Great Blue Heron
Ardea
herodias fannini
Washington State Department of
Ecology
The great blue heron is adapted for year round living along
Puget Sound. It wades in shallow waters, forages in
eelgrass meadows, hunts small mammals in fields, and nests
in large shoreline trees. Great blue herons nest in groups
called "heronries." Some heronry locations along the Sound
include Samish Island, Camano Island, and Hartstene Island.
Herons
Nest Near Eelgrass
The large number of fish attracted to eelgrass meadows is
the staple of the great blue heron diet. Many heronries are
located next to eelgrass beds. These feeding areas are
vital to the survival of the colonies. Great blue herons
can be seen hunting in eelgrass meadows at Padilla Bay,
Bellingham Bay, and Quilcene Bay.
Heron
Facts
Barbecue
Tongs - The great
blue heron seldom stabs prey. Rather, the heron uses its
bill like barbecue tongs and clamps on prey.
Hollow
Bones - Adults are 4
ft. tall with a 6 ft. wingspan - but most only weigh about
5 lbs. How can that be? Heron bones are hollow.
Spring
Action Neck - The great
blue heron has special neck vertebrae that create an "s"
shape. This bone structure allows the neck to curl up like
a spring to attack prey. It also allows the heron to fold
its neck while flying.
Herons
Nest In Large Trees
Herons build nests in a variety of tree species including:
alder, cedar, hemlock, Douglas fir, spruce, cottonwood, and
hawthorn. But most often, herons nest in big alders over 75
feet tall.
At first glance, the long-legged herons might appear
awkward nesting in trees; but they are adept at weaving
nests in high tree canopies. With long toes, they grip
branches and twigs and construct nests side by side
"condominium" style. The size of the heronry grows with the
amount of food available nearby.
Do
Not Disturb
In general, herons select nesting sites away from human
activity, in quiet clusters of trees. If humans disturb
heronries during breeding season, several studies show, the
reproductive rate of the colony can drop or adult herons
may move the entire colony. Bald Eagles may also attack
heron chicks and cause a colony to move.
Winter
Survival
Herons also seek undisturbed areas for winter hunting. In
the fall and winter, many great blue herons survive by
catching meadow voles - a tiny mouse-like mammal that
tunnels in grass. Herons stalk these small mammals in quiet
meadows, marshes, and farm fields.
For many, the great blue heron is a symbol of pristine
Puget Sound. The heron is also an important biological
indicator of the health of Puget Sound shorelines. Herons
need abundant small fish, as frequently found in eelgrass
meadows, and older shoreline trees for breeding. As
development spreads along the Sound, shoreline trees are
removed, nesting sites are disturbed, and eelgrass beds are
destroyed.
Saving
Heron Habitat
You can help preserve heron habitat...
• Preserve shoreline trees.
• What comes off your boat and your land can pollute.
Prevent water quality problems.
• Protect eelgrass meadows.
• Keep pets away from herons and under control.
• While visiting the beach or boating, give herons and
heronries plenty of space. Avoid going ashore near a
nesting heron colony.