Great blue herons adapt Birds utilize both marine and fresh water habitats

Recently, as I jogged along my favorite path parallel to the shoreline, I heard a great commotion coming from the water below. Dozens of gulls were floating just offshore, among the rocks, and dozens more were flying in from all directions. At intervals, something would excite the birds and they’d go into a frenzy of calling.

I joined an older gentleman on the small lookout platform; he had apparently been watching the spectacle for some time, for he turned to inform me the gulls were feeding on an abundance of small fish that were concentrated in that area.

“The fish are coming in waves,” he said. “Each time, the gulls start screaming.”

Intrigued, I watched for a time. It did appear the gulls were having a feast, darting their heads underwater and seeming to be successful at catching whatever it was they were after; although I never was able to discern what was in their beaks before they gulped it down.

Gulls were everywhere, it seemed, and I almost missed the arrival of a great blue heron.

Huge – especially in relation to the gulls – and prehistoric-looking, it glided past a few feet above the water, its beautiful blue-gray plumage seeming to absorb the similar hues of the sea. Surprisingly, it didn’t land among the commotion, but alighted a short distance away on a ledge exposed by the falling tide. It began to preen. I wondered if the heron had already gotten its fill of the banquet, for it seemed unconcerned with what was happening nearby.

I had quite a different view of a great blue heron on the evening of the full moon this week.

I had gone to the beach for my evening walk. The day had been unseasonably hot and humid, and although the sun had set, several people were still out enjoying the coolness near the ocean. A large expanse of beach was exposed by the low tide.

At one end of the beach, a small group of children probed in the shallows for hermit crabs. I was astonished to see a great blue heron only a few dozen feet away from them, wading through the calm water searching for food.

The heron stalked slowly through the shallows, at times stretching its neck straight, at times folding it into an S-curve as it tried to get a bead on its quarry. It moved in slow motion, and froze, before darting its bill beneath the surface and coming up with a small, wriggling silver fish, which it swallowed whole. It then repeated its maneuvers, zigzagging along the tide line. A few herring gulls and a ring-billed gull, along with a pair of black ducks that had just glided in, were also hunting the fish.

It was quite a tableau: children with plastic pails playing in the sand, while the herons, ducks and gulls foraged nearby. Every once in awhile, the small fish broke the surface of the water, and I thought there must have been quite a number of them.

Great blue herons have proven to be quite adaptable in the face of human encroachment. They utilize both marine and fresh water habitats, and, according to the Birds of North America species account, they are also able to “habituate to non-threatening repeated activities.”

Great blues are also generalists when it comes to food, eating crustaceans, fish, amphibians, insects, and even other birds (most likely nestlings if it happens upon them), and mammals.

The heron I observed on the beach that evening was only after the fish, however. And it was obviously habituated to the people, as long as someone didn’t get too close. Surprisingly, it remained unconcerned when a group of humans showed up with their dogs – a large yellow lab (who took one look at the heron and wisely choose to ignore it), and four super-energized terriers, who were too intent on each other to notice the giant bird.

As the full moon rose over Casco Bay and cast a golden swath over the water, I turned for home, the image of the heron wading unconcernedly through the shallows, surrounded by people and dogs, making me smile.

BDN bird columnist Chris Corio can be reached at bdnsports@bangordailynews.net