The Edinburgh Zoo is recently providing and laying out pebbles to help its male Gentoo penguins (Pygoscelis papua) find a mate. The keepers place large doughnut-shaped nesting rings in the enclosures during the mating season for the Gentoo penguins to build their nests in, and then pebbles are gathered and placed within the ring as a blanket for the eggs to be laid on. Pebbles are useful materials for nest-building especially in areas without plants; such nests could possibly save an egg or a chick from drowning if there is a flood.
The male penguin basically sifts through the available pebbles to find the smoothest (slightly flat) one — these pebbles tend to sit the best in the nesting rings — to present to its intended mate, and if the female penguin accepts the pebble and puts it on the nest she’s sitting on, a marriage would be formed — she has accepted the male penguin. Zookeeper Roslyn Talbot mentions that this courtship process also provides an opportunity for the penguin couple to bond. And ‘pebble envy’ could even occur, where the male penguin actually steals pebbles from other penguins, but naturally not without some defensive behaviour from the pebble owners.
Pebbles in Gentoo penguin enclosure at the Edinburgh Zoo
This courtship/mating ritual is not only evident in the Gentoo penguins, but also in the Adelie penguins (Pygoscelis adeliae) of Antarctica. In fact, this rather cute courtship behaviour inspired the production of an animated musical film The Pebble and the Penguin back in 1995!
I guess this gives new meaning to “picking someone up”!
“Gentoo Penguin nesting,” by M. Pettitt. Flickr, 10 Jul 2006. URL: http://www.flickr.com/photos/mdpettitt/186727159/
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“Pebbles help penguins mate,” by BBC News. BBC News, 31 Mar 2010. URL: http://news.bbc.co.uk/2/hi/science/nature/8597520.stm (accessed on 3 Apr 2010).
Stone, L.M, 2002. Penguins. Google Books, URL: http://books.google.com.sg/books?id=qws0gwkvc4gC&dq=gentoo+penguins+and+pebble+and+mating&lr=&source=gbs_navlinks_s (accessed on 7 Apr 2010).
“The Pebble and the Penguin family fun edition DVD,” by FunkMonk. Wikipedia, 11 Dec 2008. URL: http://upload.wikimedia.org/wikipedia/en/8/80/PEBBLE.JPG (accessed on 6 Apr 2010).
“The way to a Penguin’s heart… a pebble?,” by P. Dickinson. Zoo News Digest, 31 Mar 2010. URL: http://zoonewsdigest.blogspot.com/2010/03/way-to-penguins-hearta-pebble.html (accessed on 6 Apr 2010).