touch on topics like
- study type (longitudinal study, quantitative vs. qualitative data),
- behaviors of scientists (conducting literature reviews, collaborating with other specialists, replicating earlier studies),
- the practice of science (the scientific method, engineering design, data collection, randomization, controls and variables),
- or other aspects of science (bias, correlation vs. causation).
Use this section to:
- Reinforce steps in the scientific method and the process of science
- Encourage students to think about the practice of science and what it can and cannot tell us
- Consider the many types of scientific study and what information each type can provide
Next Generation Science Standards applications:
- Science and Engineering Practices
- Life Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular journal are linked on this educator guide tab.

Other resources:

You can use key words to search for other or related scientific topics on our website (e.g. “longitudinal study,” “bias,” or “sampling”).
Thinking About the Environment
This section provides a brief overview of a topic or concept in environmental/life science. The topic or concept is directly related to the research study that follows. Examples of topics include the carbon cycle, the water cycle, habitat fragmentation, phenology, biodiversity, and ecosystem services.

Use this section to:
- Provide important background information to help students understand the research study
- Serve as a quick reference during reading or class instruction
- Connect the research article with other activities or media on the same topic
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular journal are linked on this educator guide tab.

Other resources:

You can use key words to search for more resources on life or earth science topics on our website (e.g. “habitat,” “carbon,” or “genetics”).
Introduction
This section begins the scientific article format. Much like the published, peer-reviewed study this article is based on, the introduction provides background information for the study – what is currently known and what remains unknown. The introduction culminates in the question(s) the study hopes to answer.

The introduction is also the first section with a Reflection Section. This section includes two or three questions to help kids reflect on what they’ve just learned in the Introduction. If they are using the online distraction-free reading mode, they can answer these questions directly on the website.

Use this section to:
- Review important background information that kids need to understand the study
- Connect the study to the concepts addressed in the Thinking About Science and Thinking About the Environment sections
- Understand research questions and hypotheses, including generating their own hypotheses given what they already know
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular journal are linked on this educator guide tab.

Other resources:

Use one of the guided reading lesson plans to help kids follow the format of a scientific paper.
Methods
This section is the nuts and bolts of the study design – the who, what, when, where, why, and how of the research. Contained within the Methods section are usually maps of the study location or the set-up of study plots, as well as details about what data was collected and how.

The Methods section also ends with a Reflection Section – two or three questions to help students think through what they just read. These questions are interactive on the distraction-free reading mode.

Use this section to:
- Show students how experiments and studies are designed and carried out
- Explore sampling methods and randomization
- Introduce various data collection tools (e.g. camera traps, surveys, insect collection tools, weather stations, etc.)
- Explain bias and how studies are designed to remove bias
- Help students gain experience with map reading
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular journal are linked on this educator guide tab.

Other resources:

Many Methods and Findings sections contain Number Crunches, which are simple math exercises designed to help students interact with the data from the study.
Findings
This section summarizes the data collected during the study. The Findings section usually includes data tables or graphs and highlights the significant data points from the study. This section often mentions statistical analysis or the use of computer programs to model or analyze the data, though these methods are only discussed generally.

The Findings section also ends with a Reflection Section – two or three questions to help students think through what they just read. These questions are interactive on the distraction-free reading mode.

Use this section to:
- Have students practice reading and interpreting graphs and tables
- Compare results between variables and controls
- Explain the concept of statistical significance
- Discuss how no data or negative results still provide valuable information
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular journal are linked on this educator guide tab.

Other resources:

Search the website for “map” or “graph” to find activities where students can practice making and reading maps and graphs.
Discussion
This section concludes each article. In it, we summarize the main findings of the scientists’ study. Additionally, we present the scientists’ ideas about the limitations of their study, the big-picture impacts of their research, and the scientists’ plans for future study or action.

The Discussion section ends with a Reflection Section – two or three questions to help students think through what they just read, especially general take-aways from the study. These questions are interactive on the distraction-free reading mode.

Use this section to:
- Discuss what conclusions can and cannot be drawn from the available data
- Explain the difference between correlation and causation
- Explore study limitations and opportunities for further study
- Brainstorm ways the study findings could be applied to real-world situations
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular journal are linked on this educator guide tab.

Other resources:

Use the “Designing Your Own Study” resource page for videos of scientists discussing their own research studies. The page also includes educator resources to help students plan their own scientific studies.

