by Kristen Green, Ichthyology Lab
Seven species of penguins can be found on the Antarctic continent and sub-Antarctic islands. King George Island has been described as a ‘cosmopolitan’ place for penguins, as three of these seven species can be found here: Adelies, Gentoos, and Chinstraps. Each species has evolved to fill different niche to coexist successfully. Adelie, Gentoo, and Chinstrap lay their eggs a few weeks apart. This means that the chick hatching and fledging (when the chicks enter the water to forage on their own) are also separated by a few weeks for each species.
This may be one adaptation to lessen the competition for shared food resources, i.e. Antarctic krill, during the critical time period when chicks are being nurtured. The are the last to lay eggs, and the first Chinstrap penguin observation on the island was actually 6-foot-tall Dave, the field leader who created a fairly elaborate Chinstrap penguin costume for Halloween from our excellent supply of trash bags, rags, and cardboard!
Meanwhile, we are still tracking and banding Adelie and Gentoo penguins to monitor reproductive success. We take daily attendance at each site where we have banded birds. This kind of makes me feel like a schoolteacher, as I check off whether the female or male is present and incubating the eggs on a particular day……except for the day when a nest with banded birds simply disappeared. I walked into the colony, and checked off all the other birds at my site, only to realize I couldn’t find the banded bird that should be at my feet. I consulted my map, looked down…..consulted my map, looked down….but couldn’t find the bird I had recorded in this spot every other day this week. Surrounded by hundreds of identical, cackling birds, I had a sinking feeling I was losing my mind.
I guiltily admitted this to the field leader. He laughed and said if a nest fails i.e. the eggs have been lost due to predation, weather etc., the penguins will abandon it. Regardless, working alone around penguins sure makes you second guess your sanity sometimes!