Thursday, August 20, 2015

Great Trinity Forest Wading Birds


Birds of the Great Trinity Forest hunting quarry near Joppa at dawn
The Trinity River's flooding events bring an immense volume of water and aquatic life into over banked areas of the floodplain. The primal urge of many aquatic species is to migrate from the permanent river channel and into temporary ephemeral water bodies. This new landscape affords bountiful forage and prime breeding habitat especially during spring and summer months.

Eagle Scouts Richard Grayson and Bill Holston talk to local Joppa fisherman Edward about his luck catching catfish
Many Trinity River fish species successfully spawn and feed in shallow waters. The majority of the populations move back into the permanent river channel as the water recedes. Those that don't heed the warnings of falling waters face an uncertain future. The hot summer Texas sun eventually evaporates the water down to nothing.

Flock of White Ibis with a second year immature coming into land near Cell G Lower Chain of Wetlands
There is a sweet spot for watching bird life during these ephemeral ponding events when the recipe of shallow water and concentrated aquatic species converge to create a feeding frenzy few people see.
The dedicated fishermen of Joppa
Game planning where the prey species of birds will be when the water recedes starts during the highest inundations of flood waters. Places that the local fishermen of Joppa call their "honey hole" hot spots. Places where the fish are numerous and come easy. The stories of catfish hauls that could fill a five gallon bucket in mere minutes permeate this area. Stories that have not been told since the last great over banking and flooding events of the early 1990s.

The hot fishing places during flooding turn into premier birding spots down the road once the sun works the ponds over for a few weeks.
Willie with a crawfish he caught by hand using kite string and a chicken liver
White Ibis with crawfish
It's the Dallas no one really sees or knows about, if you are into the human experience of such places. For the residents, it is in their blood and courses through their DNA as who they are. It is their first time to fish many of these places on land that was once a private golf course turned flood protection lake system. The private country club always kept the local residents away. Behind high fences. Behind the barriers of admission fees. Behind the price of discrimination. Now the locals claim the wetland cells as their own. Their park. In their neighborhood.


 When the rains from the heavens stop and the skies clear. When the flood waters began to fall, the wading bird action can begin.

Hack Guide To Birding The Lower Chain of Wetlands
The dried, silted and scoured lower chain of wetlands north of Loop 12 in Dallas. Master Naturalists Bill Holston and Richard Grayson begin the walk north from the old Sleepy Hollow Country Club lot.

























Early bird gets the worm when it comes to seeing wildlife during the summer months along the Trinity. Before the crack of dawn, getting down into the woods or high grasses before the birds stir is really the only chance to get up close and personal.












Like the world of real estate, location is everything. Timing and some keen observation skills fill the gaps on where to see birds.

The focus is Wetland Cell G and the recently flooded wooded and high grass areas to the immediate west of Cell G in an area known as Honey Springs by locals. At right, an area bounded loosely by about 75 acres inside the red circle, serves as a prescribed path beginning at the old Sleepy Hollow Country Club parking lot.

Crested Caracara hovering over the Lower Chain of Wetlands enjoying a rising thermal

Little Blue Heron catching a crawfish
Feeding is a wading bird’s most spontaneous activity and occurs throughout the Great Trinity Forest's lakes, ponds, woodland pools, swamps, rivers, sloughs, creeks, canals, and ditches. Breeding and nesting most often occur near these carefully selected swamp or lake habitats. Roosting sites employ the tallest canopy tree layers available along rivers and streams as well as within and along the edges of swamps and lakes.


As a group, the wading birds are primarily carnivorous and eat just about anything that does not eat them first. Prey items range from insects, spiders, and other invertebrates, including substantial amounts of shellfish, amphibians like frogs, tadpoles, salamanders, and skinks. Reptiles such as lizards and snakes, small bird species and nestling birds, and small mammals such as mice are in the wheel house of their diet.
Yellow Crowned Night Heron
The herons and egrets (family Ardeidae) are true hunters, foraging via a combination of deliberate stalking interspersed by long periods of stillness, simply waiting for prey to reveal its location, at which time the prey is apprehended with lightning speed.

