It is important to note that Fact #3 is correct in the fact that deforestation undoubtedly contributed to the extinction of the passenger pigeon, but to this day there is no actual data to support that passenger pigeons evolved any kind of “dependence” on large flocks to survive. This was suggested as a plausible explanation for how so many birds could go extinct so quickly, but no science or historic records have ever shed light upon the hypothesis. Genomic evidence recently published shows that passenger pigeons fluctuated from large to small numbers - a point that suggests that there was no dependence on large flocks, as the species recovered multiple times from declines. Most publications regarding passenger pigeon research, however, are inconclusive in most points due to the difficulty in reconciling historic observations with testable hypotheses. Also, fact #4 has changed with new knowledge in the past year: the last wild passenger pigeon that can be confirmed was shot in 1902, not 1900. This was discovered by Joel Greenberg as he researched and compiled his book “A feathered river across the sky”.