I don't want anyone to get the wrong idea. As much beauty as there is here at Cape Royds, this is the wild. Perhaps there is not much life to compete with here in Antarctica, but the penguins do have their foes.
First there are the Adelie penguins themselves. They are very territorial, and there are many squabbles that break out. Usually it is fighting over a mate or fighting over space. When one of these fights break out it's usually in the middle of the sub-colony. Birds get knocked over or out of their nests, and eggs will often get dislodged. Once the egg rolls out of the nest, the owner will most likely not bring it back, and the penguin chick that would have been dies.
In the video below two penguins fight over a potential mate. During these fights eggs in nearby nests often get knocked out.
http://youtu.be/AzDKKlsSCrM
Then there are the Skua. Skua are birds, and at a glance appear to be a lot like crows similar to those seen in the US. Skua almost always operate in pairs (with their mate) when going after penguin eggs. One Skua will distract the penguin and the other will swoop in and steal the egg. However sometimes, as in the case of the video below, a single skua can be skilled enough to do it themselves. But that doesn't mean other skua won't try and steal from their own kind. The video below shows a skua stealing a penguin egg and then another skua trying to steal the egg from the original thief.
http://youtu.be/R8Bo6FK_Dtg
Unfortunately the Skua do not just limit themselves to stealing eggs. Skua actually time their on breeding and nesting with the hatching of the Adelie penguin eggs. When the Adelie chicks hatch the Skua will steal and eat the chicks providing nourishment for their own young. I'm sure its not a pretty site, and personally I'm am glad I won't be here to see or hear it.
In addition to squabbles between penguins in the colony and skua, there is the harshness of the Antarctic environment. There's a reason why the area is void of plants, insects, etc. … it's darn cold here. There is a window of opportunity for the Adelie to breed and get the new chicks strong enough to head out to sea. If that window is missed then death is almost certain for those that remain. Below are corpses of penguins that never made it. Since the dead bodies decay very slowly over time it takes many years before the remains of the dead penguins, skua, and seals vanish. It's hard to walk more than 20 feet or so without seeing the clear evidence of something that has died.
The remains of a juvenile Adelie penguin that never made it off the island. The remains have likely been here for 5 years or more.
The remains of an Adelie penguin (adult and chick). Probably died more than 10 years ago.
The remains of a skua. This particular skua was probably injured by Adelie penguins as it was trying to snag an egg or chick, and died from the injury.
The remains of a seal. This is a reminder of just how dry and arid the climate is here. The seal remains have been mummified over what is likely many decades.