Sherlock Holmes (1984)

S2E17 Blinky Bill and the Egg Rescue

Flap discovers a cuckoo egg nestled in a basket out on the grasslands. Blinky and his crew make several attempts to place it in different birds' nests, but none of their efforts succeed. When a bulldozer threatens the area, Blinky and his gang spring into action, saving all the other birds' eggs. Eventually, the eggs hatch, and the ducks take the cuckoo under their wing, embracing it as one of their own.