Common Yellowthroat (Geothlypis trichas sinuosa) 23 April 2016. Alviso, Santa Clara County, California.
Photos © Joseph Morlan
This male was singing in a small marshy area. Note dull pink mouth lining. This race is endemic to the San Francisco Bay Area and is considered a "species of special concern" because of its small population size. It is said to have declined by 80% from historic levels. Digiscoped with Panasonic DMC-LZ5 | Nikon FieldScope 3 | 30X WA | hand-held (no adapter).