Here is the full list of all 46 Natural Instincts achievements.
Finish all quests with bears
Finish all quests with rabbits
Have at least 10 pregnant female rabbits at the same time
Breed every species to at least 20 animals living in the forest at the same time
Finish all quests with wolfs
Finish all quests with boars
Have at least 1 animal with the "long-living" trait in each species at the same time
Finish all quests with deers
Fill all three needs to a minimum of 90% of all wolves in a pack
Have at least one female with litter in each of the 5 animal species at the same time
Witness 25 deaths of old age
Save a species from extinction
Increase the number of animals to 50
Increase the number of animals to 25
Finish the boars campaign
Fill all three needs to a minimum of 90% of all boars in a herd
Get the sick wild boars out of the forest before the poachers come
Finish the rabbits campaign
Witness 50 animals becoming adult
Have at least 4 bunnies with the “agile” trait at the same time
Complete 10 animal matings
Spend an hour in the game
Breed a rabbit to have the speed trait at maximum
Breed an animal with at least two positive traits (for example: “fertile”, “long-living”, “agile”, “very-fast regeneration”)
Name all of the animals in the forest
Finish the wolves campaign
Lead animals to a source of food 25 times
Complete 10 successful wolf hunts
Choose the strongest wolf in the pack to become the alpha. Required traits: fertile, long-living
Fill all three of any animal's needs to a minimum of 90% for the first time
Complete the tutorial
Order any predator to hunt for the first time
Start the tutorial
Hunt a deer that has offspring
Complete 10 successful bear hunts
Witness 10 deaths from hunger
Spend a total of 10 hours in the game
Breed a wolf to have the speed trait at maximum
Don’t allow hunters to kill any of the animals in your forest
Create a pack with at least 4 wolves with the "Strong Health" trait
Fill all three needs to a minimum of 90% of all rabbits in a herd
Fill all three needs to a minimum of 90% of all deer in a herd
Fill all three needs to a minimum of 90% of all bears in a forest
Have at least 1 animal with the "fast regeneration" trait in each species at the same time
Witness 25 deaths caused by a car crash
Allow at least 4 boars to eat garbage out of the dumpsite