Tag Archives: great egret (Ardea alba)

Tropical haven

There is a place where spring calls forth all the magic of the tropics …

White ibises (Eudocimus albus) flying overhead (2009_05_17_019243)

A place where white ibises circle overhead …

A great egret (Ardea alba) collecting nesting material in the understory (2009_05_17_019056)

A place where great egrets lurk in the understory …

A little blue heron (Egretta caerulea) perched on a branch (2009_05_17_019428)

A place where little blue herons keep watch at eye level …

A black-crowned night-heron (Nycticorax nycticorax) perched in a tree (2009_05_17_019912)

A place where black-crowned night-herons peer back from their ligneous perches …

A snowy egret (Egretta thula) perching on a limb (2009_05_17_019767)

A place where snowy egrets observe the observers …

Close-up of a tricolored heron (a.k.a. Louisiana heron; Egretta tricolor) perched in a tree (2009_07_12_026569_n)

A place where tricolored herons remain vigilant even at rest …

A cattle egret (Bubulcus ibis) standing in a tree displaying its mating plumage (2009_05_17_019354)

A place where cattle egrets display their beauty …

It’s amazing that this tropical haven rests just a few miles north of downtown Dallas.

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Photos (taken at the University of Texas Southwestern Medical Center campus in Dallas’s hospital district):

  1. White ibises (Eudocimus albus)
  2. Great egret (Ardea alba)
  3. Little blue heron (Egretta caerulea)
  4. Black-crowned night-heron (Nycticorax nycticorax)
  5. Snowy egret (Egretta thula)
  6. Tricolored heron (a.k.a. Louisiana heron; Egretta tricolor)
  7. Cattle egret (Bubulcus ibis)

The observer effect

Close-up of a killdeer (Charadrius vociferus) giving me a little peep (2009_06_03_021880)

When I began voraciously studying physics in high school, the term “observer effect” intrigued me.  It applies to all observational methods, and although quantum mechanics was studied only in the cursory way an AP Physics class can cover any one topic, it put a whole new spin on the premise of the observer effect by showing it remained valid for all observers, even those who weren’t aware they were observing anything (e.g., an electron can cause the observer effect just as easily as a human can).

What the observer effect helps us understand is that the act of observing a phenomenon changes the state of that phenomenon, even if only a small bit.  Consider this: When you take a baby’s temperature, the thermometer must draw heat from the infant’s body in order to measure it, therefore the child’s temperature is changed by the act of observing it.

Although focused on quantum mechanics, a highly controlled study more than ten years ago proved a startling truth: “The experiment revealed that the greater the amount of ‘watching,’ the greater the observer’s influence on what actually takes place.”  But what does this have to do with the environment, saving the planet or nature in general?

Let’s start with this:

It features regularly on lists of things people want to do before they die, but swimming with stingray may not be the life-enhancing experience expected — at least not for the animals.

A new study has revealed that stingray at a tourist hotspot in the Cayman Islands are suffering because of all the human attention. The Grand Cayman sandbank, dubbed Stingray City, is regularly swamped with up to 2,500 visitors at a time, most of whom have paid handsomely for the chance to feed, stroke and swim with the creatures.

The study highlights the risks to animals posed by the growing “wildlife tourism” industry. Experts say wild populations of creatures such as dolphins, penguins and sharks are also affected by increased contact with curious people.

Other examples of the observer effect and how it impacts nature:

Dolphins: Creatures in Australia targeted by tourists are more likely to abandon their young

Killer whales: Whale watching in Canadian waters is shown to reduce animal feeding time

Penguins: Even minimal human contact is shown to double the heart rate of New Zealand’s yellow-eyed penguins

Apes: Mountain gorillas of Uganda, Rwanda and the Democratic Republic of the Congo are known to be susceptible to human diseases

Yet not all manifestations of the observer effect mean obvious harm to nature.  In some cases humans are not seen as predators because they supply food and because they reduce the risk of predation.  Certain species react well to this arrangement, and it allows them to focus more time and energy on reproduction.  Take this video for example:

Simply by being there and observing, the people in the boat drastically change the outcome of the orca hunt, but their impact is not intentional and it is not entirely detrimental.  No one would argue that the penguin thought they were interfering, though it can be asked if the lack of a kill negatively impacted the whale pod, perhaps because of an ill or older member, or a very young member, who did not eat because of the observer effect.

Months ago on the TEXBIRDS mailing list, I remember reading from one woman who gleefully explained how she and another person traveled nearly 2,000 miles over the course of three or four days in order to see two or three rare birds in Texas.  I had to wonder what kind of environmental impact they had in their travels, what with driving all that way, consuming as they went, affecting nature through the act of observation.  If the carbon footprint of that trip could be measured…

Yet it’s part of a growing trend of eco-tourism.  People travel mind-boggling distances to swim with the stingrays, to observe the orcas, to see a rare bird.  They say getting there is half the fun, but it’s also part of the problem—and an integral part of the observer effect.

