Nov 11, Storms and Snow Challenge the Penguins
The purpose of an Adelie nest is to keep the egg warm and dry, and prevent it from rolling away. Since it is always near or below 0oC here in coastal Antarctica one adult must be on the eggs at all times or they will freeze very quickly. This year the breeding colony at Cape Royds has experienced several large snow storms. A little snow is okay, but this year the amount is more than usual. The storms, the amount of snow and then the melt run-off all have provided challenges for this years breeding pairs. On the other hand, these penguins are Antarctic born and raised; we may feel cold but they don’t!!
When storms come the penguin will not leave their nests. To do so would mean their eggs would be blown away or freeze very quickly. During the storm they sit quietly with their face to the wind and wait for it to be over. The above images show penguins sitting on eggs. In the right-most picture the very busy mate has continued to bring rocks to the nest, to place them on top of the snow.
Adelie Penguins seem to have a strong sense of where their nest site is even if it is covered with snow! For the group on the left, their sites from last year are under 3 feet of snow. Not discouraged, they simply built their nests on top of the snow pile. How this will affect the egg and chick brooding, hatching and rearing as the snow melts, we are going to find out
The pair above right, returned to find their long time nest site covered with snow. Instead of building on top of the snow they decided to move elsewhere and found a cozy nest site with a couple of large rocks for protection from the Skuas about 12 meters away. This is Nest #3 in our Nest Check and you can follow them throughout the breeding season by seeing the daily pictures here: http://www.penguinscience.com/education/royds_nestcheck.php
Because of their body heat some of the birds are sinking into the snow pile as the days go by. This bird, below, built his nest on top of the pile, but as you can see he is slowly sinking into a larger and larger hole. He is on a nest of a few rocks with two eggs under him. When the female came back it was a challenge to do the nest exchange. We will observe and record the success of this nest. These pictures were taken over 10 days.
When the sun comes out and the snow melts, there are small streams everywhere. Small depressions (scrapes) where penguins have built nests in the past fill up with water. This makes it harder to build the nest and the penguins need more rocks. A successful nest will be high enough to keep the egg out of any water run off. The egg will not hatch if it is sitting in freezing water.
In the picture above, the first two penguins have a challenge to build a dry nest above the water. The third picture shows the result of a poorly built nest in the mud. The egg rolled out and moments later it was picked up by the ever watchful Skuas. The nest shown to the right is a well built nest above the mud, these eggs will be kept dry.
Did You Know that Adelie Penguins are sturdy birds, but stronger and more summer storms pose a challenge to their breeding success. Read how these birds are coping with the effects of climate change here. (http://www.penguinscience.com/clim_change.php)
you for following along with the 2009 Adelie Penguin Journal for 2009.
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more about Adelie penguins at www.penguinscience.com
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