Here's what a professional ecologist, Dr Paul Colinvaux, said about this entry:

Carrions and hoodies. I have wondered about those two as you have, and I too like the idea that they are a character displacement pair. The one point I suggest you check on if you can (and if the data exist) is the the molecular data testing the hypothesis that they are two true, genetically isolated species. I know this has been done with some corvids, the American crows Corvus brachyrhynchos (known here simply as ' a crow') and C. assifragus (fish crow) which look like two peas in a pod, (plain black, gregarious versions of the European carrion crow, but a bit smaller) have been pronounced to be 'good' species by molecular methods (or so scuttle-butt says, I have not seen the original papers as not up with the bird literature). If the hoodie really is a distinct species, then I plump for the character displacement model as you have. Possibly you have not exhausted the possibilities of behavioral differences (including preferred diets) as characters for selective advantage. I am no bird man, but my impression is that hoodies can be really gregarious. I once saw huge flocks flighting into a village in Russia to roost for the night, thousands of them behaving like-over grown starlings, complete with the chatter. Like rook flights in England, the crowd had jackdaws as hangers on. I doubt that animals so gregarious can be carrion feeders (though it is my cynical view of crow life that any crow will eat anything if it gets the chance). I have little doubt that the great flocks I saw in Russia were coming in from a day of feeding on the lands of the local collective farm (this was in Soviet times). Another hint is also from Russia. Hooded crows are the common birds of Moscow, roosting in the linden trees that line Moscow avenues and pottering around your feet like pigeons: again does not sound like carrion eatiers to me.

Your account of character displacement and competitive exclusion seems O.K.

I only read your piece through once, not being able to print it. I hope the above is of some use to you.