Natural disasters, the curse makes all possible and makes them more likely to happen.

Attacks, happens when the border drops and gets more likely the lower it gets. What can attack are,
Dogs, will scare away prey if they are not defeated and might decide to settle on the territory.
Badgers, make a lot of noise will kill any cat that is alone and scare prey off if not defeated
Large Birds, take prey and small or weak cats if not defeated.
Rouges, will take herbs, prey, and maybe some cats as well as destroy dens if not deafened.

Apprentice Sickness, happens when an apprentice gets the sickness. All apprentices should be kept away from sick apprentices and the apprentice is most likely going to die.

That's all of them for now suggest any more that you want to.