The two constructions you've asked about "to see it end" and "to see it ending" have slightly different meanings. The first means that animals hate a particular instant of time, namely when the monotony ends. The second means that animals hate an interval of time, over which an end develops and then occurs. The interval is indicated by the progressive form -ing.
If we transpose this to our favorite anthropoids, a person may hate to see a movie end, which means he's disconsolate when the screen goes dark, or he may hate to see a movie ending, which means his depression starts when the end credits start to roll.
But don't you really want to know why it's written "to see it end" instead of "seeing it end"? Again, the analysis indicates that "to see" means a single sight; "seeing" means an interval of watching. But the difference is very small because the view is of an end point.