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Walking the walk


Walking the walk
Photo Information
Copyright: Anna Eksteen (Miss_Piggy) Gold Star Critiquer/Gold Note Writer [C: 2285 W: 5 N: 5300] (18714)
Genre: Animals
Medium: Color
Date Taken: 2010-10-06
Categories: Reptiles
Camera: Sony Cybershot DSC H9, Carl Zeiss Vario-Tessar 15x Optical zoom, Digital ISO 100
Exposure: f/5.0, 1/500 seconds
More Photo Info: [view]
Photo Version: Original Version
Theme(s): CeltickRanger's favorite African animal photos 2, Camouflage [view contributor(s)]
Date Submitted: 2011-03-21 0:20
Viewed: 4509
Favorites: 1 [view]
Points: 70
[Note Guidelines] Photographer's Note
Nile Crocodile / Crocodylus niloticus

This image of the crocodile covered with algae was taken at the Sweni Bird Hide in the Satara area. We (both Loot and I) were fortunate to capture some lovely images here of various birds and other animals, and I remember how excited I was when the crocodile which was just lazily lying in the water, emerged and slowly started to walk away from the water's edge. Although the algae are a serious problem for the animals of the Kruger, it actually was such a "pretty" scene.

A spot of forensic detective work by Kruger National Park (KNP) and state veterinarians has revealed the cause of a number of animal deaths could be that of possible poisoning by algae. Please go and read more about Microcystis (blue-green algae), which one can see so clearly in this image of mine, as the information I am giving is about how the crocodile walk and not about the algae. Besides the "High walk" this reptile can also belly walk, gallop, jump and swim.


Description of the walk
The "high walk" is so called because the crocodile lifts its entire body trunk and at least the anterior half of its tail clear of the ground when it walks. It is usually a relatively slow gait, not exceeding 2 to 3 kph. However, the crocodile can speed the gait up when required to exceed 5 kph.

During the belly crawl, crocodilians hold and move their limbs very much like a typical lizard would (by the way, crocodiles are not lizards!) splayed out to the side, giving the body a low centre of gravity, and causing it to flex in a sinusoidal manner at slightly higher speeds. Like lizards, most or the entire ventral body surface is in contact with the ground, which adds friction over some substrates like grass or rock. The high walk differs because the whole posture of the limbs change, the body is lifted up and the limbs positioned virtually underneath it. This kind of posture is unique amongst reptiles, and the reason lies in the structure of the ankle joint.

In a typical lizard, the ankle joint (along which the plane of movement runs) passes in roughly a straight line between the upper (astragalus and calcaneum) and lower bones of the ankle. This means that the foot can only really move in one plane. In crocodilians, however (and their ancestral thecodonts, which also gave rise to the dinosaurs and birds), the plane passes between the astragalus and calcaneum bones. The astragalus does not move when the calcaneum (effectively the heel) moves. This gives the ankle the ability to twist.

So what difference does this make? The arrangement of the joint means that crocodiles, unlike lizards, can easily rotate the foot about 90 degrees so that it is facing forwards rather than out to the side. This enables the crocodile to move the legs much closer to the body so that they project downwards, almost beneath the body trunk. The crocodile can therefore lift its entire body trunk clear of the ground and provide good support. The limbs move forwards and backwards without swinging out to the sides very far, although the alternating diagonal of the "belly crawl" remains. At slow speeds, there is hardly any sinusoidal movement of the body trunk, although the tail falls first to one side and then to the other as the axis of the body changes slightly - in other words, crocodiles wiggle their hips slightly as they walk.

At higher speeds, the limbs are thrown slightly further out from the body, although the trunk is still lifted clear of the ground. The sinusoidal movement of the body trunk also becomes more pronounced. This fast high walk cannot usually be sustained for very long as it requires a considerable amount of effort. It is also inherently less stable as the centre of gravity is lifted higher off the ground. As the crocodile accelerates, therefore, the body eventually falls to the ground, and the gait turns into a rapid "belly crawl" with the limbs cycling and the whole body and tail thrashing from side to side.

It is reasonable to assume that the high walk is simply a remnant of the style of walking used by ancestral thecodonts and extinct crocodyliforms, many of which were more terrestrial and often able to run and gallop for some distance over land. Modern crocodiles can still employ this method of locomotion, the advantage of which is that it provides a means of lifting the body clear of the ground, unlike the belly crawl. The stride length increases, and friction decreases. Crocodiles use the high walk to step over rough ground, or raised obstacles such as rocks, branches, or other crocodiles, or when climbing a steep bank out of water. The ability to high walk varies from one species of crocodile to the next. Most species of crocodilians have relatively powerful limbs, enough to sustain the high walk for several metres, although most walks are short, slow and to the point. Crocodiles often travel overland for distances of 1km or more, and the high walk is frequently employed, although it is probably intermittent. Larger adults are less able to high walk for long distances than small animals because the power of the legs is not sufficient to support the weight of the body for long periods. The Indian gharial, Gavialis gangeticus, apparently cannot perform the high walk at all as an adult (although it is likely that the juveniles still can) because its limbs simple aren't strong enough to lift the body clear of the ground. The gharial is adapted to spend more time in the water, generally emerging only to bask and nest, so the loss of the high walk is not surprising. Source

