Apes are pretty sophisticated creatures. I'm not sure how they really respond when one of their own family or "tribe" is ill, but I'm sure those who work closely with them, (like Jane Goodall), would be able to elucidate a lot more about that.
Knowing what I do from my own experience with animals that were part of my own family, and what I've read and gleaned from my partner who is a naturalist, I would not dismiss the animal kingdom as having a less developed consciousness than our own. In fact, I think this is a highly prejudicial and humanly superior attitude, which is based on ignorance of the natural world and being out of touch with one's own inner nature--as most of us have been trained/acculturated to do. Unfortunately, certain aspects of our scientific method were very influenced by the early Christian church, and their twisted belief that "MAN HAS DOMINION OVER THE EARTH." This reduced nature and all non-human creatures (and even women) to a "less than" status, and placed humans (white men in particular) on a pedestal as the "masters" of everything alive on this earth. It's now very obvious, what a disaster that has proven to be!
I have learned a lot from nature and from the animal kingdom in this long retreat from the world brought about by CFS. I have learned how to listen more carefully, to pay attention more closely, and to trust my instincts to a far greater degree. I have learned that the best way to find out who someone really is, is to give much less credence to what they TELL me, and pay much better attention to what they actually do. A lot of people can give you a brilliant earful about what they think/feel/know about compassion and commitment and loyalty and integrity, but do they show up when they say they will, and do what they had promised? Just that alone can be VERY revealing.
When I look back at all the people who disappointed, hurt, abandoned or even hated me for being ill, during these 33 years of CFS, I have to admit that some part of me just knew that would happen... even if I hoped against hope that it wouldn't. Even though it was often painful to face the truth, in some ways it was a relief to let go of the bad friends, the ones who just did not care and didn't want to. In many ways this illness has been a great filter to help sort out the little chunks of gold that proved to be worth keeping. I am very grateful I found a few of those.