The rise of eco-tourism is a product of humanity’s sudden interest in the environment as something more than a source of fuel and food.  This newfound appreciation can benefit the environment and the creatures inhabiting it.  It can reduce the killing of wildlife, it can save habitat from destruction, and it can change people and economies in ways that allow humans to make a living by protecting the planet.

The catch, though, stems from the observer effect.  It behooves us to understand the impact we have and to manage that impact as best we can.  Long has been my hope in sharing my nature photography that it would allow people to see and better appreciate what will be lost through inaction, what often goes unnoticed by others until it’s pointed out.  I share this goal with those individuals and organizations that provide eco-tourism services whereby people can experience the breathtaking splendor too long hidden by consumerism.

But we must tread carefully and be certain throngs of appreciative people don’t trample all the life we’re trying to save.  And we must be certain that we do not drastically impact that which we observe.

A great egret (Ardea alba) in breeding plumage hunting in the shallows at sunset (2009_06_04_022126)

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Photos (just to give some eye candy to my little rant):

  1. Close-up of a killdeer (Charadrius vociferus) giving me a little peep.
  2. A great egret (Ardea alba) in breeding plumage hunting in the shallows at sunset.

Never eat more than you can lift

Man is the only animal that can remain on friendly terms with the victims he intends to eat until he eats them.
— Samuel Butler

A great egret (Ardea alba) perched on a log with two Texas river cooters (Pseudemys texana) sunning nearby (2009_06_21_024660)

As I processed that photo of a great egret (Ardea alba) perched on a log with a couple of Texas river cooters (Pseudemys texana), I giggled at the thought of the egret trying to munch on one of the turtles.  Obviously the size of the reptiles would prohibit that.  But the same could not be said of a small turtle I watched become breakfast for a yellow-crowned night-heron (Nyctanassa violacea).

A yellow-crowned night-heron (Nyctanassa violacea) trying to eat a small turtle (20080722_09794)

Along the bank of one of the nearby creeks, a bit of movement caught my eye.  It was the night-heron trying to eat something.  I couldn’t quite determine what was in its beak.

A yellow-crowned night-heron (Nyctanassa violacea) trying to eat a small turtle (20080722_09800)

The bird dipped it in the water, bludgeoned it against a rock, tossed it to and fro, and appeared to be resigned to not eating it since it couldn’t break it open.

A yellow-crowned night-heron (Nyctanassa violacea) trying to eat a small turtle (20080722_09812)

It was at this point that I got a better look at the food and realized it was a small turtle.  Here’s a crop of that image.

A yellow-crowned night-heron (Nyctanassa violacea) holding a small turtle in its beak (20080722_09812_c)

You can see the legs sticking out and the head hanging down, though the whole thing is covered with mud and identifying marks are obscured.  Still, it was definitely a turtle.

It seemed too large to swallow whole, and the bird had struggled with it for several minutes such that I felt certain it would give up.  After all the banging and washing, the carapace remained intact.  Unless the heron could pull the flesh from the shell by the dangling bits, it seemed breakfast would not be served this day.

But then…

A yellow-crowned night-heron (Nyctanassa violacea) swallowing a small turtle (20080722_09813)
A yellow-crowned night-heron (Nyctanassa violacea) swallowing a small turtle (20080722_09814)
A yellow-crowned night-heron (Nyctanassa violacea) swallowing a small turtle (20080722_09815)

In one swift move, down it went.  The whole turtle.  Shell and all.

After which the heron turned, took a drink of water, and proceeded to look quite satisfied.

Close-up of a yellow-crowned night-heron (Nyctanassa violacea) (20080722_09852)

It stood around for a while after that.  I’d probably need a rest, too, if I’d spent all that time and energy trying to break open breakfast only to swallow something as hard as a brick lest I be forced to give up the entire meal.

I was left to wonder how long it would take to digest the intact turtle.  And some time later, I was left to giggle at the thought of that scene as I watched the egret and its turtle companions.

It’s not always pretty

I recently realized how much my blogging focused on the more attractive aspects of nature.  What a shame!  Any true naturalist worth the label will spend as much time picking through scat and vomit, let alone investigating carcasses, as they will admiring the mimetic properties of certain moths or the varied glories of warbler songs.

Nature isn’t always pretty.  In fact, it’s often full of things people find horrifying or disgusting.  To appreciate it all—the good and the bad—is a sign of a true naturalist.  Because discoveries and knowledge can be found in both the beautiful and the terrible.  I would just as readily show a dead animal or a parasitized live animal as I would a slithering snake in good health.  Yet I haven’t shown much of the bad.  So now it’s time to fix that.

