Sunday, August 26, 2012

The Historic Filter Building of White Rock Lake

The historic Filter Building at White Rock Lake, Dallas is an excellent example of the urban industrial style of the 1920’s. It was built in 1911 in response to an increased population and extended droughts in the early 1900s.

The historic filter building at White Rock Lake, Dallas
The Filter Building at White Rock Lake was built in 1911

The Filter Building was designed and built by the City Engineering Department to provide an additional chlorinated water supply for the City of Dallas, which it started supplying in 1913.

A view of the White Rock Filter Building from across the lake
A view of the Filter Building from across the lake

The Filter Building is a historic landmark and has a Texas Historical Commission medallion attached to the exterior wall of the building.

The Filter Building at White Rock Lake is a historic landmark
The Filter Building is a historic landmark

The Texas Historical Commission medallion reads:

WHITE ROCK PUMP HOUSE

In response to increased population and extended droughts in the early 1900s, this facility was built to provide an additional water supply for the City of Dallas. Designed and built in 1911 by the City Engineering Department, the Renaissance Revival structure features corbelled brick and terra cotta details. Although its use has varied, and much of its original equipment is no longer intact, it remains an important water utility structure.

Recorded Texas Historic Landmark, 1989.

A view from the side: The Filter Building at White Rock Lake, Dallas
A view from the side: The Filter Building at White Rock Lake

In 1929 the city of Dallas stopped using White Rock Lake as a source of water supply (except for a few years during the drought of the 1950s).

The Filter Building at White Rock Lake features exposed red brick walls & original iron trusses
The building features exposed red brick walls & original iron trusses

The building features exposed red brick walls, original iron trusses, and a multitude of windows overlooking White Rock Lake, and was renovated in the late 1980s.

The Filter Building has many windows overlooking White Rock Lake
The building has many windows overlooking White Rock Lake

The Filter Building is located on the southwest shore of White Rock Lake. The address is 2900 White Rock Road, and it is currently being used as the Water Operations Control Center of the Dallas Water Utilities.


Wednesday, June 13, 2012

White Rock Lake in Dallas Was Once an Ancient Sea


Did you know that White Rock Lake in Dallas, Texas was once an ancient sea?     

North America was literally divided into two landmasses by a large inland sea called the Western Interior Seaway (also called the Cretaceous Seaway and the North American Inland Sea) that existed during the Mid-to-Late Cretaceous Period.

 Western Interior Seaway - 100 million years ago

This ancient, shallow sea had abundant marine life and stretched from the Gulf of Mexico in the south and through the middle of what we now know as the United States and Canada, meeting with the Arctic Ocean to the north. This sea was 600 miles wide and over 2,000 miles long. All of Texas would have been covered by this ancient sea.

The Cretaceous period succeeded the Jurassic Period approximately 144 million years ago and lasted to approximately 65 million years ago. The word Cretaceous comes from the word for "chalk," a soft, white, porous sedimentary rock that is a form of limestone. Indeed, if you walk around White Rock Lake, you will see intermittent outcrops of white limestone, and this is how the lake got its name: White Rock Lake.

If you look carefully at these limestone outcrops, you may be lucky enough to identify crustacean shells dating back to the Cretaceous Period, such as these found at Winfrey Point.

 Shells and other items found in the limestone at Winfrey Point

The sea began to wane about 70 million years ago and the ancient sea bed gradually became exposed over time through erosion and other upheavals. This ancient sea bed is the white rock that we now see exposed around the lake, especially the area below the spillway where large tracts of limestone are clearly visible, and known locally as Austin stone.

It is during the Cretaceous Period that we find the first fossils of many insect groups, modern mammal and bird groups, and the first flowering plants (called angiosperms). Around White Rock Lake, the most common fossils to be found are organisms such as clams and oysters. Shark teeth, fish and marine reptile remains have also been found at the lake on rare occasions.

