Penguin populations falling steeply: biologist
July 1, 2008
Courtesy University of Washington
and World Science staff
Like the proverbial canary in the coal mine, penguins are sounding
the alarm for potentially catastrophic changes in the world’s
oceans, a University of Washington biologist says.
The culprits are global warming, oil pollution, depletion of
fisheries and rampant coastline development, which threaten
breeding habitats for many penguin species, she argues.
Rain has soaked this Adélie penguin chick in Antarctica before its
feathers are capable of repelling water. Though the icy
continent is in essence a dessert, coastal rainfall is becoming
more common with changing climate. (Courtesy Dee Boersma)
These factors are behind rapid population declines among the
birds, said the university’s Dee Boersma, an authority on penguins.
“Penguins are among those species that show us that we are making
fundamental changes to our world,” she said. “The fate of all
species is to go extinct, but there are some species that go extinct
before their time and we are facing that possibility with some
In a paper published in the July-August edition of the research
journal BioScience, Boersma notes there are 16 to 19 penguin
species, and most penguins are at 43 sites, virtually all in the
For most of these colonies, population trends have been unclear,
so few people realized that many penguins were suffering sharp
population declines, Boersma said. She advocates an
international effort to check on the largest colonies of each
penguin species at least every five years.
Working with the Wildlife Conservation Society and colleagues,
Boersma has studied the world’s largest breeding colony of
Magellanic penguins at Punta Tombo on Argentina’s Atlantic
coast. That population probably peaked at about 400,000 pairs
between the late 1960s and early 1980s, and today is half that, she said.
There are similar stories from other regions. African penguins
decreased from 1.5 million pairs a century ago to just 63,000 pairs
by 2005, Boersma claimed. Galapagos Islands penguins, the only
species whose range extends into the Northern Hemisphere, now
number around 2,500, about a quarter of what their population was
when Boersma first studied them in the 1970s.
Boersma recounts watching in 2006 as climate anomalies wreaked
havoc on the same population of Emperor penguins featured in the
popular 2005 film “March of the Penguins.” The colony bred in the
same place as in other years, where the ice is protected from the open
sea and wind keeps snow from piling up and freezing the eggs. But in
September, with the chicks just more than half-grown, the adults
apparently sensed danger and uncharacteristically marched the
colony more than three miles to different ice.
The ice they chose remained intact the longest, but in late
September a strong storm broke it up and the chicks were forced into
the water, Boersma said. While the adults could survive, the chicks
needed two more months of feather growth and buildup of insulating
fat to be independent. The likely result, Boersma said, was a
total colonywide breeding failure that year.
Global warming also appears to be key in the decline of Galapagos
penguins, she said: as the atmosphere and ocean get warmer, El Niño
Southern Oscillation events, which affect weather worldwide, seem
to occur more often. During those times, ocean currents that carry
the small fish that penguins eat are pushed farther away from the
islands and the birds often starve or are left too weak to breed.
These problems raise the question of whether humans are making it
too hard for other species to coexist, Boersma argued. Penguins in
places like Argentina, the Falklands and Africa run rising risks
of being fouled by oil, either from ocean drilling or because of
petroleum discharge from passing ships, she continued. The birds’
chances of getting oiled are also rising because they often have to
forage much farther than before to find prey.
“As the fish humans have traditionally eaten get more and more
scarce, we are fishing down the food chain and now we are beginning
to compete more directly with smaller organisms for the food they
depend on,” she said. As the world’s population continues to
explode and more and more people live in coastal areas, the
negative effects are growing for both marine and shore-based
habitats used by a variety of species, Boersma added.
“I don’t think we can wait. In 1960 we had three billion people in the
world. Now it’s 6.7 billion and it’s expected to be eight billion by
2025,” she said. “We’ve waited a very long time. It’s clear that humans
have changed the face of the Earth and we have changed the face of the
oceans, but we just can’t see it. We’ve already waited too long.”