Life and Death in a Hawaiian Lagoon

Greg Patent Newsletter

Greg Patent

Feb 21, 2023

Night Heron on a tree branch surveying the water below for a potential meal of fish. When he finds a likely spot, he’ll fly to the water’s edge.

Black-crowned Night Herons, or just Night Herons, are the most widely dispersed herons in the world. Here in Kaua’i, we see these stately birds hunting for fish at the water’s edge of a lagoon. When I say “hunting” I mean the birds are as still as statues staring into the water with their piercingly red eyes seeking a fish for a meal.

The heron remains perfetly still as he focuses his gaze.

The adult birds have a striking appearance and their sharp pointed bills are perfect instruments for a life devoted to capturing and feeding on fish.

On our almost daily walks around the lagoon we’ve seen many birds in their feeding pose, but never have we witnessed any heron attempting to or actually catching a fish.

Several months ago we did happen upon a heron who had just captured a fish. We watched him manipulating his catch with his tongue and swallowing his prey head first. The whole action lasted about 3 seconds. Wow!

A few days ago, on a late afternoon walk, we stopped in our tracks and gasped at the following sight.

The heron must have just caught the fish because we could see it opening and closing its mouth as the heron tightened his grip.

To us it seemed that this fish was too large for the heron. How was he going to swallow that?

We had to find out. So for about 15 minutes we stood quietly, barely moving, as we watched this life and death drama unfold.

Because of the fish’s size, the heron had to kill it before swallowing it. And he did that by clamping his powerful jaws down hard around the animal’s throat to suffocate it. Over the next few minutes we could see him repeatedly squeezing the fish right behind its head.

A better view of the fish showing its size relative to the heron.

When it looked to us as though the fish was dead, the heron dipped its tail in the water. I’m guessing this action would have told the heron that the fish was, in fact dead. If the tail twitched, it would signal the heron that his job wasn’t done yet.

After the first tail dip, the heron applied more pressure on the fish, followed a few minutes later by another tail dip.

By then the fish was dead. Its body was completely still. The heron began manipulating the position of the fish between his jaws, trying to position it for a clean swallow. He kept shifting the fish’s position over and over and never seemed satisfied.

You can see that this fish is pretty long! Its head is now in the heron’s mouth.

Finally, several minutes later, with the head of the fish firmly secured in the heron’s mouth and the fish’s body dangling from it, the heron did something we had not expected. It flew up and across the water and landed in a tree!

Now what, we wondered? Did the heron have a nest there?

A few seconds later a second heron flew to the tree and landed right next to our heron. We are guessing that this intruder had been watching the whole time and figured he could steal the fish right out of our heron’s mouth.

But this is what happened. The arrival of the intruder so startled our heron that he flew off instantly, and the fish he had killed left his grip and dropped into the lagoon with a tiny splash, as if to say end of story.

We felt so sad for our heron. We lost sight of him after the fish fell. The intruder heron stayed in the tree and just kept looking at the spot where the dead fish had re-entered its domain. As a corpse.

This is not how we wanted our story to end. In our version our heron would’ve remained on the shore. Throwing his head backward, he’d widen his throat to a size even he never knew was possible, and down would slide his precious fish. After swallowing, he’d flick his tongue in and out within his bill and rest for a few minutes before flying off to roost for the night.

Nature doesn’t work the way we want it to. Being a predator is hard work. Often there’s no payoff. But the heron survived and would fish successfully another day. The fish’s body would become fodder for aquatic beings. And life would go on.