Early Summer Adelie breeding behavior

In late October, male Adelie Penguins begin to arrive at the colony from their winter foraging areas to stake out a territory. They often attempt to hold the same territory as in previous years, and fighting will break out if another male is on the old territory. The behavior seen above is called "flipper bashing". Adelies may seem cute and cuddly, but those flippers have a lot of muscle behind them. It is not uncommon to find bloodied, territory-less males wandering around in early November.



The territories are only as large as they need to be so that closely neighboring males cannot reach each other with their bills. These territory holding males will defend their territories and wait for their mate to arrive for up to several weeks.


As we arrived at Cape Crozier in mid November, most of the males were already at the colony with very well defined territories, and the females were arriving in droves from the sea. Here is a line of female Adelies making their way across the sea ice to the colony. They will go to the same nest they nested in last year in hopes that their partner is waiting for them there with a well built nest. If not, they will shop in the area for another suitable candidate.



Males will advertise themselves and their territory by performing the EV display or Ecstatic Vocalization. The EV is characterized by the penguin thrusting out his chest, throwing his head back, and vibrating his chest to make a repeated chuckling call. It is very sexy. This display lets other males know about the territory holding male and it is not uncommon to find an area with multiple males EVing at the same time.



The males will also collect rocks and build a large pile with a bowl in the middle, perfect for keeping eggs and hatchlings out of the mud. They often steal rocks from their neighbors' nests when they aren't watching. Early in the season, males seem to alternate between EVing, stealing rocks from each other, and trying to bite males that are stealing rocks from their own nests. Constant vigilance is very important.



Here is a female examining this male performing the EV display. He has a pretty decent pile of rocks and has yet to find his mate. If his mate does not arrive soon, he will attempt to attract a different female to mate with.



Penguin pair bonding involves lots of eyeing each other with their heads down and sidestepping towards each other.



They also perform the LHV, which is the standard way in which penguins greet each other. The LHV consists of both members of the pair waving their heads back and forth in time with each other and loudly calling. They will continue to LHV throughout the season any time one partner returns to the nest from a foraging trip.



Pairs that were mates in previous years briefly become acquainted with each other and then get down to the business of breeding. They will copulate several times over the next week until the female has laid two eggs. This time of year it is very easy to differentiate between males and females because the females always have two muddy footprints on their backs.



When the second egg is laid the female will quickly gather some more rocks for the nest and then head out to sea to forage for Crystal Krill. By this time she is very skinny from producing two very large eggs and must bulk up before beginning the long and difficult task of raising two fully grown chicks to nearly adult size.



She will forage at sea for one or two weeks, while the male incubates the egg. This is no small task for him, as he has already been fasting for a several weeks defending the territory. He will continue to burn fuel by keeping the eggs warm and defending the nest from other adult penguins and the resident egg-predators: the skuas. If she does not return before he uses all of his fat reserves, he will abandon the nest to feed himself.



Over the next month they will take turns incubating the eggs and foraging. The foraging trips will get shorter and shorter as the hatch date approaches, and in mid-December it is not uncommon to find both members of the pair at the nest, waiting for the chicks to hatch. By this time they have hopefully fattened up enough to last them until the end of the breeding season, as almost all of the fish and krill they gather from now on will go towards feeding two voracious chicks.

First Day at Cape Crozier

11/17/2009


Today we hopped on an A-Star helicopter in McMurdo and took a 45 minute flight to the Cape Crozier Hut. The hut is a 18 by 10 foot building equipped with a propane heater, a propane stove, solar panels, a wind generator, 4 bunks, a food pantry, and a small sitting area. There is also two small lean-tos on the side of the hut, one for the "toilet", which is a bucket with a seat over it, and one for the "freezer", where frozen or mostly frozen food can be stored. The hut is located about 1km away and out of site of the penguin colony, to reduce disturbance.

At the helo pad we were greeted by Jeff Wilson and Mark Smith, two wildlife film guys who are working for the BBC filming the Icy Planet series.

Once we had unloaded the helecopter of 3 months worth of food, our tents, our own gear, and the penguin weigh-bridge, we began making camp. This involved digging out level ground for our tents and setting them up. We had a choice between a North Face Mountain Tent and a Scott Tent. I chose a Scott Tent.

We got done at about 8pm and ate a quick dinner. After our spaghetti, Scott, Grant, myself, and the BBC hiked to the penguin colony to finally get a look at some penguins! We first hiked to the top of Pat's Peak, a crest of volcanic rock that is overlooks the colony and the Ross Sea Ice Shelf from the South. I'm not sure how to go about describing the awesomeness of my first glimpse of 300,000 breeding penguins. Needless to say it was one of the more striking scenes I've witnessed. Also, when walking up to the peak from the back side, where the hut is located, we couldn't hear anything but the wind and the South Polar Skuas calling. Then, just when we got near the top, we began to be able to differentiate thousands of faint penguins calls filtering up towards us.

We walked down the face of Pat's Peak, through the Adelie Penguin colony, and out onto the fast ice where lines of Adelie penguins were arriving at the colony from sea. Grant gave up a quick rundown on penguin behavior and sea ice safety. Cape Crozier is also home to an Emperor Penguin colony. We were followed by 4 very curious Emperor Penguins as we walked around on the sea ice. In addition, we were treated to a flyby by several Snow Petrels, likely drawn to the colony by the strong odor of Crystal krill. At about 1am we were getting very tired, despite the constant daylight, and headed back to the hut for some much needed rest.