This is a simple nest to go with Simple Bird by VikKon. It is sized to fit a 50% scale bird with feet and tail attached.
You can find the bird model here https://www.printables.com/model/95198-simple-bird
Print with fuzzy skin enabled or you will end up with a flat bottom doughnut!
Fuzzy skin thickness 5mm
Print at .2 layer height
The author hasn't provided the model origin yet.