Wednesday, February 08, 2017Register
 Federally Threatened and Endangered Mammals and Plants of the Ozarks Aquifer

Gray Bat
Myotis grisescens

Image of Gray Bat, courtesy of Adam Mann, Environmental Solutions and Innovations/US Fish and Wildlife Service
[Photo: Adam Mann, Environmental Solutions and Innovations/USFWS]

Description: The gray bat is a medium-sized bat which is 3 inches (7.5 cm) long, weighs 0.33 ounces (7-16 g), and has a wingspan of 10-11 inches (25-28 cm). The gray bat can be distinguished by its entirely gray fur, in contrast to other closely related bi-color or tri-color Myotis species. In the summer, its fur can lighten to a rust-colored brown. The gray bat is also distinct from other members of its genus because its wing membrane connects at the ankle, instead of the toe.

Life History: Gray bats enter deep vertical hibernation caves in September and October where they hibernate in large clusters (up 1 million) on ceilings and walls until spring. From March through mid-April female bats leave the hibernation cave, followed by males in mid-April to May, as they migrate to summer roosting caves up to 200 miles away. From late May to June females roost in maternity colonies, eventually giving birth in June to one live young. After four weeks, mothers and their young rejoin the male colonies. Gray bats eat a variety of flying aquatic and terrestrial insects. They forage at night in riparian areas for mayflies, caddisflies, stoneflies and occasionally beetles and moths, and may forage up to twelve miles from the roosting caves.

Habitat: The gray bats lives in caves year round, utilizing deep vertical caves for hibernation in the winter (34-48 degrees F [1-9 degrees C] ) and domed caves along rivers in the summer (58-77 degrees F [14.4-25 degrees C]). Ninety-five percent of all gray bats hibernate in just eight caves within their range.

Distribution: Myotis grisescens is limited to limestone (karst) cave areas in the central and southeastern US. Gray bats occur extensively in the Ozark aquifer region.

Critical habitat for this species has not been determined. The map below depicts the counties in the Ozarks aquifer region where this species has been reported (USFWS). 

Species Distribution of the Gray bat (Myotis grisescens) in the Ozarks aquifer region [Figure: Houston Advanced Research Center using US Fish and Wildlife data]

Species Distribution of the Gray bat (Myotis grisescens) in the Ozarks aquifer region [Figure: Houston Advanced Research Center using US Fish and Wildlife data]. Click on map for larger image.


Status: The gray bat was listed on the federally endangered species list in 1976. There is a recovery plan in place for this species. The decline in the gray bat population was due to four factors: human disturbance, cave modifications, pesticides and pollution, and destruction of riparian areas. Human exploration of caves can disturb both hibernating and roosting bats, causing them to lose stored fat and abandon their young. Cave modification in the form of gates or fences can alter conditions in the cave (i.e. temperature, humidity, etc) enough to impact the gray bat. Pesticides may reduce local insect populations which serve as prey for the bats. The pesticides may also bioaccumulate in the bats. Additionally, water pollution can negatively impact aquatic insects that the bats feed upon. Deforestation along rivers destroys riparian corridors that are important for movement of bats between summer roosting caves and areas where they forage. Gray bat populations are currently rebounding in many locations due to the protection and restoration of critical habitats. An emerging threat to the gray bat population is White Nose Syndrome. This disease is caused by the fungus Geomyces destructans, which invades the skin of bats, and can cause widespread death within a hibernaculum. Protection of the gray bat is important to many other cave-dwelling animals in the Ozarks region due to the nutrients their guano supplies to nutrient-limited cave ecosystems.

