December 1, 2007Even the most gluttonous hummingbird consumes fewer than 8 calories a day. But hummingbirds weigh only 0.06 to .8 ounce, so relative to their body size they eat about seventy-seven times more than the average human.
Hummingbirds need to feed almost constantly throughout the day because of their amazingly high metabolism. The heart rate of a ruby-throated hummingbird is around 250 beats per minute at rest and over 1,200 while hovering. To conserve energy on cool nights, the hummingbird can go into a state of torpor, lowering its body temperature by about 30 degrees F and slowing its breathing and heart rates.
Hummingbirds eat mostly nectar, with the occasional small insect or spider thrown in for some protein. Cats falcons, jays and snakes will eat hummingbirds, but they have to catch them first. One hummingbird species has been clocked at 93 mph.
From Sierra Club "Knowledge Cards" Text by Don Root
posted by Peggy or Guy at 9:07 PM 