Additional Resources on the Website

A screenshot of the product tabs for an NI monograph On the website, we pair each journal with a variety of other resources, as well. Use the tabs on the product page to browse through the following:

Related activities, including the FACTivity for each article
An “About” essay that gives some larger context for the research the scientists conducted or more information about the science topic from the journal
A glossary of all boldfaced terms from the journal
A “Scientists and Collaborators” page that lists the people involved in the studies in the journal; click on a researcher to reach their bio page and see what other articles they might be featured in
A “Related Content” page that lists both Natural Inquirer resources about similar topics and also outside reference materials

Article Selection and Review

Natural Inquirer partners with the USDA Forest Service, so we source research studies by Forest Service scientists that have been peer-reviewed and published in reputable journals. Some of our articles have also been created in collaboration with scientists from other Federal agencies, such as U.S. Geological Survey and the United Nations Food and Agriculture Organization, universities, and other non-profits.

All journal articles are reviewed by scientists who conducted the original research study to verify scientific accuracy. Journals are also reviewed by student editorial review boards of middle or high school students before publication. Additionally, all journals are reviewed by the Forest Service and the U.S. Department of Agriculture before publication.

A screenshot of the citation for "Lights, Camera, Tracks" Every journal article includes a citation of its source study. Many educators pair the original research paper with our article to help more advanced students learn how to read formal research papers. The journal article then serves as adapted primary literature, bridging the two articles.

Lessons

In this lesson plan, students will complete a guided reading activity while reading their chosen article. As they read, they will complete a double-entry graphic organizer where they will note...
Lesson Plan – Haikus
In this lesson plan, students will complete a guided reading activity while reading their chosen article. As they read, they will complete a double-entry graphic organizer where they will note...
- Explore Lesson Plan
- Download Lesson Plan (PDF)
- Explore Lesson Plan
- Download Lesson Plan (PDF)
Part Of

Caves and Karst Natural Inquirer - Vol. 20 No. 1
Identify and write the main idea of the section using one sentence. Fill out the provided graphic organizer. This lesson plan can be used with any Natural Inquirer article.
Lesson Plan – Block Graphic Organizer
Identify and write the main idea of the section using one sentence. Fill out the provided graphic organizer. This lesson plan can be used with any Natural Inquirer article.
- Explore Lesson Plan
- Download Lesson Plan (PDF)
- Explore Lesson Plan
- Download Lesson Plan (PDF)
Part Of

Flower Power: Planting for the Past and the Future
In this lesson plan, students will read a Natural Inquirer article and write short summary notes from each section. Students will then create “6-W Poems” that reflect their understanding of...
Lesson Plan – The 6-W Questions
In this lesson plan, students will read a Natural Inquirer article and write short summary notes from each section. Students will then create “6-W Poems” that reflect their understanding of...
- Explore Lesson Plan
- Download Lesson Plan (PDF)
- Explore Lesson Plan
- Download Lesson Plan (PDF)
Part Of

Show Me the Money: Promoting Sustainable Forests in the South

Education Files

Project Learning Tree

If you are a trained Project Learning Tree educator, you may use “Life on the Edge,” “Dynamic Duos,” “Our Changing World,” and “Earth Manners” as additional resources.

Download all resources - FREE!

Journals & Monographs

Collector Cards

Readers

Coloring and Activity Books

Please login to bookmark

FACTivity – Cave Conundrum

Standards addressed in this Article:

What Is a Natural Inquirer Journal?

Reading Modes

What's in a Natural Inquirer Article?

Meet the Scientists

Thinking About Science

Thinking About the Environment

Introduction

Methods

Findings

Discussion

Additional Resources on the Website

Article Selection and Review

Lessons

Lesson Plan – Haikus

Lesson Plan – Block Graphic Organizer

Lesson Plan – The 6-W Questions

Education Files

Project Learning Tree

Glossary

degradation

hibernacula

indicator species

insectivore

mortality

pathogen

representation

route

transmission

Sybill Amelon

Brent Sewall

Related Resources from the Natural Inquirer

The Trees Have Gone Batty! How Bat Scat Helped Restore a Tropical Forest

Moving Spore-adically: The Spread of Sudden Oak Death in California Forests

Additional Resources

USDA National Invasive Species Information Center: White-Nose Syndrome

National Park Service: What Is White-Nose Syndrome?