Arquivos de periódicos de dezembro 2017

15 de dezembro de 2017

R.I.P. LCRA's Pedernales River Nature Park.

Update: 4/24/2018

Hello all,

I had a horrible experience this past week at my local LCRA Pedernales River Nature Park yesterday. First I discovered they had mowed the wild brush and bushes absolutely to the water's edge on the lake the lawn of which they keep manicured. This time they encroached to water's edge, including a small spit into the lake which was the one spot previously left natural. Cut clean to the soil almost. All the brush, bushes and plants along the lake's edge were species that many butterflies utilized when blooming for feeding, including migrating Monarch. Now all that is gone. It will take years for the foliage to grow back, but under LCRA's Pedernales River Nature Park maintenance plan, the whole riparian zone and flood plain downstream to the park boundary will be 'managed'. That is not good news for wildlife or migrating species that used to depend on the area for foraging in an increasingly developed Hill Country.

That's bad enough, but now the trees lining the lake have even more fishing lures and lines caught up in the branches from the few 'fishermen' that go there to fish. I have numerous photos of lures and hooks swinging in the branches now that I'll put on flickr soon. All of this was bad enough but then - because now you have to pay to go to this 'nature' park, there were few - very few - visitors. But all it took was one to do what I watched or almost witnessed. I barely missed the actual event, but as I was leaving on the paved 15 mile per hour road, I came upon a five or six foot Western Coachwhip that had just been run over and squashed. I stopped, yelled at the person driving away at the top of the hill (too far for me to be heard), cursed and took photos of the carnage (pun not intended). I am sick of the uncaring, indeed, hostility to wildlife and nature ever present in our society.

Update 12/17/2017:

I have put two album of photos on flickr; a before and after the recent work carried out by contractors at LCRA Pedernales River Nature Park. The links to the albums are as follows:

Thursday afternoon, December 30th, 2017. I had a meeting with one of the LCRA persons familiar with the agencies' project to redo the natural habitat at LCRA Pedernales River Nature Park. He actually lives in the same town as I do. We had an amicable discussion, but I was never told the purpose of the land clearing which included many endemic shrubs, bushes, and small trees. I am guessing, based on earlier conversations with various agency personnel, that establishing conditions similar to a prairie was the goal, an all too familiar scheme of local government agencies in possession of chunks of Texas Hill Country land. It also dawns on me that perhaps LCRA has something else in mind for the park as it now seems the altered area has been reduced to mostly Live Oaks and grass, as my photos show. I have many problems with this view of our portion of the Hill Country because it is fraught with issues over description and misunderstanding. For example, the nearby Lyndon B. Johnson National Historical Park has embarked on its own Prairie Restoration Project at the LBJ NHP Settlement about a mile upstream from the LCRA park, both of which encompass Town Creek, a recharge stream that flows through both parks and downtown Johnson City.

I doubt the LCRA spokesman thinks the brush clearing was as extreme as I do. Perhaps because there is a movement in government agencies to 'restore' prairie habitats across the country. Organizations and websites have sprung up over the years advocating the restoration of native prairie landscapes in areas that turned out to be unsuitable for dry farming agriculture, critical habitat, or for many other reasons. This may be LCRA's vision which is shared (and, I might add, is typical of most 'habitat restoration' projects) by the LCRA employee, for the nature park . I was told LCRA doesn't intend to treat the property as a manicured lawn, which is helpful, but does not answer the question: what is the goal? Now that all the bulldozing is completed, as I was told, the clearing is finished, (but I can't believe it wasn't stopped because of my complaints). From this point forward, LCRA will just let whatever grows in place to grow back naturally. (Aside: what was already growing naturally has been eradicated and now we are just repeating the regeneration step, get it? No? Me neither. If you are just going to let what survives to survive, what was the point?) I worry that in time, the agency will try to make the area a permanent urban like park, complete with routine mowing and continuous cutting back of encroaching 'woody' invasives at the expense of biodiversity. I don't know why it's necessary to destroy the habitat (and all the critters in it) and then leave it alone. Honestly. I'll believe it when I see it.

