Reviving a Legacy Citizen Science Project to Illuminate Shifts in Bird Phenology

Figure 2

Difference in mean first arrival dates (±S.E.) of Ruby-throated Hummingbirds in the Central (𝑁=2002), Appalachian (𝑁=1075), and Eastern Regions (𝑁=1988; see Figure 1 for region designations). Arrival days are expressed in “day of year” and corrected for leap years; for example, “130” corresponds to May 10. Inset letters represent differences that are significant at the 𝑃<0.05 level.