It's a predator, so I guess the skills should probably look like Listen 6, Spot 6.
You know, before we get to this (and feats), we should probably fill in some of the blanks. Like speed, AC, etc. 30 ft speed with 60 ft fly (poor)?
The duckbunny has a 30 ft swim speed, so I could go with that for the black boobrie. I'd probably bump the land speed to 20 ft also. The great boobrie seems quite fast on land, but I guess it's still slower than the ToH axe beak, so that's ok.
I approve of the AC division, also.
I still think the black boobrie's wing buffet should be lethal.![]()
Only the MC11 version mentions looking imposing, so I'd suggest giving a +4? Intimidate bonus to the great boobrie only. The MC11 text also talks about ambushing, so a Hide bonus might be appropriate for the great boobrie, too. As for a Spot bonus, I'm not terribly sure, but I wouldn't necessarily be against one.
How about I give you 10 ft on the black boobrie land speed if you give me the lethal wing buffet?
I wouldn't mind having the Intimidate bonus only on the great version just to distinguish the two, but I'll give if it's important to you. As for the Hide bonus, I'm ok with giving it to both.
I like what you've got for those speed, full attack, and skill lines. Let's do that. I don't think I would limit the wing-buffet to every 3 rounds, just because I don't quite get the logic for it. Maybe it can't do it while flying, though.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.