Canaries in a Coalmine: Birds and Forest Degradation in Canada
Most people are familiar with the plight of tropical rainforests, having seen shocking images of once-lush and diverse forests converted to cattle pasture or monoculture soy crops.
In Canada, although some forests have been converted to agricultural lands and other uses, in most forests that are logged for wood products, trees generally regrow. Governments in Canada have relied heavily on this tree regrowth to dismiss criticism of forestry practices. The idea that logging replicates or replaces fire is also used to downplay impacts, despite ecological differences between the two.
Even where trees grow back, however, scientists say forest harvesting and regeneration practices can “simplify forest structure, reduce tree species diversity and truncate old-forest age classes”; this is known as forest degradation. It diminishes the ecological value and services of forests. Thus, while Canada may not be implicated in significant “deforestation”, degradation has exacerbated climate change and contributed to biodiversity loss.
Despite the fact that Canada has made a commitment to halt and reverse forest degradation by 2030, it does not currently acknowledge where and to what extent forest degradation is occurring domestically. Canada instead raises facile arguments about the comparatively small percentage of the entire managed forest that is logged each year and ignores the cumulative footprint and associated impacts of decades of industrial logging and other development activities that have degraded and fragmented forests in Canada.
What can birds show us about forest degradation?
Birds are one of the most monitored classes of animals. From scientific studies to backyard bird counts, the data on birds is a valuable source of information on the state of ecosystems more broadly. Birds as a class are also particularly reflective of ecosystem health; they can help highlight where forest degradation is occurring as one bird species, or another, occupies almost every niche in dynamic forest ecosystems throughout Canada.
Here are some examples of forest degradation and its impacts on birds in Canada:
EASTERN CANADA: Bird decline has been explicitly linked to forest degradation in Acadian forests in Eastern Canada. Recent research shows that forest degradation led to habitat declines for the majority of forest bird species, with negative consequences for bird populations, particularly species associated with older forests. While trees in this region regrew after logging (and there was no decline in the area covered by forests), logging changed the forest composition. The researchers estimated that the current average age of trees is approximately 55 years, in contrast to the pre-settlement forest, which had trees averaging 200 years of age. As a result of this forest degradation, the researchers estimated that the Maritime provinces have lost between 30 million and 100 million birds since 1985. Species experiencing the greatest decreases in habitat included the golden-crowned kinglet and Blackburnian warbler, which showed habitat declines greater than 25 per cent. Nine bird species in the study area declined at rates exceeding 30 per cent over the past 10 years, meeting criteria to be listed as threatened under Canadian endangered species legislation.
