William Beebe,
The Log of the Sun: A Chronicle of Nature's Year
“ The last pin-feather of the new winter plumage has burst its sheath, and is sleek and glistening from its thorough oiling with waterproof dressing, which the birds squeeze out with their bills from a special gland, and which they rub into every part of their plumage. The youngsters, now grown as large as their parents, have become proficient in fly-catching or berry-picking, as the case may be. ”
