To answer your question about the longest feather in the data set studied by Jerome regarding adult wood ducks, I would need to know the specific lengths provided in the data set. Generally, the longest feather can be identified as the maximum value among all the measured lengths.
If you have the data (i.e., the lengths of the feathers), please share that, and I can help determine the longest feather length. Otherwise, you may look for the highest value in whatever data set you have to answer that question.