Isolated pairs breed nearby Prince Rupert and on the southern Queen Charlotte Islands. The centres of abundance are the Fraser Lowlands, southeast Vancouver Island, and the southern Gulf Islands. Breeding occurs at elevations between sea level and 1,100 m. On the coast, colonies are usually situated on islands or mainland sites near tidal mud flats. Inland colonies are usually situated on the banks of slow-moving rivers, sloughs, or marshy lakes.
Colonies can be ephemeral, abandoned one year only to be used the next.
A colony at Brisco was abandoned in 1979 when an Osprey used one of the nests, and ably new colony was built about 500 m south. In 1980, the herons returned to the old site. Forbes et al. The nest cup was a shallow depression lined with small twigs, bark strips, fresh evergreen boughs, or rushes. Fifteen species of trees were reported as nest sites.