In the springtime adult male and female rubythroated hummingbirds are easy to distinguish. As summer progresses and juvenile rubythroats fledge the nest, their gender is nearly impossible to distinguish. Both male and female juvenile rubythroats will look identical to adult females.
This week in Bellingham, Washington, John Doerper reported seeing his first juvenile rufous male. This is not unusually early in the Pacific Northwest where some rufous overwinter. How was he able to identify a juvenile male rufous? Very young male rufous may show green with little or no rufous-colored feathers on the back. However, often their backs will show both green, their fledging color, and rufous-colored feathers like the bird below captured on camera.
Young male rufous have white tips on their outer tail feathers (rectrices), similar to adult rufous females. After a full molt, males will have an entirely rufous-colored back and an all dark tail.
John Doerper Bellingham, Washington 05/08/14
