This is a planned mod! It isn't made now, but I begun to work!
In GlacialCraft, you are playing as an early human in Pleistocene, 35 000 years ago, in the time of famous "ice age". You can't make some crafts now, even crafting table or a pickaxe! You can make only things that Paleolithic humans can make, for example - wooden spears and chopping tools. So it is a little bit TerraFirmaCraft-like, but more Paleolithic-based.
WORLD GENERATOR AND BIOMES
World generator is changed a little bit:
1. Now world generate more like continents, with some large ground patches separated by water. And yes, mountains are rare there.
2. Biomes now generate differently. That means no taiga, desert, swamp and jungle close, only similar biomes closely.
And there we have only 2 vanilla biomes. They are:
But there are some new biomes:
This mod removes all vanilla mobs, except creepers, BUT they exist only as an "easter egg". Instead, it adds some more unique mobs, for example - famous sabertooth cats and woolly mammoths.
BEHAVIOUR - timid, but females at nests - territorial
Black grouses are common birds in Pleistocene. They look like similar to chickens, but their behaviour is different. Usually they will fastly run or fly away if they see a player. Grouses usually eat seeds, insects, berries or pinecones, and rarely - small stones (using them as gastroliths). They are peaceful and will escape from any predators. Grouses are hard to hunt due to their speed and small size, and yes, if you stay even on distance of 20 blocks, they will see you and escape.
At spring, males will lek at marshes, and at summer female grouses make nests and lay eggs that will hatch after 4-5 days. Females will not escape and protect their nests, but if they will be damaged too seriously, they will escape. Chicks usually hide in the grass, but if player or any carnivore close, chicks will start to leap and fly to trees. They will not get down until danger will get far. And yes, parents will feed chicks. After 1 year chicks will become adults.
Grouses can be tamed by feeding them seeds, but due to their skittish nature you can feed them only if you're are sneaking by pressing shift (and even this way they will escape when you get as close as 2 blocks). After taming, grouses will follow you and (if female) lay eggs, BUT only at spring and summer. After 12 days they will leave you, BUT if you tame chicks, they will not leave you.
Grouse drop is same as with chickens. And yes, they are the best way to get eggs because they are easiest birds to tame.