The intertidal sand flats along the edges of the Yellow Sea are disappearing. Why would it be unlikely that migratory shorebirds could use another feeding location if these habitats disappear? choose all of the correct answers_____
a. Migration patterns are genetically coded so the birds must take the same migration route every year.
b. The bird's bills are highly specialized to feed on specific prey resources that are found in the intertidal area along the Yellow Sea coast.
c. Highly productive areas in the Yellow Sea are critical for the bird's survival.
d. There are no other large expanses of intertidal areas or marsh along their migratory flyway.