Posts tagged ‘great blue heron’

Don’t Mess with the GBH

It’s nesting time now in our protected wetlands, and a really fun time — the biggest and smallest waders are settled into their annual nests (some of them, including the Great Blue Herons, return to the same nests each year). I’m running a bit behind on the nest-building activities, always a fascinating process to watch. But in the meantime, I couldn’t resist this episode that caught me unawares the other evening. I heard a GBH’s croaking cacophony (select the last option in this list — croaking calls, wing noise — for the best example) in one of the usually quiet rookeries. He or she was obviously not very happy.

And the tantrum begins… Echoing through the wetlands

At the time, I couldn’t see the source of torment for the heron, who was probably chasing something away from a newly-created nest. The previous night, a group of GBHs was screaming in another rookery, because an alligator swam too close for comfort to their nests. I didn’t see the gator actually nab anything, but the collective croaking, screaming noise could be heard throughout the wetlands.

As it turns out, an anhinga had the gumption to impede on this heron’s space.

Flushing out the enemy anhinga

The look on the poor anhinga’s face as it’s being flushed out of the rookery is priceless…. Of course I was worried for the poor anhinga: Did he have a nest too, or was he just looking for a comfy spot for the night? Either way, I wish I wasn’t walking onto the scene so suddenly, and had some time to properly prepare for the shot, to include his appalled mug.

Respect the wingspan

And for the Great Blue Heron? Unabashed triumph.

I am queen

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