Is Izzie the night heron nocturnal or not?

My dad, some friends, and I had just returned to the dock from a recent fishing trip when something unusual caught my eye.

 

“Isn’t that a night heron?” I asked our friend, who owns the marina.

 

“Yes,” he said, “that’s Izzie.”

 

I apologize, but I couldn’t help but wonder, “Izzie nocturnal or not?”

 

Generally speaking, night herons are active – shocker alert – at night. It was odd to see one hanging out on a dock railing, near people, and in broad daylight. Izzie, however, has apparently decided that being fed fish trimmings in the daytime is easier than catching his own food in the dark.

 

Ornithologists use some esoteric terms to describe when birds are active and when they rest. Most of us know the words diurnal (active during the day) and nocturnal (active at night). But have you ever heard of a crepuscular bird? How about one that is matutinal or vespertine?

 

Crepuscular, from the Latin word meaning twilight, refers to being most active just before sunrise or just after sunset, with matutinal being the morning variety and vespertine being the evening one. Birds don’t read ornithology books, though, and will deviate from the script if circumstances allow.

 

Now, back to Izzie.

 

Black-crowned night herons, Nycticorax nycticorax, are common in the Lowcountry. In fact, this is the widest-ranging heron on the planet. According to the Audubon Society, these birds nest on every continent except Australia and Antarctica. They are just not as familiar as the better-known species because they are most active at night. 

 

If you have ever seen a stocky, yet heron-shaped, silhouette take flight just before dark, and especially if that flight was accompanied by a loud quawk, sounding like a mallard’s quack mixed with a crow’s caw, you have probably seen a night heron.

 

These birds frequent almost anywhere that’s wet, including saltwater marshes, freshwater ponds, swamps, and even flooded fields. Here, they eat whatever they can catch, including fish, crabs, snakes, insects, smaller birds, bird eggs, worms, and even leeches.

 

Night herons are colonial roosters and nesters, and are generally social birds. Males begin nest construction alone, gathering sticks to build a nest that is typically over water in a tree, in cattails or brush on an island, or in some other protected area.

 

The males then advertise for a partner by making bowing motions and raising the plumes on their heads. Once a mate is found, the male will continue to bring materials, and the female will integrate them into the nest. The female typically lays three to five greenish blue-eggs, which both parents incubate, that will hatch in three to four weeks.

 

While captive specimens can live up to 30 years, the average night heron’s lifespan is less than 20 years. The oldest known wild night heron, which was tracked and banded in California, was at least 21 years old.

 

It’s not certain just how old Izzie is, but it seems likely that he has nixed his naturally nocturnal ways for good.