Bear Dens in Coastal British Columbia
Helping Land Managers Identify and Retain Black Bear Dens
American black bears (Ursus americanus) require suitable winter den sites to provide security and cover to successfully survive and reproduce during the critical winter denning period. Dens are reused intermittently over decades, if not longer, and may be used by successive generations of bears. On Vancouver Island, winter dens used by black bears have been found in or beneath large diameter (mean of hollow tree dens = 160 cm) trees or structures derived from trees (i.e., logs, root boles and stumps). Current and historic land management activities in coastal forests have affected the supply of these critical element-level features. Most significantly, forest harvesting has removed many large trees that form these den structures. Furthermore, these large structures are not replaced during forest rotations because the new crops of trees are not allowed to grow to sufficient size for replacement dens to develop.
The large, old trees that black bears need to survive the wet, cool conditions in coastal BC are often lost during forest harvest operations, sometimes because field staff cannot easily tell which trees are dens. Using information collected over 25 years, Artemis Wildlife Consultants has developed training and tools to help forest licensees and their contractors identify and retain these critical wildlife habitat features within their operations. Learn about general bear ecology, how to differentiate bear dens from day beds, and different strategies for den retention and how the supply of dens affects bear populations.
Den Identification Workshops for foresters and field staff are available for delivery throughout coastal British Columbia. Please contact Helen Davis for more information or to schedule a workshop.
Coastal Bear Den Identification Manual Version 2 (PDF, 13 Mb)
This manual is meant to help field crews identify winter dens used by black bears and grizzly bears in coastal British Columbia. Specifically, this manual provides information on types of dens, a brief description of how cavities that produce dens are formed in trees and characteristics of trees or excavations that field staff can use to identify potential dens. The final decision as to whether a tree or excavation is a bear den and worthy of protection should be made by a Qualified Professional whose scope of expertise includes bear ecology and den identification. As such, a great deal of responsibility lies with Qualified Professionals to identify these critical habitat elements.
Hollow tree dens (video): Woody debris dens (video):
If you are surveying for bear dens in coastal BC, please consider using our standardized field data form to help field crews collect information that will help development and operations foresters work towards retaining the structure within their operations. The Avenza Maps® schema for entering den data has many fields that will aid in future analyses of what coastal bears are selecting for when choosing den sites. The Avenza Maps® schema automatically records the date and coordinates of “den pins” dropped using the schema. Download AWC Bear Den Schema Jan 2020 (Avenza Maps® schema, 16 kb)
Stand-Level Retention Guidelines for Bear Dens (PDF, 3.4 MB)
This document provides guidance to help forest managers and field crews to:
1. identify black bear dens in coastal forestry operations,2. develop effective prescriptions for retaining these critical habitat features within operational harvest units (i.e., cutblocks), and3. provide on-going management of retention areas.
Stand-level den retention video:
How to Create a Bear Den In a Stump (PDF, 1.6 MB)
This how-to guide will show you how to create a potential den for a black bear! All you need is a suitable stump, a piece of plywood, a chainsaw and some enthusiasm!
See video (https://www.youtube.com/watch?v=AKGcz7CC-fA) of creation of a stump den and a bear gathering plants for bedding.
Check out "A Bear's Necessities" by Wild Bus Films about Helen's work on protecting bear dens: