[Campbell Biology P.1205] The blackcap migration study revealed a significant change in migra... | Practice Question

The blackcap migration study revealed a significant change in migratory patterns. Which statement correctly describes this phenomenon?

  • A: The new westward migration pattern emerged before 1950 due to environmental pressures.
  • B: Researchers found no genetic basis for the shift, attributing it solely to learned behavior.
  • C: By the 1990s, 7-11% of German blackcaps were westward migrants, partly due to winter bird feeders in Britain.
  • D: The study concluded that migration patterns are entirely fixed and unaffected by genetic variations.

Explanation

The blackcap study clearly states that westward migration emerged after 1950, growing to 7-11% of the German population by the 1990s. This shift was attributed to genetic differences and facilitated by factors like winter bird feeders in Britain, which offered a new, viable wintering ground.