The Reaping of the Cloudtusk Plains

Outside the Myrdhor Desert and the tundra, the bamboo forests of the Cloudtusk Plains are the largest stretch of land without a single city, town, fort, outpost or other permanent structure you are likely to find anywhere. Might seem strange with so much buildign material and fertile soil around, but then again there is The Reaping.

— Jasper Cameron, Leader of The Bronze Ravens.

Notes from the Journal of Nyx Glitterquill

There are very few things in nature as majestically destructive as a Reaping on the Cloudtusk Plains. Like all such events, I have found its best viewed from a distance, although doing so is rather hard unless one is actively trying to do so. Outside of my journal your best bet at finding a description is talking to one of the caravans that crosses the plains. But why not just experience it for yourself.
The first sign of a reaping, as with almost all things related to Cloudtusks, will be the coming of a fog. I think the dwarven description which roughly translates to "the falling of a cloud to the ground" is probably more apt, but from inside the forests this is hard to see, hence "the coming of a fog."
Next will come the noise, starting as a quiet rustling of leaves and snapping of twigs as the adolescent members the storm make their dives and strip the top leafy portions of the tallest bamboos away. If you did not do so at the coming of fog, this is your sign to duck and cover. Lay as flat on the ground as you can, preferably under some sort of hard cover (although not anything that sticks up too high) and probably plug your ears.
The adults are coming
Take the axes of a thousand lumberjacks and creaking and crashing of the trees they fell and combine that with the wind of a cyclone and you will understand a bit of what it is like when a storm of Cloudtusts is feeding. Cutting swaths through the forest a few hundred yards at a time. This is, I'm convinced, where the greater magic of the cloudtusks is, not in their supposed control of the weather, or at least clouds, but in the fact that when they eat, cutting wide swaths through forests of bamboo, they lose little momentum. Their tusks pass through the bamboo, and most other materials, as easily as the sharpest blades cut cloth.
Ah, but I have fallen into the trap of writing about a reaping, not The Reaping. An event of destruction that happens with such clockwork regularity that in olden times it was taken as a sign that the gods had cursed these plains...

The Reaping

Cloudtusks mating season happens once every 7 years, occuring somewhere over the Outh Mountains where they border the Myrdhor Desert. Prior to this, cloudtusks harvest the plains that bear their name. There is no other word for it besides the name it has been given by the cultures that border the Cloudtusk Plains, a reaping. It is not as clean and orderly as a harvest you might expect in a wheat field, but it is no less effective for the supposed lack of intelligence in the animals.
In the spring, starting in the southern reaches of the plains, the cloudtusks start to form larger and larger groups, called quite rightly storms. Over the course of the year they fly up east side of the plains and then down the western side, glutting on anything they can eat. Males need the energy to fight, as is so common in the animal world, for the right to mate. The females that are pregnant from the last mating season protect the adolescents from the agressive males and build up their energy stores for their migration the the Sapphire sands to give birth in the coming winter before returning in the spring, a journey of some 8000 miles.
All this activity, understandably, takes a lot of food to sustain, and as a result the forests of the Cloudtusk Plains are very nearly clearcut down to between 4 and 8 feet over the course of the year. Likely why only bamboo grows here, as opposed to actual trees. Luckily for the other native fauna cloudtusks are not as thorough as inteligent farmers are. There are scattered patches here and there that survive the Reaping evey time, totaling around quarter million square miles. If this seems a lot for "scattered patches here and there" consider that it is only around 20% of the area Cloudtusks call home, and much of that, especially in the northern reaches, will sustain the cloudtusks that remain throughout the winter months.