Hummingbirds depend on precise timing of flower blooms to fuel their extreme metabolism, and climate change is disrupting this synchrony across their range.
Hummingbird welfare is tightly coupled to flower phenology. When spring warming advances bloom timing faster than hummingbird migration, arriving birds find depleted flower resources and face acute starvation risk. Individual hummingbirds failing to find adequate nectar may enter torpor and fail to emerge. Clean, well-maintained supplemental feeders provide a welfare buffer during these gaps. Window strikes cause traumatic injury and death at enormous scale. Simple deterrents — window decals, external screens, and repositioning feeders away from reflective glass — reduce collision mortality for hummingbirds and all garden birds.