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Northern Long-eared Bat Surveys

To discuss your project, contact

John Chenger, President • • Tel/Text: 814.442.4246 • USFWS permitted range-wide since 2000

Northern lingered bat survey

About the Northern Long-eared bat

As of 2015, the Northern Long-eared bat (Myotis septentrionalis), also referred to as the Northern myotis or Northern long-eared myotis is a newly listed federally threatened species of bat listed under section 4(d) of the Endangered Species Act. Weighing between 5 and 10 grams, this small "mouse-eared" bat has a dark to medium brown coat with a paler brown underside. More notable are this bat¹s long ears compared to other Myotis bats, which it uses for both feeding on the wing, as well as gleaning motionless insects. This bat has also been one of the hardest-hit by White-nose Syndrome, which has been a major contributing factor to the species population decline and current listing as "federally threatened", by the U.S. Fish and Wildlife Service.

Preferred Habitat

 Northern long-eared bats spend their summer roosting under loose bark, inside cavities of live and dead trees, and occasionally man-made structures such as barns. Known to roost in both colonies and individually, this bat has been observed to be more adaptable in its selection of roosts. During the winter months, the Northern long-eared bat with utilize both caves and mines where temperatures humid, cool temperatures that remain consistent throughout the season. Although generally used for winter hibernation only, these bats can also be also be found in caves and mines during the summer months. Conservation efforts have been made to reduce the likelihood of these exposures through things like cave gating and the practice of recommended decontamination techniques.

Reasons for Listing

The Northern long-eared bat is one of the most greatly affected by White-nose Syndrome, with a population decline of approximately 99% in the Northeast since its introduction. A large portion of the Northern long-eared bat¹s range has been affected by this psychrophilic fungus remains a blight to the surviving population. Additional factors such as loss of habitat and wind farm activity also contribute to the decline in this species numbers.


Northern Long-eared Bat Services We Provide

Habitat Survey. Do you have Northern Long-eared Bat habitat? BCM will provide a team of biologists to fully inspect and examine potential habitat for your species of interest. During your habitat survey, any potential suitable habitat that is encountered will be permanently documented with photographs, appropriate forms, as well as GPS search tracks to and from the areas of interest. In providing the highest quality data possible, BCM is also diligent in recording areas surveyed that may be of sub-par quality, (noted as: "For the record only") but useful in creating a more robust assessment of your entire project area.

Summer Mist Net Survey

BCM has successfully surveyed thousands of individual mist net sites over the years. Due to recent regulations, the USFWS now requires surveys for the Northern Long-eared bat. If your project is in need of mist-netting, BCM is able to offer thorough, fast, and efficient sampling of your project area. This type of summer bat surveying technique is most often conducted for one or more of the following reasons:

  • Cataloguing species presence in areas that may be impacted by new construction
  • Searching for threatened or endangered species in areas prior to timber sales or development
  • Acquiring baseline data for a region or rare species that has not been fully studied

Once your mist-netting project has been planned, BCM is very efficient in carrying your survey from start to finish. Sampling in accordance with the draft Indiana bat recovery plan, your local US Fish and Wildlife office, as well as your state¹s wildlife agency guidelines, we make sure you are in full compliance with the latest protocols and guidelines.

As with most of the fieldwork studies that are offered by BCM, mist-netting is very season-specific and requires a good amount of attention to planning. However, BCM offers several levels of this service from technical assistance and equipment, to complete and all-inclusive project management.

 Radio Telemetry

Often times radio telemetry is conducted in conjunction with an ongoing mist-netting project, and is even required in some instances. Depending on your specific needs, BCM is capable of providing the necessary equipment and expertise that will thoroughly and effectively satisfy your telemetry requirements. Having one of the most extensive arrays of telemetry equipment, we are equipped to take on small to very large projects that other contractors may not be outfitted to do. Due to a bat¹s propensity to sometimes travel long distances, an ill-equipped crew can lead to ³lost² bats, ultimately causing delays and repeat work that quickly add up in time and money. Keep in mind that depending on your species of interest, transmitters can take up to 3 months to receive once ordered, so plan accordingly!

Whether you are interested in summer foraging routes, roost identification, or Indiana bat migration, these surveys are best planned in conjunction with advisement from the regional US Fish and Wildlife Service office and state wildlife agencies. In addition, having a team of highly experienced trackers can be essential to successful telemetry efforts, a commodity that BCM is proud to be able to offer its clients.

Acoustic Monitoring

Conducting summer mist net surveys alone have the potential to leave some bat species in your sample area under-represented. Adding acoustic monitoring to your project can help draw a much more complete picture of your study area. However, depending on your specific project you may want to conduct an entirely acoustic survey.

BCM has been on the forefront of acoustic monitoring, hosting a large variety of workshops and instructional programs for both bat capture and acoustic monitoring techniques and survey methods. With a wide array of full-spectrum acoustic monitoring and survey options and services, BCM is fully equipped with the necessary tools and equipment to provide you with the highest quality custom acoustic monitoring survey possible.

BCM understands the oft-experienced time constraints associated with certain projects and is happy to consult with clients in order to determine what the best approach is in order to complete the work needed while remaining in compliance with state and federal agency regulations.

As with all results of the fieldwork studies we offer, acoustic data is saved and permanently recorded in its original form for reporting and future recall.

Next steps . . .

If you have any questions regarding any of these field study services or would like a custom quote, please contact John Chenger at

Have you already conducted an acoustic survey and looking for a second opinion on your data? BCM may be able to help with its Professional Acoustic Data Analysis Service.