Obviously, a set of animal personalities would be great, especially if they had actual effects on how individual animals could be housed. I would be fine with, say, four different personalities:
Relaxed - basically the vanilla personality, that is comfortable with almost anything.
Curious - has lower shyness and is well-suited for walkthrough enclosures but, as with real hand-reared or strongly humanised animals, it may not associate so well with its own kind and so they are less likely to breed - they are also less suitable for reintroduction
Timid - has elevated shyness and needs to be kept in an enclosure that will accommodate its need to avoid people; however they are preferable for reintroduction because they do not investigate every potential threat
Assertive - has higher aggressiveness and so is not suited for either walkthrough or mixed-species enclosures; however, because they are dominant animals they are more likely to be good at breeding
This could then be used to change the requirements for reintroductions - at the moment, it is simply sending them away to the wild and that being the end of it. With this, an animal's personality and upbringing can affect the outcome and determine if the reintroduction succeeds or fails.
Another thing I would quite like for mixed exhibits (which would hopefully be easier to implement) is for animals to respond to the proximity of other species in various ways. So, for example, a herd of springbok would move out of the way of a rhino if it started walking towards them, or a tapir would react to fighting capuchin monkeys by stopping and staring in their direction. This would be more accurate to many mixed exhibits I have seen, where animals will tolerate one another but still prefer the company of their own species to anything else.
Relaxed - basically the vanilla personality, that is comfortable with almost anything.
Curious - has lower shyness and is well-suited for walkthrough enclosures but, as with real hand-reared or strongly humanised animals, it may not associate so well with its own kind and so they are less likely to breed - they are also less suitable for reintroduction
Timid - has elevated shyness and needs to be kept in an enclosure that will accommodate its need to avoid people; however they are preferable for reintroduction because they do not investigate every potential threat
Assertive - has higher aggressiveness and so is not suited for either walkthrough or mixed-species enclosures; however, because they are dominant animals they are more likely to be good at breeding
This could then be used to change the requirements for reintroductions - at the moment, it is simply sending them away to the wild and that being the end of it. With this, an animal's personality and upbringing can affect the outcome and determine if the reintroduction succeeds or fails.
Another thing I would quite like for mixed exhibits (which would hopefully be easier to implement) is for animals to respond to the proximity of other species in various ways. So, for example, a herd of springbok would move out of the way of a rhino if it started walking towards them, or a tapir would react to fighting capuchin monkeys by stopping and staring in their direction. This would be more accurate to many mixed exhibits I have seen, where animals will tolerate one another but still prefer the company of their own species to anything else.