In the meantime, both LBJ NHP and their Settlement Prairie Restoration Project (ongoing) and this one by LCRA have native plants as their focus. Alien and invasive plants are targeted for removal by either herbicides or mechanical means in an effort to rid the landscape of onerous species. That has to be appreciated as a positive. The native species that are desired for planting range from indigenous grasses, shrub, brush or trees in place of the often invading alien species that more likely got here by way of escaping home gardens and farming practices should be naturally beneficial. Keeping in mind that land here in the Texas Hill Country has been historically cleared of vegetation to enhance grazing and farming. Reclamation or restoring native species is seen as an enlightened correction to past practices that have negatively impacted and transformed the Texas Hill Country in ways that is contrary to an idealized historical view of the land. In both the case of the LBJ National Historical Park effort and this LCRA effort, a view of what the property should look like have been decided in offices by specialists who have studied the flora of the landscapes. Problem is, the Edwards Plateau and eastern Texas Hill Country are being treated as adjuncts of the Great Plains, hence 'prairie' restorations. Again, undesirable plants are slated for elimination with the plan to reinstate the similar native species in place of the intruder. That's the general plans for both places as far as I can tell. But the devil is in the details and from what I see and hear, the details aren't as they should be. Let me let the following link of noted Hill Country expert, Steve Nelle, make my argument for my above criticisms.

Steve Nelle has published many articles that basically helped form my opinions about both the Texas Hill Country in general and our precious and fragile riparian habitats as well. His website offers a wealth of information and suggestions on where, when and how to proceed. I think his suggestions should be applied literally to both our special parks, the LCRA Pedernales River Nature Park, and the LBJ National Historical Park Settlement here in Johnson City, hometown of the 36th President of the United States:

Important Update - see bottom of this message:

This week the riparian area of this unique Hill Country river park will become like your manicured lawn from this day on. From the old road south of the Pedernales an area that stretches from east of the dam on the river to the park's boundary near Deer Creek is being bulldozed of saplings, brush and small trees. From what I can tell, and my observation is a tentative one, the flood plain is being cleared of all vegetation - mesquite trees, cedar elms, pecans, you name it and they have been stripped and smashed into oblivion. This means there is now no natural vegetation to help waterfowl and wildlife hide from humans. I am going to post the progress of this destruction (you can be assured LCRA will take issue with this point of view of their activities). I'll include photos I have of the area before this action was initiated as the one above, and will update the journal post with additional observations as this destructive project proceeds.

Photos now posted showing area and species affected. None of the landscapes depicted here appear as they did in these pictures. To be continued...

I have created a place for the riparian habitat on the land adjoining the river. You can see the species observed before development here and add any you may have in your photo archives. Just follow this link:

I just revised the size of the above place here on iNat. The riparian area along both the Pedernales River and Town Creek have now been nearly cleared of vegetation. There is now no cover for waterbirds and other species to hide from humans and the area of clearing has progressed up slope out of the river flood plain. My latest boundaries take the expanded area into count, but I am now certain I will even have to expand it further because it is obvious the clearing is not complete. I now have complete before and after photos that I will post here and on flickr to enable a wider audience to see what we're loosing.

Updated 11-17-2017
Hi everyone

I have additional information to give you about LCRA's Pedernales River Nature Park development and how this activity is going to affect more of LCRA parks in our Hill Country and Austin metropolitan area. Any of you with interests in such places as Canyon of the Eagles, or McKinney Roughs Nature Park, the Bastrop LCRA parks might want to contact LCRA officials or others who may be able to bring the destructive development proposed for all these parks to a stop. Here's what I learned Wednesday.

