Forest Investment Account (FIA) - Forest Science Program
FIA Project Y091088

    Badger Habitat Use and Movements in Forested Ecosystems
 
Project lead: Larsen, Karl (Thompson Rivers University)
Contributing Authors: Larsen, Karl W.; Klafki, Richard; Packham, Roger; Persello, Brent
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Description:
The BC subspecies of badger (ssp. jeffersoni)is one of BC’s most endangered mammals, with estimates placing the total provincial population at fewer than 340 [1]. Consequently, badgers are on the ‘red list’ within the province, and are considered ‘endangered’ at the federal level. The animals generally are restricted to the south-central portion of the province, where research projects have been conducted on sub-populations found in and around the Thompson-Nicola and East Kootenay valleys.

Badgers often are stereotyped as a grassland species, yet recent research [2, 3] has revealed that they are much more of a habitat generalist than previously believed. These research projects also have isolated two main factors contributing to the continued decline of badgers in BC: (1) a historical and current deterioration of habitat, and (2) road mortality caused by major transportation corridors running through valley bottoms where badgers exist. Badgers in BC have extremely large home ranges [2, 3] as compared to conspecifics further south, suggesting that habitat is suboptimal and/or access to mates is constrained by low densities of animals. The large home ranges cause animals to make long forays, bringing them onto roads and railway lines. However, data collected on the home range of these animals also reveals their use of a wide range of habitats other than the valley-bottom grasslands. For example, badgers have been shown to use higher-elevation forests, including recent cutblocks where food (e.g., ground squirrels) is available. These studies have indicated that plans to maintain badgers in this province must encompass a wider range of habitat types and management activities than previously thought.

In 2003, members of our research team (notably Packham) started to become increasingly aware of the presence of badgers in the Cariboo region of BC. The Cariboo is a broad, flat plateau, composed of a matrix of grasslands (used heavily for livestock grazing), wetlands, aspen, and pine/Douglas-fir forests. From a conservation standpoint, the Cariboo badgers are inherently of interest because they represent the northernmost periphery of the animals in the province. Peripheral populations often represent 'strongholds' for species undergoing declines, and may be important reservoirs of genetic diversity [4]. In many cases, broad landscape approaches may be efficient in protecting peripheral populations such as the Cariboo badgers [5,6], but variations in life-history and a different demography often make detailed information on these peripheral populations critical [6], especially for maintaining genetic variability [7].

Further attention to the Cariboo badgers also appears warranted because they appear increasingly affected by human activity, following the fate of their more-southern conspecifics. Preliminary research (Packham) using DNA sampling at burrows has demonstrated home ranges may be even larger than seen further south (up to 1200 km2), and the growing awareness of the animals has revealed that road mortality is also taking its toll. Forest harvesting, the recent mountain pine beetle epidemic, and a projected increase in vehicular traffic in the region all indicate the animals in the Cariboo could face extirpation, not unlike that seen within the southern parts of the province. Fortunately, the fact that pressure on the population from human activities may be relatively recent suggests there may still be time to prevent the drastic decline of the animals as seen in other regions. However, this will not be an easy task: other preliminary research (Packham unpubl.) using sightings, burrow records, and scat analysis indicates the Cariboo badgers are not only using grassland habitats, but also travel and den in forested areas,and feed on species linked to forests (e.g. red-backed voles, hares, squirrels) and even riparian zones (muskrats, waterfowl). Effective management plans therefore will need to be broad, but data on the animals needed to craft such plans are still far from complete.

The need to collect precise data on the population, movements and habitat associations of badgers in the Cariboo region was identified by the national Recovery Team in 2006, and in the following year, the investigators behind this proposal initiated telemetry work on the animals. Recognizing the current and potential impacts that road improvements and increased vehicle traffic will have on badger mortality, the BC Ministry of Transportation has provided core funding to study the interaction between badgers and roads in the Cariboo. These funds must be primarily directed towards understanding the road ecology [8] of the species, so mitigations to reduce road mortality can be implemented. Through telemetry, we are focusing on whether road crossings by the animals occur at predictable locations, and at what time(s) of the year the animals are predisposed to longer movements. This work provides an excellent foundation to study the animals in a wider array of locations, not just along transportation corridors. As discussed, this broader information base is required to formulate wider, more-inclusive management plans that encompass the full range of habitats and land-use conflicts likely to affect the long-term persistence of the animals in the region.

Last year, we implanted 6 Cariboo badgers with conventional VHF radio-transmitters, and monitoring of these animals has been since ongoing. Although we have targeted individual badgers with home ranges abutting transportation corridors in order to collect data on road crossings, the telemetry program also has started to reveal patterns of how the animals use the habitat matrix. For example, radio-tagged animals and burrows frequently are found in forested sites and regenerating cutblocks adjacent to open range areas. However, a limitation of telemetry is that animals usually are located during daylight hours, and our estimates of road-crossing points are not as precise as one would prefer. Until recently, limitations on Global Positioning System (GPS) technology has prevented the continuous tracking of animals as small as badgers. However, working with a New Zealand company, we have developed and received the first GPS dataloggers small enough to be deployed on badgers. Starting in 2008, we will be outfitting our study animals with these instruments. This will be the first time this technology has been used on these animals, and it will provide much greater resolution on the precise movements and habitat associations of badgers.

With this FSP application we are seeking the funding needed to broaden the focus of our project, allowing us to collect much-needed data on the forest and grassland (open range) use of these animals in the Cariboo region. This project will enable science-based forest management that will address critical core use habitats (e.g., natal and maternal dens) for badgers in the region, and facilitate habitat supply analyses to ensure that badger habitat is maintained over the long term. Potential forest management issues we will be able to address include the effects of increased harvesting of beetle-impacted stands, recently harvested areas and/or burns being used by badgers, grazing practices on small mammal abundance, development of forest roads, and forest encroachment and ingrowth.

[1] jeffersonii Badger Recovery Team 2006. In: Species at Risk Act Recovery Strategy Series. Ottawa 36 pp + append [2] Weir et al. 2003. Conservation strategies for North American Badgers in the Thompson & Okanagan: Final report. Artemis Wildlife Consultants, Armstrong, BC [3] Newhouse & Kinley 2004. East Kootenay badger project 2003-04 update. Sylvan Consulting, Invermere, BC [4] Lesica & Allendorf 1995. Cons. Biol. 9:753-760. [5] Noss 1987. Bio. Cons. 41:11-37 [6] Franklin 1993. Ecol. Appl. 3:202-205 [7] Millar & Marshall 1992. For. Sci. 37:1060-1077 [8] Forman 2000. Cons. Biol. 14:31-35

    Deliverables:

Executive summary (63Kb)
Powerpoint presentation (1.4Mb)
2008-09 Progress and Summary (0.3Mb)
Brochure 2008 (2.1Mb)
Badger underpass summary (2.4Mb)

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Updated August 16, 2010 

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