Tree Enhancement and Roost Mitigation Project

A project focused on tree roost enhancement, old growth gap mitigation, and bat-friendly forestry techniques for the forestry industry.

The Project:

Due to cumulative human impacts, maternity roosts for bats are increasingly limiting on the landscape. This has an impact on reproductive females who need specific microclimate requirements to raise a pup. This project focuses on bat roost enhancement in the Cooumbia basin in British Columbia in which bark roosts are created or enhanced in areas critical to tree-roosting dependent species such the currently endangered Northern Myotis.   WCS Canada is working with a large multidisciplinary suite of partners (see below) to integrate critical roosting habitat into ecosystem restoration and enhancement initiatives, using a staged approach to ensure that maternity roosts are immediately available and that they remain available to bats while natural tree roosts recover.  WCS Canada is designing, constructing, and evaluating long-lasting artificial or modified trees for use by bats.  We are varying crevice sizes, solar exposure, elevation and habitat type to examine bat updtake of these roost creations. Roosts are created in three main ways: wrapping a flexible artificial bark called  BrandenBark  around poles or trees, and creating snags with crevices using chainsaws. Ongoing genetic testing of guano samples will identify species that use the sites. 

 In order to fill knowledge gaps about tree and roost use by bats, WCS Canada has partnered with UNBC and Dr. Erin Baerwald  and Masters student Emily DeFreitas to describe seasonal use of tree roosts by silver-haired bats (Lasionycteris noctivagans) in an area where they are known to occur year-round just outside Nelson, BC. Tree roosts are located using temperature-sensitive radiotransmitters affixed to free-flying bats to investigate duration of roost use, internal microclimate, torpor use and tree characteristics.  Artificial bark roosting structures have been installed in this study area to compare microclimates in known roost trees to those in artificial bark roosts to determine potential effectiveness as habitat compensation in the event of tree roost loss.


1) Why are the trees completely limbed?

The trees are limbed to reduce perches for predators.  In addition, there will be guano catchers installed at the base of each roost when the weather is suitable. Having the branches removed allows the guano to fall into the guano catcher without getting caught up on limbs.  The guano collected is sent away for DNA analysis to determine which species are using the roosts.

2) How are the trees were limbed?

Professional arborists did the limbing and installation of the sheets of BrandenBark,as well as the chainsaw modifications (plunge cuts and "lightning strikes") for the wildlife trees.


3) Is the intention is to leave the limbs on the ground below the trees?

The limbs will be left.  We scattered them around rather than leaving them at the bases of the trees.

4) What are the 2 bands (one wider than the other) around the bare trees are for?

The trees receive two girdles (also done by the arborists at the time of limbing/BrandenBark installation) to ensure that they die to become a wildlife tree.  One girdle is likely sufficient, but there is always chance of sap filling one and the tree surviving.


5) How is the ‘bark’ wrapped around the top of the bare tree?

The BrandenBark is a flexible polyurethane elastomer which is wrapped around the tree and affixed with roofing screws.

6) Why is a cap put on top of the ‘bark’ and how it was done?

The original trees did have metal flashing around the top but we have moved away from that when the BrandenBark is installed.  Instead, when installing on a tree, the arborists chamfer the tree where they install the top of the sheet.  This allows the top to be "tucked into" the tree's bark in a way that acts as weatherproofing.  Predator deterrents, or bird spikes, are not used on trees.

We use a slightly different process for installation on poles, and we do install predator deterrents on the top of poles.

Funders and Collaborators:

 WCS Canada is partnering with the Columbia Basin Trust, the Kootenay Connect project of the Kootenay Conservation Program, Environment and Climate Change Canada (Habitat Stewardship Program), the Okanagan Nation Alliance, Integrated Ecological Research, Strategic Resource Solutions, BC Parks, Nature Trust BC and many private landowners on this project.  In 2022 we broadened our partners to include the Nature Conservancy of Canada, Valhalla Wilderness Society, and the Creston Valley Wildlife Management Area

Links to Articles:

Biologists work towards bat conservation in Creston Valley, Creston Valley Advance, November 16, 2022

Kaslo biologist questions logging at unique West Kootenay bat site, The Nelson Star, January 19, 2021

Bats captured in Douglas fir beetle traps, Valley Voice Newspaper, August 13, 2020, pg 12

Artificial old growth trees provide roosts for bats in Golden area, The Golden Star, November 6, 2020.


Partnership Highlight:  

Bat-friendly Fir Beetle traps

WCS Canada has recently partnered with NACFOR (Nakusp and Area Community Forest) and consultant Darcie Quamme of Integrated Ecological Research to develop an exclusion method to prevent the accidental capture of bats in Fir Beetle pheromone traps. 

 A simple solution is often the best solution!   This method will help to prevent the accidental capture of bats (Myotis evotis) cuing in on Douglas Fir Beetle as prey within pheromone traps used for monitoring this forest pest.  The goals of this project were to: 1) encourage stewardship and education non the ecological services provided by bats to the forest industry, 2) collect data on incidental bat captures and 3) provide solutions to prevent capture. This is a win-win solution to prevent the need to handle bats and promote conservation of natural enemies of forest pests.  To learn more about this partnership project, please click here.

Partnership Highlight:

Beyond the Box!

While many people gravitate to erecting bat boxes to help bats, these box structures in fact generally only appeal to two species of bats in the East Kootenay, so erecting  tree-bark structures to use as additional roosting habitat can help many more species of bats.  

Dr. Cori Lausen and Nelson biologist Darcie Quamme have partnered up with landowners Sigi Liebmann and Brian Amies near Burges James Gadsen Park of Golden, BC to erect two unique bat roosts: one is designed by Liebmann, using large slabs of bark attached to a pole, and the other wrapped  with Branden Bark, a commercially available bark mimic from US-based Copperhead Consulting. Using a bat detector, local bat ambassador Joyce deBoer and Lausen discovered that there are at least 6 species of bats using this area, all of which would benefit from bark roosts to raise their young. This is only the second location in BC to erect the Branden Bark bat roosts.

Many locals assisted with this project, including donation of equipment, labour, materials, land and ideas:  Sigi Liebmann, Brian Amies, Joyce deBoer, Travis Cochran, Ron Appleton, Brian Jackson (Jackson Contracting & Excavation), Rob Kinsey, Cory Schacher, Fischer Schacher, Moritz Kohler.  This project is part of a larger effort to conserve bats in the Columbia Wetlands, and is supported in part by funding from Columbia Basin Trust and Environment Canada and Climate Change Strategy (“Kootenay Connect” Initiative).  Read more here.

Photo Credits: Header photo- Cori Lausen,  body photo of Myotis evotis (long-eared myotis)- E. McLeod, body photo of partnership project-Cori Lausen

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Contact Information
Address: Western Canada Bat Conservation Program; Kaslo, British Columbia | |