Cavity-nester habitat development in artificially made Douglas-fir snags

  • Published source details Brandeis T.J., Newton M., Filip G.M. & Cole E.C. (2002) Cavity-nester habitat development in artificially made Douglas-fir snags. Journal of Wildlife Management, 66, 625-633.


This study is summarised as evidence for the following.

Action Category

Use ring-barking (girdling), cutting or silvicides to produce snags

Action Link
Bird Conservation
  1. Use ring-barking (girdling), cutting or silvicides to produce snags

    A replicated study over four years in Oregon, USA (Brandeis et al. 2002), found no differences in the rate of use by woodpeckers of Douglas-fir Pseudotsuga menziesii snags created by different methods. Instead, only the length of time that a tree had been dead for affected foraging rates. Girdling (ring-barking), injecting with two different silvicides and cutting the tree just below the crown all had similar effects, killing most trees within two years (silvicide and cut trees died after a year or so, girdled trees died after two years but a higher proportion died overall). Chopping at the middle of the crown was the least effective in killing trees, taking over three years and killing fewer trees. Eighteen trees were treated with each method and some snags were inoculated with saprophytic (decaying) fungi.


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