A Good Place to be a Heron

A chance encounter with a nearly 5-foot-tall great blue heron (Ardea herodias), standing still as a statue as it waits for its next meal to swim, hop, or wriggle by, is a marvel.

As its name implies, this beautiful bird is the largest heron in North America. Slate blue feathers cover its large body, accented by pale plumed chest feathers. A long, sinuous neck is tinged a chestnut color and striped black at the front. The great blue’s white feathered head with its daggerlike orange-yellow beak is topped with a distinctive black stripe that extends from its piercing golden eyes to the back of its head, ending in an elegant plume.

When the big bird takes off with its two-toned gray, 6-foot wing spread and its long wading legs extended behind it, it is a sight to behold.

Great Blues in Missouri

“Great blue herons are common and widespread,” said Missouri State Ornithologist Kristen Heath-Acre. “Wherever I’ve lived, including Missouri, they’ve always been there.

“They are a wetland generalist and can thrive in marine or freshwater habitats, which helps bolster their populations. They’re very adaptable.”

The great blue has an over-wintering range that historically has stretched into the northern parts of South America, 

but climate change has affected its migratory patterns, Heath-Acre said.

“They have a mix of migratory and non-migratory behavior. Where they can find water that doesn’t freeze over, they sometimes stick around,” she said. “With climate change, they are able to stay farther north.”

Habits and Habitat

Great blue herons frequently build nests in tall trees in wooded areas close to water. They avoid human interference and roadways, which explains why heron colonies, which can consist of dozens of nests, are not commonly observed.

A colony of heron nests high in the trees is an awe-inspiring sight. Heron homes are barely more than stick platforms but can reach 6 feet across, sometimes lined with leaves or moss. Nests are fortified and used year after year, though not necessarily by the same occupants. Birds choose new mates each year, often returning to the same colony.

Unlike many bird species with distinct male and female physical characteristics, great blue herons can be differentiated only by size. Females are slightly smaller.

A male great blue takes charge of choosing a nesting site and then defends it from interlopers as he works to attract a mate. His selection serves as his displaying platform where he puts on his best performance to woo an observant female, stretching, swaying, circling the nest, clacking his bill, and preening.

After successfully making the right impression and pairing, the female lays two to six pale blue eggs that are approximately 2-by-3 inches in size. Laid in intervals of up to two days, the eggs fade to white by the time the chicks hatch in approximately 28 days. Parents take turns incubating the eggs and share the responsibility of feeding their nestlings by regurgitating their prey.

Great blue herons most frequently hunt by standing stock still or walking slowly in shallow water. Once a potential meal is spotted, with a lightning quick lunge the heron either grasps the prey in its beak or spears it with a beak-turned-dagger. Great blues eat fish, frogs, crayfish, turtles, and other aquatic animals, and will also go after small mammals, snakes, and insects. Excellent night vision allows them to feed in the dark.

Considered quiet birds, great blue herons have a variety of vocalizations used primarily to communicate during foraging and feeding. Their most common call is a loud, primitive, very dinosaur-like Frawnk, which serves as an alarm or a warning. Males vocalize most frequently.

Juvenile great blue herons are primarily grey. They do not exhibit their parent’s attractive blue-gray plumage until their third year when they reach breeding age. Young chicks are rarely sighted as they remain in the nest for two to three months.

Approximately 70 percent of great blue herons do not live past their first year. In addition to predation and other fatal dangers, juvenile mortality rate has been linked to the difficulty of mastering stealthy heron feeding techniques.

From the mid-19th century to 1920, a leading cause of death for both herons and heron chicks was a human passion for feather fashion.

Herons Hunt with Tools

Rather than relying on stealth mode with eyes peeled to ambush passing prey, green herons have a little trick up their beaks. They ingeniously pick up a feather, a small twig, a leaf, or even an insect and drop it in the water as bait to invite investigation by a potential meal. This tool-using behavior puts green herons in rare company with birds like crows, parrots, and a handful of other observant flying, feathered creatures.

Human Predation

Feathers most certainly have served as ornamentation for as long as humans have played dress up. Beginning in the late Victorian Era, hats with exotic feathers became all the rage for stylish women. Bonnets with plumage demanded higher prices and plumassiers — craftspeople who obtained, prepared, and supplied feathers — were happy to oblige milliners with the exotic adornments.

