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....Booster Shot to Create Wildlife Trees (continued)

After trees have been inoculated, they are numbered and labelled with a wildlife tree sign to ensure that they are not accidentally cut.

Photo: © Fish & Wildlife Compensation Program.

Wildlife trees are critical to the ecosystem and about 70 species of birds, mammals and amphibians in B.C. depend on them.

“In November we inoculated 107 live trees in the 4,000 ha Hofert Hoodoos Conservation Area near Fairmont Hot Springs,” says FWCP Wildlife Biologist Irene Manley, “We have high hopes that within 10 to 15 years many of them will provide excellent habitat for a variety of birds, including woodpeckers, owls and even wood ducks.” 

The inoculation involves drilling several holes above the mid-point of the tree trunk and inserting wooden dowels impregnated with a heart rot fungi native to the local area. The fungi are introduced in the upper half of the tree because cavity nesters usually prefer to nest more than 7 metres above the ground to avoid predators. 

The trees are also semi-girdled (a cut made into the bark) several metres below the inoculation. This allows the tree to continue to live but provides the fungi with an advantage to take hold. “The idea is not to kill the tree but to have a large, strong, standing, live tree with a section of heart rot decay suitable for cavity excavators,” say Manley. “Even in the long term the fungi we use do not kill the tree, but it does create pockets of weaker wood. The tree is likely to remain standing as a valuable wildlife refuge for decades whereas a completely dead tree may just last a few years before it breaks.”   

After the idea originated in the United States, Todd Manning of Manning Habitat Enhancement Services based in Victoria, has pioneered tree inoculation in B.C. for the last five years.  Recent sampling of the very first trees inoculated in the province (on Vancouver Island) show very promising results with 100% inspected, so far, exhibiting signs of heart rot decay five years following treatment.

Changing land use patterns in the Columbia Basin have resulted in a reduced supply of suitable wildlife trees. Modern forestry practices, agriculture, human development and reservoir creation have all played their part in this decline.

“The lack of old forest structure means that the part of the ecosystem that helps break down the wood – the fungi – is not as prevalent as it once was,” says Manning. “It’s a vicious cycle – the fewer large mature trees which are present to harbour heart rot fungi, the less common the fungi becomes and the fewer fungal spores there will be available to infect other trees, creating future wildlife habitat.”

The FWCP, which is managing the project, works on behalf of BC Hydro, B.C. Ministry of Environment and Fisheries and Oceans Canada, to conserve and enhance fish and wildlife impacted by the construction of BC Hydro dams. 

The inoculated trees are marked with a yellow wildlife tree sign and given an identification number to enable biologists to monitor them for both decay, and presence of wildlife in the years ahead.

FWCP Public Representative in the East Kootenay, Greg Mustard, noted that a survey undertaken in 2000 found the presence of the red-listed (“endangered” or “threatened” in B.C.) Lewis’ Woodpecker on the Hofert property but, with a follow-up survey last year, there was no sign of the birds. “If we can facilitate the increase of suitable habitat it is our hope that they may return, as well as benefit many other species in the process.”

Article by Angus Glass, Columbia Basin Fish and Wildlife Compensation Program.

The Western Screech-owl is Endangered (Schedule 1 of the federal Species at Risk Act; Red-listed provincially), mainly due to loss of its breeding habitat in low elevation riparian areas.

Photo: © Dick Cannings.

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