In the deep coastal woods that define the Dagger Point Trail of the Aransas National Wildlife Refuge, I came upon a fresh bit of evidence that something had been suffering from an upset stomach.

Coyote vomit (2010_01_12_048659)

The whole mass was about the size of two fists.  That’s a lot of grass.  Given how much whole grass there was, it seems most likely to have been a canid.  And given the location, that means a coyote (Canis latrans).

Research on canids eating grass has resulted in an interesting truth: how they eat it determines what happens next.  If they nibble and chew the grass, it goes down like everything else and is processed normally; this seems to be a way of augmenting their diet (adding roughage as it were).  But when they gulp it down—swallow the grass whole—it becomes their syrup of ipecac, essentially acting as an emetic (something that induces vomiting).

Coyote vomit (2010_01_12_048662)

Digging through the wet pile revealed nothing more than grass with some twigs and some dead leaves.  A few bits might have been bone and a few might have been fur, but honestly there was too little of the non-grass stuff to make heads or tails of.  Well, that and it was all glued together with saliva and gastric juices that melded it all into a sort of turf stew.  I suppose the coyote in question had suffered from an upset stomach long enough to have nothing else to throw up except the grass it ate to cure its ailment.

It’s fascinating to realize canine species learn this emetic trick and use it when necessary.  Most people associate it with dogs since that’s the only experience they’ll have with it, but it’s obvious their genetic cousins also practice this home remedy to cure tummy problems.

OK, I understand if you need something to cleanse your visual and mental palates after that, so here’s a great egret (Ardea alba) to leave you with a better taste in your brain.

A great egret (Ardea alba) standing in a shallow bay (2009_10_03_030090)

Like the coyote in question, I hope you feel better now.

International Day for Biological Diversity 2010

A melanistic male red-eared slider (Trachemys scripta elegans) sunning on a log (2009_07_25_027811)

Today, May 22, 2010, is the International Day for Biological Diversity.  I began this post with the idea of celebrating the day by offering various examples of nature’s beauty.  But then I realized ‘celebrate’ connotes a positive meaning that hardly seems appropriate.  Why?  This year the International Day of Biological Diversity comes on the heels of a very disconcerting study:

In 2002, world leaders committed through the Convention on Biological Diversity to achieve a significant reduction in the rate of biodiversity loss by 2010. We compiled 31 indicators to report on progress toward this target. Most indicators of the state of biodiversity showed declines, with no significant recent reductions in rate, whereas indicators of pressures on biodiversity showed increases. Despite some local successes and increasing responses, the rate of biodiversity loss does not appear to be slowing.

A common meadow katydid (Orchelimum vulgare) resting on a leaf (2009_10_03_030227)

At present, nearly 100 species of plant and animal combined go extinct during every 24-hour period.  That equates to more than 35,000 species every year.  And despite promises to address the causes and take action to reverse trends, governments and people as a whole have actually increased pressure on nature rather than decreasing it.  Scientists call this the Holocene extinction, an ongoing mass extinction event.  Whether or not it should be called the Anthropocene extinction is irrelevant; that humans are the only hope for stopping it is what matters.

A great egret (Ardea alba) standing in a lagoon (2009_09_05_028720)

“Going green” seems like a badge people wear so they can be patted on the back and congratulated for their foresight and compassion.  Changing a light bulb helps, but changing our governments and our attitudes will make the only real differences.  Will your grandchildren think of elephants in the same way we think of the Carolina parakeet?  Will their grandchildren think of rusty blackbirds the same way our children think of the Tasmanian tiger?  Will future generations think of the Arctic in terms of open water or endless seas of ice?  Only time will tell.

A brick cap (Hypholoma sublateritium) that began drying out before it matured (2010_04_10_052872)

Biological diversity is a giant web.  As each strand breaks, the entire web becomes more unstable.  We scarcely can think ourselves immune to the effects of the slow-motion downfall of this massive interconnected system.  It feeds us, it clothes us, it shelters us, and it heals us.  But once the web no longer can support itself, we fall with the rest of it.  I wonder if it will be too late before people understand that.

Canada wildrye (Elymus canadensis) blowing in the wind (2010_04_10_053186)

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[1] Red-eared slider (Trachemys scripta elegans); admittedly the darkest melanistic male I’ve ever photographed, which makes him the oldest melanistic male I’ve ever photographed

[2] Common meadow katydid (Orchelimum vulgare)

[3] Great egret (Ardea alba)

[4] Brick cap (Hypholoma sublateritium); the mushroom did not mature before succumbing to our lack of rain this spring

[5] Canada wildrye (Elymus canadensis)

[I usually do not preach.  In fact, over the years I’ve grown increasingly adverse to doing so.  I will draw attention to someone else’s preaching if I feel the subject worthy of attention (preaching by proxy).  But sometimes things hit me just right and I have to say something.  This is just such a time because this subject is critically important and is something about which I am quite passionate.]