Posts Tagged ‘little blue heron’

The First Ever Ornithological Expedition to the Okefenokee Swamp in 1912

February 6, 2016

In 1912 an expedition composed of 4 Cornell University professors, 2 graduate assistants, the principle of Ithaca High School, 2 Georgia state entomologists, and 4 local guides conducted an ornithological survey of the Okefenokee Swamp.  The expedition lasted from May 6th-July 13th.  They found 75 species of birds, and 19 species were added to their list based on descriptions of the local guides who were considered reliable sources.  At the time of the expedition the Okefenokee was still a vast wilderness of cypress swamps, flooded marshes, hardwood hammocks, and larger islands topped by open pine savannahs.  River bottomland forests grew along the Suwanee River.  A few families lived on the edges of the swamp and within it, but a lumber company was making inroads at the time because they were felling much of the best timber.  The expedition wrongly assumed the swamp was going to be destroyed, like so many other remnants of wilderness left in North America then.  They did not know Franklin Roosevelt would eventually make it a protected wildlife refuge.

The most abundant bird in the swamp was the red-bellied woodpecker followed closely by the crested flycatcher.  Old growth forests provide plenty of food for woodpeckers.  Bobwhite quail were abundant on the larger islands where “pine barrens” prevailed.   Prothonotory warblers were also considered abundant.  The expedition found a rookery consisting of 500 little blue heron nests with eggs.  However, they saw just a few egrets because a recent fashion craze for egret feathers on women’s hats had led to the decimation of this species.  Georgia outlawed egret hunting in 1910.

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The information for this blog entry comes from an article published in The Auk from October 1913.  I purchased this vintage scientific journal from paleopublications.com .

The red-bellied woodpecker was the most abundant bird in the Okefenokee Swamp during Frances Harper’s survey of 1912.

The crested flycatcher was the 2nd most abundant bird during his survey.

File:Everglades Little Blue Heron.jpg

Harper found an active rookery of 500 little blue heron nests in the Okefenokee during his 1912 survey.

The expedition saw 150-200 wood storks feeding in shallow water, and 1 day a flock of 40 bobolinks flew over their heads.  Carolina wrens and brown-headed nuthatches were also considered very common/abundant in the swamp.

Woodpeckers in order of abundance were; 1. red-bellied, 2. pileated, 3. red-cockaded.  Hairy, downy, and red-headed woodpeckers were present but considered uncommon.  Ivory-billed woodpeckers, extinct since ~1945, still occurred in the northwestern part of the swamp on Minne Island then.  A guide heard an ivory-billed call during the expedition, and they found some recently used nests.  Red-cockaded woodpeckers, rare and endangered today, were still common here in 1912.

Ivory-billed woodpecker and nest.  Frances Harper found ivory-billed woodpecker nests in the Okefenokee that had been in use within 3 years of his survey.  One of his guides heard the call of an ivory-billed woodpecker during the survey, but Harper did not see or hear any.

Swainson’s warbler, considered uncommon now, were reported to be “not uncommon” in the swamp during the expedition.  Chimney swifts were a common bird seen hunting for mosquitoes over the water.  Evidentally, large colonies of this bird nested in hollow cypress trees for the local guides said they did not nest in their homestead chimneys.  Other common song birds included grackles, yellow-billed cuckoos, yellow throats, pine warblers, bluebirds, tufted titmice, eastern meadowlarks, and cardinals.

Red-shouldered hawks were the most common bird of prey during the day, while barred owls dominated the night.  Turkey vultures and black vultures were both common and made quick work of skinned alligators killed by hunters.  The expedition found 15 osprey nests.  They also often enjoyed seeing the aerial acrobatics of swallow-tailed kites.

Swallow-tailed Kites

Harper saw flocks of swallow-tailed kites summersaulting above the tree line.

Wood ducks were common year round residents, but the expedition came at the wrong time of the year to see winter migrants.  However, the local guides informed them that hooded mergansers, mallards, and coots commonly wintered in the swamp.  Shy sand hill cranes were  more often heard than seen because the local people hunted the delicious birds whenever they could.  The locals also relished wood ducks.  Oddly enough, white ibises were on the local menu.  I would suppose a fish-eating bird would taste too strong.

Anhingas could be found along the Suwanee River and in some of the larger bodies of water.  One of the guides was blind in 1 eye because his pet anhinga had stabbed it with its bill.

A single loggerhead shrike was seen chasing a bluebird.  A dead bluebird impaled by a shrike was further evidence of this species.

