Tree Girdling for Potential Bat Roost Creation in Northwestern West Virginia

Eric S Schroder,Ryan L Ward

doi:10.3390/f13020274

Abstract

Cavity/crevice tree-roosting bats in North America face an uncertain future with many factors impacting their populations. To benefit crevice/cavity roosting bat species, forests are often enhanced with the use of tree girdling. In October 2015, 20 maples, 22 oaks, and 18 hickories were girdled using a method with fell cut and herbicide (frilling) or double-girdling with a chainsaw. From 2016–2021, targeted trees were observed and the tree’s decay state was collected. The average time for trees to display suitable roosting characteristics for frilling trees was 3.23 years while it was 4.46 years for double girdling. The average time frilling trees contained suitable roosting characteristics was 3.20 years while it was 1.63 years for double girdling. The frilling method resulted in a quicker kill of trees than double girdling and frilling trees had suitable roosting characteristics for a longer duration. Frilling was effective killing all three types of trees, while the double girdling was less effective, especially on oaks. When grouping species and treatment in analysis, only average decay states between maple frill and oak double girdling and hickory frill and oak double girdling were significantly different. This evaluation demonstrates that roost tree creation relating to tree species and girdling methodology has a temporal component that should be considered when managing for crevice/cavity bat roosts and multiple habitat creation methods should be used in conjunction with snag creation to provide sustainable bat habitat over longer time periods.

Highlights

Crevice/cavity roosting bats rely on trees for roosting, either under loose bark or within cavities [1,2,3,4,5,6,7]
Categories in data analysis included: maples treated via double chainsaw (DC), maples treated via frillroost trees that are found via radio telemetry and for identifying potential Indiana bat ing, hickories treated via DC, hickories treated via frilling, oaks treated via DC, and oaks habitat [35]
Categories in data analysis included: maples treated via DC, maples treated via frilling, hickories treated via DC, hickories treated via frilling, oaks treated via DC, and oaks treated via frilling

Summary

Introduction

Crevice/cavity roosting bats rely on trees for roosting, either under loose bark or within cavities [1,2,3,4,5,6,7]. Many tree-roosting bats in eastern North America (including the Indiana (Myotis sodalis Miller and Allen) and northern long-eared bat Trouessart) only use caves during hibernation (approximately October–April) with the rest of the year being spent in forests. These same bat species rely on crevice/cavity tree roosts to rear their young during the summer. Indiana bats and northern long-eared bats are both cavity/crevice roosters, they differ somewhat in their roost use and selection. Indiana bats prefer roosting underneath exfoliating bark while northern long-eared bats prefer cavities [9,10]. Northern bats prefer more heavily shaded roosts in interior forest [13]

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Conclusion