Questions

Now for the questions. These are from the 8th grade class:

1. Why do you believe climate change is the primary factor influencing
the distribution of the penguin species?

Climate change is really only one of many factors that might influence the
distribution of penguins, but it is a big one. Most colonies are located
where they are because of adequate food supplies nearby. Food, especially
krill, may change in abundance and distribution with climate change. For
instance, warming trends affect the sea ice and its distribution. Sea ice
affects how much algae occurs in the ocean which further affects the krill.
So, if sea ice changes in an area, it may influence the abundance of krill
in that area. If the krill decreases, the penguin colony may not have
enough food. The peguins disperse or die out from that area as a result.
Other factor besides climate that might cause changes in penguin
distribution could include competition with other species for food or
breeding space, or loss of habitat or breeding space from volcanic
eruptions or other natural distasters. However, in the long term, climate
is probably the single most influencial factor, either directly or
indirectly, that affects penguin distributions.

2. Does volcanic activity, geothermal activity, or fault lines have to do
with pack ice melting and the Adelie penguins moving?

Not that I know of. There are no cases where this has been a problem
except perhaps at Deception Island. There, a volcano erupted in the 60's
and it has been erupting periodically for hundreds of years. Each time, the
ash buries the penguin colony nearby. If the eruption occurs in the summer,
when the penguins are there, it could be a disaster (the last eruption was
after the breeding season so no penguins were killed then). I have seen ash
deposits on this island that have layers of pebbles from penguin nests
buried in them. I have not had a change to study or excavate these yet, but
it might reveal how often the penguins have been impacted by this volcano
before humans were present in Antarctica.

3. How has the hole in the ozone changed over the last 50 years, and has
this affected the penguin migration?

The ozone hole was first identified as a problem in the late 1970's and
has been getting thinner and larger ever since. It has not been here long
enough yet to influence penguin movements, as far as anyone knows. It has
affected algal growth in the ocean, which in turn can affect krill and
penguins, but the impact so far has not been significant. Hopefully, the
ozone hole will start to heal now that the pollutants responsible for it
are banned (some are still being used illegally, however). Recent data
indicate that, while the hole has been larger and lasts longer than before,
it has not gotten thinner. So, it appears that it may be on the mend but
this will still take many years. We will continue to monitor penguins for
any sign of impact to their movements or survival.

4. What time zone do you operate in? Doesn't this get complicated at the
South Pole?

We are on the same time zone as South America (Chile or Argentina) which
is only two hours later than you (when it's noon your time, it's 2pm here,
same day). Because we are just far south of you, and not that far east or
west, our times are not that different. It can get confusing sometimes,
though, so many people operate on Grenwich Mean Time (based out of England) so that everyone knows exactly what time you're talking about regardless of local times. You should look this up to see how it was first developed--it has an interesting history.

5. In your paper titled "Abandoned Penguin Colonies..." you seemed to
imply that penguins left colonies because of glaciers covering breeding
grounds and/or because of food shortages. Which of these reasons was the
main cause of the penguins leaving the area, or do you think it was both in
conjunction?

It very well may have been both in conjunction, though food distributions
changing with climate probably occured first, then glaciers or snow covered
the terrain. Sea level change also could cause a colony to be abandoned if
it made a terrace where their colony was located too difficult to access
(penguins can't climb very well and are rather clumbsy on land). It's not
always possible to determine what single factor caused the abandonment, we
just know that it did occur and have to search for possible causes with the
climate record.

These were all great questions and I'm impressed with their detail. You
obviously are studying the issues. So, thanks very much to the 8th grade
class that sent these and I will look forward to more questions from you in
the future!

Questions, Comments
email David Hughes, djh6183@uncwil.edu
Last updated February 21, 2000