Winter Habitat Selection and Foraging Behavior of the Fisher Martes pennanti

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Winter Habitat Selection and Foraging Behavior of
the Fisher (Martes pennanti)
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General Information

• Adults weigh between 12-25 lbs
• 27-49 inches in length.
• Males are about twice the size of females
• Excellent climbers - paws able to rotate 180
• Found only in N. America
• Exists in Northeast U.S., most of Canada, and a
  portion of the NW U.S. and California

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General Information

• Snowshoe hares and porcupines make up 20 and 65
  of a fishers metabolizable energy (Powell 1994)

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Foraging Behavior

• Variation in tracks from hardwood to coniferous
• Snowshoe hare more common in coniferous areas.
  Fisher tracks meander.
• Porcupine nests usually known.
• Tracks are linear

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Purpose

• To determine the selectivity of habitat at three
  scale levels
• Stand
• Patch
• Elements

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Methods

• Live trapping and radio marking
• Tracking
• Analysis compared home range of fishers to amount
  of available forest type.
• This helps to determine positive or negative
  selectivity

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Coarse Woody Debris

• In winter, fishers selected at least double the
  amount of hardwood CWD gt20cm, than in the summer.
• Winter gt50 m3/ha
• Summer 1-25 m3/ha

• Explanation
• Fishers use hollow logs and brush piles to
  access subnivean during harsh weather
• Fishers are reported to use tree cavities
  primarily in autumn and spring, and limb nests in
  the summer

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Cover Type

• Selected up to 60 coniferous canopy and 60 high
  shrub
• Avoid gt80 low shrub in all seasons
• Explanation
• Less snow and more compact snow allows for better
  foraging.

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Conclusion

• Stand selection most important with regard to
  cover, expanse, and tree types
• Patch selection based on stand selection.
• Fishers selected patches with significantly less
  structure in stands that had extremely high
  values of coniferous canopy, high shrub, and low
  shrub closures.
• Element selection in winter is most related to
  large debris for warm resting sites

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Conclusion

• Fisher habitat selection and utilization is
  determined primarily by efficiency

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Porcupines and Fishers

• Live in hardwood forests
• Fishers do not actively avoid, but they do not
  select for
• Hunted very efficiently so time in porcupine
  habitat is decreased compared to that of hare
• Remains to be seen whether fishers select for
  porcupine habitat within the vicinity of
  coniferous stands

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References

• Powell RA. 1994. Effects of scale on habitat
  selection and foraging behavior of fishers in
  winter. J Mammal 75(2)349-56.Weir RD and
  Harestad AS. 2003. Scale-dependent habitat
  selectivity by fishers in south-central british
  columbia. The Journal of Wildlife Management
  67(1)73-82.