While the macaroni penguins have a relatively flamboyant courtship display with loud calling and swinging heads, the gentoo penguins are a bit more subtle. There is some calling, but one of the more interesting rituals is a greeting the starts with a bow. Two birds that may be attracted to one another will dip their heads low to the ground and then bring their heads up while opening their beaks and exhaling. It's almost as if they're saying to each other, "You take my breath away."
Here's what senior aviculturist Amy Graves had to say about the Tennessee Aquarium's gentoo penguins and their reactions to the "magic rocks."
"In the gentoo world, all of the same pairs from last year seem to be holding strong. There were four individuals that were just too young last year and never paired up. They really didn’t know what was going on. But this year, I think they’re starting to feel the 'tingle in their toes' and getting a little bit of excitement from the rocks. They might pair up this year or just play around in the rocks."
"Of the four youngest gentoos, Big T has been courting Bug and that leaves Flower with Nipper, which I don’t know if that’s a good thing or not because Nipper is just Nipper. He’s always underfoot and he’s always into something. Nipper was the first gentoo to pick up a rock this morning and he plunked it down right in the middle of the food pan. Last year, he dropped a rock right into the pool. If Flower and Nipper choose to get together that will be great, but I haven’t seen any courtship behavior between them. So it may just be Big T and Bug this year out of those four and Nipper and Flower may wait until next year. They are just getting started, so they don’t really know what to do just yet. They are watching the other penguins busy selecting rocks and they think they need to be doing something but they are not quite sure what that is yet."