 A closer view of the shells

At the end of the Cretaceous Period, 65 million years ago, an asteroid hit Earth in the Yucatan Peninsula, Mexico. This event resulted is what we now call the Chicxulub impact crater, buried under the Yucatan Peninsula. The crater is more than 110 miles in diameter.

It has been estimated that half of the world's species went extinct at about this time (including the Dinasaurs), either from the impact of the asteroid or other reasons, such as environmental changes. Whatever the cause of this extinction, this asteroid event marks the end of the Cretaceous Period.

The next time you take a walk around White Rock Lake, keep your eyes peeled. That stone you are kicking may just turn out to be a 60 million-year-old fossil.



Tuesday, June 12, 2012

Birds in flight: The Ring-billed Gulls of White Rock Lake

If you visited White Rock Lake, Dallas in winter, you will no doubt have witnessed the raucous behavior of the ring-billed gulls (Larus delawarensis) in and around Sunset Bay. These noisy, opportunistic birds make their presence known and are often seen taking food from less fortunate waterfowl.

All of the "birds in flight" images below were taken at Sunset Bay, White Rock Lake. 

Ring-billed gull at Sunset Bay, White Rock Lake, Dallas, Texas
A soaring ring-billed gull on the lookout for some food

If you visit White Rock Lake now you will notice that Sunset Bay is a lot quieter. The gulls have gone. Ring-billed gulls are migratory and some of them spend their winters at White Rock Lake in east Dallas, Texas.

Larus delawarensis in flight over Sunset Bay, White Rock Lake, Dallas, TX
 Ring-billed gulls migrate and spend the winter at White Rock Lake

Ring-billed gulls are easily identified from the black ring near the tip of its yellow, short bill, as well as its white head and gray wings. Its legs and feet are yellow. The eyes are yellow with red rims.

Birds in flight over Sunset Bay, White Rock Lake, Dallas, Texas
 Ring-billed gulls they were hunted for their plumage
 
Ring-billed gulls breed near lakes, rivers or the coast in Canada and the northern United States.

Larus delawarensis in flight over Sunset Bay, White Rock Lake, Dallas, TX
Larus delawarensis in flight over Sunset Bay

The gulls are pretty birds and in the late 19th century, they were hunted for their plumage.

Ring-billed gulls flying across Sunset Bay, White Rock Lake, Dallas, Texas
Ring-billed gulls flying across Sunset Bay

Ring-billed gulls nest from mid-May through June and they return to their nesting site well before it is time to nest in order to establish its territory.

A Ring-billed gull in flight flying across Sunset Bay, White Rock Lake, Dallas, Texas
The black ring at the tip of the gull's beak is clearly visible

Ring-billed gulls takes three years to reach its breeding plumage.

Ring-billed gulls foraging for food at Sunset Bay, White Rock Lake, Dallas, Texas
Ring-billed gulls foraging for food at Sunset Bay

Texas is known for its clear, blue skies in winter.

A ring-billed gull - Larus delawarensis - hovering over Sunset Bay at White Rock Lake, Dallas, TX
The gulls nest from mid-May through June

Although the gulls often visit Sunset Bay to forage for food, they love to spend a lot of their day sitting in the shallow water below the spillway, waiting for morsels that have washed over the spillway wall.

Ring-billed gulls in flight over Sunset Bay, White Rock Lake, Dallas, Texas
Ring-billed gulls in flight

Ring-billed gulls nest from mid-May through June and they return to their nesting site well before it is time to nest in order to establish its territory.

And that’s why Sunset Bay is a lot quieter this time of year.

Sunday, June 10, 2012

The Beautiful Buttonbush Begin to Bloom at White Rock Lake

The Buttonbush (Cephalanthus occidentalis) have started flowering at White Rock Lake in east Dallas. And what a spectacular sight it is! These perfect, beautiful Buttonbush flowers are clustered in white "balls," about the size of a ping-pong ball, and resemble a pincushion.