On a causal walk in New York City in 1886, Frank Chapman, the American Museum of Natural History’s ornithologist, identified feathers from dozens of native bird species on hats of fashionable women strollers, including blue jays, cedar waxwings, and northern orioles. Some hats displayed entire stuffed birds perched on their brims.

In Herbert K. Job’s 1905 Wild Wings, the author noted that at the turn of the 20th Century feathers used for adornment were twice as valuable as gold, selling for $32 an ounce.

Heron head plumes, especially those of breeding males, were in high demand along with the feathers of ostriches, egrets, peacocks, lyrebirds, bower birds, and many other unluckily beautifully plumed birds. Adult birds slaughtered for their feathers meant a death sentence for their chicks. In the case of snowy and great egrets, feather harvest nearly resulted in extinction of the species.

In 1886, Boston cousins Harriet Hemenway and Minna Hall rallied 900 socialite women to boycott feather-adorned headwear and organized the Massachusetts Audubon Society, which launched the National Audubon Society.

Congress passed the Lacey Act in 1900, prohibiting the transport of birds across state lines taken in violation of state laws. Largely ignored, a game warden in South Florida was murdered trying to enforce it.

In 1913, Massachusetts Representative John Weeks and Connecticut Senator George McLean passed the much-challenged Weeks-McLean Act, ending what they termed “millinery murder.” Then in 1918 The Migratory Bird Treaty Act went into effect. Plumed birds finally prevailed when it was upheld by the Supreme Court in 1920.

While some heron species are in decline across the country, primarily due to habitat loss, the great blue heron is listed as a species of least concern because of its adaptability.

“Missouri wetlands are diverse and widespread despite a loss of over three-quarters of their historic footprint,” Heath-Acre said. “A lot of people here are really excited about and dedicated to wetland restoration and protection. Missouri is a good place to be a heron.” 

Herons in Missouri

There are about 60 heron species throughout the world and about a dozen are found in North America. Some are better known as bitterns or egrets.

Missourians may be able spot up to 10 heron species in the state, some more commonly than others and almost always near water. These are herons to look out for in addition to the great blue heron. Note that bird size is measured from the tip of bill to tip of tail.

Least Bittern (Ixobrychus exilis): The smallest heron in Missouri is the least bittern — a pigeon-sized bird with a long pointed yellow bill. Males have a dark green back and crown, and females have a dark purple-brown back and crown. It can be found statewide and because it is small, it can perch on foliage over deeper water to hunt.

Great Egret (Ardea alba): Seen statewide as a visiting bird in the summer, the great egret is a striking 38-inch long-necked white bird with long black legs. It has a daggerlike yellow bill and tucks its neck in when it flies, dangling its legs behind like the great blue heron. Quite stunning, during breeding season great egrets grow long feathery plumes — aigrettes — on their backs used for breeding displays.

Cattle Egret (Bubulcus ibis): Small with a compact, stocky body, adult cattle egrets have yellow bills and legs, both of which turn red in breeding season. Feathers on the adult heron’s head, breast, and back are an orange-buff color. It is less seen along streams than in flooded crop fields, lawns, marshes, and roadsides. In pastures, it walks among livestock and even is seen perching on livestock backs. A nonnative species, it originated in Africa and is locally common in southeast Missouri in the summer.

Little Blue Heron (Egretta caerulea): During its first year, the juvenile little blue heron is completely white. Adults measure 26 inches and have slate-gray feathers and a maroon head and neck. Its two-toned bill is gray with a black tip. It is commonly seen in the southeast part of the state.

Green Heron (Butorides virescens): A compact bird at 19 inches, the green heron has a long daggerlike beak. Its back feathers are gray-green and its head and neck are a russet-brown except for a green-black head cap. It forages at dawn and dusk and stays out of sight during the day. Green herons are ambush hunters just like great blue herons and are reasonably common statewide.

Black-Crowned Night Heron (Nycticorax nycticorax): Common in wetlands across Missouri, black-crowned night-herons are the most widespread heron in the world, but that doesn’t mean it is commonly seen as it is most active at dusk and in the evening. It spends the day hiding in water vegetation. At 25 inches it is a small, stocky heron with a black back and head, a white belly and gray wings. It is most common in the southeast part of Missouri.

Sightings of these herons in Missouri are more rare: American bittern, snowy egret, and yellow-crowned night heron.