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They Mostly Come Out at Night… Mostly: The Black-crowned Night Herons

For my fellow sci-fi aficionados, it’s a lot prettier than the critter Newt refers to in the Aliens franchise….

Black-crowned Night Herons (Nycticorax nycticorax) are the most widespread herons in the world, and can be found on all continents except Australia and Antarctica. As their name suggests, they’re most active during the dusk and night hours, resting during the day.

Juvenile Black-crowned Night Heron in the Wetlands: Learning to Hunt

Description

Compared to other herons, these guys are small, stocky, short-necked, and short-legged — averaging 23-28″ in length and 25″ in height. The adults sport their descriptive black crown and back, accompanied by light blue-grey wings and tail, and whitish underparts. Their legs and feet are yellowish-green, changing to a pinkish-red during the breeding season. During the breeding times, they’ll also grow two or three long white plumes on their heads, that will stand up during greeting and courtship displays. Males and females look alike, but the females are a bit smaller in size. The Black-crowned juveniles display a dark grey-brown plumage, with white streaks and spots. Adult plumage is reached by 3-years-old — which is also breeding time.

But my favorite part of these herons are their eyes: a brilliant bright red. And the youngsters? They have an equally gorgeous yellow stare.

Adult Black-crowned Night Heron: Look into my eyessss….

Habitat, Diet & Hunting

Black-crowned Night Herons prefer the fresh- and salt-water wetland habitats, including marine islands, swamps, rivers, canals, marshes, mangroves, and the more overgrown edges of lakes and ponds. They remain close to the water and near their favored trees, including pond apple trees, in our area — where they roost and breed.

Their diet consists primarily of fish, but Black-crowned Night Herons will also partake in frogs, insects, crayfish, mussels, squid, reptiles, rodents, and aquatic plants. They’ll also loot the eggs and nestlings of waterbirds, such as terns, herons and ibises, and hunt small birds. Feeding takes place in the shallow waters, where they grasp their prey (instead of stabbing it). It’s a common sight to witness these herons standing stock-still at the water’s edge for long periods of time, waiting for their prey to come into range. They shake their prey until it’s been stunned or killed, at which point the heron swallows it head-first. Yummy!

Juvenile Black-crowned Night Heron

Black-crowned Night Herons are solitary hunters, and feed in the early morning and at dusk. Theories of their nocturnal habits range from wishing to minimize competition for food with other waders, to avoiding harassment from other birds that are aware of the night herons’ habits of feeding on their eggs and young, and have, therefore, learned to attack night herons on sight.

Threats

In the 1960s, Black-crowned Night Herons’ populations suffered a decline that was attributed to the use of DDT. They’re also hunted for food — particularly the juveniles. Additionally these herons are killed at fish farms, where they’re seen as a nuisance. Fortunately, alternate methods for managing many of the associated “issues” with these birds have been implemented, eradicating the need to slaughter these lovely herons.

Adult Black-crowned Night Heron, Hunting in the Wetlands

As with other wading birds, habitat loss and destruction (in addition to water pollution) of their wetland habitats in more recent history have had detrimental impacts in their decreased populations.

Adult Black-crowned Night Heron, Near the Roost

SAVE THE WETLANDS and their most lovely and amazing inhabitants!

Fun Facts:

  • If you want to hear a Black-crowned Night heron, listen for a loud and somewhat harsh ‘Qua,’ ‘Quak,’ ‘Quark’, ‘kwark’ or ‘kwok.’
  • In many parts of the world, this heron is named for its calls. In the Falkland Islands, it’s referred to as quark; kwak in Dutch and Frisian; and similarly in Czech, Ukrainian, Russian, Vietnamese, Indonesian, and other languages.
  • Black-crowned Night Herons can live up to 30 years in captivity, and 20 years in the wild.
  • While hunting, these herons use a technique called “bill vibrating.” They open and close their bill rapidly in the water, which creates a disturbance that lures prey.

Part of:

The Eyes Have It

An animal’s eyes have the power to speak a great language. ―Martin Buber

In preparation of an upcoming post on Black-crowned Night Herons, and in honor of Halloween, I give you the lovely and brilliant red and orange glowing pumpkin stares of these lovely wetland waders. I’m always captivated by birds’ eyes, but some are especially striking….

An adult’s red glowing gaze

A juvenile’s changing orange sight

 

A Young Great Blue’s Meal

I had been watching one of the Great Blue Herons at our local wetland preserves a few weeks ago; she only had one baby, which is a bit unusual for the species. I watched as she built her nest high in the cypress trees, then dutifully guarded it, alone…. There was no male in sight, which is likewise unusual. Usually both the male and female remain at the nest, and hunt for the young. There aren’t as many human visitors at these particular wetlands, due to the lack of active rookeries — which suits me just fine; the baby alligators, birds, butterflies, marsh rabbits (or swamp bunnies as I’m fond to call them), and if I’m lucky, bobcats, keep me company.