Buttonbush flowers at White Rock Lake, Dallas, Texas
A Buttonbush cluster of stunning white flowers

Cephalanthus occidentalis is part of the coffee family, Rubiaceae, and is native to eastern and southern North America. The common names for this plant include Buttonbush, Common Buttonbush, Button-willow and Honey-bells (probably because of their fragrance).

Bees and butterflies visit the Buttonbush flowers for nectar, and they assist the plant with pollination. 

Cephalanthus occidentalis at White Rock Lake, Dallas, TX
 Bees and butterflies visit the Buttonbush flowers for nectar

The Buttonbush is a semi-aquatic shrub that grows in water or moist soil. The plants in the images below were growing along the bank of the lake. Because of their love of water, Buttonbush plants are often seen in marsh areas, and bordering streams, ponds, and lakes. 

Crab spiders (see image below) blend in well with the white Buttonbush flowers, and the spiders love laying in wait for an unsuspecting insect to drop by. 

Crab Spider visiting Buttonbush flowers at White Rock Lake, Dallas, Texas
 Crab spider waiting for the insect to get closer
They also grow in w
Buttonbush blooms from June to August. In the image below, the flowers have begun to die off. When the flowers disappear, they leave brown, ball-like fruits filled with seeds. The seeds are eaten by ducks (especially loved by Mallards), geese, and shorebirds, so the waterfowl of White Rock Lake are in for a treat. The fruits stay on the plant from September to October.

Bee visiting Cephalanthus occidentalis at White Rock Lake, Dallas, TX
 When the Buttonbush flowers die, seed balls will form





Thursday, June 7, 2012

Giant Spider Webs at White Rock Lake, Dallas

There are several giant spider webs around White Rock Lake that envelop portions of trees and shrubs. Presumably, these webs are the combined work of many spiders. The images below were taken along the banks of the lake. 

Whilst these spider webs are unsightly, they are nowhere near as big as the phenomenon that made world-wide news in the summer of 2007 when Lake Tawakoni State Park, about 50 miles east of Dallas, had huge trees completely enveloped in spider webs.

Giant spider webs envelop portions of trees at White Rock Lake

The giant spider webs of Lake Tawakoni were apparently the work of the Guatemalan long-jawed spider (Tetragantha guatemalensis ) that is found from Canada to Panama, and even the islands of the Caribbean. These spiders do their work at dawn and dusk.

In the image above and below, the web is so thick that it presumably prevents sunlight from getting to the leaves for photosynthesis which is why the leaves are dying.

The webs prevent sunlight from getting to the leaves of the plants

The dead leaves below are no longer covered by a spider web. The web may have been washed off by the heavy rains that we had in the past twenty-four hours, or the spiders may have removed the web. Sometimes spiders tear down their web in the morning (although it is unlikely in this case). They roll up the silk into a ball and eat it. The web provides protein for the next time the spiders have to make a web.

The leaves quickly die off when covered by the spider webs

Let’s hope this phenomenon does not escalate to the extent that it did at Lake Tawakoni.



Sunday, May 27, 2012

The Feral Pigeons of White Rock Lake, Dallas


Most cities around the world have one thing in common: feral pigeons (Columba livia), also known as rock doves. White Rock Lake in east Dallas is no exception. The pigeon images below were all taken at Sunset Bay at White Rock Lake.

Pigeons arrived in North America with European settlers in the 17th-century. They were brought here as domestic birds, caged and kept as a source of food.

A feral pigeon at White Rock Lake, Dallas, Texas
A pigeon at White Rock Lake

Feral pigeons are derived from wild rock doves that were domesticated in the Middle East over 6,000 years ago. Rock doves were domesticated initially as a source of food, and for religious purposes. The terms "dove" and "pigeon" are interchangeable. Most people refer to smaller species as doves.

Pigeons are regular visitors to White Rock Lake, especially Sunset Bay.
Pigeons are regular visitors to White Rock Lake, especially Sunset Bay.

Humans soon produced variants that could be used in other ways e.g. 3,000 years ago pigeons were being bred not only for the table, but for delivering messages and for racing. By the fifth century BC, Syria and Persia had widespread networks of message-carrying pigeons.