Resources:

Missouri Dept. of Conservation, Gray Bat Profile

USFWS, Gray Bat 5-Year Review

USFWS, White Nose Syndrome

USFWS, Gray Bat Factsheet

 

Indiana Bat
Myotis sodalis

Image of Indiana Bat, courtesy of Adam Mann, Environmental Solutions and Innovations/US Fish and Wildlife Service
[Photo: Adam Mann, Environmental Solutions and Innovations/USFWS]

Description: The Indiana bat is a medium-sized bat in the genus Myotis. It is 1.6-1.9 inches (4.1-4.9 cm) long, weighs 0.25 ounces (7 g), and has a wingspan of 9-11 inches (23-28 cm). The Indiana bat has dark brown to black fur and has small, delicate hind feet. The Indiana bat looks very similar to the brown bat (Myotis lucifugus) and the northern long-eared bat (M. septentrionalis) but can be distinguished by variations in fur color and the conformation of its calcar (part of the wing membrane).

Life History: The Indiana bat mates in the fall (peaks in September and October) in a process called "swarming." They swarm outside of their chosen hibernaculum and enter hibernation by November. Indiana bats often return to the same hibernaculum each year, where they cluster in large groups of 20,000-50,000 bats, at densities up to 500 per square foot. After mating, females store sperm until the spring emergence in mid-April or May, at which time fertilization occurs. Shortly after emergence, pregnant females leave the hibernaculum to migrate long distances (up to three hundred miles) to their summer maternity roosts. Non-pregnant females and males often roost within a short distance of their winter hibernaculum (2-10 miles away), and may form solitary or small group roosts. Pregnant females form maternity colonies (often less than 100 bats) from May to June and young are born from late June to early July. Each Indiana bat gives birth to one live young, which can fly within 3-5 weeks. In August, females and young begin migration back to the hibernaculum. Indiana bats forage at night along rivers and lakes, emerging around sunset and eating moths, beetles, true flies, caddisflies, and occasionally spiders.

Habitat: The Indiana bat occupies two main habitats: winter hibernacula and summer roosts. The winter hibernacula consist of karst caves and mines. Optimal cave temperatures for Indiana bat populations are 41-45 degrees F (5-7 degrees C) with temperatures no higher than 50 degrees F (10 deg C) and no lower than freezing (32 degrees F [ 0 deg C]). Large, complex caves are often preferred because they offer a wide variety of microclimates that Indiana bats can utilize, depending on outside temperatures. Summer roosts are typically found under the peeling bark of deciduous trees that are dead or dying. Indiana bats can roost on a large variety of trees including ash, elm, hickory, maple oak, poplar and others with peeling bark. These trees are often found near forest edges, where bats forage for food. Spring and fall roosts are often located near hibernacula and are similar in structure to summer roosts.

Distribution: Myotis sodalis is found throughout the central and eastern US. There are 218 known winter hibernacula for the Indiana bat in the Midwest and eastern US. The hibernacula are concentrated in Indiana (half of all Indiana bats hibernate here), Missouri, Kentucky, Illinois, and New York. Fourteen percent of winter hibernacula occur in Missouri, providing habitat for approximately 65,000 Indiana bats. Summer roosts are more widely disbursed and are mainly concentrated in the upper Midwest.

Critical habitat for this species has been determined. The map below depicts the counties in the Ozarks aquifer region where this species has been reported (USFWS).

Species Distribution of the Indiana bat (Myotis sodalis) [Figure: Houston Advanced Research Center using US Fish and Wildlife data]

Species Distribution of the Indiana bat (Myotis sodalis) [Figure: Houston Advanced Research Center using US Fish and Wildlife data]

Status: The Indiana bat is a federally listed (1967) endangered species. There is a recovery plan in place for this species. This species was listed due to threats from human disturbance of caves and summer habitat loss. When the bat was listed in 1967 there were an estimated 880,000 Indiana bats. From 1965-2001, USFWS measured an overall declining trend (57% decline) in bat populations. As of 2007, there were approximately 468,000 bats throughout its range, and numbers are increasing. Human disturbance from commercial and recreational use of caves constitutes the major threat to bat populations. Disturbance during hibernation can cause bats to arouse from hibernation using up fat stores, which can lead to starvation or low reproductive rates. Additionally, modification of bat hibernacula, even at a few sites, can significantly impact the species, as few caves or mines meet the habitat requirements required by the Indiana bat. Modification of caves can alter the temperature regime enough so that they are no longer suitable as habitat. Loss and degradation of forest habitat can affect foraging and roosting behavior of both male and female bats. An emerging threat to the Indiana bat population is White Nose Syndrome. This disease is caused by the fungus Geomyces destructans, which invades the skin of bats, and can cause widespread death within a hibernaculum.

