This is a juvenile. This species sometimes (e.g. IOC) goes under the English name, Nankeen Night Heron. Interestingly, Howard & Moore called it Nankeen Night-Heron through their 2nd edition, but changed to Rufous Night-Heron in the 3rd & 4th editions. Meanwhile IOC called it Rufous through their 2.2 edition but switched to Nankeen in version 2.3. True to their compound-noun aversion policy, IOC removed the hyphen. HBW retained the hyphen but spells "heron" in lower case. "Nankeen" is an archaic term
for a pale yellow cotton fabric, made in Nanjing, China, but not really descriptive of this heron's adult plumage. Six subspecies are currently recognized (one extinct), with birds from Australia now assigned to N. c. australasiae; formerly N. c. hilli. However australasiae apparently has priority. Adults of this race have chestnut-brown upperparts. This species is a close relative of the widespread Black-crowned Night-Heron (N. nycticorax). The juveniles of the two are very similar although the birds we saw had larger white spotting. Photo of an adult.
Nikon P510 Coolpix Point & Shoot; photo taken from a boat.