ML639499955

Observation details

This unusual dark-plumaged adult Black-crowned Night Heron was photographed on May 10, 2025, in a wild, single-species BCNH rookery that has existed in Lincoln Park Zoo in Chicago, Illinois, for over ten years. The rookery census exceeded 700 adult BCNH by the zoo’s count at the start of nesting in 2025 and there were subsequently over 500 nestlings by their count. Despite observing and photographing the rookery on a regular basis, I have not seen this bird again. It was there for at least an hour and fifteen minutes on the afternoon of May 10 and to my knowledge it has not been seen since. It arrived suddenly, engaged in courtship behavior (stretching of its neck and wings with feathers erect), but it appeared to be ignored by the other BCNH and it was not observed interacting with them.