Feral pigeons are derived from wild rock doves
Feral pigeons are derived from wild rock doves

Pigeons are regular visitors to White Rock Lake, especially Sunset Bay. The image above was captured from the pier at Sunset Bay.

The average lifespan of a pigeon is 10 to 15 years. The oldest recorded pigeon was around 33 years.

Pigeongram stamps are eagerly collected for their novelty value
 Pigeongram stamps are eagerly collected for their novelty value

We have all heard of the international news service, Reuters. Guess how they started?

In 1850, Paul Julius Reuter’s fledgling news service used homing pigeons to fly the 120km between Aachen and Brussels, thereby laying the foundations for a global news agency.

Pigeons were also used to send messages from the Great Barrier Island in New Zealand (90 kilometers northeast of Auckland) to the mainland. It was referred to as a pigeongram service. The pigeon post service began between the island and Auckland in 1897, and ended when the first telegraph cable was laid between the island and the mainland in 1908.

Feral pigeons sharing a meal with a red winged blackbird at White Rock Lake, Dallas, TX
 Feral pigeons sharing a meal with a red winged blackbird
whilst a squirrel looks on

We are all so impressed by the speed, power and efficiency of the Internet. Now consider this. As part of a PR stunt in South Africa, a pigeon carried a 4GB memory stick 80 kilometers. During the time it took the pigeon to deliver the memory stick, the country’s biggest Internet service provider only managed to transfer just 4% of the data on the memory stick. That’s amazing!

Feral pigeons at Sunset Bay, White Rock Lake, Dallas, Texas
The average lifespan of a pigeon is 10 to 15 years

Homing pigeons played a vital part in both World Wars as military messengers. In World War I, pigeons proved to be an extremely reliable way of sending messages. Over 100,000 pigeons were used in the war with an incredible success rate of 95% of the messages being delivered.  

Pigeons did such extraordinary and valuable work during WW1 that the British government protected them by law: “Killing, wounding or molesting homing pigeons is punishable under the Defense of the Realm Regulations by Six Months Imprisonment or £100 Fine. The public are reminded that homing pigeons are doing valuable work for the government, and are requested to assist in the suppression of the shooting of these birds.”

During World War II, the United Kingdom used about 250,000 homing pigeons. The American Signal Pigeon Corps consisted of 3,150 soldiers and 54,000 birds. Some 90% of the messages got to their destination. 

These avian secret agents saved innumerable human lives as well. Of the 54 Dickin Medals (the highest possible decoration for valor given to animals - the animal’s VC) awarded in World War II, 32 went to pigeons!

But don’t think the use of pigeons as a means of communication is outdated. Even today, homing pigeons are used in remote areas. In fact, the Police Pigeon Service in Orissa, India, was retired only in 2002.

A pair of feral pigeons on the pier at Sunset Bay, White Rock Lake, Dallas, Texas
A pair of pigeons on the pier at Sunset Bay, White Rock Lake

Some religious groups feed pigeons for cultural reasons. For example, Sikhs feed pigeons to honor the high priest and warrior, Guru Govind Singh. Some Sikhs also believe that when they are reincarnated they will never go hungry if they have fed pigeons in their previous life. 

Christians believe that the pigeon is both a symbol of peace and of the Holy Spirit.  

In the image below, the male pigeon is going through a courtship ritual in an attempt to woo the female in the foreground. Feral pigeons mate for life.

The male pigeon is going through a courtship ritual in an attempt to woo the female at White Rock Lake
The male pigeon is going through a courtship ritual in an attempt
to woo the female

The next time you see feral pigeons, show them some respect. They are far from being a pest, and we have so much to thank them for. These beautiful creatures were a source of food for our ancestors, they kept us informed by delivering the latest news, and these brave birds helped us win both World Wars.

