– The metabolic rates of some birds are amazing: The hummingbird has a basal rate about a hundred times that of an elephant. It needs to consume about its own body weight in nectar each day, plus insects and spiders to supply protein.
– The dark-eyed junco is the most widespread bird at North American feeders.
– House sparrows are declining in many areas, while house finches continue to increase.
– Some feeder birds may be abundant one winter but absent the next.
Source: Project FeederWatch, and the book “Feed the Birds.”