I have read all the Redwall books, excluding Doomwyte, and I have noticed a big change from species to species in the protogonists of the books.
Mice are the most commonly seen creatures in the Redwall series, and some famous ones are Matthias, Mattimeo, Cornflower, and Martin the Warrior. I noticed that in the books after Mariel of Redwall that mice being the main characters thinned out, and others took their place. My opinion on this is that Brian Jacques wanted to explore other creatures and such.
Badgers then took over, with Salamandastron, Outcast of Redwall, and Eulalia!. They are the least seen creatures, but when they are in a book they are either a big character or the main one. Examples: Constance, Mara, Sunflash the Mace, and many more.
I like to call hedgehogs "just there characters", becuase they aren't all too critical in the books, with the exception of Abbess Tansy. They are usually for parties, because they are cellarhogs of Redwall.
There, as of 2008, has NEVER been a protagonist that is a mole, though Foremole and Arula are pretty important, but they are never that critical, and their "mole logic" is useful. My personal favorite of all the characters.
Otters are pretty much like mice, because they are main characters in many books. Like High Rhulain, and Taggerung. Those are the only two, but many, many are like secondary protogonists. For example, Winifred, Skipper, and all the other skippers.
Hares are only main in one book, which is The Long Patrol, being Tamello De Fformelo Tussock. Basil Stag Hare is pretty big and needed in Redwall and Mattimeo, being a great fighter. I think hares are much like Badgers, because they are fighters, and more common in the Redwall universe.