In an Experiment on Wayfinding, Indigo Buntings Were Housed in Outdoor

Multiple Choice

In an experiment on wayfinding, indigo buntings were housed in outdoor cages with blotting paper walls and inkpads on the floors. Which line of evidence demonstrated to researchers that the indigo bunting uses the positions of stars to orient its migration?

A) The birds' inky feet made prints indicating the direction in which they attempted to fly.
B) In spring, the inky footprints were mostly on the northern side of the cage.
C) In fall, the inky footprints were mostly on the south side of the cage.
D) On cloudy nights, the inky footprint patterns were evenly distributed in all directions.
E) In spring, the birds' anterior pituitary gland generated a series of hormonal changes.