Wildlife Diversity In Middle Tennessee
The Wildlife Diversity Program in Region II oversees data collection, data management, monitoring, and assists with the management of all non-game wildlife throughout the region. The three dedicated staff works with multiple faunal groups, including amphibians, reptiles, small mammals, bats, birds, as well as many others. In 2005, TWRA developed a Comprehensive Wildlife Conservation Strategy (CWCS), now termed the State Wildlife Action Plan or SWAP, detailing the significance of the rare, threatened and endangered wildlife and their habitats in Tennessee. As a part of this State Wildlife Action Plan, TWRA Wildlife Diversity Staff conduct surveys across the state, collecting data on the absence, presence, or probable presence of species of greatest conservation need. This data is used in a model developed as a part of the 2005 CWCS.
Wildlife Diversity Biologists from across the state revised the State Wildlife Action Plan, a process that was completed in September 2015. As a part of this revision, the conservation statuses of all wildlife within the state were assessed. The habitat preferences of all terrestrial species were reviewed, linking species with their preferred habitats. These preferences, along with species occurrences were also mapped. A new addition to 2015 SWAP was the development of Conservation Opportunity Areas throughout the state. Management and conservation opportunities will be determined within these conservation areas to maximize the conservation of all wildlife.
The inclusion of climate change and assessment of impacts as a result of climate change was also a main goal of 2015 SWAP. To aid conservation efforts in a world with a changing climate, biologists and conservationists will seek to identify areas where conservation actions may be needed to conserve the diversity of wildlife despite changes to habitats resulting from a change in climate.
Wildlife Diversity Projects
Wildlife Diversity staff conduct numerous projects within Region II as well as participates in projects occurring across the state. These surveys are used to monitor populations of nongame species, collect data and information beyond the typical presence / probable absence data, and further our knowledge of these unique animals within middle Tennessee.
Projects Region II personnel have participated in or are currently participating in include:
- Hellbender Presence/Absence Surveys and Habitat Quantification
Hellbenders, Crypotobranchus alleganiensis, are the largest salamander in the state of Tennessee, reaching lengths up to three feet long. They occur only in rivers and streams and feed primarily on crayfish. Hellbenders require large slab rocks for cover and nesting and cobble for development of larvae. Once the eggs are laid, males stay at the nesting site, providing protection from predators. One of the main threats facing this species is habitat loss or degradation of current habitat. Hellbenders require clean, cool water, and siltation and sedimentation can have adverse, long lost lasting impacts to populations.
The initial goal of this project was to document the occurrence of hellbenders in as many streams in middle Tennessee as possible. Unfortunately, few individuals were captured and few populations were identified. When comparing current occurrence information to historical data, it appears several populations have possibly been lost in middle Tennessee. Habitat within several of these streams appears to have degraded not allowing populations to be supported anymore. The embeddedness of the stream substrate due to sedimentation and siltation appears to be the main reason for the loss of habitat. Despite these findings, several populations do remain and occur in areas that will be protected into the future. One goal will be to ensure land use changes upstream of these populations will not impact these remaining populations.
Currently, propagation efforts have been initiated with animals captured from across the state. One goal is to reintroduce Hellbenders in to streams they once occurred. These efforts may take several years because propagation of the species is extremely difficult. Many other aspects of this species life history and reasons behind their decline within the state are also being assessed.
- Indiana Bat Migration and Summer Habitat Use
The Indiana bat, Myotis sodalis, is listed as an endangered species by the U.S. Fish and Wildlife Services. Like many of the bats that make Tennessee their home, Indiana bats spend the winter in caves across middle Tennessee. Larger winter populations can be found in east Tennessee. During the spring, Indiana bat, primarily the females, make migrations from these caves to their summer maternity grounds. We initiated a migration telemetry study several years ago in an effort to identify maternity trees for this species within Tennessee. In 2013, we were able to identify several maternity trees in middle Tennessee for the first time. Identifying these trees is very important because they only use dead or dying trees that have sloughing bark. Indiana bats crawl under this bark, forming colonies from just a few individuals to several hundred and the pups are born and reared under this same bark. This type of narrow habitat preference is one of many reasons why this species is endangered in the United States. Identifying maternity trees is important to aiding with conservation efforts of this species.
