There are two ravens that have ability: crack an egg from another bird to get two of any food from the supply.
The killdeer/franklins gull have the ability crack an egg to draw two cards.
Why are they powerful? Well, they can allow you do do things outside of a normal habitats function. And if you join together, you only need to take “grassland” actions to lay eggs, whilst also drawing cards and getting food.
So by the time it was a couple of cubes into the second round I could “lay eggs” to;
- lay three eggs
- crack an egg for two good (raven)
- crack an egg for two cards (killdeer)
- lay an egg on this bird (quail)
One action netted me
- two eggs
- two food of any type
- two cards