I hope you enjoyed looking at this photo as much as I took pleasure in taking it.

siggi, joska, corjan3, matatur, maurydv, KOMSIS, ramthakur, nagraj, CeltickRanger, maaciejka, PeterZ, brech, Argus, tuslaw, Noisette, Luis52, paolo49, vanni2009, Emi_1987, Ingrid1 has marked this note useful
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Critiques [Translate]

  • Great 
  • siggi Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 3097 W: 109 N: 12399] (52850)
  • [2011-03-21 1:14]

Hello Anna.
Beautiful shot of thisNile Crocodile with extraordinary pov, focus, colors and composition.Excellent sharpness too.My compliments and TFS.
Best regards Siggi

  • Great 
  • joska Gold Star Critiquer/Gold Note Writer [C: 806 W: 0 N: 4092] (22535)
  • [2011-03-21 1:47]

Excellent photo-presentation, TFS!

Hello Anna,
Another unusual image from you and a very informative note. It will not be surprising if it is the algae that are causing the animal deaths. Algae have played a major role in the evolution of the environment. Blue-green algae (cyanobacteria), not classified as algae anymore as they are bacteria, were amongst the earliest life forms on Earth and already were around before there was oxygen in the atmosphere. In fact, they played a major role in converting the atmosphere from reducing to oxidising by extracting carbon dioxide from the seawater and releasing the oxygen into the atmosphere.
Thank you and best wishes.
Neels

A fine, environmentalist capture in great taste Anna, which also demonstrates the camouflage power of the live algae on the denizens of the aquatic world. Thanks for sharing this beautiful image with us my friend.
Mehmet

Hallo Anna,
a very beautiful capture of the Nile Crocodile, what a extraordinary involuntary
camouflage, superb sharpness, great timing in a very pleasant dynamic composition
TFS
Best regards
Maurizio

Hi Anna,
a very interesting subject and information. The jacana seems to look with much interest at the crocodile - perhaps because it looks soo funny?
The subject of your pic is very good, but the quality could be better. It seems as if you had cropped to much or sharpend it to much?
best regards and thanks for the interesting information
Pierre

  • Great 
  • KOMSIS Gold Star Critiquer/Gold Note Writer [C: 820 W: 0 N: 2419] (10674)
  • [2011-03-21 4:11]

Hallo Anna,
Presentation and composition very witty!
Very interesting capture. Perfect sharpness and nice natural colours.
Best wishes,
Seyfi

Algae is not an inviting sight anywhere, Anna, and this croc does not seem too pleased to be smeared in it. As a matter of fact, the bird on the dry ground looks on with concern at the fellow doing the "walk" out of the slimy stuff.
You have apparently captured the moment with the same concern but certainly not with any "pleasure" at the plight of the animal.
Your note on the "walk" of a Crocodile is enlightening and goes well with the picture.
Thanks and regards.
Ram

Ciao Anna. Interesting example of camouflage. Beautiful brilliant colours and very good details. Lovely compo.

Roberto

  • Great 
  • nagraj Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 1618 W: 106 N: 3208] (15166)
  • [2011-03-21 8:12]

Hi,
Oh! So much about walking, very interesting to learn so much, the image is beautiful with algae on the crocodile and the bird's position and pose makes it more lovely. tfs.
nagraj.v

Anna - a fantastic capture of the duo. It seems the bird is matching step by step with the croc. Noce compositon. tfs

hello Anna
very good picture with great pose of the
Crocodille
very nice details and good naturel colours
greeting lou

Hello Anna

WOW ! what a great photo of the Nile Crocodile
camouflaged with his habitat, very fine POV
and the way it is framed, excellent contrast
between background's and foreground's color tones,
great focus sharpness and details, beautiful glance
of the bird to the Crocodile and what a great
expressive eye-contact of the Crocodile with you, TFS

Asbed

Hello Anna,
beautiful photo. Interesting animals. Amazing colours. Excellent point of view and depth of field.
Thanks for sharing,
Maciek

Hello Anna
Interesting note and impressive scene with excellent composition and wonderful colours.
Regards,
Christodoulos

  • Great 
  • PeterZ Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 5137 W: 166 N: 13121] (49139)
  • [2011-03-21 10:05]

Hello Anna,
Interesting photo of this Nile Crocodile covered with algae. Beautiful colours, great sharpness and a good POV and composition. The African Jacana is a nice bonus.
Regards,
Peter

I did with the little rail providing a comic side note!

very well done!

cheers
J

Ciao Anna, great capture of very strange walking couple, wonderful ambientation, beautiful natural colors and splendid sharpness, very well done my friend, ciao Silvio

Hello Anna
very interesting scene, this algae covered Nil Crocodile is captured with sharp details in a natural environment, great composition
the bird on the left is a great bonus
Have a good night
Jacqueline