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Preening Mallard Duck at Sunset Bay, White Rock Lake

Ducks need to protect themselves against becoming water-logged whilst swimming, and in wet weather. They do this by keeping their feathers in top condition by preening themselves on a regular basis.This series of images of a Mallard duck preening itself was captured at Sunset Bay, White Rock Lake in east Dallas.

A Mallard hen preens herself at Sunset Bay, White Rock Lake, Dallas, Texas
A Mallard hen preens herself at Sunset Bay, White Rock Lake

Ducks bathe often to remove dirt from their feathers. Using their bills, they comb the barbs on their feathers so that the barbules and even smaller hooks called barbicelli interlock and form a protective layer to repel water.

A Mallard hen has dull, brown feathers used as camouflage
A Mallard hen has dull, brown feathers used as camouflage

The process of preening removes parasites and scales that cover newly sprouting feathers, but also involves the spreading of oil over clean feathers.

Preening removes parasites and scales that cover newly sprouting feathers
Preening removes parasites and scales that cover newly
sprouting feathers

Beneath the water-proof coat are fluffy and soft feathers that keep the duck warm.

A Mallard hen preening herself
A Mallard hen preening herself

There is a gland called the 'Preen Gland' near the duck’s tail. The duck uses this patch to roll and stroke its head over the oil.

The 'Preen Gland' is near the duck’s tail

The head is then rubbed over the body feathers to spread the oil evenly. This keeps the feathers bright and supple, and allows water to run off in droplets – hence the expression “like like water off a duck’s back.”

The process of preening involves the spreading of oil over clean feathers

And after all that hard work, it was finally time to tuck in for a quick snooze. Ducks sleep with half their brains awake and their eyes open. This enables them to see approaching predators.

Ducks sleep with half their brains awake and their eyes open

Compared to the male, the Mallard female duck (called a 'hen') has dull, brown feathers used as camouflage so that they can hide from their enemies and predators. The camouflage also helps nesting females to blend in better, and offers greater protection for the ducklings.


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Saturday, May 26, 2012

Winfrey Point: New Documentation Reveals the True Purpose of the Dallas Arboretum’s Proposed Land Grab


Please click here and listen to this music while you read this blog

This blog is about nature, specifically the environment of White Rock Lake. However, when local politicians and business combine to deliberately mislead the public, it’s difficult to remain silent when it affects nature and the heritage of generations to come. 

Stunning wildflowers at Winfrey Point, White Rock Lake, Dallas, Texas
Stunning wildflowers at Winfrey Point, White Rock Lake

You can read about the history of this ongoing saga by clicking here.

On May 9, 2012, the leadership of the Dallas Arboretum issued a press release that was phrased in such a manner as to make them look like the good guys. It stated that they had requested the local officials not to proceed with plans to mow Winfrey Point, a plan that the Arboretum leadership had hatched in the first place. The wording of this press release was intriguing:

“… any plans to temporarily park at Winfrey Point have resulted in serious misunderstandings …” Any plans? Why did they not simply say “the plans”? Why could the leadership of the Arboretum not have the courage to admit that they had made such plans?

From their last sentence in their press release, it is obvious that the current management of the Arboretum intends to continue with their plans for Winfrey Point. The last sentence reads: “It is our pledge to endeavor to make such planning transparent.”

And why could the leadership of the Arboretum not simply say: “It is our pledge to make such planning transparent”? Why did they include the word “endeavor”?

It is innuendo and legal-speak such as this that makes one question the bona fides of the Arboretum leadership.

The press release can be found here.  

The Dallas Arboretum posted a comment on their website this week, stating that it was a misconception that they planned to build a parking garage at Winfrey Point. The comment read: "The concept for a parking garage at Winfrey Point was never shown to the Arboretum, nor to the Park Board or city Council members ..” 

Really? 

The latest documentation uncovered by researcher, Hal Barker, has categorically revealed that the idea to turn Winfrey Point into a parking lot was first mooted by Mary Brinegar a couple of years ago. In a detailed email to Paul Dyer, Director Dallas Park and Recreation Department, dated August 8, 2010, Brinegar spells out her vision for Winfrey Point in detail. You can read her email by clicking here.

