Two keepers in one habitat, it is possible.

[Dr4gon]

I have two keepers working on this habitat. One is cleaning and the other is feeding. This was an emergency, since at first nobody was feeding the snow leopard. So I assumed, since I hadn't played that zoo for a week or so, that there was no keeper assigned to this habitat. I built an other working place for a mechanic and one for a keeper, and called him to work go feed the hungry leopard!
And guess what, there was an other keeper, and he also came to the habitat.

 

[HeatherG]

I’ve had 2 keepers also. I was surprised when I saw that. It seems to happen, for me, when I have to many animals for only 1 keeper to handle. For example 25 flamingos.

 

[Dr4gon]

I’ve had 2 keepers also. I was surprised when I saw that. It seems to happen, for me, when I have to many animals for only 1 keeper to handle. For example 25 flamingos.

Yes, and they only need one entrance, not two. That is a pity, because with large habitats, one staff entrance in the north and one in the south would be perfect.

 

[Dae]

Yes it happens but it happens almost by accident, I have a large habitat with mixed species, and many times there was a cleaning issue with the first zookeeper busy feeding everyone... I tried to get a second one in the habitat and I can't make it happen (because the call button is linked to the one feeding and it's a link that can't be broken). When very occasionally it happens it's because by chance the game affected a second one, but I wish I could call 2 or 3 keepers in (one feeding and one or two cleaning), and not just "call a keeper" that will always start by feeding instead of the emergency cleaning although animals are not starving... and I end up with sick animals and protesters, just because I can't set priorities in the tasks orders or call many keepers.