According to the contractor working at LCRA Pedernales River Nature Park, the officials in charge of the park have decided against a natural park in favor of a manicured park that I assume they believe will bring more visitors to their parks. What this means for Pederanles Nature Park is that the river front riparian habitat between Town Lake and the park boundary at the Stanton Ranch has been removed entirely. Additionally, the clearing (and poisoning) of all species including native species such as persimmon, cedar elms, small oaks, mesquite and basically any small tree has taken place. Additionally, the clearing has now proceeded up the hill above the old road that runs east and west south of Town Creek, in addition to the area on both sides of Town Creek itself both above and below the low water crossing that takes visitors to the lake. The clearing of brush also included all Agarita growing anywhere between the entrance, the pavilion at the top of the hill and downhill to the river. In other words, the prairie you drove along on your way to the river is gone. In its place are a few oak trees (logs and dead trees removed) and you now have an unrestricted view of the hillside (like a lawn). The pond on Town Creek, home to so many types of birds and waterfowl has been completely cleared of Rattlebush. In the words of the contractor, the person in charge declared that no Rattlebush be allowed to remain. Of course, that applied to the river bank as well. There is no place between Town Creek, where it enters the Pedernales and the eastern boundary where any vegetation has been allowed to remain as cover for wildlife.

The contractor told me - being a country guy - he knew the operation was destroying endangered species and animal habitat and the first iteration of 'the plan' included preserving much of the native brush, but the latest person in charge overruled the whole operation and ordered the extreme clearing to take place. I have both before and after photos I'll place on flickr as soon as possible, but it won't be in time to save the area from devastation. The results are obvious. The crews are about done here at Pedernales Nature Park, unless the officials at LCRA decide to completely clear the remaining 200 acres of land at the park. The impact of this activity makes a mockery of the idea of a 'nature' park as it's obvious nature will only survive now in spite of LCRA, not because of it.

Don't forget that LCRA's plan is to follow the same brush removal at all the aforementioned parks; Canyon of the Eagles, McKinny Roughs, and one or both of the LCRA parks in Bastrop.

to be continued...

**Update as of December 3, 2017

Posted on 15 de dezembro de 2017, 06:48 AM by billarbon billarbon | 10 observações | 10 comentários | Deixar um comentário

31 de dezembro de 2017

Bird Flight Or My Contribution to Science

Wings and flight are at the very essence of what is a bird, are they not? Humans have long regarded birds as heavenly creatures for their ability to slip gravity, to defy our own terrestrial existence. During most of human history here on earth, we've looked at birds and particularly, bird's wings for inspiration to find ways to do that ourselves - giving us the dream of flight. Beyond the power of flight and travel, few of us ever considered there might be more to bird flight than meets the eye. What has perplexed us is how birds have the lung capacity to achieve not only flight itself, but the ability to span the globe on wings hardly larger than our own hands or on huge wings, fly at altitudes [And have been reported to fly to 33,000 feet (some 12,000 meters or more Protor and Lynch, Manual of Ornithology, 1993, pg 16).] and endure cold temperatures at which humans couldn't live. But we've never combined into the same thought bird's two advantages that enables birds to achieve the feats they do on the wing: the ability to fly at all and the ability to fly tirelessly. The two abilities are linked in a most unexpected way.

For many years scientists puzzled over the avian respiratory system and proposed novel and extremely complicated ideas to explain all the elements of the avian breathing such as the link at the bottom of this page.* I especially remember one long and credible explanation of bird respiration that appeared in Scientific American in the early 70's. The model bird was a duck standing on the ground and the hard-to-follow explanation for air flow and air sac function was a 'had to' read over and over again proposition in order to grasp the whole breathing cycle because to understand it, you had to consider chemistry, physics as well as biology. Realizing that birds have all these air sacs and pneumatic bones that intercommunicate with each other and are in turn connected to the lungs results in a confused mess to try to understand how the whole system functions, it being so alien to mammal's system. Needless to say, the author was trying to convince that birds received adequate O2 just by compressing its lungs with its feeble thoracic muscles attached to the ribs. In this scenario, birds inhaled and air via the lungs passed through the lungs to the air sacs and then out again (in stages) resulting in an exchange of atmospheric chemistry sufficient to enable birds to rise above the world's tallest summits and span oceans on just a few breaths of air. It was my understanding that the air sacs would be full of stale air as there was no physical ability to adequately compress the air sac. While none of that was claimed in the article - because it avian respiration was not as thoroughly understood then, what turns out true enough is a bird's ability to span oceans and scale peaks the like of which humans can only dream. There is that word again.

