On 13 August 2005 an immature Yellow-crowned Night-Heron was reported at Painted Rock Dam. This was a first record for Maricopa County and one of only a handful of records for Arizona. Knowing the subtle differences between subadult Black-crowned and Yellow-crowned Night-Herons helped identify this bird.
Yellow-crowned night heron, photo by U.S. Fish and Wildlife Service Headquarters via Wikimedia Commons.