I have included a video that illustrates hostile territorial behavior amongst male peacocks. In the video you can see that the two peacocks sort of circle around each other until one peacock hints that he is about to attack the other, where at this point they both proceed to charge at each other by flying up into the air. Territorial contact amongst peacocks can get pretty gruesome, making it a primary reason why it is very difficult to house multiple male peacocks in one place. Due to the fact that peacocks tend to prefer having multiple peahens in a harem-like setting to mate with, they don't particularly enjoy when other males are trying to do the same. At times peacocks can go as far as knocking off a fellow peacock off of his peahen partner while they are mating in order to cause mating complications. On top of fighting for the most potential peahen mates, peacocks also fight to rank highest in the peacock pecking order. At times this territorial fighting can become highly aggressive and can end up hurting one of the peacock fighters, ultimately decreasing the peacock's spot in the peacock pecking order.
Perhaps peacocks aren't the best example of aggressive territorial behavior, but from the video how do you think peacock territorial behavior compares to other animal territorial behaviors? How does their aggressive behavior compare to other birds?
Sources: eHow