Trying to learn to distinguish a female hummingbird is quite difficult. It is important to study field guide carefully. It is also important to study about the status and distribution of the various species. The information contained in this list can also be used to assist you with your efforts:
The female Ruby-Throated Hummingbirds and female Black-Chinned Hummingbirds are virtually undistinguishable in the field. It may help you to tell the two species apart if you remember that female Black-Chinned Hummingbirds usually have a longer bill and they pump their tails. Both species are green the base of the tail. The Black-Chinned Hummingbird may contain more gray on the crown.
Rufous and Allen’s females are virtually impossible to distinguish in the field. Those who are responsible for banding the birds say that the tail feathers of an Allen’s Hummingbird are narrower and more pointed, but this is virtually impossible to see. Both Rufous and Allen’s have a rufous wash on the flanks. It is best not to try to identify an Allen’s Hummingbird away from its breeding grounds in California unless the bird is a male with a full gorget and a green back.
Female Calliope Hummingbirds have an apricot-colored wash on their under parts. These birds have a short, very straight bill and a short green tail with white corners. Whenever these birds are perched, the wings should extend beyond the tail. This hummingbird tends to feed on lower flowering plants than most other hummingbirds.
Female Costa’s Hummingbirds are small. These birds have a bill that is medium in length and very straight bill, and they also have very white under parts. They have a green crown and white cheeks. This species of hummingbird often seems a little plump. You may see faint dots on their throats. The flanks of this bird are green.
The female Broad-Tailed Hummingbird is a little larger than the Rufous or Allen’s Hummingbird. She has pale rufous flanks and a small amount of rufous on the tail.
The female Anna’s Hummingbird usually has fine red spots on the throat. The under parts of this bird are usually dingy gray in color. The flanks of this bird are green. The bill of this bird is long and straight. It has been noted by many people, this species of hummingbird holds her tail perfectly still while feeding.
The female Blue-Throated and Magnificent Hummingbirds are quite large. The Blue-Throated Hummingbird has much more extensive white areas on the tail. The Blue-Throat has more of a whisker mark; she also is smoothly gray on the under parts.
The female Lucifer Hummingbird is noted for having an arched bill. This bird has a big whisker mark. The under parts of this bird can be described as buffy. This hummingbird is located in only localized areas near the Mexican border.
The female Broad-Billed Hummingbird has a red bill. Her under parts are gray. Her flanks are green.
The female White-Eared Hummingbird is located near the Mexican border in Arizona. It is similar to the female Broad-Billed Hummingbird, but has a shorter bill, a much bolder eye stripe, and green speckling on the throat.