This is when their long, graceful, “S” shaped necks come into play. In a classic case of form following function, the cervical (neck) vertebrae of the ardeids have evolved into a long, snake-like coil configuration, allowing for an incredible store of coiled flex and extension.
Great Egret snatching a shad from the surface of a pond adjacent to the Lower Chain of Wetlands Cell G
 About midway through the “S” of the neck, the esophagus of herons and egrets actually detours behind the vertebral column, allowing for a completely unhindered forward thrust of the neck, head, and bill when the moment of truth arrives.
Little Blue Heron with a Largemouth Bass at the Lower Chain of Wetlands
Reddish Egret, Great Trinity Forest, 2015
Lastly, the business end of the ardeid foraging machine – the bill – is long, strong, and relatively heavy, allowing for greater leverage in grasping and holding all types of prey, from “jittering” crawfish to slick, wildly thrashing bass. Not all ardeids are so tightly bound to the stealthy foraging philosophy.

In fact, the Reddish Egret possesses one of the most aggressive foraging modes of any North American bird species. The Reddish Egret at left was in the Great Trinity Forest summer 2015. Listed as a threatened bird by the State of Texas, it represents a special sighting for Dallas County. As far as endangered birds go, only the Whooping Crane, Wood Stork, White Faced Ibis and Reddish Egret are on the list.  The Whooping Crane is the only bird not documented in the Great Trinity Forest. Radio data and GPS tracking suggests a group of Louisiana Whooping Cranes briefly visited the forest in the summer of 2013.
https://tpwd.texas.gov/huntwild/wild/wildlife_diversity/nongame/listed-species/birds.phtml

Egrets and Ibises in the early morning summer light
Wading birds forage many different ways and have different adaptations that allow them to successfully find food. While the light-colored bodies of birds such as great and snowy egrets may stand out and make the birds very noticeable from a human perspective, their white bodies actually blend in with the sky when viewed from below, or from a prey perspective. This allows them to stand in the water without being noticed from below while waiting for prey to come near enough to be caught.

White Ibis
Second year immature White Ibis in foreground with adult White Ibis in background

 The White Ibis (Eudocimus albus). Highly sociable in all seasons, the White Ibis roost and feed in flocks. White Ibises are often seen flying in lines or V-formations, with several quick flaps followed by a short glide. When groups wade through shallows, probing with their long bills, other wading birds such as egrets may follow them to catch prey stirred up by the ibises.

Until recently the White Ibis was an uncommon sight here in Dallas. From late May through September they are now easy to spot along the wetland cells and in the shallow evaporating lakes that dot the Great Trinity Forest.

At right, a White Ibis tackles an enormous crawfish in the Lower Chain of Wetlands, summer 2015. Many of the crawfish(crayfish) have grown to enormous size due to ideal habitat conditions.


Master Naturalists Bill Holston and Richard Grayson on a dirt road next to Cell G
Moving away from the shallow drying pools and to the north, one is afforded more distant vistas of far treelines that form the mouth of White Rock Creek at the Trinity River. Some 3/4 of a mile distant in the photo above, it can often provide raptor sightings, the occasional coyote or bobcat sighting too.

18 wheeled dump trucks kick up dust along the Lower Chain of Wetlands August 2015
The Lower Chain of Wetlands undergoes constant changes in landscape. From flooding to construction, there are few times of rest for the place. As soon as the silt became dry enough to drive upon, Cell G's quiet little dirt road was turned into an excavation route for soils headed towards a new golf course across the river. Often the logic of such activities cannot be comprehended and need remedy by the TCEQ and EPA for air quality violations.
Great Blue Herons intermixed with Great Egrets
It is away from the construction dust where many of the larger wading birds find solace. Many of these birds, the Great Blue Herons especially, are juveniles. Young birds who recently fledged nests in a rookery in the Lower Chain of Wetlands. Their nesting grounds would have been degraded and uninhabitable this spring by clear cutting of forest along the river. Their success in fledging nests was only possible due to the Trinity River flooding that kept bulldozers away.

