Penguin Awareness Day 2014
Today is Penguin Awareness Day, and what better way to celebrate than recapping a visit to some great penguins (and their awesome keepers). Recently I ventured out Jenkinson’s Aquarium in New Jersey. While interacting with penguins is always worthwhile, this trip is tied to a research project aiming to get better estimates of the sizes of extinct penguin species. Paleontologists have long been aware of “giant” penguins in the fossil record, but the estimates for their sizes have fluctuated wildly. Old sources proposed that some species were up to six feet tall, which we now know is a gross overestimate. The tricky part is that some fossil penguins had very different skeletal proportions than modern species, so it is not safe to just “scale up” any one bone. For example, we know from nearly complete skeletons of Kairuku that the humerus was longer compared to the rest of the body than in modern penguins, whereas the coracoid was shorter. If we tried to guess the height from just the humerus, we’d end up with a bird roughly five feet tall, versus a height of just over three feet if we instead scaled up the coracoid bone. The truth lies in between – reassembling the skeleton suggests the extinct penguin’s height was about four feet and two inches in “normal” pose.
At the aquarium, two fine birds named Dunlop and Kringle offered some perspective. These two are part of the aquarium’s colony of Black-footed Penguins (Spheniscus demersus). With the help of penguin manager Reagan Quarg, I collected measurements of their standing heights. With these measurements (and many more from other penguins), we hope to calculate the range of variation in extant species. One thing we have emphasized is that there is no single standing pose for penguins. Depending on their mood and the temperature, penguins may stand tall with their neck mostly extended, or hunch down like a grumpy child. The penguins at the aquarium showed quite a range of heights. Dunlop measures about 20 inches to the top of his head (not counting the beak) when reaching for a treat but only about a foot tall when hunched over.