Creature Feature: A Different Kind of Bird - The Great Blue Heron

In honor of Thanksgiving, we are celebrating a local feathered friend-the great blue heron!

This bird sports grey-blue plumage on its body with a thick black stripe over its eyes. It is the largest of North America’s heron species, reaching about 4.5 feet in height with a 6-foot wingspan. At least half of this bird’s height is in its long legs.

They can be found throughout North America, with some pairs nesting as far north as Alaska! Although some great blue herons migrate between summer breeding grounds and winter nesting sites, most of our Pacific coast individuals are year-round residents. In our bay alone, we are lucky enough to have around 600 nesting pairs of great blue herons-one pair was spotted nesting at Alcatraz!

This bird’s varied diet helps it survive year-round in areas that other bird species leave for the winter. Great blue herons use their flat, pointy beaks to forage for food in marshes, calm shores, and mudflats. They stand statue-still as they hunt in grasses or by slow-moving water. Once they spot their prey, they strike out with their pointed beak to snatch up their food and swallow it whole. This species eats an extremely mixed diet of fish, birds, reptiles, amphibians, insects, and rodents. Several individuals have even been spotted swallowing fish bigger than their own heads!

If you look carefully at the tall trees or shrubs of a marsh, you might spot a great blue heron nest. Breeding pairs nesting further north only breed once a year, while pairs further south can have up to two broods per year. When a pair gets ready to nest, the male gathers sticks and the female builds a 2-4 foot wide platform. After the nest is ready and the female has laid 3-5 light blue eggs, the pair takes turns incubating the eggs by sitting on them.

Once the eggs hatch, both parents regurgitate food to feed their brood of hatchlings. After about sixty-five days in the nest, these baby birds take flight and leave the nest for good. If you’re lucky, you might catch a glimpse of a great blue heron cruising through the air, neck tucked close against its body, long legs trailing behind. Better look quickly, though-some report these birds reaching a flight speed of 20-30 miles per hour!