Our understanding about the respiration system of a bird at rest is complicated because we know birds don't have large muscular diaphragms - like we mammals - to inflate and deflate their lungs like a bellows as we do. That's why we now know that bird's weak chest muscles can't possibly generate sufficient air to enable energetic and sustained activity, even if, apparently, the air birds breath passes through their lungs twice. But the amount of energy a bird uses at rest is miniscule compared to that which would be needed in flight. What nagged me for years was the claim that a bird at rest, despite breathing only a small amount of atmosphere, used the same mechanism and respiratory system for flight. That is, that birds thoracic muscles was sufficient to move all the air needed for strenuous flight as well as for rest. Added to that of course, was the idea that air sacs in birds exchanged their dead air - air sacs being dead ends anyway - for fresh air strictly by chemical means. That's how I remembered the Scientific American articles' claim.

Still, this explanation worked for me (and apparently still does for legions of Ornithologists) until, in the late 1980s, I met Timothy Rowe, co-author with Lowell Dingus of The Mistaken Extinction - Dinosaur Evolution and the Origin of Birds. Tim invited me to a talk at annual convention of comparative anatomists at the University of Texas given by the late Farish Jenkins, a Harvard researcher. Dr. Jenkins discovered that the wishbone (furcula) of a flying bird functioned like a spring and aided the bird's muscles in lifting the wing for its wing beat cycle when flying. Dr. Jenkins had measured energy production in every muscle in the wing and determined its energy demand vs what was available via respiration demonstrated the furcula was an energy saving device and aid that helped enable a bird to fly without becoming exhausted. How he determined this was amazing. Dr. Jenkins had trained starlings to fly in a wind tunnel(not his innovation as Ornithologists have been flying budgies in a wind tunnel in 1966) and he filmed the birds while flying...with both normal and X-ray cameras. Using X-ray was Jenkin's innovation. What the developed film revealed was the function of the birds' bones and muscles during flight. In both regular film and X-Ray film you could see the bird up close and all the mechanics of flight provided by feather, bone, and muscle. But there was more and that's what I saw.

I watched in amazement as the starlings' wings - bones, muscles, and feathers - worked in unison during each and every up and down stroke of the wings (complete breath cycle from wing up to wing down). Most unexpected for me was the fact that the sternum rocked back and forth alternately depressing and allowing for expansion of the posterior and associated air sacs - the most prominent in birds. Since the air sacs are not muscular, they cannot expand and contract like the lungs (via thoracic muscles). It turns out that the action of the sternum assures the enlargement of the air supply, enabling a double passing of air through a bird's lungs providing for maximum gas exchange efficiency why in flight, but not when stationary. When at rest, the air sacs are not sufficiently depressed, instead, it was assumed for years that air exchange with the air sacs was chemical and not dynamic. Thus the ability - the need - of a bird to fly and the bird's need for maximum pulmonary efficiency for sustained flight are intricately connected. Bones, muscles, feathers, lungs and air sacs work together to produce a complicated, but amazingly most highly efficient breathing apparatus in the Animal Kingdom.

After the conference there was a reception for Dr. Jenkins at Tim and Elizabeth Rowe's home and Elaine and I were invited. There I explained what I had seen. Afterwards, once Dr. Jenkins had gone home, he refined his understanding of bird flight to include the evidence that the sternum in addition to the furcula directly enhance the ability of a bird to breathe and thus fly seemingly without reaching exhaustion as we would expect for ourselves - from our own understanding of mammal respiration and mobility. In other words, the bird respiratory system is bio-mechanical involving the bones, muscles, air sacs, and lungs to achieve maximum efficiency, not strictly anatomical like it is in mammals with only diaphragms and a set of closed lungs that allows short bursts of strenuous activity. Birds have to fly to breathe.

