You get Experience every time you you give food to a nest.
The amount of food given is limited by:
- Remaining space in the nest
- The amount of food you have
- ... and 50
This means that you can give away food several times to the same nest if you have a lot, the nest have available space, and get one exp. every time. Or just be pleased with giving them 50 and keep the rest.
Experience: +3 per food