Conserving Federally Endangered Indiana Bats
on Private Woodlands
By Scott Pruitt and Andy King
Hoosiers who manage woodlands are probably aware that their lands support a wide variety of wildlife species. What they might not know is that their woodlands likely harbor bats, and that bats play a critical role in keeping woodlands – and farm fields – healthy and productive. Indiana is home to a number of bat species, including the federally endangered Indiana bat. What does it mean to woodland owners that a federally listed species may be present? Well, it may surprise some that it’s possible to manage woodlands for timber production and at the same time, conserve an endangered species.
The Indiana bat (Myotis sodalis) was one of the original species to be listed as federally endangered under the Endangered Species Act of 1973. Although the species occurs in 22 different states in the eastern United States, it became the Hoosier state’s namesake bat in 1928 when it was first identified as a unique species based on a specimen from Wyandotte Cave in Crawford County, Indiana. Once numbering in the millions, Indiana bat populations have dropped steadily due to human disturbance and vandalism at winter hibernacula (caves and mines where they hibernate), deforestation, stream channelization, pesticide use and cave commercialization. Significant population increases occurred in the early and mid-2000s in Indiana and elsewhere, but these hard-fought gains appear to be quickly eroding due to unprecedented bat mortality rates associated with the fungal disease known as white-nose syndrome. White-nose syndrome has killed more than 5.7 million bats in the Northeast and Midwest since it was discovered in 2006.
But, why would woodland managers care about bats? It’s economics. Bats are voracious predators of night-flying insects, including many crop and forest pests, making bats very important to agriculture and natural ecosystems. Pest-control services provided by insect-eating bats in the United States likely save the U.S. agricultural industry at least $3 billion a year, and that’s just savings to farmers. In addition is the incalculable value to forests from insect-eating bats. Insectivorous bats are among the most overlooked economically important, non-domesticated animals in North America.
Bats in general, including federally endangered Indiana bats, clearly have enormous potential to inﬂuence the economics and health of agricultural crops and forests. And Indiana is an Indiana bat stronghold. A 2011 survey found the caves and surrounding forest habitat in south-central Indiana support over half of the species’ range wide winter population, so maintaining high-quality summer and winter habitat in Indiana is essential to the Indiana bat’s long-term recovery and will benefit our farms and forests in the process.
The goal for the Indiana bat, as for any federally listed species, is to recover the species so that it can survive without the protection of the Endangered Species Act. The US Fish and Wildlife Service’s (Service) Bloomington Field Office has the national lead for Indiana bat recovery efforts and is also responsible for administering the ESA within the State of Indiana. The Bloomington Office routinely works with federal and state agencies, non-government organizations and private landowners to help them comply with the Endangered Species Act by avoiding and minimizing incidental take1,2 of Indiana bats and by taking steps that will help recover the species.
For many woodland managers, who have no known Indiana bats on their property, complying with the ESA is not an issue. For others who know or suspect they have Indiana bats, the Bloomington Office can help the manager avoid incidental take of Indiana bats whenever possible, minimize adverse effects of timber harvest on Indiana bats, and even give advice for interested landowners to take steps toward recovery of the species.
Over 10 years ago, the Bloomington Field Office (BFO) developed guidelines to help federal land managers to avoid accidental/incidental take of Indiana bats during their forest management activities and to ensure compliance with the ESA. Although numerous tweaks have been made to these guidelines as new information became available over the years, the primary goals of the BFO Forest Management Guidelines remain the same: to avoid the potential for accidentally killing/taking roosting bats and to ensure a continual supply of suitable roost trees/snags and foraging habitat remain across the landscape.
In a nutshell, the BFO Forest Management Guidelines require the following:
• Maintaining 60 percent of canopy cover after timber harvests
• No harvest or TSI (timber stand improvement) removal of shagbark hickories, unless this species’ density exceeds 16 per acre.
• Not felling/removing standing snags (except where they pose a human safety hazard) (i.e., the goal is to let them fall naturally so they can be used as roost trees as long as possible
• Do not harvest all of the large trees, but leave at least a small number of the largest trees on every acre and allow those same trees to grow old and die. When present, those trees should be from the species listed below, which Indiana bats are known to use in Indiana:
shagbark hickory green ash white oak
shellbark hickory white ash slippery elm
bitternut hickory silver maple northern red oak
American elm black locust sugar maple
post oak eastern cottonwood
• No timber harvest within 100 feet of a perennial stream or within 50 feet of an intermittent stream (as designated on a USGS 7.5-min quadrangle map).
• No felling of trees/snags >3” dbh while Indiana bats may be present from 1 April through 30 September (i.e., trees may be felled from 1 October through 31 March).
Adherence to these guidelines will avoid incidental take of Indiana bats and result in forest habitat that is suitable for the species’ use, although it may or may not result in optimal habitat, which may require more intensive management practices.
Do these federal forest management guidelines apply to private woodland owners in Indiana too? Yes, if Indiana bats are known to be present. However, we know where the species occurs in Indiana only where biologists have previously conducted surveys, and most surveys for Indiana bats have been on public lands. The Service does not require private landowners to conduct surveys for federally endangered species on their lands and nor do we require our guidelines to be followed on lands where no records are known. If you know Indiana bats are present on your property, you should contact the Service for help in managing your woodlot in compliance with ESA. Even if you don’t know Indiana bats are present, and you are interested in bat conservation, consider incorporating our guidelines in your timber management plans.
What if you know you have Indiana bats on your property but are unable to follow the Forest Management Guidelines fully? In that case, landowners are encouraged to contact the Bloomington Field Office (see contact information below) to discuss alternative processes. In some cases, the Service can issue an Incidental Take Permit (ITP) to a non-federal land owner that allows a specified amount of incidental take of a listed species. This provision of the Endangered Species Act provides some flexibility for activities such as timber harvests in exchange for conservation measures spelled out in a Habitat Conservation Plan (HCP). For example, the Indiana DNR, Division of Forestry is pursuing an ITP and is preparing an HCP with the Service which would allow more management flexibility on state forest lands that have Indiana bats. The Service has provided the Division of Forestry with funds to help them prepare this HCP. Again, an ITP/HCP is not needed where Indiana bats are known to occur and the BFO Forest Management Guidelines are being followed.
To receive a copy of the BFO Forest Management Guidelines or to discuss questions you may have regarding Indiana bats, forest management practices or ESA compliance issues in Indiana, please email Scott Pruitt (firstname.lastname@example.org) or Andy King (email@example.com) or call us at the Bloomington Field Office at 812-334-4261.
Scott Pruitt is the Field Supervisor of the U.S. Fish and Wildlife Service’s Bloomington Field Office. Andy King is a Fish and Wildlife Biologist with the U.S. Fish and Wildlife Service.
The Indiana bat:
Endangered species issues on private lands and HCPs:
Economic importance of bats:
1 “Incidental take” – Take that results from, but is not the purpose of, carrying out an otherwise lawful activity
2 “take” is defined by the ESA as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, collect or to attempt to engage in any such conduct. The term “harm” is further defined to include significant habitat modification or degradation that results in death or injury to listed species by significantly impairing behavioral patterns such as breeding, feeding or sheltering. [NOTE: Take of federally listed species is prohibited by Section 9 of the ESA regardless of whether the taking occurs on federal, state, or privately owned lands]