Quartz92,
I can't REALLY tell you what goes on during Keeper for a Day! That would ruin the surprise
What you do in the program really depends on which area you signed up for, and even then it can change between days. We all start work at a morning meeting, where we 'check in' with our supervisors, get a briefing of yesterday's happenings as well as events for the day, then head off to work.
As a KFAD (acronym), you will be following one (or a team) of keepers through their daily routine; we usually try to make sure that you see all of the coolest stuff, and sometimes take some time to visit other areas of the zoo as well. You'll probably be involved in every aspect of being a keeper ... making diets, checking exhibits, cleaning holdings, working with the animals ... if we do it, you'll do it too!
Yes, the zoo does have some sort of masterplan, but I haven't seen it recently (and it changes regularly based on things that need to get done ASAP).
Re: giraffes, I'm very sure that Shomari was the last baby; he was born in August of 2006, and with a gestation of 15 months, if Twiga had gotten pregnant right away, we wouldn't have had another calf until November-December 2007. As far as I can remember, the only time that we have ever had five giraffes is when both Twiga and Ginetta had babies - the house just isn't big enough to handle more!
Aisha DID get her name in a contest (the name she was given by keepers was "Naima")
Oh, and Meaghan, the last hirola passed away a few years ago - they should be on the "species extinct in North America" list.