What physiological change occurs to the pectoral (flight) muscles during the fall staging period as the bird focuses on fuel storage?

Answer

They atrophy, shrinking by roughly 50%

During the fall staging period when they are consuming vast amounts of food, the grebe undergoes internal reorganization where its pectoral muscles shrink by approximately 50%, rendering the bird temporarily flightless.

What physiological change occurs to the pectoral (flight) muscles during the fall staging period as the bird focuses on fuel storage?
birdanimalFeaturewaterfowlGrebe