Nature Number of Bird Species by U.S. County December 6, 2016 Alex Reddit user: buttfuck_warbler California has the highest numbers of bird species of any state. Related Posts:Which country has the most palm species?The Most Isolated City in Each U.S. State MappedThe Wealthiest and Poorest County in Every U.S. StateU.S. Non-Hispanic White Population by County (1990 - 2017)The Best National Parks In The United States For…Life expectancy in the United StatesGeography Facts About the U.S. CountiesExotic Animal Laws by U.S. State Mapped