Resources:

USFWS, Indiana Bat 5-Year Review

USFWS, Indiana Bat Factsheet

USFWS, Indiana Bat Recovery Plan

USFWS, White Nose Syndrome

Ozark Big-eared Bat
Corynorhinus townsendii ingens

Image of Ozark big-eared bat, courtesy of US Fish and Wildlife
[Photo: US Fish and Wildlife]

Description: The Ozark big-eared bat is one of five subspecies of C. townsendii that acquired their name due to their extremely large ears. The Ozark big-eared bat is a medium size bat, from 3.6-4.6 inches (9.0-11.6 cm) long with a wingspan of 11.7-12.9 inches (29.5-32.5 cm), and weighing 0.25-0.45 ounces (7-13 grams). Females are usually slightly larger than males. In relation to their body size, their ears, which are attached at their forehead and measure over 1 inch long (2.5 cm), are very large. The Ozark big-eared bat has dark reddish brown fur (with tan underparts) and a distinctive facial gland on either side of its snout. Juvenile bats appear darker than adult bats. Of the five subspecies of C. townsendii, the Ozark big-eared bat is the largest and has the darkest coloration.

Life History: Ozark big-eared bats can live up to sixteen years. They breed in fall and winter with females mating their first breeding season. Sperm is stored by females during the winter hibernating months and fertilization occurs shortly after hibernation ends. Maternity colonies form from late April to early June. In June the live young are born, can fly in two to three weeks and are weaned after six weeks. Ozark big-eared bats do not migrate and their roosts and hibernacula are generally no more than twenty miles apart. Bats leave the cave 45 minutes after sunset to forage for moths, which comprise greater than 85% of their diet.

Habitat: The habitat of the Ozark big-eared bat is found at overhanging cliffs and limestone and sandstone caves of oak-hickory forests. Ozark big-eared bats are most often found in the coldest areas of the caves they inhabit. These bats live in caves at temperatures ranging from 40 to 59 degrees F (4.4-15 degrees C), depending on hibernation and life stage. Big-eared bats forage for moths and other insects along the edges of Ozark oak-hickory forests.

Distribution: Corynorhinus townsendii ingens is known to occur in the Ozarks in northwest Arkansas and northeast Oklahoma. In Oklahoma, Ozark big-eared bats occur in Adair, Cherokee, and Sequoyah counties and in Arkansas in Crawford, Franklin, Marion, and Washington counties. The bat is suspected to occur in several additional counties in northwest Arkansas and southern Missouri.

Critical habitat for this species has not been determined. The map below depicts the counties within the Ozarks aquifer region where this species has been reported (USFWS).

Species Distribution of the Ozark big-eared bat (Corynorhinus townsendii ingens) in the Ozarks aquifer region [Figure: Houston Advanced Research Center using US Fish and Wildlife data]

Species Distribution of the Ozark big-eared bat (Corynorhinus townsendii ingens) in the Ozarks aquifer region [Figure: Houston Advanced Research Center using US Fish and Wildlife data]. Click on map for larger image. 

Status: The Ozark big-eared bat is a federally listed endangered species (1979). There is a recovery plan in place for this species. These bats are in decline due to extreme sensitivity to human disturbance and habitat loss due to residential and commercial construction and timber harvesting. Identification and protection of maternity and hibernation caves, as well as moth conservation are vital to the recovery of this species. White Nose Syndrome, a deadly disease caused by the fungus Geomyces destructans, could be a future threat to the Ozark big-eared bat. The occurrence of this disease does not currently overlap the range of the Ozark big-eared bat, but the fungus is rapidly moving west.

