Birds of Oneida Lake - Great Blue Heron
by Robert Gang

Early in April, I like to put out a few sections of my dock and at dusk, try the bullhead fishing in front of my house.  I seldom catch more than one or two because the lake bottom there consists mostly of small stones and cobbles and is poor for bullheads. There is, however, a certain amount of satisfaction to be gained from fishing off of one's doorstep.  Besides, fishing at this time provides me with the chance of a visit from a far better fisherman--the Great Blue Heron.

There may not be many bullheads in front of my house, but there are a lot of minnows and crayfish.  Usually not very long after dusk, a Great Blue Heron will come along out of the gathering darkness, and by braking and rapidly flapping its wings, make an awkward landing in the shallow water by gingerly dropping down on its feet.  If I'm lucky, he lands close by and I get to observe him minutely.  The Heron will slowly walk a short distance taking silent steps, keeping a keen lookout for the silver reflection from the moonlight of a school of minnows.  When in close proximity to the school, he'll stand stiff-legged and motionless.  Sometimes he will rake the bottom with a leg to flush his prey, or if a minnow swims into range, he'll slowly stretch his long neck.  Then, like a rocket, his head will dart to the water, returning with a fish.  Smaller minnows are caught lengthwise; larger fish are sometimes speared with the Heron's bill.  Either way, the fish is flipped into position as he straightens his neck and swallowed whole, head first.

 

Perhaps because of the activity of our four children, we seldom see the Great Blue Heron during the daytime.  Maybe they have better fishing spots during the day.  Whatever the reason, they do frequent our area at dusk and at dawn.  Great Blue Herons are very shy, and will seldom let anyone get very close.  If disturbed, the Heron will emit a low pitched "gronk" in alarm, sounding and looking much like how I would imagine a Pterodactyl to have appeared and behaved.

The Great Blue Heron is one of our most easily identifiable birds.  This species of Heron stands about four feet tall, with a wing span of about six feet.  It has a long neck and long legs with a slender body.  Both sexes are very similar in appearance, the major difference being the male's slightly larger size.  Its primary color is blue-gray, with a white crown and throat.  It has a four-inch long bill with a black patch at the base.  Black eyebrows accentuate yellow eyes, and above the head is a long slender black plume.  When in flight, it has slow lumbering wingbeats.  Legs extend stiffly behind, with its neck folded in an "S" curve back above its shoulders.

Great Blue Herons nest in colonies called heronries, or rookeries, which consist of any number from a few to hundreds of pairs.  They migrate individually in the spring, usually one of the first species to arrive in this area.  The males arrive a few days before the females.  These heronries consist of many large nests that are placed high in mature hardwood trees in swamps or other low lying areas.  There can be dozens of nests in the same tree.  The nests are large, loose, bulky affairs of sticks and twigs.  These nests can grow into platforms up to four feet across, as the Herons will re-nest on the same pile as the years go by.  The immediate area of these heronries is said to be unpleasant because of the stench from the large volume of excrement from the concentrated numbers of birds.  This "whitewashing" from above will eventually kill the tree.

The males will pick and defend the best nest site they can find.  Courtship displays often involve large groups in a circle.  The males will fight among themselves, pecking at each other with their beaks while the females look on.  Eventually the females will pick a mate, based more on the qualities of the nest site than of the male himself.  The male then starts bringing nest materials to the nest site, where the female waits for him.  She will closely inspect and utilize some of these materials, which range from moss and pine needles to large sticks up to half an inch in diameter.  Eventually, she will build a nest topped with a shallow depression, and lined with grass, moss and other fine, soft materials.

Usually by May or early June, three to four greenish blue eggs are laid, which need 28 days of incubation.  Both sexes handle the incubation chores.  These eggs require constant attention, as they have to be turned every two hours to prevent the embryos from getting cold.

When the nestlings hatch, the gray downy chicks have trouble regulating their temperature, and need to be brooded by the parents for about 12 days to help them keep warm.  These chicks also need to be constantly fed, which the parents do by regurgitating partially digested food. 

