Thursday, June 7, 2012

Green Herons

Green Heron in the old Erie Canal southeast of Clyde, NY.

Green Herons -- © Dave Spier

For a time, the Green Heron (Butorides virescens) was known as the Little Green Heron, in reference to its relative size, but the joke became “it’s called that because there is so little green on it.”  Green-backed Heron was another name it once held, and that is a little closer to its appearance, but just slightly.  In bright sunlight, the back is dark grayish-green.  Adults are gray underneath with dark rufous (red) necks, streaked throats and dark crowns.  Young birds are more streaked on the neck and throat.  As the birds age, the legs vary from yellow-green to yellow and then finally orange on adults during breeding season.

At 18 inches long, it is small for a heron, but large compared to most birds we see regularly.  It is the length of a crow, but the heron’s wings are much shorter.  Seen flying overhead, on its way to the next swamp or back to its nest, the heron might be mistaken for a crow, but there are subtle differences.  The heron often travels alone in a straight line, deliberately heading for its next destination.  Crows are likely to travel in noisy flocks that swoop and turn as they decide where to go.  I’ve seen only crows harassing and chasing raptors.

Green Heron in the Old Erie Canal at Lock Berlin County Park off Route 31, between Lyons and Clyde.

Being shorter legged than other wading birds, the Green Heron prefers to hunt by walking down a fallen log that dips into the water at the end.  There it crouches and waits for a small fish or sometimes a frog.  The Green Heron is one of a growing list of animals observed using tools (inanimate objects that make a job easier or more efficient).  In the case of the heron, it uses food pellets, cereal, feathers or short sticks dropped on the water to lure fish close enough to catch.  The heron also might be found perched on the branch of a tree overhanging the edge of a stream or pond.  If it sees you first, it retracts its neck until the head seems to touch the shoulders.  Looking like a burl on the limb, the smaller posture helps it hide.  As a last resort, the heron leaps into the air with a loud “kee-ow” or “skow” and flies away.

Most herons nest in colonies, but not the Green.  Each pair nests by itself, sometimes far from water.  One spring, I watched two adults raise their family in the top of a tall spruce plantation about a mile from the river where they went to hunt for food.  I haven’t been back, but assuming they returned to nest again, life probably got easier for them when a pond was built nearby.

Green Heron flying over the Montezuma Audubon Center 
just north of Savannah, NY (in southeastern Wayne County). 
all photos © Dave Spier
Here's the hyperlink mentioned in the first comment:
Corrections, questions and suggestions are always welcome at northeastnaturalist@yahoo.com  For more information on wetland birds in the Montezuma Wetlands Complex and northern  Finger Lakes Region, please visit the Montezuma Birding Trail website http://montezumabirding.webs.com and look on the Montezuma birds page.  For information on the Eaton Birding Club that covers Wayne, Seneca, Ontario and Yates Counties, please visit http://eatonbirds.webs.com 

2 comments:

Susannah said...

Dave,
Check out my blog post from Cape Cod last summer - about halfway down the page you'll see photos of a green heron and a young red-tail with a paragraph describing their antics. It was one of the strangest and most heart-rending events I've seen in the wild.
http://utterloonacy.blogspot.com/2011/07/first-of-two-planned-summer-trips-this.html

Barb (aka Susannah)

The Northeast Naturalist said...

Thanks Barb. I put it in the blog as an active link near the end so readers don't have to copy and paste.