Resources:

Arkansas Game and Fish Commission, Ozark Big-eared Bat Profile

USFWS, Ozark Big-eared Bat 5-Year Review

USFWS, Ozark Big-eared Bat Recovery Plan

USFWS, White Nose Syndrome

Virginia Sneezeweed
Helenium virginicum

Image of Virginia Sneezeweed, courtesy of Steve Croy, US Forest Service
[Photo: Steve Croy, US Forest Service]

Description: The Virginia sneezeweed is a perennial forb of the Asteraceae family which grows from 2.3-3.6 feet (0.7-1.1 m) tall. The sneezeweed has a single, slender stem leading to a cluster of flowering heads (2-20 heads) which are each 1-1.2 inches (2.5-3 cm ) wide. The petals of the sneezeweed are wedge shaped, yellow, and tri-lobed. They are arranged in a ray around a spherical central disk. The disk corollas are also a golden-yellow color and bloom from July to September. The basal rosette has both toothed and untoothed coarsely hairy leaves. The Virginia sneezeweed is similar in appearance to the common sneezeweed (H. autumnale).

Life History: The Virginia sneezeweed emerges as a basal rosette for its first year and during its second year produces a flowering stem with 2-20 flowering heads. The sneezeweed blooms from July through October, peaking in late July or early August and disperses its seed in the fall. The seeds undergo a dormancy period until germination the following late summer or fall. The Virginia sneezeweed flowers two to three times over its five year life span. Virginia sneezeweed is pollinated by bees, wasps, butterflies and hoverflies. Virginia sneezeweed populations exhibit self-incompatible breeding and require a plant with a least one allele difference to breed. Virginia sneezeweed displays limited vegetative reproduction.

Habitat: In the Ozark region, the Virginia sneezeweed grows at the edges of sinkhole ponds and in wet meadows over underlying karst bedrock. Optimal habitat for sneezeweed requires a variable hydrologic scheme in which the plant is periodically submerged.

Distribution: In the Ozark region, Helenium virginicum has been confirmed at 40 sites in six counties in Missouri (Boone, Howell, Shannon, Texas, Webster and Wright). The first population of Helenium virginicum was discovered in Virginia in Augusta County in 1935. Sneezeweed is now found at 25 sites in Augusta, Nelson, and Rockingham counties in Virginia.

Critical habitat for this species has not been determined. The map below depicts the counties in the Ozarks aquifer region where this species has been reported (USFWS).

 Species Distribution of the Virginia sneezeweed (Helenium virginicum) [Figure: Houston Advanced Research Center using US Fish and Wildlife data]

Species Distribution of the Virginia sneezeweed (Helenium virginicum) [Figure: Houston Advanced Research Center using US Fish and Wildlife data]. Click on the map for larger image. 

Status: The Virginia sneezeweed is a state endangered (Missouri) and federal (1998) listed threatened species. A draft recovery plan is in place for this species. The Virginia sneezeweed was listed due to its narrow range, small disjunctive populations, and threats from habitat loss. Habitat loss due to filling and draining of sinkhole and wetland habitats comprises the greatest threat to this species. Disruption of hydrology can also occur due to water draw-downs in the underlying karst aquifer, which may lessen the amount of inundation time for the sneezeweed. Because the Virginia sneezeweed uses its tolerance of variable hydrology as a competitive advantage, it may not be able to compete without these periodic inundations. Other threats to this species include overgrazing and mowing during the flowering period. Due to the isolated populations of Virginia sneezeweed with a small number of individuals, the issue of self-incompatible breeding may lead to local extinction.

Resources:

Center for Plant Conservation, Helenium virginicum profile

Missouri Dept. of Conservation, Best Management Practices

USFWS, Virginia Sneezeweed Recovery Plan

 


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