Summoned Animal type from terrain
 

I am curious whether anyone experienced with summon animals / animal horde can provide the summonable units by terrain? And if there are 2 terrains mixed (mountain + forest) which terrain will be used for the summoning?

Recently I cast animal horde in a forest + swamp province and received only giant spiders + horned serpents (Nice for the cost), I have fuzzy memory of summoning wolves and bears in a pure forest so it seems the summoning is based on purely swamp terrain.

I would be grateful if someone can save me the testing time :D

Fuzzy memories and guesses:

Plains: ?wolves, ???
Farmland: ???
Mountain: ?wolves, ?bear, ?eagles, ???
Forest: ?wolves, ?moose, ?bear, ?boar, ???
Swamp: Horned serpent, spiders, ???
Wasteland: ???
Water: ?sea dog, ?sea lion, ?ichty horsey thingy, ?kraken, ???
Deep water: ?kraken, ???
terrain combination rules: ???