The nestlings stimulate the adults to do this by nudging and tugging on their beaks.  Later on--as the young grow older--small fish, crustaceans, frogs, small rodents and aquatic insects will be offered.  The adults make no effort to feed any individual young bird, so each feeding results in a free-for-all, with the runt often going hungry if the fishing is poor.

 

Photo provided by margie Hastings

After four or five weeks, the nestlings will get ready to fly, and practice by holding onto a perch and vigorously flapping their wings.  Eventually they will make their hazardous first flight.  If this flight results in a poor landing in a lower branch where the young Heron becomes entangled or falls over, the bird can die.  Being such a large bird, the weak youngsters have trouble righting themselves by forcing their way upright through the branches of the tree.  If the nestling ends up on the ground, it will be fed by its parents, but it may fall victim to a predator before it is able to fly.  Often, the only way for the young bird to get off the ground is to climb up to a perch where it can successfully take off.

Today, Great Blue Herons are quite common throughout New York State.  There was a time, however, when their numbers were dangerously low.  Around the turn of the Century and before, Great Blue Herons were rigorously persecuted by man.  Fishermen felt that they were depleting game fish populations.  Others sought Great Blue Herons for their plumage.  Still others found the Great Blue Heron, lumbering along in flight, much too easy a target to let go by.

While the Great Blue Heron will eat some game fish, it is overall highly beneficial to man and worthy of every protection.  Most of the minnows and fish eaten are non-game species.  The aquatic insects that it feeds on are known to eat the eggs of game fish, so the Great Blue Heron's pluses far outweigh its minuses.

 

Though the Great Blue Heron was once an endangered species, Oneida Lake has always been a stronghold for this magnificent bird.  In 1910, E. H. Eaton observed that "Breeding colonies formerly existed in every large swamp in the state, but constant persecution and the destruction of the large trees which furnished their nesting sites have greatly reduced the number of heronries.  The largest remaining colony, near Constantia, Oswego County, still had about 500 pairs of Great Blue Herons early in this century.  At that time other colonies were located in the Tonawanda Swamp, Orleans County; the Clyde River, Wayne County; and several Adirondack localities, but most others had passed into history within the last two decades."

In 1932, D. Stoner wrote that the Great Blue Heron was "one of the ever present and most conspicuous birds of the Oneida Lake region. . . . The famous nesting colony in the Constantia swamp and also the one in the Big Bay swamp continue to exist, but in 
considerably reduced numbers as compared with their status 25 years ago."  During the summer of 1928, Dr. Stoner reported seeing, on numerous occasions, from 12 to 19 Great Blue Herons around Shaw Point, Potter Bay, Wantry Island, Long Island and other areas of the lake.

Today, J. M. C. Peterson writes, in The Atlas of Breeding Birds of New York State, that "The Great Blue Heron has clearly recovered from the killing and habitat loss that occurred at the turn of the Century."  The Atlas shows that the Great Blue Heron is "a local but fairly commmon species throughout most of Upstate New York during the breeding season."

While perhaps not as abundant as in 1910 or 1928, there are numerous Great Blue Herons using the Oneida Lake region today.  I have sighted several at a time along the shores of Frenchman's Island, Long Island and at Lower South Bay while out boating.  They may still be as numerous as they were in 1928 along the north shore, though I suspect not.  On the occasions when I have been there, I have seldom seen more than two or three at a time.

In addition to the reported heronries in Big Bay and Three-Mile Bay, which are undoubtedly still in use, there is a heronry in the McGary marsh by Rattlesnake Gulch in the Cicero Swamp.  Another heronry is located along the north shore of the Oneida River west of Brewerton.  As the Great Blue Heron is a shy bird with excellent senses of sight and hearing, it is best that photographers and others avoid these areas during the breeding season.  While individual visits may be inobtrusive and harmless by themselves, one never knows how many other people are visiting the area as well.  Numerous visits could cause the Herons to desert their nestlings, so please resist the urge and avoid these sites until the nesting season is over.


Reprinted (with minor modifications) from The Oneida Lake Bulletin:  Spring, 1990.