Increased bird biodiversity and greater habitat diversity in urban green spaces were associated with increased human happiness according to a study of visitors to 945 green spaces in Sheffield, United Kingdom.
Cameron, Ross W. F., Paul Brindley, Meghann Mears, Kirsten McEwan, Fiona Ferguson, David Sheffield, Anna Jorgensen, Julie Riley, Jon Goodrick, Liz Ballard, and Miles Richardson. “Where the wild things are! Do urban green spaces with greater avian biodiversity promote more positive emotions in humans?” Urban Ecosystems, 23 (2020): 301–317. https://doi.org/10.1007/s11252-020-00929-z
