If you’re looking today for action photos of birds or acrobatic flight shots, you’ve come to the wrong place. The hunch-backed, thick-necked, short-legged Night Herons will not tear up the dance floor, but on further review they do have some interesting characteristics. The Bird-naming Gods nailed it with the “Night” part, but not so much with “Heron”. These birds are clearly nocturnal; I’ve only infrequently seen them foraging or flying in daylight. But their body type is not typical of the long-legged and graceful posture of most other herons and egrets.
The world’s Night Herons are divided among three genera with the most cosmopolitan bird, the Black-crowned Night Heron (BCNH), found on all continents except Antartica and Australia. It belongs to the genus Nycticorax which has a Greek origin meaning “night raven”. This refers to its croaking wock wock Raven-like call. The BCNH is also our most common and widespread Night Heron in the New World, found from Canada to Patagonia.
The genus Nycticorax also includes the extant Rufous or Nankeen Night Heron (N. caleconicus) found in SE Asia, Australia, and New Zealand, and at least five extinct endemics that didn’t survive on Bermuda and the Ascension and Mascarene Islands.
The Yellow-crowned Night Heron (YCNH) belongs to the genus Nyctanassa and is found exclusively in the New World and primarily in the SE United States, Mexico, and Central and northern South America. For completeness I mention the the third and last genus of Night Herons, Gorsachius. It contains four species only found in the Old World, three in Asia and one in Africa.
So what’s so special about these herons, other than their nocturnal hunts? You will on occasion catch them foraging in shallow wetlands in daylight, especially during nesting season when they are struggling to satisfy their famished young heronettes. Night Herons are one of the few bird groups to employ “baiting” techniques to attract small fish. They spread small twigs and food on the water’s surface to lure the unsuspecting. If that doesn’t work they also vibrate their bill in the water to attract the curious but less intelligent Pisces.
There’s no problem IDing the adult birds. You’ll usually find them snoozing in shrubs along the water’s edge at about 3 to 15 feet elevation. The juveniles are not so colorful and quite similar to each other, but if you pay attention to their bills the ID becomes easy. If there’s yellow in the bill you have a BCNH and if its entirely black, the bird is a juvenile YCNH. Guide books also mention the different patterns of white spots on the brown plumage, but those field marks have not been as obvious or useful for me. The juveniles will obtain the adult plumage in their third year.
BCNH tend to nest in large rookeries, often with diverse species, while the YCNH tends to nest alone or in small groups. It’s the courtship displays of the BCNH that are most interesting. Apparently due to hormonal fluctuations the male becomes aggressive and begins a “Snap Display”, clicking his bill while crouching and pacing in his staked out territory. This is followed by the “Stretch Display” as he extends his neck fully, bobs his head, and begins hissing. For some reason all this commotion attracts curious females and spurs on nearby males to start their own competing displays. But wait, it’s not over yet.
The male initially rejects the females, taking his sweet time to pick the perfect mate. Monogamous pair formation occurs when one lucky female is finally allowed to enter his territory and rewarded with mutual preening and billing. Finally, at or near the time of copulation, the legs and feet of both partners turn pink.
I’m fortunate to see the two species of Western Hemisphere Night Herons all year long in my patch in SW Florida, and was also surprised to recently see the BCNH at dusk on the Ganges River. We had a nesting pair of YCNH’s on the edge of the mangroves of Clam Pass in Florida for the last two seasons, but unfortunately their favorite tree did not survive the recent hurricane and I have not seen them this year. But from now on, whenever I do see a Night Heron, I’m going to pay more attention to leg and foot color. That observation offers just another glimpse into the private lives of these interesting birds.