When Bart accidentally kills a mother bird, he tries to make amends by raising the eggs.
After accidentally killing a nesting bird, Bart looks after her eggs, but when they hatch the babies are not fledgelings but tree lizards, who deposit their own eggs in birds' nests. They are quite unattractive but Bart takes to them, giving them names. They do, however, come into their own when it comes to ridding Springfield of its pigeon problem.—don @ minifie-1