NSF PR 02-91 - November 7, 2002
Scripps Institution of Oceanography
Emperor Penguin Colony Struggling With Iceberg
The movements of two gigantic Antarctic icebergs appear
to have dramatically reduced the number of Emperor
penguins living and breeding in a colony at Cape Crozier,
according to two researchers who visited the site
The colony is one of the first ever visited by human
beings early in the 20th century.
"It's certain that the number of breeding birds is
way down" from previous years, said Gerald Kooyman,
a National Science Foundation-funded researcher at
the Scripps Institution of Oceanography in La Jolla,
Kooyman took aerial photos of the colony in August
during the flight missions that preceded the official
start of the Antarctic research season. He returned
to visit the colony in October, after the season was
underway, with Paul Ponganis, another NSF-funded Emperor
researcher who also is at Scripps.
The photographic evidence and the scientists' observations
on the ground, Kooyman said, indicate the colony has
scattered into at least five subgroups. The disruption
appears to be caused by grounding in the past two
years of two enormous icebergs-B-15 and C-19-near
He said that two years ago the colony was home to approximately
2,400 adult Emperors and approximately 1,200 chicks.
Aerial photographs showed the researchers the current
distribution of the birds and the number of groups,
but they did not provide details about the number
of breeding birds and the conditions in the colony.
Kooyman said the site visits confirm what the photographic
evidence appeared to show: ice conditions produced
by the collisions of the giant bergs with the shoreline
forced the bird colony to break up into smaller subgroups
and also indicated the numbers of chicks and breeding
pairs is greatly reduced from previous years.
"The colony had been fragmented into at least five
groups. I think that's a habitat problem," he said.
"The habitat is disturbed from the previous years,
and I think it stays that way."
But, Kooyman said, his visit showed conditions for
the birds are not as severe as he expected.
"I was expecting to see just about total failure,"
But a comparison with another Emperor colony at Beaufort
Island, Kooyman said, also shows that the Crozier
birds have been less successful finding food for their
"It looks like the development of the chicks has been
slower than at Beaufort," he said. "And development
is related to food sources. It looks like they were
not as well fed."
He also said that shifts in the ice might have caused
additional fatalities. "We could not find one group.
It looks like they were in an ice canyon that was
eliminated by two ice plates running together," he
said. As to the fate of the birds, "It's a question
of whether they got out of there or got crushed. It's
impossible for us to determine that."
The Cape Crozier colony is noted in the history of
Antarctic exploration. In 1911, three members of Robert
Falcon Scott's ill-fated South Pole expedition hauled
a sledge 60 miles from Scott's base at Cape Evans
to Cape Crozier, on the far side of Ross Island, in
complete darkness and sub-zero degree (F) temperatures,
to acquire three unhatched Emperor egg from the colony.
At the time, Emperors were thought to perhaps represent
an evolutionary "missing link" between reptiles and
Kooyman the recent survey of the colony was conducted
in "very demanding" conditions almost exactly a century
after that episode. Airlifted to the ice near the
colony by helicopter, "we took three days in fine
weather to traverse the entire area because the ice
was so broken up." The period of fine weather was
followed by a summer storm.
Kooyman and Ponganis will compare notes on the health
of the Emperor colony with David Ainley, an NSF-funded
researcher who, as part of a long-term study on Adelie
penguins, has been following the effects of the icebergs
on Adelie colonies.
Ponganis noted that the icebergs causing the environmental
change affecting the Emperor colony appear to be moving
away from the area. But he added that the opportunity
to study their effects on the birds adds to scientific
knowledge of Emperors and their ability to adapt to
"It's an incredible natural experiment as far as the
physical effects on the colony and how they deal with
it," he said. "Crozier is a good test of all kinds
of conditions that Emperors can deal with."
Video available upon request: Contact Dena Headlee