10,000 Birds

DECEMBER 14, 2021

As of mid-November 2021, the Collaborative had submitted more than 4,200 checklists (up from 1,700 in 2018) and has observed 691 species in the United States (up from 618). Thus, there are now seven states with 200+ observed species. The state with the largest increase was Arizona , with 139 species added.

United States 220

United States West Virginia Puerto Rico Minnesota 220

10,000 Birds

MARCH 4, 2011

Among these white-headed/dark-winged gulls formerly lumped into the genus Larus , there were 18+ recognized species the last time I checked, sharing similarities that make telling them apart for the amateur birdwatcher very difficult. 1998), then the proper name for this species is L. fuscus – should be separated as species.

2011 157

2011 Cyprus Species Deer 157

10,000 Birds

NOVEMBER 13, 2018

As of mid-October 2018, the Collaborative had submitted more than 1,700 checklists and observed 618 species in the United States. The heat map is revealing: Unsurprisingly for a site founded and run by two New Yorkers (one of whom literally wrote the book on birding New York), the Empire State boasts the highest number of species (316).

Rhode Island 114

Rhode Island United States West Virginia Puerto Rico 114