Here is the full list of all 19 Secrets of Rætikon achievements.
Find all hidden rune orbs
Hurt an animal with a stone you dropped
Throw and Catch rabbit in mid air
Dive the deepest well
Lift a lynx in the air by its tail
Get a buzzard to hit a lynx
Hit an animal with a thistle
Feed the daw with prey
Bring an animal from one area to another
Hurt a buzzard by letting it dash into a solid
Hatch a bird
Get a daw to fight a buzzard
Get a female rabbit to give birth to 8 babies
Carry a total of 130 slivers
Hatch a buzzard and let it kill a lynx
Avoid the unavoidable
Don't hurt anything
Never get critical health
Never get hurt