Apr 29 2009
Question: What roles do each of the parents play in feeding and raising the chicks?
Answer: The roles vary as time passes due to the changing needs of the nestlings.
The chicks must be brooded in their first week because they can’t regulate their body temperature. The mother bird does most of the brooding, especially the night shift, while the father bird does most of the hunting. Both parents feed the young and “take out the garbage” and both guard against predators. The male tends to guard the wider territory while the female guards the nest.
By their second week the chicks don’t need an adult to keep them warm but they do need a lot of food. The mother is now freed from constant nest duty so she hunts too. Their ability to find prey varies - bad weather is bad for hunting - so the adults hunt more during good weather and cache the extras for a rainy day.
Note that in all of these descriptions the exact division of labor varies among mated pairs and from year to year. For instance, at Pitt this year (2009) E2 is doing more brooding than he did last year, which frees up some of Dorothy’s time for guard duty or hunting.