Great Blue Heron
Great Blue Heron in a pond at the Lower Chain of Wetlands near Honey Springs, summer 2015
Great Blue Herons appear blue-gray from a distance, with a wide black stripe over the eye. In flight, the upper side of the wing is two-toned: pale on the forewing and darker on the flight feathers. Seen above, the Great Blue Heron is a multi-toned and colorful bird with shades of red, brown and orange. This stately heron with its subtle blue-gray plumage often stands motionless as it scans for prey or wades belly deep with long, deliberate steps. They may move slowly, but Great Blue Herons can strike like lightning to grab a fish or snap up a snake.


Night Herons
Juvenile Black Crowned Night Heron standing among a flock of feeding White Ibis
There are two types of night-herons in North America. The Black-crowned Night-Heron is the most abundant and widespread and habitat covers most of the United States.
A pair of Black crowned night herons in a dead willow next to the old Sleepy Hollow Country Club parking lot

The Black-Crowned Night Heron is a small, wading bird that reaches lengths of about 2 feet with a wingspan of up to 4 feet. They have black plumage on top of the head and back with grayish-blue wings. The underside of the neck and belly usually a brilliant white. It also has a thick black bill and short yellow legs.

The night herons have a shorter neck than other herons assisting them in their stocky appearance when compared to other wading birds.

Two long white slender plumes extend from the back of the head while in breeding plumage. There unique vocalization, “quock”, is often heard at or around dusk as they fly to their feeding grounds


Black crowned night heron coming in for a landing
The Yellow-crowned Night-Heron has a smaller range which covers the eastern portions of the United States. These two species of night-herons feed mainly at night. In the daytime they can be found dozing in marshes or standing on logs or rocks. These birds will also fly up into trees to avoid predators or to sleep. Like most other night-herons, these birds give loud squawks when alarmed.
Yellow crowned night heron
The Yellow-Crowned Night Heron is a migratory bird that resides here along in the Dallas Texas area during the summer months. During the winter, it can be found as far south as South America, but can be found almost anywhere along the Gulf and Atlantic Coast year round.  Unlike other night heron species, the yellow-crowned forages both late in the day and night. It forages much like other herons by wading through water waiting for its prey to come within striking distance. Also, unlike the great heron which many have seen standing motionless like a statue in many Texas waters, the yellow-crowned will stir up its quarry by wading briskly at the waters edge. With a quick dancing motion, the dagger like bill stabs its prey.  The prey of a Yellow-Crowned Night Heron normally consists of fish, frogs, grasshoppers, and occasionally snakes, but its primary diet is crustaceans (crayfish).

Snowy Egret
Snowy Egrets stalking breakfast in the early morning sun, summer 2015
The snowy egret is a wading bird that feeds primarily in the early morning and late afternoon, has perfected a wide range of foraging behaviors.  Stalking in the shallows, often in collusion with other snowy egrets, it may shuffle its yellow emblazed feet to flush out prey, which it then runs down as the meal attempts to flee.
Walking on water, a Snowy Egret nails a small shad right on the surface
Alternatively it may lie in wait, perfectly still, then ambush victims that happen to swim or drift past.  It may hunt by flying just above the water, its yellow feet almost skimming the surface, then dropping suddenly, like a demon from the sky, on unsuspecting prey.

As its name implies, the Snowy Egret is all white. It has a long thin black bill, grey to yellow at its base during the nonbreeding season. The lores and irises are yellow. The long, thin legs are black with contrasting yellow feet, sometimes with yellow green extending up the back of the lower legs.

Snowy Egret with a fish
Like the meandering path of the river itself, the wayward motion of wading birds across the floodplain makes for an interesting study. The inevitable departure of flood waters adds another dimension to a fascinating slice of Dallas few will ever see. The connections between animals, water and the land are not studied with any scientific method by anyone here.

Many incorrectly see the land down here as a durable asset. When in fact it is fragile, rare and disappears as fast as the setting sun.



3 comments:

  1. Dallas must be a sight from sent from heaven on this time of the year. Its probably hot around the summer time. And hopefully cold/or at least colder than the other time of the year.

    ReplyDelete
  2. If this was in our place, I wouldn't see anything like this. I think Dallas trails are pretty this much amazing.

    ReplyDelete