  • Great 
  • Argus Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 5038 W: 260 N: 15594] (50626)
  • [2011-03-22 4:31]

Hello Anna,
A fine capture of an algae-covered Nile Crocodile as he emerges from the water.
The POV is excellent and taken with great sharpness and natural colours with the African Jacana or Lily-trotter add ing nicely to the composition.
Thanks and kind regards,
Ivan

Hello Anna,
Oh, what an amazing photo, fantastic contrast between the delicate bird and the terrible crocodile. Crocodile great masked by algae. Bravo!
Regards

Hello Anna
Another title would be Beauty and the Beast.I pity the poor animals in the algae covered water but I suppose they get used to it. So here we get two for the price of one! A jacana and a croc! This is a typical scene at a hide and you managed to capture it beautifully, as usual.There is a definite sense of movement, so vital in nature photography. And I think we have the only "green" crocs in the world! Well done and well captured!
Peter

Hello Anna,

Hopefully you were in a safe place when capturing this fellow, he looks like hungry!
An amazing situation, enhanced by the bird walking on the pondside...
The cunning expression of the crocodile is well recorded, all together a stunning picture of Africa!

Greetings,
Pablo -

  • Great 
  • tuslaw Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 2754 W: 282 N: 4931] (19883)
  • [2011-03-27 20:42]

Hello Anna,
What a neat shot of this algae covered Crocodile doing the high walk while his little side kick looks on. The composition is very eye appealing as it shows him in a nice low POV in his natural habitat. Your f/5.0 aperture resulted in some great DOF allowing you to capture the entire croc. in nice detail. Beautiful presentation with very informative notes!!
Ron

Impresionante espectáculo en un paisaje que no deja de ser curioso para los que habitamos estas latitudes. Bien recreado el ambiente de esas ciénagas con unos colores bien descriptivos.
Dinamismo del conjunto y habilidad para captar las especies en su entorno.
Saludos Anna: Josep Ignasi.

Splendid photo, congratulations!!!
Fabrizio

  • Great 
  • fiyo Gold Star Critiquer/Gold Note Writer [C: 1053 W: 5 N: 3475] (15161)
  • [2011-04-07 8:41]

Hi Anna,
A wonderful composition of natural environment
Congratulations, regards ..

  • Great 
  • Luis52 Gold Star Critiquer/Gold Note Writer [C: 1175 W: 8 N: 4240] (15809)
  • [2011-04-07 9:52]

Hola Ana.
Your photos have a lot of Natural Environmet and thats why I like them a lot Ana, and they have a lot of value for those who take them. Very clear image, sharpness, focus, light, are in a high quality level.
TFS this photo, and many thanks for Your kind words an my last picture.

Ps.... I also miss the "good old days" times when we where a real family of photographers, knowing each other not only for the photos we post or share, bur for the kindness to each others. Things are geting colder each day here, but people like You and some others friends keep me hanging here.
Saludos
Luis52.

Hello Anna, disturbing image of this little alligator with friendly intentions, the perfect shot and great details and the time you read. All the best, Paul

Bonjour Anna
Prise de vue rare, et surprenante
Bravo pour le résultat
Amicalement
Laurent

Hello Anna
beautiful composition, beautiful colors and the natural environment.
Congratulations and thanks for sharing
Hello Vanni

  • Great 
  • horias Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 837 W: 58 N: 2084] (11033)
  • [2011-04-10 5:47]

Hi Ana
Wow....what a fantastic shot....is like in National Geographic..
what a great capture!!!!
Great shot ,great sharp details and colors.
CONGRATULATION'S for this beauty!!!
Horia

Hello Anna
Awesome composed shot, I would get too close to that crocodile if I were that bird :) , what you have captured here show what is wildlife photography really about, showing the habitat and the sorroundings of an given animal or insect, and by giving that beautiful description..it is like looking at a documentary of animal behavior.
Job very well done and thanks for sharing!
Friendly regards
Hedesan

  • Great 
  • foozi Gold Star Critiquer/Gold Note Writer [C: 2791 W: 0 N: 6696] (25839)
  • [2011-04-22 2:39]

Hello Anna,
such a special shot of these two creatures! The thin croc is so well shown with weeds on its body.
i like the presence of the bird too, giving this presentation a very natural photo.
simple yet effective in style and nature.

Regards,
Foozi

My dear friend Anna,

This shot is a real "COUP"

The sight of the algae covered crocodile makes me laugh as well as cry.

The pollution of our dams and rivers is heart breaking!

One day the whole planet will suffocate in filth. Worst of all the so called 'good- doers' do not know, that they do not know and make matters worse.

The Hartebeespoort dam was declared unsafe for humans, when we were there approx 6 years ago, and it looked like thick pea soup on a good day, on a bad one it was covered with a layer of dead brown Algae ca 300 mm thick and stinking horribly. It was so bad that we had to close the windows...

Researching the matter I discovered, that the water hyacinths had upset some residents' view of the water, and they pad for spraying the whole dam to eradicate the plants!

At least that crocodile was still alive enabling you to take an amazing photo.

Thanks for sharing
Hugs
Ingrid

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