Once an Indiana bat is captured, transmitters are attached prior to migration and last approximately 21 days. Shortly after the transmitter fails, it falls off the bat. Migrations to the maternity grounds rarely last longer than 21 days and normally only take approximately 7-10 days. Migration distances of 50 to almost 290 miles have been observed during this study. We have been able to identify maternity roosts in 5 states, including states south of Tennessee. Maternity colonies located south are unique because it has been believed this species only migrates north from winter sites to summer sites.
Following the location of a maternity colony, Wildlife Diversity personnel continue to monitor these colonies with nightly emergence counts, mist netting for attachment of new transmitters and continued telemetry, and analysis of vegetation surrounding the maternity trees and across the landscape. During the project in 2013, we identified 11 primary or secondary roost trees in middle Tennessee. The largest colony had 56 bats emerge during a single nightly emergence count. Late summer telemetry at one colony allowed for the identification of a foraging area a short distance away from the roost tree. Roost trees were found in a variety of habitats on the landscape and include ridge tops, edges of fields and forested areas.
- Barrens Top Minnow Population Monitoring
Monitoring of Barrens Top Minnows, Fundulus julisia, began several years ago. This species occupies springs and spring influenced streams in the Barrens of southeastern middle Tennessee. Barrens top minnows prefer submergent vegetation for egg laying, but this is not a requirement. This species is short lived, living approximately three years in the wild. Brightly colored males are easily preyed upon. Population declines are strongly linked to the presence of the Western Mosquitofish, Gambusia affinis.
Monitoring efforts take place during the winter with biologists seining habitats to census populations. Three passes are made with the seines with all fish being identified and counted. During the summer months, the water levels of some springs are checked frequently, especially during times of drought. Some springs may dry completely potentially resulting in the loss of an entire population. If it is thought a spring will completely dry, biologists remove all Barrens Top Minnows and take them to a facility where they are maintained until typical hydrology resumes.
- Golden Eagle Surveys and Telemetry
The Golden Eagle, Aquila chrysaetos, is one of the most widely distributed eagles in North America. This species migrates larges distances between summer and winter grounds and are typically only present in Tennessee during the winter. However, there are some Golden Eagles in Tennessee year round and these birds are likely decedents of a hacking program implemented by TWRA between 1995 and 2006. Golden Eagles migrate to Tennessee from Canada during the winter, spending much of this time in large tracts of forests. They have been observed feeding on carrion in fields and along roads. It was once thought migrating Golden Eagles were only located in eastern Tennessee, but recent surveys indicate high densities of birds in southern Tennessee along the Alabama state line.
Wildlife Diversity personnel have established multiple survey sites across middle Tennessee to document wintering Golden Eagles. Trail cameras are used to take photographs throughout the day at each site. Once Golden Eagles begin frequenting the site, all efforts are made to capture the animals. Once captured, the birds are tested for lead poisoning and a large transmitter is attached to their back. This transmitter records location data for 2-3 years. Migration data has become extremely important in identifying routes of migration and wintering areas within the state.
Further information regarding trapping efforts and migration of Golden Eagles can be found on the Watchable Wildlife website
- Gray Bat Winter Monitoring and Summer Banding
The gray bat, Myotis grisescens, is listed as endangered by the United States Fish and Wildlife Service. Unlike many of species of bats that inhabit Tennessee, the gray bat uses caves throughout the year in Tennessee. During the summer, gray bats form large maternity colonies in caves where the females give birth to the pups, raising them until they can fly, or become volant. At this same time, male gray bats form bachelor colonies in the same caves as the females or these colonies may be found in different caves. In the winter, gray bats, like many species of bat in Tennessee, enter caves to hibernate; however, this species requires specific temperature and humidity levels and the reason gray bats only have three primary caves used for hibernation within the state. Each of these three caves is protected by TWRA or The Nature Conservancy of Tennessee. Winter colony sizes may range from 160,000 bats to well over 500,000 bats during this critical period of the year.
