The association between objective and perceived bird diversity and the mental health of minoritized communities living near disused parks in Detroit

• The role of biodiversity in the relationship between nature and human health remains unresolved, especially in underrepresented communities. • Potential associations between bird diversity and mental health, and the moderating effect of nature relatedness, were explored in Detroit, USA. • Objective and perceived bird diversity had a positive association with mental health. • Community-led greenspace restoration in Detroit that promotes diverse bird communities could improve mental health outcomes in minoritized neighbourhoods. Exposure to nature provides mental health benefits, yet the role of biodiversity is unresolved. The relationship between biodiversity and mental health has received some research attention but has yet to be explored thoroughly in minoritized communities where major health disparities occur. We explored the relationship between objective and perceived bird diversity and mental health in Detroit, USA. We collected mental health metrics, perceptions of neighbourhood bird diversity, systolic blood pressure, nature relatedness scores, and sociodemographic information from 209 adults across 11 Detroit neighbourhoods in 2023. To predict objective bird species diversity, we collected acoustic recordings from 10 random sites in each neighbourhood and identified bird vocalizations to species level. We found a negative association between anxiety and objective bird species richness (OR = 0.52, 95% CI [0.32, 0.83]) and between depression and perceived neighbourhood bird diversity (OR = 0.69, 95% CI [0.48, 0.99]). Nature relatedness was not a significant moderator of the relationship between bird diversity and mental health. Our results suggest that both perceived and objective bird diversity may promote positive mental health outcomes. These results signal an important role for greenspace rehabilitation in Detroit that promotes biodiversity and reduces barriers to nature for minoritized residents, thus enhancing social and environmental justice.