Calves are born without the thick layer of blubber (fat) that they need to keep warm in the colder ocean of their summer feeding grounds.
(Calves; are born; ) Context(Calves are born,List([0, 15))):(they; need; to keep warm in the colder ocean of their summer feeding grounds) Context(Calves are born they need,List([0, 71))):(they; need to keep; warm; in the colder ocean of their summer feeding grounds)
Calves are born,List([0, 15)) Calves are born they need,List([0, 71))
Calves they they
are born need need to keep
to keep warm in the colder ocean of their summer feeding grounds
warm in the colder ocean of their summer feeding grounds