Researchers looked at data from an online database of bird observations and correlated it with levels of admissions to hospital for mental health problems
“Our study shows that if species diversity can affect mental health at the severe end of the spectrum (hospitalisations), it is possible that the decline in biodiversity across the globe may be intricately connected with our anxiety and mood on a day-to-day basis." Dr Rachel Buxton, assistant professor, Institute of Environmental and Interdisciplinary Sciences, Carleton University
Areas with lower bird diversity seem to have a higher number of hospital admissions related to mental illness, according to new research from the US.
The researchers analysed data from eBird, an online database of bird observations by citizen scientists, enabling them to estimate the level of bird diversity in Michigan.
They then compared this information with data about hospital admissions for anxiety and mood disorders in the state, and found that lower bird diversity was correlated with higher numbers of hospital admissions for mental health conditions.
The findings were published in the journal Geo: Geography And Environment.
Dr Rachel Buxton, assistant professor at the Institute of Environmental and Interdisciplinary Sciences at Carleton University in Canada and lead author on the study, said: “Often we consider nature as representing the amount of green space near homes or the distance to the nearest park, but the link between species diversity and health is underexplored.
“Our study shows that if species diversity can affect mental health at the severe end of the spectrum (hospitalisations), it is possible that the decline in biodiversity across the globe may be intricately connected with our anxiety and mood on a day-to-day basis.
“It is critical we take a holistic approach to our mental health and nature.
“Investing in nature should not be viewed as a luxury, but a necessity, and evaluated in the context of the support for wellbeing it offers individuals and communities living in urban or nature-scarce environments.
“Restoring and conserving diverse bird communities could be one avenue to improving mental health in cities and factored into urban restoration projects and public health policies.”
This is not the first research to find a correlation between the presence of bird life and mental health. Last year researchers at King’s College London found an association between seeing or hearing birds and an improvement in mental wellbeing.
This is a potentially interesting study, but the findings need to be interpreted with caution. Correlation does not equal causation, and it is quite likely that areas with higher bird diversity also happen to have more green spaces and cleaner air, and are generally more pleasant places to live. It is far from obvious that the absence of birds is causing poor mental health.