This is a relatively uncommon bird – not rare. It is the eastern version of the very common yellow-rumped warbler. The variety we get in these climes, often in large numbers, is the western version – Audubon’s warbler. This species will likely be split into two in the near future.
This is an eastern and northern warbler, common into the Yukon, northern Colorado and east Texas. The migrational route takes this species intro eastern California and they are often seen along the coast in the Tijuana River Valley. Adult males have these bright orange feathers. Female and juveniles have bright yellow in place of the orange. This bird was too shy to pose for my camera. Typical warble behavior.
The yellow spot is an important field mark to use when trying to differentiate this bird from the similar Black-and-White.