Forest clearcutting led to loss of up to 104 million birds in the Maritimes since 1985: study

A new study has found that bird species in woodland areas of Canada's Maritime provinces are under threat from habitat loss due to changes in forest composition driven by clearcutting.

The findings were outlined in a paper published on 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 during the 35-year period due to forest degradation, which refers to the loss of biological diversity and health of the forest.

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Since 1985, more than three million hectares in the Acadian Forest have been clearcut while the older forests have declined by 39 per cent.

"Due to increased global demand for wood, more and more of the Earth’s surface is being used for timber extraction," said author Matt Betts in a news release published Friday.

When forests are clearcut, they're usually replanted with a single species of trees, resulting in a far less ecologically diverse environment.

"Our paper presents a new way to quantify these sorts of changes," Betts said.

These practices were found to have serious implications for bird habitats. The researchers found that 66 per cent of these species had experienced habitat loss in the breeding grounds and this was strongly associated with a loss of older forests.

The golden-crowned kinglet was the bird species that experienced the greatest loss, having experienced a habitat decline of 38 per cent during the study period. This was followed by the Blackburnian warbler, which was found to have lost 33 per cent of its habitat. There were seven species that had habitat declines that exceeded 25 per cent.

Nine bird species also saw population declines that exceeded 30 per cent over 10 years, which would qualify these species to be labelled as 'threatened' according to the Committee on the Status of Endangered Wildlife in Canada.

"Overall, our findings indicate broad-scale declines in forest birds of the Acadian Forest, and for most species, abundance is strongly associated with habitat amount," Betts said.