The Black Crowned Night Heron (Scientific name - Nycticorax nycticorax) is a medium sized heron that is found in many parts of the world. In many places it is simply known as a Night Heron.
This heron is said to be the most widespread heron in the world. It is distinguished by it's dark crown and back and short neck and dark bill. This species is most active at dusk and during the night.
While I have seen these birds closer to home in B.C. (most notably at the George C. Reifel Migratory Bird Sanctuary), the photos shown were taken at Kahului, Maui, Hawaii in November 2012.