Dorthy:
The hummingbirds you have are all of the "Ruby Throat" species. The male has the red throat. Young males usually have not gotten adult coloring yet, but a few may have a darker throat or a few red feathers. On the East Coast all we have are Ruby Throat species, with an occassional "Anna's" species. The Migration will soon be over. We saw a lone female 2 days ago, but my feeders are not going down. They hit them hard 2 weeks ago, before heading south. This site has tons of info on migration & great close up photos of many species of hummingbirds:
http://www.hummingbirds.net/index.html
I just want to say thank you for taking the time to care for these little jewels. Without humans to help, many would never survive migration.