The swollen bill shape and dark bill color help distinguish this immature from that of the similar and more expected Black-crowned Night-heron (Nycticorax nycticorax). Yellow-crowned is a crab eating specialist. This one is feeding on a Striped Shore Crab (Pachygrapsus crassipes). Yellow-crowned Night Herons have expanded their breeding range and multiple pairs now nest in a restricted area at the nearby Point Mugu Naval Air Station in Ventura County, which is now the northern end of their West Coast breeding range. First successful nesting of this species in California was in 2006 at Imperial Beach, San Diego County. Despite its recent range expansion, it remains a rarity in most of California. Six subspecies are recognized. This is N. v. bancrofti characterized by pale coloration, narrower dorsal streaks and having a thicker bill than the nominate East Coast race. Distribution of N. v. bancrofti is weird with two widely spaced populations, one centered in NW Mexico and the other in the Bahamas and West Indies. Canon PowerShot SX60 HS.
References:
Lehman, P. E. "The Birds of Santa Barbara County, California", Revised edition, July 2018, available at https://sites.google.com/site/lehmanbosbc/, 2018. Original edition: The Vertebrate Museum, University of California, Santa Barbara, 1994.
Martínez-Vilalta, A., Motis, A. & Kirwan, G.M. (2018). Yellow-crowned Night-heron (Nyctanassa violacea). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/52706 on 17 October 2018).
Watts, B. D. (2011). Yellow-crowned Night-Heron (Nyctanassa violacea), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.161