Many years ago a University of California, Davis, study demonstrated that cockatiels allowed to fly were more successful breeders than non-flying ones. This is not surprising. These revelations mean that flight is not an either or proposition for flying birds, but a necessary, if not an evolutionary (not to speak of revolutionary) advantage. Farish Jenkin's information has now made its way to ornithological and veterinarian texts in one form or another these days and I would expect further developments on the subject in the future. By 1993, Noble Proctor and Patrick Lynch in MANUAL OF ORNITHOLOGY - Avian Structure and Function, basing their comments on Jenkin's work, included the fact that the furcula (wishbone) acts in birds like a spring that not only aids birds in flight by reducing the work load required by the flight muscles, but also deflates the anterior air sacs resulting in a more complete exchange of respiratory gases. Now we know thanks to the conference I attended that birds have a highly efficient pulmonary system that operates best during maximum utilization. For flying birds, that means in flight. These revelations help explain bird's abilities to fly continuously for long periods of time. One species of shorebird, the Bar Tailed Godwit, migrates non stop across the whole Pacific Ocean between its Alaska breeding ground and its New Zealand winter hunting grounds! What, besides magic, would explain little shore birds' breath taking annual globe trotting migrations from northern and southern hemispheres, or the mind boggling knowledge that migrating birds such as geese routinely scale high mountain ranges around the world during their twice a year pilgrimages from breeding grounds to wintering grounds - and from basically sea level to Tibet in a matter of hours without using rising air currents or other 'energy saving' devices. Geese are not alone, as everyone knows, even the tiny hummingbirds span the Gulf of Mexico twice a year during their annual migrations; they are not alone, of course. Incidentally, there is another surprising ramification of the form, function and evolution of bird flight. This information has been generated by paleontologists and ornithologists regarding our understanding of the origin of birds - what they are and what animals were their ancestors and the like. The evidence such as the possession by dinosaurs of a furcula points to the fact - not the possibility - that birds are directly descended from dinosaurs, actually, just another type of Theropod related to the largest land predators ever!

After the conference, I did a couple of things to spread the word as to what we had seen and understood. I wrote an article for a parrot organization newsletter I edited describing the implications of the information as I understood it at the time. I also called a couple of friends - an ecologist and an ornithologist - to tell them what I had discovered. I sent my article to Dr. Catherine Toft at the University of California, Davis, and talked to Dr. John O'Neill at LSU and discussed my observations. Both scientists had collaborated with the parrot breeder organization whose newsletter I edited on a number of projects and I distinctly remembered Dr. O'Neill asking me if what I saw was true, what about non flying birds like Ratites, the Ostrich, Emus and the like. I told him that sounded like a good research project for him - X-ray those obligate bipedals while running on a tread mill!

Ornithologists are a hard headed group. Apparently, Ornithologists have yet to understand how birds are able to achieve the feats of flight they do around the world and research continues to probe into the avian respiratory and cardiovascular system in search of clues to solving the mystery of flight. Recent research is still mostly focused on energy generation, chemical exchange and cardio function without incorporating the bio-mechanical evidence reveled by Dr. Jenkins. Blood components and mitochondria is under scrutiny as if the question of how birds achieve the feats they do cannot be explained simply by an understanding of their anatomy and the way their bodies work. BTW, in my opinion, the mystery of flight has been established without a doubt, without debate that a bird can fly without a wishbone, i.e., wishbone is not essential to a successful flight. Determining the function performed by the wishbone was Farrish Jenkin's first discovery.1 Adding my observation about the function of the sternum - in addition to securing the powerful flight muscles to the body serving as an integral part of the whole respiratory system - was his second important revelation.


Even after Dr. Jenkin's ornithological research continues to center around blood chemistry (trying to reveal differences in avian hemoglobin/mitochondria and other highly technical, but ultimately invasive procedures to explain bird's flying ability. A sample of these efforts can be reviewed below but what I notice is a continuing reluctance to accept Dr. Jenkin's discoveries which really offer a much more simple explanation of how birds fly - and breathe.2



sad note added October 4, 2018: Obituary for Dr. Catherine Toft, University of California, Davis .

Birds just have to fit into this diagram for us to understand the complexity of different species ability to fly high and widely.

No statistical difference in lung size of high altitude and low altitude related species

One flap, one breath but 5-6 fold increase in heart rate which keeps the chemistry constant at altitude

Related: How birds fly high and far without drinking water:

Compare this journal entry with this article. Notice any difference between the two?:

***Important Breaking News from the New York Times. Please read:

Posted on 31 de dezembro de 2017, 06:35 PM by billarbon billarbon | 6 observações | 5 comentários | Deixar um comentário