This was followed up by a presentation to Paul Dyer.

In a document prepared by the Arboretum entitled “Presentation to Paul Dyer and Willis Winters On Winfrey Point Use For The Dallas Arboretum”, it was revealed that one of the proposals (Proposal 5) presented by the Arboretum was to develop “the property into botanical gardens with three stories of parking underneath, accommodating over 4000cars. The model is Millennium Park in Chicago with most of the gardens above the parking facility. It allows those who are members to stop in to the garden for early breakfast or lunch while riding or walking around the lake and at the beginning or end of their ride. Winfrey Point is rebuilt in a circular structure with observation decks giving visitors the ability to see the developed gardens and the downtown vistas.”

So let’s understand this. 
  1. The Arboretum wants Winfrey Point - prime real estate -  for nothing, depriving Dallasites free use of this spectacular location. 
  2. The rate payers of Dallas foot the bill for much of the related expense.         
  3.  If Dallasites wish to enjoy Winfrey Point in future they will have to pay for the privilege.  
  4. Dallasites will be further deprived of their natural heritage. In its place will be beautifully contrived gardens and other facilities generating more revenue for the Arboretum.
So exactly how do the inhabitants of Dallas benefit from all of this? This smacks of a land grab - the Arboretum wins, Dallasites lose!

It would appear that the leadership of the Dallas Arboretum has lost their focus. They have become property developers at the expense of conserving nature.

As Gregory Bateson once said, "The major problems in the world are the result of the difference between how nature works and the way people think." Unfortunately, people are often driven by greed, and it is difficult to arrive at a different conclusion given the facts at our disposal.

After all the subterfuge surrounding Winfrey Point, maybe it’s time for heads to roll. 

And this is enough to make anyone gag. Mary Brinegar, the President and Chief Executive Officer of the Dallas Arboretum and Botanical Garden, signs off her emails with the following slogan: “Let Nature Nurture You.”

Seriously?

Based on the manner in which Brinegar has handled herself, we’re beginning to question whether she cares about nature at all. We now know that turning Winfrey Point into a parking lot was her idea in the first place, despite denials that she had no knowledge of what was going on.

To be precise, what Brinegar is advocating is to take a natural environment, a scarce resource, and turn it into a parking lot and other facilities that would generate revenue for the Arboretum. This is crass to say the least.

We have always supported the Dallas Arboretum. It is a wonderful place to get lost for a few hours. It saddens us that the leadership of the Arboretum would resort to these tactics in order to improve their bottom line. 

The latest documents discovered by Hal Barker leave a bad taste in our mouths, and reminds us of Mao Zedong’s slogan: "Man must conquer Nature." But one needs to heed the warning of legendary author, Fritz Schumacher, who once wrote, "man talks of a battle with Nature, forgetting that if he won the battle, he would find himself on the losing side."

Of course the Arboretum wants Winfrey Point. The land will add considerably to the asset value of the Dallas Arboretum. But Winfrey Point is more than an exceptional location with stunning views of the city. It contains several acres of protected Blackland Prairie grasses, it is covered in beautiful wildflowers, it is home to rare birds and many animals, and it supports all kinds of insect life, including spectacular butterflies.

A Monarch butterfly nectaring on a Texas Thistle at Winfrey Point, White Rock Lake, Dallas, TX
A Monarch butterfly nectaring on a Texas Thistle at Winfrey Point

We doubt that the remake of the soap series Dallas could have a better storyline than this saga. Clearly, the battle to Save Winfrey Point is not over.

It would be appropriate to give the final word to a great Texan, President Lyndon B. Johnson, who upon signing the Wilderness Act, 1964, stated: “If future generations are to remember us with gratitude rather than contempt, we must leave them more than the miracles of technology. We must leave them a glimpse of the world as it was in the beginning, not just after we got through with it."

Wise words, and all the more reason to Save Winfrey Point.