2019-06-11 · birds (1970 baseline, N. America)
Three billion birds gone since 1970
North American breeding birds collapsed — grassland and forest species led the loss. A continent-scale warning.
1 cell = 10 million birds (1970 baseline, N. America) (0.1% of breeding birds 1970) · 1,000 cells
Context
North American breeding birds collapsed — grassland and forest species led the loss. A continent-scale warning.
Science 2019: ~3B fewer birds in US/Canada since 1970.
This grid fixes breeding birds 1970 at 1,000 equal cells (0.1% of breeding birds 1970). Figures follow Science — bird decline as summarized in the source line — rounded so cell counts sum to the chart.