My first idea was spawned by Albertus Magnus. Albertus states that animals all act in the same general ways (because of the "natural powers" which dictate the passions and actions of a species)1. This general way of thinking about the actions of animals (that they have predictable and common habits and actions) should carry over into literature. For instance, if there are two foxes in a fable, they should have similar personality characteristics and perform similar actions.
However, we come into further complexity when we talk about talking animals. Speech, at least in the modern sense, conveys intelligence and memory (and probably free will). We choose what to say, formulate it based on our intelligence, and often reference memories of prior events or knowledge and extrapolate them to the current situation. Although medieval scholars indicate animals can produce sounds to communicate certain things (Albertus, for instance, states that birds make certain sounds when searching for a mate), I doubt any of them would have called this "speech". Similarly, although Albertus talks about training animals, he does not express any belief that this learning indicates an understanding of speech similar to that of humans. According to Aristotle's tripartite model of the soul (which Albertus uses), although animals have sensory abilities and some cognitive ones (estimation, imagination, memory of a sort), animals do not have higher reasoning abilities like intelligence and free will 2.
Thus, talking animals presents a problem for analyzing these characters. As animals, they should all act alike and be incapable of the higher intelligences necessary to speak and form complete thoughts. Talking animals have taken on the human characteristics of free will and intelligence. Given this new "humanness" of the animals in the story, can we still analyze them according to medieval understandings of animals? Are there different conventions about the capabilities of animals when they are the focus of fictional literature? Does this convey something different about the mindset of the author about animals? Does it suggest medieval scholars were more flexible in their understandings of animals than their scientific/theological writings suggest? Or does it mean commoners were more likely to believe animals had human-like minds (and thus stories intended for children or commoners included human-like animals)?
Drawing on Albertus and the bestiaries, I could also discuss how talking animals in literature follow their animal descriptions (or not). Do they share the same symbolic or 'personality' traits discussed in the bestiaries? Are some animals (for instance, minor characters or non-speaking characters) more likely to adhere to their traditional description than main characters? Do the talking animals adhere more to their theological significance (as discussed in the bestiaries) or their natural behaviors (as discussed by Albertus)? I would anticipate that animals would adhere more to their theological significance, given that the animals are already betraying a part of their nature by talking (see above).
Similar to Idea 2, I could try to find several versions of a single story (Renard the Fox comes to mind) over a period of several centuries. These versions could be new translations of the same story or 'related' stories featuring the same characters but differing plot lines. I'm not sure which, if either, of these would be reliably available. However, if a chronology of one story or character can be developed, it would be interesting to map these onto the increase in knowledge about animals in the period. For instance, how did the portrayal of animals in fiction change after the rediscovery of Aristotle? After more empirical knowledge made its way into the knowledge base through people like Albertus, did talking animals become more like their real-life counterparts?
Sort of an inverse of Idea 3, would we expect regional variation from the same time period in the treatment of animals in stories and literature? Would cultures in Europe closer to the Byzantine empire use different animals that were more common in that region? Or would their common Christianity be enough to convince them to use similar animals? Would the bestiaries give them enough information do use the same animals or do animals not found in the bestiaries make appearances? If they use different animals, do the animals they choose have similar symbolism in Christianity or similar habits, suggesting that they're trying to tell the same kind of story or emphasize a similar moral? (I'm not sure how easy it will be to find stories from cultures not from Britain or France. We seem to have some sources that reference German sources but not anything farther east.)
So, those are my four competing ideas right now. Obviously, they're rather similar and all draw on Albertus Magnus and the bestiaries. Do you think one is a better topic than another (I've never done a research paper like this before)? Do you think there are more sources available for one or another? Are there ways to combine ideas or a fifth idea I haven't thought of?
1. Albertus Magnus, On Animals: A Medieval Summa Zoologica, trans. Kenneth F. Kitchell and Irven Michael Resnick, 2 vols. (Baltimore: Johns Hopkins University Press, 1999), vol. 1, book 8, tract 1
2. Class notes, Animals in the Middle Ages, Professor Rachel Fulton Brown, October 6, 2010.