This study examined the associations between bird and tree species diversity in Canadian cities and self-rated mental health metrics from the Canadian Community Health Survey. Data from 36 Canadian Metropolitan Areas (2007–2022) were linked at the postal code level. After controlling for covariates, bird and tree species diversity showed significant positive relationships with good self-reported mental health. A one-standard-deviation increase in bird diversity corresponded to a 6.64% increase in good mental health reports, while a similar increase in tree species richness resulted in a 5.36% increase. The findings suggest that supporting healthy urban ecosystems could benefit human well-being.

Rachel T. Buxton, Emma J. Hudgins, Eric Lavigne, Paul J. Villeneuve, Stephanie A. Prince, Amber L. Pearson, Tanya Halsall, Courtney Robichaud, Joseph R. Bennett