I'm just going to give you a tiny taste of what my critz are like, so if you meant you want 'constructive' critz such as "WOW Dani thisisfriggindamnawesome!", then let me know and I'll stay out of the thread.
If my bluntness offends you or you feel under attack because I dissect every single little thing, it's not because I'm being nasty or trying to discourage you. It's all constructive critz, REALLY, but a lot of young writers just aren't thick skinned enough to take it well. And, I've got the 14 years of persistent daily writing experience behind me to back up the fact that I pretty much do know what I'm talking about.
So...here:
The humans had seemed to give up hope. Only coming out at night to get food and go to the bathroom.
Could be:
The humans had seemed to give up hope, only to come out at night to get food.
Or,
Humanity had abandoned hope and reverted to instinctual survival mode, emerging only in the safety veils of night to scrounge the earth for food.
Etc.
Notice that I've completely left out the 'bathroom' bit. This is because you need to give your reader's intellect a bit more credit. You don't need to put down that the humans went looking for food AND to use the bathroom at night (apart from putting both those visuals in the same sentence drafting up a very unhygienic picture) It's human nature. Obviously, people need to use the can from time to time. You don't need to add that detail, because 1. readers don't want to read about other people relieving themselves, and 2. readers wouldn't wonder where or when the characters need to go. It's an unnecessary detail that can be left out and overlooked easily in face of the bigger picture.
It's like, for example, writing that Bella went over to the stove with a big metal spoon, smelling the pasta her dad had left on it starting to burn, and stirred it to losen the burnt pasta from the bottom of the pot before taking it off the stove, and then painstakingly picking all the burnt little pieces out before dishing up. What's the point? Just write, Bella caught the pungent odour of something burning, rushed over to remove the pot from the stove, and tried to save what she could from the pasta dish.
They only mated during a specific season that varied on each tribe.
I always say that good writers are exceptional liars, because if you're really good, you can make the reader believe that the world you created is real and the characters you created are real. That obviously means you need to have answers to
everything. You need to make it plausible.
With that in mind, why do the tribes only 'mate' during specific seaons? Why does it differ from tribe to tribe? Why is the word 'mate' used? Have the humans become animalistic in their behaviour? Also, you need to consider irl, it can take a lot of couples 6 months to a year to conceive, often with medical aids to help them, seeing as natural fertility is being replaced by artificially advanced fertility pills lately, so if people are trying to conceive to keep the human race going in your story, and this after a global war with all those toxins in the air, probably contaminating their water and food supply, it might be more believable if you play that in. Fertility is and would be drastically declining in the circumstances you created, so... I don't know, you could opt to have very very few births actually taking place in the tribes, most of them being unsuccessful as you've stated, why don't you make it be a big and rare accomplishment if they do manage to reproduce? So all the tribes are notified somehow and everyone knows about these little kids. I mean, this is the future of the human race we're talking, right?
All that rambling aside, what is the plot? I know the setting and the circumstances, but what does the story itself revolve around?
It's a good idea you've got, the prologue does need a lot of fine tuning, but seeing as you're not aiming for publishing there's no need for me to really hammer on all the tiny dents to create a smooth piece, y'know? Unless you want that type of critz.
So. >phew<
If you want me to GTFO your thread, I'm sure you'll let me know.