So the primary item I wanted to place on my expanded map is the summer auroch pastures. [Which reminds me – I need to remove the auroch from the random encounter table during the summer months and replace them with horses.] I also needed to show the migration path between the two areas. The winter pastures are 3483 sq. mi in area (which may be small, but I think it is do-able), so the summer pastures have to be at least that large. Plus I need a route between the two that is believably long. I also need a reason for the migration to happen, both in the fall and in the spring.
So I put that on the map in a way that looked OK without worrying about distances and areas too much. The summer pastures spill off the bottom of the map, but that’s OK for the moment. Later I’ll add more map. I may also extend the route between the two pastures and push the summer pastures onto the next page.
Now I’ve set up the two locations by seasons, so weather shifts must be at least one of the causes. The easiest thing to do is make the summer pastures nice and relatively safe, but frigid in the winter. As close as I drew the two pastures (only ~105 miles apart right now - that might change, see above), I need a darn good reason for the two areas to have different weather. Clearly the summer pasture must be at a higher altitude, so I need a series of plateaus or an escarpment (or two) to denote the altitude differences. [Note to self: add the escarpments and some passes for the auroch herds to use.]
These passes will make good hunting for humanoids at least twice a year, so this is where I’ll assign some of the humanoids I avoided using on the starting map. I can also put some tension between population pressures and conflict over prime hunting areas, making the area tense for the players to explore, but rife with role-playing opportunities (that's my theory anyways).
So the aurochs leave the summer pasture when it gets cold. Why don’t they stay in the winter pasture all year? Predators and lots of them. Cheetahs, worgs, chimeras, bulettes, and a ton of other monsters that live in the area. The studies I read (well, skimmed anyways) indicate that while herbivores often migrate and some of those tremendous distances, predators don’t. So during the winter, the area predators eat a lot of aurochs and tend to give birth to their young, while the food is plentiful.
The aurochs on the other hand are merely wintering here. They will not give birth until the spring when they return to the summer pastures, but their mating season happens in the winter pastures, near the end of the winter. This is one of the major triggers for the migration. They are also fiercely territorial at this time and adventurers should beware.
Yeah, that’s about all I’ve got on that for the moment. Next week I’ll discuss the swamp area and possibly the jungle I’ve added. Tonight is the next game session, so there will be an adventure log on Monday.