Ardea herodias

[Deadrise]

If your goal was 12 lines of IP more or less you succeeded. Its a start

There are errors like has been pointed out like "into", however with my initial read it was not disruptive. If it isn't disruptive, let it stay. I agree!

This line was problematic:

"one more primeval contest to unfold" I replaced unfold with behold, I think it fits betters?  Need to think about the beginning of the line some?

As neither "one" nor "more" are accented syllables it makes the line start weak.
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There does appear to be some tense disagreement:

"In time his patient stalking brings reward,
His prey by movement gave itself away." I dumped the whole line, couldn't get it to work

brings/ gave   no  --> brings/gives   yes

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Overall I think the biggest problem is that the lines seem to be a struggle. There is no smoothness, the words seem to be fighting themselves.
Notice the following line:

"Prepared, his neck contorts in reflex mode,"

If one were talking normally, such a line would never be uttered. It would read either,

Now prepared, his neck contorts in reflex mode,  Of course this puts the action after the point where it was supposed to be already accomplished and so should read:

Preparing to strike  his neck contorts in reflex mode.

Of course what I think was meant was:                Prepared (properly expectant) when he receives his reward, his neck reacts by instinct making to strike.

Prepared, his neck contorts in reflex mode and strikes at the prey.

A title should not be something that causes confusion, it generally should be free of ambiguity. There are of course exception such as when the title is a double entendre. The general idea is that the title will not be a stumbling block for the reader. It is often easy for the writer to assume that the reader has the knowledge he has, especially when it comes to nomenclature that he knows well, or uses often as does all the people with whom he associates. It becomes easy to generalize that to the rest of the world. This is what happens when a person is part of a sub-culture, as are most people. The writer must be aware of this and compensate accordingly. In another vein, if a person knows the word heron, or here, "Great Blue Heron," but does not know the Latin classification name, he should not then go look up to use as a title in order to give his poem (in his mind) more gravitas (I'm not saying this is you, mainly I am including it for others who might read this). Or as my great aunt use to say, "People shouldn't go gettin' all highfalutin just to impress other people; it just makes them look like damn fools."  That exactly what i did  

This is a difficult thing for people to realize when starting to write in IP as they become so focused on the metrical pattern, they forget that they need to write in sentences that make sense by following the normal rules that apply to sentences. One does not escape the rules of grammar, and syntax simply because he is writing in IP.

I am very new to "attempting" poetry and even newer to meter. So far my attempts at converting a free form piece into Iambic meter was akin to pounding a large round ball into a small square hole. I finally got it to fit but there are still some filling and sanding to do.  I will say that all in all it has been a wonderful experience.

Overall I think the biggest problem is that the lines seem to be a struggle. There is no smoothness, the words seem to be fighting themselves. I agree

Based on your feedback I gave it another whack:

Great Blue (rev2)

An ancient creature hunts a stagnant slough
with onyx eyes he peers into the pool (eyes of onyx)
in search of scattered quarry veiled from view.
 
Aloft on boney stilts he strides with grace
inspecting every likely hiding place (new line)
on watch for signs of movement out of place. (new line)

In time his patient stalking brings reward
prepared, his neck contorts in reflex mode,
one more primeval contest to behold. (unfold)

Abruptly interrupted by a foe
the creature wary, spews a wretched sound, (noise)
a raspy “kraak” before he leaves the ground. (flies away)

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An ancient creature hunts a stagnant slough,
His eyes of onyx peer into the pool     (onyx eyes)
in search of scattered quarry veiled from view.

Aloft on bony stilts he slinks along, (strides with grace)

In time his patient stalking brings reward,
His prey by movement gave itself away.

Prepared, his neck contorts in reflex mode,
one more primeval contest to unfold, (behold)
abruptly interrupted by a foe.

the creature wary, spews a wretched noise (sound)
a raspy “kraak” before he flies away (leaves the ground)
propelled by mighty wings in weighty beat.



Look forward to your future post. Thank you for your informative feedback, it motivated me to try harder.

Take care,
John