Questions

Now for the questions. These are from the 6th grade class:

1. We've just learned about binomial nomenclature and were wondering what
the scientific names are for the 3 penguin types you study; Adelie,
Chinstrap, and Gentoo?

The scientific names for these species are Pygoscelis adeliae, P.
antarctica, and P. papua (all should be in italics since they are Latin
words, but I can't do this on email). The genus Pygoscelis is the same for
all three species, indicating their close relationship to one another. The
genus refers to the 'brush tail' or long stiff tail feathers that all three
species have.

2. Do all three types compete for the same foods?

Yes, all three of these species primarily eat krill, though some fish
and squid also are taken. However, studies have shown that the three
species tend to feed in different areas. Adelies like the edge of the pack
ice, chinstraps prefer open ocean, and gentoos tend to feed near their
breeding colonies. They may be avoiding competition with one another by
using these strategies.

3. In one of our videos we saw leopard seals catching penguins as they
flew out of the water onto the ice. Are there any other predators of the
penguin, and what are they?

Yes, there are other predators depending on where you are. Penguins in the
Antarctic Peninsula also are preyed upon by skuas (a bird related to gulls)
and giant petrels (a bird the size of an albatross with a powerful bill). Skuas will take penguin eggs and small chicks from the colony. I have
watched them hover above the penguins, then dive down and quickly steal an
egg or chick. They are very adept at doing this, but cannot kill the chicks
after they get as big as the adults. Then, the giant petrels are able to
kill the large chicks, either at the colony or in the water when the chicks
go to sea for the first time. None of these predators, including the
leopard seal, eats penguins all the time. Most of the year, they eat krill
and fish like many of the other marine species down here.

One other predator is the orca, or killer whale. They will kill penguins
for sport or to practice their hunting techniques. From a ship last month,
we watched as two adults and one calf orca chased and killed gentoo
penguins, probably to train the calf to how to hunt. They did not eat the
penguin after they caught it, just threw it around and left it to find
another. Skuas and giant petrels finished the job after the orcas. We did
see one gentoo escape--after being chased for 10 minutes by the orcas, it
swam into the turbulence (white water) caused by the ship and the orcas
couldn't find it and left. Pretty smart penguin!

4. How do penguins protect themselves from predators? Do they have any
defenses?

The only defense a penguin has from a predator is its flippers and bill.
It can use its flippers to hit a predator or to fight with other penguins.
The bones in the flipper are thick and hard. When I have worked with these
birds where I have to approach their nest, they will attack me with their
flippers and hit my leg with rapid strikes from both sides. It can be
painful! Imagine being hit repeatedly in the shin with the edge side of a
ruler and you'll know what it's like to be hit by a penguin. They can bite
with their bill too and that can hurt as well. However, while these
defenses might help against skuas and giant petrels, there is little they
can do if attacked by a seal or orca.

5. Do the Adelie, Chinstrap, and Gentoo all have similar habits? Do
their nest sites look the same? Do they stay in one place all the time, or
do they migrate seasonally? Besides looking physically different, are they
different in any other ways?

Overall, they do have similar habits with some variations. All build
nests with pebbles in the Antarctic, but gentoos also use grass at colonies
in the Falklands and other warmer regions. The nests of Adelie and
chinstrap penguins are placed closer together, while those of gentoo are
spaced more apart. In general, I find the gentoos to be 'neater' at the
colony and to build nicer and larger pebble nests than the other species. During winter, the Adelies and chinstraps migrate to other areas. We don't
know much about where they go--it's very difficult to study these species
away from their colonies and in the Antarctic winter. However, the Adelies
seem to be going to the ice edges while the chinstraps head for open waters
and spend much of their time at sea. Gentoos will stay near the breeding
colonies as long as the surrounding waters remain unfrozen. They will move
if sea ice forms so they can keep feeding in the water. As for other
differences, I think they all differ in their personalities. Gentoos seem
to be more 'well mannered' and relaxed at the colonies than Adelies and
chinstraps. The colonies of these last two species are always very busy,
crowded, and hectic--not nearly as clean and neat as the gentoo colonies. It's a good question and really hard to describe without seeing for
yourself.

As far as Emperor penguins, they are unusual in that they begin their
breeding season in the middle of the cold, dark Antarctic winter. They do
this because, being the largest penguin with the largest egg (only one is
laid each year), it takes longer to incubate the egg to hatching and raise
the chick to independence. They want the egg to hatch by early to mid
summer, when food is most abundant, so they can feed the chick lots of food
and help it survive its first year. They walk up to 120 km to their
colonies to lay the egg in winter because it's mostly sea ice they are
traversing. By the time the egg is hatched (after two months of
incubation) it is summer, the sea ice has disappeared, and the open water
is nearer to the colony. So, they don't have to go far to get to the water
and obtain food for the chick. They couldn't lay the egg on the sea ice
because the ice would breakup before the egg was hatched and be lost. Producing the egg takes lots of energy by the female. Once she lays the
egg, she needs to return to sea to feed and be ready to help raise the
chick when it hatches. The male does the entire incubation, fasting the
whole time, until the female returns two months later.

Thank you for your questions--they were all very good and I will be happy
to answer more in the time I have remaining here. You also asked for
Jenny's thoughts about the work here. (Click here to see her remarks)

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