I always spied this Great Blue hunting in the same area — a swath of dry land near a small swamp frequented by the bobcats. Visitors would stroll right by her, she blended so perfectly with the landscape. This choice of hunting grounds would explain her meal below — Yummers! It’s no surprise that these birds have been known to choke to death while trying to swallow meals that are too large for them.

What has she been trying to regurgitate…?

Well, oh my.

Courtship Colors

The next time you look into an animal’s eyes look deep and long. You will see their inner beauty and feel their living soul. —A.D. Williams

The Tricolored Juveniles and the Tricolored Adults of our Florida wetlands have been highlighted; and now…. A most lovely Egretta tricolor displays his brilliant breeding colors. During courtship, these already beautifully colored herons become even more vibrant: the eyes turn a striking scarlet, and the otherwise long, pointed yellow bill turns blue. Breeding plumage involves filamentous plumes on the head and neck, and buff plumes on the back.

The juxtaposition of the deep scarlet eye against slate blue feathers is perfect; Nature needs no retouching.

Tricolored Heron in Breeding Colors, Florida Wetlands

Tricolored Herons: The Grown-Ups

Tricolored Heron (Juvenile) in the Florida Wetlands

As recently mentioned — in Tricolored Herons: The Young Ones — there are a few physical differences between the juveniles and adults of the species Egretta tricolor.

Beautiful blue feathers cover most of this heron’s body, save a white-striped chest and belly, and a rust-colored neck. The juveniles eventually lose much of the rust coloring, with only a bit of the hue peeping through the slate blue feathers as they age. The eyes of the juveniles are a yellowish-white, turning brown with pink inner margins into adulthood. Males and females of the species look alike.

Below, an adult female carefully watches over her nest, recently built with her mate and filled with a precious cargo. Another fishes in the brown-tinted waters of the wetlands (hued as such by the mangroves and other tree roots) — most likely a parent, as both Tricolored Heron males and females hunt for their young.

We’re fortunate to have secure and protective habitats for these most lovely creatures; without continued preservation efforts however, many amazing and unique ecosystems — the Everglades, Longleaf Pine, Scrub, Mangrove, and more — will remain in decline. As they disappear, so do the plant species and wildlife that depend upon them for survival. According to the study Endangered Ecosystems: A Status Report on America’s Vanishing Habitat and Wildlife, Florida contains ecosystems at the most risk. There are no other Everglades; it behooves us to not only protect what’s left, but to return what we’ve so rudely taken.

Tricolored Heron (Adult) in the Florida Wetlands

Tricolored Heron (Adult), Nesting in the Florida Wetlands

Tricolored Heron (Adult), Fishing in the Florida Wetlands

Tricolored Herons: The Young Ones

This guy actually brings to mind Rick from the oh-so-excellent The Young Ones….

The Tricolored Heron (Egretta tricolor) was formerly known as the Louisiana Heron, as it was one of the most abundant herons found in the Deep South. It’s a medium-sized and slender heron that lives in the southeastern United States (but as far north as coastal New Jersey), Central America, and the Caribbean. Standing approximately 22 inches tall on long yellow legs, this heron’s wingspan reaches 3 feet. Beautiful slate blue feathers cover most of its body, save a white-striped chest and belly, and a rust-colored neck. The eyes of the juveniles are a yellowish-white, turning brown with pink inner margins as they age. Males and females of the species look alike. During courtship, these already beautifully colored herons become even more vibrant: the eyes turn a lovely and striking scarlet, and their otherwise long, pointed yellow bill turns blue. Breeding plumage involves filamentous plumes on the head and neck, and buff plumes on the back.

This seemingly peeved Tricolored (such a face, sweetheart!) — despite my distance with a telephoto — is a juvenile, as is the second heron.

Their natural habitats are swamps, marshes, bayous, lagoons, and coastal ponds. It’s a common sight in our wetlands to see them nesting in colonies, in the trees and shrubs, with other herons. The male selects the nesting location, and builds the nest with the female. As with other herons, both parents care for the chicks, feeding them regurgitated food. Tricoloreds stalk their prey in the shallow waters, looking for fish, crustaceans, reptiles, and insects. They’ve been known to delve into the deeper waters however, with only their bodies visible.

These herons are the favorites of many in our area, and are a great joy to watch…. But like so many other species, despite their non-threatened status, they’re losing their natural habitats. It’s truly our duty to protect and preserve these complex ecosystems not just for the flora and fauna they are home to, but for ourselves.