The only species the expedition was surprised to find was the spotted sandpiper.  This bird prefers open shore type habitat, but apparently some individuals were content to forage around fallen logs adjacent to marshes.  Spotted sandpipers winter south of this region and spend summers to the north.  The birds the expedition saw were probably in the process of migrating north.

Remarkably, not a single common crow was seen in the swamp.  The crow is 1 of the most common birds in my neighborhood in Augusta, Georgia, and I always see them wherever a travel.  This demonstrates just how attached crows are to the neighborhoods of man.  They thrive in manmade environments but avoid deep wilderness.  They like to eat human agricultural waste and garbage–a rich source of food compared to what they can forage in deep wilderness.  The expedition did identify a few fish crows along the Suwannee River.

Carolina parakeets became extinct in 1914.  Sadly, this species had been gone for so long from the Okefenokee that none of the old-timers were able to give any personal accounts of their encounters with them.

Reference:

Wright, Albert; and Frances Harper

“A Biological Reconnaissance of the Okefinokee Swamp: the birds”

The Auk 30 (4) October 1913

Alligator and Heron

July 28, 2013

I once proposed that alligators saved all terrestrial life on earth.  An adult alligator establishes a territory and digs a deep hole in a marsh or swamp where water pools deeper than in the surrounding environment.  These gator holes help them survive droughts and cold fronts, and they also attract other aquatic animals such as fish, frogs, turtles, waterfowl, wading birds, raccoons and other mammals.  Following the fiery K-T impact 65 million years ago, all the dinosaurs died, but crocodiles and alligators along with the animals that sought refuge in their holes, survived.  Everything above ground literally cooked in the superheated atmosphere caused by the friction of asteroid fragments igniting oxygen.  I shared my hypothesis with a paleontologist, but she was skeptical.  She acknowledged that freshwater organisms suffered a lower extinction rate than dry land and marine species.  However, she didn’t think my hypothesis was testable.  Maybe, it’s an exaggeration to claim that alligators saved all  terrestrial life, but ecologists agree they play a crucial role in fostering wildlife populations in the modern day world.

Gator hole in the Big Cypress Preserve in Florida.

The presence of alligators is beneficial for heron and egret rookeries.  Herons and egrets nest in trees located in wetlands, particularly on islands surounded by alligator-patrolled waters.  Alligators do feed upon the occasional nestling that falls from the nest, but they also take a heavy toll on raccoons, opposums, and even bobcats that would otherwise swim to the island, climb into the rookery, and feast on the eggs or nestlings.  The herons in turn benefit the alligators because their manure fertilizes the water and this increases the abundance of fish.

Heron rookery in Venice, Florida.

alligator eating an opossum

Alligator tearing up a possum.  Possums are notorius egg-eaters.

The great blue heron (Ardea herodias) is one of the most spectacular birds of America, and they are common–I see them quite often everywhere.  Green herons (Butoroides stroutal) are supposed to be the most common heron, but I’ve only seen them a handful of times.   Great egrets (Cameroides albus) are about as common as great blue herons, though they seem more tied to larger bodies of water.  By contrast, I’ve seen great blue herons flying over busy highways and hunting in small creeks.  Little blue herons (Egretta caerulea) are supposed to be uncommon, but I’ve seen them more often than I’ve seen green herons.  I saw a yellow crowned night heron (Nyctocorax urolicea) for the first time this summer at Wakulla Springs, Florida.  It was shy and ducked into the weeds.

Great gray heron catching a European rabbit in the Netherlands.  Great blue herons also prey upon rabbits and rodents.  Audubon kept a great blue heron as a pet.  His children were upset when it swallowed their sleeping pet cat.

Yellow crowned night heron with a crayfish.

Scientists studying the Clarks Quarry fossil site near Brunswick, Georgia expressed surprise over the relative lack of abundance of alligator fossils, though the site yielded plenty of remains of aquatic birds.  Alligator fossils were found here, just not as many as one would expect.  Random chance may explain why there were fewer alligator fossils than expected, but I recently realized a possible alternative explanation.  Fossils from Clarks Quarry date to ~14,000 calender years BP.  This was before sea levels and the water table rose to  those of the present day.  Between ~30,000 BP-~7,000 BP, swamps and other wetlands where alligators thrive were rare relic habitats.  Moreover, winters were harsher and summers cooler, even in south Georgia during much of this era.  Alligator populations were at a low ebb in Georgia during the Ice Age.  Yet, they continued to live in low numbers wherever suitable habitat remained.  Alligators withstood the fire of the K-T impact and the icy dry conditions of the Pleistocene.  They are amazing survivers.