The ostrich.
A cuckoo does not make a nest, a cuckoo will lay an egg in another birds nest, the other bird will then care for the egg and chick as if it was it's own.
egg
Oystercatcher birds lay white eggs with black speckles. Oystercatchers typically lay between one and four eggs. These birds are known to practice "egg dumping", which is where they lay their eggs in the nest of another bird, leaving the other bird to raise their young.
The Cuckoo is notorious for laying an egg in another bird's nest, leaving the host bird to raise the cuckoo chick. Once the cuckoo chick hatches, it instinctively pushes any unhatched eggs and chicks out of the nest, leaving the cuckoo chick the sole occupant.
A Crow???
No. It will be pushed out of the nest.
the mother bird will not come back to the nest, and will just leave the egg there.
they hatched or some other bird ate them
Canaries do knock eggs out of their nest. This is done sometimes if the bird knows the egg is not thriving. Eggs may be knocked out of nest by predators to the canary bird also.
press space on the nest
First, you make a nest. Then, when an egg picture appears on the upper left corner of your screen, you press the space bar while you are on your nest and an egg appears.