Birdist Rule #115: Learn to Identify and Differentiate Night-Herons

Don't panic: There are only two.

Their name makes them sound like a team of minor-league Marvel superheroes: The Night-Herons! They sit motionless in the shadows, not making a sound. They wait for unsuspecting criminals to come close, and then they . . .  STRIKE!

I dunno. Maybe waiting around for criminals to walk by isn’t the most impressive super power. It is a great way to catch fish, though, and it’s a technique employed by these very cool birds you might have seen around but weren’t sure how to identify. 

Our two species of night-heron, the Black-crowned Night-Heron and the Yellow-crowned Night-Heron, belong to a family of large wading birds that also includes the familiar Great Blue Heron and the cryptic bitterns. Each of these birds feeds in about the same way: hanging around in shallow waters looking to snap up little fish and other goodies. But our birds differ slightly from their cousins. How? Here’s a hint: The people who name birds aren’t always that creative. That’s right: Night-herons are primarily active at night.

And it’s for this reason that you might not be familiar with them, though one could easily live nearby. Black-crowned Night-Herons are the more widespread of the two species, living full-time on both coasts and spending the breeding season throughout the lower 48 states. The Yellow-crowned Night-Heron is more restricted, found year-round only in Florida and in parts of the Southeast while breeding.

Luckily, adult birds of the two species are very easy to tell apart. The stature of both looks pretty much the same—shorter and stockier than other herons—but the coloring on the bodies and the head (especially the head) is where the ID is made. Black-crowned Night-Herons have a white body and face, gray wings, and a blueish-black crown and back. Yellow-crowned Night-Herons have gray bodies, black cheeks, and—you guessed it—a yellow crown on their head. Remember what I said about people not always being creative with names?

That’s the adults, though. Juvenile night-herons, like the ones you might be seeing around now, are much trickier to identify. Both are brown with streaked breasts and white-spotted wings. The bill of the juvenile Black-crowned is partly yellow while the bill of the juvenile Yellow-crowned is mostly black, which is kind of confusing, but this isn’t really a reliable field mark anyway because the bird's bill is often covered in mud. So, instead of focusing on the bill, focus on the white spots on the wings. Juvenile Black-crowned Night-Herons have big thick spots. Juvenile Yellow-crowned Night-Herons have white edging on their wing feathers that connect to very small white spots on the tips, creating a much more mottled look.  

Got all that? Good, it’ll come in handy. Everyone knows Great Blue Herons and Great Egrets, but few know the night-herons, even though they’re just as common. In fact, night-herons are one of the most frequent birds I get asked to identify. You’ll see them, so you should be ready. But if they’re nocturnal, how are you going to see them?

One way is to see them at their roost, where night-herons typically spend their days. They’ll just nestle into a tree or some dense brush and have a daylong snooze. Despite being a few feet tall and not exactly having great camouflage, night-herons can be surprisingly hard to see while roosting.  Many times I’ve looked up from some pond edge and seen a Black-crowned Night-Heron dozing just overhead. In some places they’re more obvious, like their famous rookery at the National Zoo here in Washington, DC.

Night-herons are most frequently encountered at dawn or dusk as they skulk the water's edge or fly to and from their feeding areas and roosts. Keep an eye out for chunky little herons flying at these times, though identification might be tough in the low light.

Or, you could get lucky and just see them out in broad daylight. Considering the fact that night-herons are primarily nocturnal, it’s a fairly rare occurrence, but as any parent reading this knows, sleeping habits change when you’ve got kids. In the summer, after the chicks hatch and when there are hungry mouths to feed, it’s possible to see night-herons out feeding at all hours

And if you do catch them during the day, they’re worth watching. Night-herons have some cool feeding tricks in addition to the not-that-exciting tactic of standing motionless and waiting for a fish to show up. For one, they’re one of the few birds known to exhibit “baiting” behavior: putting twigs or bread on the surface of the water to lure fish in. Night-herons are also infamous for feasting on the eggs of terns and gulls, a habit that sometimes hinders recovery efforts of rare species like the Roseate Tern.

Alright, I think that covers it. Now you’re armed with all the information you need to move on from easy the Great Blue Heron and Great Egret to the next step in heron identification. So get out there, and don’t forget a flashlight.