What do dating penguins offer each other to show their interest?

Mr. Bill

The male places a pebble at the feet of the female. May 04 00, 9:19 PM

Odonnell

The pygoscelid penguins build their nests from whatever material is available. Since these penguins nest on the edge of the Antarctic continent (Adelies) or on southern sub-Antarctic Islands, the choice and availablity of nesting material is very limited. Nests usually consist of a rough circle of stones. The value of these stones can be judged from the fact that they are offered as presents during mating and re-bonding rituals. Stones are frequently stolen by penguins from other penguins' nests. May 04 00, 11:11 PM

zbeckabee

For gentoo penguins, it's all about who's got the best rocks. Like a human offering jewelry, this gentoo male at the Edinburgh Zoo presents a large pebble on Tuesday in hopes of winning over a female. But sometimes finding the flashiest gifts isn't enough. During the mating season—which begins in March and lasts up to six weeks—males suffering from "pebble envy" will steal the best-looking rocks and pawn them off as their own. The pebbles will eventually become parts of the penguins' nests—large circular piles of stone that can reach 8 inches (20 centimeters) in height and 10 inches (25 centimeters) in diameter. GREAT PHOTO: http://news.nationalgeographic.com/news/2007/03/070316-week-photos.html?source=rss Feb 04 08, 7:30 PM