May 19, 2000

     Ruby-throated hummingbirds

Hummingbirds are found only in North America, Central America and South America and adjacent Caribbean islands.  Out of some 300 species, only about a dozen are native to the United States, and only one species, the ruby-throat, nests east of the Rocky Mountains.  It is a summer resident of Minnesota and is the tiniest of all the birds here.

Ruby-throated hummingbirds are only about 3 inches long and weigh a little more than 3 grams each; about 150 birds together would weigh a pound.  Their feathers are metallic green on their upper bodies and mainly white on their lower, with the adult male having a bright red throat.

The top speed of the ruby-throated hummingbird is just slower than 30 miles per hour, and the humming sound of their wings in flight accounts for their name.  The rapidity of their wing beat registers as a blur to the human eye, but an analysis of high-speed video pictures shows the rate to be about 70 beats per second for a male and 50 for a female.  The difference in rate is because the female is larger.