
avr |

What's the human culture like? Human-specific feats are impossible without this, unless you want to use the feats to define the culture rather than vice versa.
There might be a feat to allow gathering poison when in the jungle, using rules like those under survival for gathering food while travelling.
Possibly a feat for brachiation (swinging from tree to tree). I've seen brachiation handled as a climb speed in trees only but you could certainly get more fancy.
A feat for arcane casters to learn spells directly from the spirits might be useful if there are no cities and nothing like a magic-mart. If there are cities then never mind that.

avr |

Ex-slaves, huh. Slaves are most likely labourers and house servants, but there's probably some skilled workers, maybe the odd gladiator, possibly some non-slaves who got swept up via having friends or relatives liberated. Just thinking as I go along here.
Slaves are often forbidden weapons. Perhaps steal Superior Unarmed Strike from D&D 3.5's Book of Nine Swords - basically it gives a progression for unarmed damage to non-monks.
There's no real chance of being a full-time religious figure and little of being a full-time scholar as a slave, but there's certainly a call for someone who can do some sort of magic. Translation: spellcasters (especially 9-level) may be rare but occult rituals might be known. Perhaps a feat to give one known to the character and a bonus to perform rituals?
Whatever secret organisation existed to allow slaves to cooperate and communicate presumably still exists. It's probably powerful. Being a member in good standing might carry advantages as far as locating people or goods go, and if it's the new government it might carry law enforcement powers. Worth a feat?

avr |

Another thought. Not being noticed is a valuable skill for a slave. Not sneaking, that would get them beaten at best if they're caught, being part of the background and overlooked. I'm not sure how to model that but something like the mage of the veil archetype ability (but not magical) might do:

Bodhizen |

Thank you for the suggestions. I've now moved on to the "strix" portion of my setting. Still considering general feats for the jungle-type setting, but also now considering feats for strix characters; their role in the jungle-world is an aloof race that views "walkers" as beneath them (both figuratively and literally). They're not slavers (a different race fit that bill), but they are a rather martial and rigid society with a vast empire. They are adept at both war and trade, and while they haven't expanded their empire in centuries, they're about to peak (culturally speaking) and have the potential to enter a phase of decline. Political corruption is just beginning to emerge, family values are just beginning to erode, and paranoia is just beginning to spread (although it hasn't blossomed into xenophobia yet). Effectively, they're the equivalent of 1950's America in terms of their economic power and military stature.

avr |

Arrogance might be a shield against influence from other races. I could see a feat which gives a bonus on saves vs. such influence and against some skill uses upon them. More of an NPC feat considering that PCs are rarely diplomanced by NPCs.
I don't know what their traditional military style is but it's probable they'd have a feat or two related to it. Formation flying teamwork feats perhaps?
Most of the benefits I can think of are social, economic, or already covered by some feat or another though.