Biologists perform routine surveys of wintering gray bats biennially. Historically, these surveys were performed every three years to minimize disturbance. Because of white-nose syndrome, surveys were performed annually for a short period to assess any impacts from this devastating disease. During these surveys, biologists try to determine the density of gray bats within each square foot of cave wall where bats are found. At the end of the survey, all estimations are tallied to determine the approximate number of wintering bats within the cave.
Wildlife Diversity personnel began capturing gray bats during nightly emergences to apply bands, determine the demographics of the colony, reproductive statuses, and assess the impacts from white-nose syndrome. Captures are made with a large trap design to safely capture these flying mammals as they emerge to feed on insects. The banding of gray bats allows Wildlife Diversity personnel to determine site fidelity, migration distances, and longevity for the species. Many of the bands recovered are made within the same cave in which they were placed or within one of the primary caves within the state. These recoveries indicate a strong preference for these caves and movement between the caves. Wildlife Diversity personnel have recovered bands in Tennessee from as far north as the Shawnee National Forest in Illinois, and TWRA bands have been recovered in a cave in north Alabama. These recoveries indicate gray bats migrate great distances between caves.
- White-nose Syndrome Monitoring
White-nose Syndrome (WNS) is a disease caused by the fungus Pseudogymnoascus destructans and affects hibernating bats. First documented in New York during the winter of 2006-2007, WNS is responsible for more than 5.5 million bat deaths in the Northeastern U.S. and Canada. WNS exhibits itself as a white fungus growing on the muzzle of infected bats, hence the name White-nose Syndrome. The fungus can also grow on and affect wing and ear tissue. To date, 29 states and 5 Canadian provinces are considered WNS - positive, including Tennessee, and the fungus has been documented in three additional states. Large numbers of cave bats are being impacted in Tennessee. There are over 10,000 caves within the state increasing the challenges of assessing impacts of WNS to bats in Tennessee. WNS has been documented in 52 of the 78 Tennessee counties that have caves.
TWRA has responded to this threat in several ways. First, the TWRA is a member of the WNS Advisory Council of Tennessee. This council is comprised of biologists and researchers from multiple state and federal agencies, non-government agencies, and researchers from numerous academic institutions from across the state who meet annually to discuss the current status of WNS in the state, prioritize and schedule cave surveys to monitor bats and impacts from WNS, and to discuss and coordinate bat and WNS research throughout the state. Secondly, TWRA biologists and wildlife diversity personnel participate in the Tennessee Bat Working Group (TNBWG), an organization created in 2004 to help conserve bat species in the Southeastern U.S. The TNBWG meets annually and researchers from across Tennessee and adjoining states present the results of research conducted in the state or give information regarding species of bats found in the state.
To date multiple tools are being developed that may allow options to combat this deadly epidemic. Since the discovery of WNS in Tennessee, biologists have implemented surveys and research projects to gauge the impacts of WNS. In an effort to minimize human spread of the fungus, TWRA and other participants adhere to a strict gear decontamination protocol when working with bats in caves and on the landscape. Despite controversy, the TWRA made the decision to close all agency-owned caves to public access in 2012. The closure is an attempt to limit the spread of WNS due to contaminated clothing and gear. Finally, the TWRA provides funding and personnel to support ongoing research and education.
- Wildlife Diversity Surveys
In an effort to document the presence or probable absence of nongame species inhabiting TWRA’s wildlife management areas, our wildlife diversity survey manager conducts surveys throughout the year. The data collected from these efforts aides with management decisions of our lands. The data is also used in models developed as a part of the State Wildlife Action Plan.
A number of methods are used to document nongame wildlife on our wildlife management areas. Drift fences are established to capture amphibians, reptiles, and small mammals. Coverboards are used to capture amphibians and reptiles. Live capture Havahart and Sherman traps are used in the documentation of small mammals. Bats are captured with mist nets and harp traps, and the calls of bats are recorded with acoustical devices. Standard point counts are used to document the presence of birds. Many more techniques are used to document the wildlife on state lands and are used in differing situations based on the species being targeted.
Previous surveys have been conducted on:
- Bark Camp Barrens WMA
- Hickory Flats WMA & May Prairie SNA
- Maple Springs WMA
- Cowan Swamp Wetland
- Owl Hollow Mill WMA
- Mingo Swamp WMA
- Bear Hollow Mountain WMA