Question regarding getting Black Moa Chick

On the wiki page for Black Moa Chick here, it says:

# Most of the scavenger hunt activities can be performed by anyone. However, only your character can take care of these three tasks (one for each Campaign):

* Factions: Only your character can buy the Incubator Kit (as noted above);
* Nightfall: The nesting material requires that your character carry the kit into Resplendent Makkun;
* Prophecies: Your character must bring the fully loaded kit into Sorrow's Furnace.

Does this mean that I need one character that has done all the missions up to these points? Can I do this with three different characters that have completed one of the campaigns each? Thanks.

one char that can do each of those. All the same char.

You'll have to do everything on a single character. Those items the character gets are costumized to that character, so you can't use another character's costumized items.

Regarding the Nightfall trade of Skree Wings for the Nesting Material;
I just got the Black Moa Chick 2 days ago, and I didn't need the Incubator Kit to trade for the Nesting Material, I just needed Zho's Journal on my character.

The requirement that it be that specific character, is still accurate, as far as I know.
The other requirements that you listed are correct, as well, though there may be 1 other requirement that I am not totally sure about, and that is taking the egg to Mourning Veil Falls to have it hardened.

I took the egg there on the character that was on the Scavenger Hunt, just to be sure...
And yes, it is a grueling task to take a character to all 3 campaign areas, especially if you try to knock it all out within a couple days

But, I admit, I really do like that little bird...I thought I might consider selling t for some nice coin, but wow...I put a LOT of effort into getting that critter, I think I might hold onto the little bird for awhile...

Good luck in your endeavors!

Hardening the egg can be done by any character. I have taken batches of eggs to harden a couple of times for the use of guildies and allies.

Yeah, I bought two Nesting Materials, one for my character and one for a guildie. Nesting Materials are customized when you buy them, waste of Skree Wings.