Ruby-Throated Hummingbird

I heard that Ruby-Throated Hummingbirds are the only hummingbird which is found in South Carolina area. I usually find this hummingbird around April 10th first time each year, but this year (2012) I saw male Ruby-Throated Hummingbird on March 20th and female hummingbird on April 10th. These years I saw male hummingbirds first and 2~3 weeks later I start seeing female hummingbirds in spring season. And when they leave, male hummingbirds disappear first and after 2~3 weeks female hummingbirds disappear. I’m not sure whether their migrations are done separately between male and female hummingbirds.

These pictures are taken middle of September of 2009.