Context: Species that have no long-distance migratory relatives, such as the waxwings Bombycilla, are effectively moving in response to winter weather and the loss of their usual winter food, rather than enhanced breeding opportunities.

Question: What species has no long-distance migratory relatives?
Answer: the waxwings Bombycilla

Question: What are the waxwings Bombycilla moving in response to?
Answer: winter weather and the loss of their usual winter food

Question: Why are the waxwing Bombycilla not migrating for?
Answer: enhanced breeding opportunities