AUTHOR=Bonter David N. , Greig Emma I. 

TITLE=Over 30 Years of Standardized Bird Counts at Supplementary Feeding Stations in North America: A Citizen Science Data Report for Project FeederWatch

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2021.619682

DOI=10.3389/fevo.2021.619682

ISSN=2296-701X