The storm washed away sand and vegetation that many species spawn in or call home, or polluted habitats with oil and sewage.
Particularly troublesome is damage to the beaches of the Delaware Bay in southern New Jersey. The area is known for birds including the red knot. The shorebird stops there to feed on crab eggs on the way from South America to the Arctic.
But Sandy washed away sand that the crabs need to spawn. And repair work will cost millions of dollars.
The money for it and other repairs to help habitats will come from federal and state governments and nonprofit organizations.