Effect of Krill Oil Supplements on Gentoo Penguin Coloration and Feather Quality

Student: Nicole Barney*
Mentor: Mark Beekey
Major: Biology 

Penguins are a popular exhibit at numerous zoos and aquariums around the world as these species attract the public due to their appearance and behavior. Rearing penguins in captivity presents specific problems pertaining to maintaining a diet that supports overall penguin health. For example, many penguins in captivity lack the coloration commonly found in wild populations.  Traditional captive diets mainly consist of white fish supplemented by squid, clams, and mussels.  However, many zoological programs are now encouraging the addition of specific nutrient and vitamin supplement routines to improve overall penguin health. One supplement that has been proposed to increase penguin health is krill oil. Krill oil is available commercially in tablet form and is frequently used by humans to provide Omega-3 fatty acids in their diet. In the wild, krill accounts for 70% of the Gentoo penguins’ diet, therefore I hypothesized that adding krill oil tablets to the Gentoo diet would increase their overall health with respect to coloration.  Over the course of eight weeks I conducted a study at Oceanworld Aquarium in Dingle, Ireland where I administered 500 milligram tablets of krill oil daily to the 12 adult Gentoo penguins housed there. Specifically, I examined whether krill oil supplementation returned captive penguin beak and feet coloration along with feather quality to that observed in the wild. The beaks, feet, and feathers of the 12 adults were photographed three times per week and ranked on a scale of 1-10 for coloration.  Body mass and the amount of food consumed were recorded daily.  Based on my results, I concluded that krill oil supplementation resulted in increased beak coloration, but did not affect foot coloration or feather quality.

*Honors Senior