A new study has found that bird species in forested areas of Canada’s Maritime provinces are threatened by habitat loss due to changes in forest composition driven by clear-cutting.
The findings were outlined in an article published Thursday in the journal Nature Ecology & Evolution. Researchers from the University of Oregon examined data on 54 of the most common bird species in the Acadian forests of New Brunswick, Nova Scotia and Prince Edward Island between 1985 and 2020.
In total, the researchers estimate that 33 to 104 million birds died over the 35-year period due to forest degradation, which refers to the loss of biological diversity and forest health.
Since 1985, more than three million hectares of the Acadian forest have been clearcut while older forests have shrunk by 39%.
“Due to the increase in global demand for timber, more and more of the Earth’s surface is being used for timber extraction,” said author Matt Betts in a press release published on Friday.
When forests are clearcut, they are usually replanted with a single tree species, resulting in a much less ecologically diverse environment.
“Our paper presents a new way to quantify these types of changes,” Betts said.
These practices have been shown to have serious impacts on bird habitats. The researchers found that 66% of these species had suffered habitat loss on breeding grounds, which was strongly associated with a loss of older forests.
The golden-crowned kinglet is the bird species that suffered the greatest loss, having suffered a 38% decline in habitat over the study period. This was followed by the black warbler, which lost 33% of its habitat. Seven species have experienced habitat declines greater than 25%.
Nine bird species have also experienced population declines greater than 30% over 10 years, which would qualify these species to be labeled as “threatened” according to the Committee on the Status of Endangered Wildlife in Canada.
“Overall, our results indicate large-scale declines in Acadian forest forest birds, and for most species, abundance is strongly associated with the amount of habitat,” Betts said.