Over four seasons of birding, I have seen a lot of variations of Yellow-rumped Warblers. The one pictured here is a first. This must be a fledgling right out of the nest. Heavy streaking and gray tones still can't disguise this little "yump." Note the body shape, the white throat and the distinct tail markings.
This series of photos, all taken this year, show the Yellow-rumped Warblers in Spring and Summer, from their crisp breeding plumage to the scruffy, fluffy look brought on by molting. Soon, these birds will transition to their drab brown, winter plumage.
For now, it is interesting to observe how each one goes through the transition just a little differently from another.
Yellow-rumped Warblers molt twice a year. The molt into breeding plumage can begin as early as January so that by spring, they are looking their best.
They remain in breeding plumage through July. By August the winter molt begins.
This species is quite variable with the color of some birds being much brighter than others. Some are more "streaky" than others.
Some are just cuter than others.
The single most important field mark of this species is the yellow rump. Even if the overall look of the bird is different, it is pretty easy to catch sight of the consistently-present yellow rump as it flies away.
Just came up with another one. This male looks quite different from most Yellow-rumped Warblers.