It seems the males develop and protect territories and the girls move in if they think the whole package works for them. The females some-times develop rivalry but the nests are surprisingly close in many cases, sometimes as close as 20 ft. I have also observed females visiting other nesting mothers. This area has a colony of Anna’s hummingbirds which stay all winter and have developed a social structure which is fascinating to observe. They have very distinct territories and many of the birds are identifable by subtle markings and calls which allow me to detail their nesting be-haviour. Their territories are pretty small in general and defned by natu-ral objects like trees and clearings. 22 Hummingbirds Up Close Magazine Hummingbirds Up Close Magazine 23