Each species is a masterpiece, a creation assembled with extreme care and genius. —Edward O. Wilson (Biologist, researcher, theorist, naturalist, and author)

Tricolored, or Louisiana Heron (Juvenile) in the Florida Wetlands

Tricolored, or Louisiana Heron (Juvenile) in the Florida Wetlands

The Great Blues, and Another Baby

Great Blue Heron at Dusk, Arthur R. Marshall Loxahatchee Wildlife Refuge

Nesting season continues at our protected wetlands, and the ever-graceful and regal Great Blue Herons consistently fuel the attentions of nature lovers and photographers. Now that Florida’s “Season” has ended however, the more timid (*me*) can enjoy these creatures. I haven’t written much on them, so here’s a bit of general info on the species.

Description & Habitat

Great Blues — also known Blue Cranes, California or Florida Herons, Espiritu Santo Herons, San Lucas Herons, and Treganza’s Herons — can be found in North and Central America, as well as in the West Indies and the Galápagos. They’re the largest of the herons in North America, and globally their size is surpassed only by the Goliath Heron and the White-bellied Heron. At 4 feet tall, and with a wingspan of 7 feet, they’re a stunning sight in our swamps and wetlands, as they stalk the shallow waters with long and deliberate steps, and fly overhead with slow and strong wing beats. In flight, they tuck in their necks, and their long legs trail behind. Save for migratory and nesting periods, Great Blues hunt and travel alone. They’re typically found near the shores of open water and in wetland environments, in both saltwater and freshwater habitats — including marshes, rivers, lakes, bays, lagoons, coasts, shores, and ponds. Like many other wading birds, Great Blues are primarily active at dawn or dusk, when fishing’s at its best. To observe them standing stock still, scanning and stalking the waters and surrounding vegetation for prey, is mesmerizing. Once they spot a fish, they strike with lightning-fast precision to grab or stab it — but they’ll also eat frogs, shrimp, crabs, insects, reptiles, rodents, and small birds.

Nesting & Breeding

Great Blue Heron in Flight

Great Blues are monogamous, and will remain with their mate for the breeding season. Usually only one brood a year is produced; however, a Great Blue may raise another, if the original clutch is destroyed or abandoned. They breed in groups, or colonies, alongside other herons (and egrets). These breeding colonies, or rookeries, are located in all types of trees that can support their nests — in our area, tree islands are the preferred structure for the Great Blues’ rookeries. Tall tree branches or shrubs may also suffice — as long as the nest sits near water or wetlands. They build their nests out of sticks and twigs, and line them with a softer material, such as plants, feathers, or down.

Great Blue Heron Pair at Their Nest

Great Blues will try to nest in the same spot each year, using the old nest. Ours definitely do, and defend their nests aggressively against each other as well as against predators. Females lay 2-7 pale blue eggs, which are incubated for about 25-30 days. The young hatch over several days, and the Great Blue parents share the responsibility of feeding the young at the nest, by hunting on a full-time schedule and regurgitating the food. The battle for food is brutal among the chicks; the first to hatch is more experienced in food handling, and consequently grows more quickly than the younger hatchlings. Such aggression in the interaction with the sibling chicks (as well as the discrepancy in size) can be seen at the wetland rookeries, where it’s hard not to root for the younger, weaker chicks that are consistently beaten after fierce battles for food. The young Great Blues leave the nest at 2-3 months (60-90 days).

Great Blue Heron Pair at Their Nest

See The Nesting Great Blues for images of earlier nests and the growing young….

Threats

The average lifespan for a Great Blue in the wild is 15 years — although a maximum lifespan of 24.5 years has been recorded. Sadly, nearly 70% of Great Blues die before reaching the age of one year; contributing factors include repeated human disturbance to their nesting sites, resulting in abandonment of eggs or chicks. Other factors of premature death include accidents, harsh weather conditions, illegal hunting, and predation of eggs, nestlings and adults.

But as mentioned, we’re fortunate that Palm Beach County has created and preserved a marsh and wetland ecosystem for these and so many more animals in Wakodahatchee(Seminole for “created waters”) and Green Cay — so on to the new baby!

Oddly, there was only one hatchling at this Great Blue’s nest. I missed this event, but there were several hours of the mother Great Blue fiercely defending her newborn from a Turkey Vulture.

Great Blue Heron Mother and Her Baby at the Nest

…And the same growing baby, one week later!

Great Blue Heron Mother and Her Growing Baby at the Nest

They grow quickly — but fortunately, the above little one won’t have to fight for food like these nearby juveniles, waiting patiently at their nest for the next meal…

Great Blue Heron Juveniles Waiting Patiently at the Nest

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