Life’s Little Treats
by Bryce W. Robinson
Costa's Hummingbird fledgling
Costa's Hummingbird Fledgling
Costa's Hummingbird fledgling
A studio for bird study
Costa's Hummingbird fledgling
Costa's Hummingbird Fledgling
Costa's Hummingbird fledgling
ornithologi.com 
how do you know its a fledgling and where did u see it? As you seem i’m catching up on all your blogging!
There were two birds in a tree outside the hotel room. Both apparently not male. They each were attempting to fly, and could only move from branch to branch without getting fatigued. They would rest for five minutes before making another go at the sky. So far as differentiating between adult female and immature based on plumage alone, I do not know the difference.