Penguin Puzzle - Olive Heffernan
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Penguin I
t is one of the most desolate
places on Earth. The ice-capped
mountain of Elephant Island is
an inhospitable crag whose sheer
to this chinstrap stronghold to survey
the breeding population. The chinstrap
may be the most abundant of Antarctica’s
penguins, with an estimated 7.5 million
Puzzle
cliffs feel the full force of the breeding pairs, but their populations
Southern Ocean on all sides. Yet, have plummeted in the past 40 years.
each December, this tiny Antarctic Signy, Deception and Penguin Islands,
outpost transforms into a riot of sound for instance, have experienced declines
and colour as tens of thousands of of 50–70 per cent. By carrying out counts
chinstrap penguins gather here to breed. on Elephant Island, last surveyed in
Nesting in rookeries almost 200m 1971, plus a string of other, little-studied
above the sea, these charismatic birds – islands, the team wanted to find out if the
named for the thin black line that gives pattern was true elsewhere.
them a helmeted appearance – stain huge
swathes of the island pink with guano. Bird’s-eye view
The stench is matched in intensity only Day one involves scaling a 70m cliff to
Antarctica’s chinstrap by the noise. “It’s like being in a football count one of the island’s largest colonies.
stadium – it’s an assault on your senses,” Thousands of penguins gather in the
penguins are in decline, says Noah Strycker, one of four penguin amphitheatre-like space below, watching
biologists that I accompanied to this over their fluffball chicks, while others
their demise a sign of remote outpost in early January. splash in an acrid pool. One solitary
greater changes at play. Elephant Island – so called because
of the elephant seals that sprawl on its
individual stands guard on a raised
pinnacle, surveying the Southern Ocean
Now, scientists are trying beaches, plus its distinctive, elephant- like a sentinel. Occasionally, a brown
James Lowen/FLPA
like shape – lies within the South skua descends and threatens to steal
to find out what’s ailing Shetlands, an archipelago just north of a youngster, its presence provoking
the Antarctic Peninsula. The team from piercing, murderous cries. At least
this feathered trekker. Stony Brook University, New York, sailed once, it succeeds.
By Olive Heffernan
A quick glance at their
markings and it’s easy
to see how chinstrap
penguins got their name.
CHINSTRAP PENGUINS
Protecting
maritime
Antarctica
Nations are currently considering
a proposal to protect the waters
around the western Antarctic
Peninsula, where chinstraps live and
forage for krill. The proposal for a
marine sanctuary will be considered
by CCAMLR (the Commission for the
Conservation of Antarctic Marine
Living Resources) in December 2020.
One of the main goals of CCAMLR
is to establish a network of nine
marine sanctuaries in the Southern
Ocean, to protect the thousands of “You have to hold
unique species that live there and
are found nowhere else – such as poses, balanced on
bioluminescent worms and pastel
starfish as well as the better-known
one toe on a slope
seals and penguins.
● bit.ly/pew-trust
greased with guano.”
Antarctica. Further north, they run out of
krill; further south, it is too icy to build their
stony nests. Heather thinks that chinstraps,
considered a species of Least Concern, have
remained off the radar because of their
abundance. “People assume that there is
safety in numbers – and there is, to a point,”
she says. “But there have been spectacular
collapses of species that we thought would
never disappear, like the passenger pigeon.
I think the term ‘collapse’ becomes a pretty
Chinstraps, unlike the ice-loving real estate,” says Steve. “They’ve essentially Clockwise from southern elephant reasonable description at this point – half
above: the dramatic seal is an unwelcome
emperors and Adélies, are built for a life bought a house together, which they return of the population has disappeared in a very
landscape of Half visitor among nesting
at sea, spending nine months of the year to year after year – so, in all likelihood, Moon Island in the chinstraps; creating a short period.”
fishing in the open ocean. They are agile they’ll end up with the same mate.” After South Shetlands; nest from stones – the
swimmers, able to dive to 100m and several weeks, the chicks are large enough gentoo penguins fish arrangement needs to Getting warm
venture up to 30km offshore. But when to enter a crèche, huddling with other from an iceberg; a be just so. There are several theories that could explain
the breeding season rolls in, they transform youngsters while the parents hunt for food. the decline of chinstraps, the most obvious
into sturdy monochrome mountaineers. being climate change. In fossil fuel terms,
We watch them waddle, hop and jump Tracking and tallying just 70cm in height. But what chinstraps one of every eight carbon molecules emitted
in twos and threes from their rookeries To survey the breeding population, the lack in size, they make up for in aggression. by a car’s exhaust ends up in the Southern
at the summit of tall, exposed cliff-faces, scientists count the nests, not the birds “They are fierce birds,” says Steve. “They’ll Ocean, changing conditions for every living
Skua: Graeme Snow/Alamy; Half Moon island & iceberg: Abbie Trayler-Smith/Greenpeace;
down ‘penguin highways’ to the frigid themselves. The task is easier when family fight over anything… a pebble, a space or snow and the racket of the thousands of birds 52,786 breeding adults on the island, 56 per creature from plankton to blue whales.
waters below, where they feast on krill to groups are still together, so timing is key. access to a penguin highway.” around you and become part of the scenery. cent fewer than in the early 1970s. “This is Around the Antarctic Peninsula, ocean
later regurgitate to their raucous chicks. The chicks are just a few weeks old when we Counting penguin nests sounds serene, At any given moment, only one thing matters the best window we have into the past 50 temperatures have risen by 1°C since 1955,
elephant seal: Otto Plantema/Minden/FLPA; nesting: Peter Barritt/Alamy
“Chinstraps are tough – they can handle arrive and only slightly smaller almost meditative, but comes with incredible – nest or not?” years for these birds,” says Steve. “It’s a and the waters of the Antarctic Circumpolar
a real pummelling,” says team than their parents, who average challenges. A day’s work usually sees the During a count, each scientist is allotted very dramatic decline and it’s tragic.” Current – which flows west to east around
leader Steve Forrest, a scientists negotiating a tricky landing by an area, which is then divided into smaller Departing Elephant Island, the team the continent – are warming faster than
veteran biologist with Zodiac, often on an exposed, windswept sections. Nests within each sub-section weaves around the South Shetlands, the rest of the global ocean as a whole. On
more than 25 Antarctic shore, then – owing to the birds’ penchant are counted three times using mechanical counting chinstrap nests at, among others, land, the situation is even more dramatic.
seasons under his belt. for high and remote nest sites – scaling sheer counters, with the figures only deemed Low, Snow and King George Islands. Every Temperatures on the Antarctic Peninsula
When it comes to breeding, cliffs, all the while keeping their distance, valid if the variance is less than 5 per cent. day, the scientists trek across beaches and have soared by at least 3°C between 1950
chinstraps have a classic co-parenting so as not to stress the birds. To complicate “A good pace of counting is 1,000 nests an up cliffs, and everywhere the same pattern and 2000, five times faster than anywhere
arrangement. Typically, the male builds a matters further, the penguins tend to cluster hour,” says Noah. “That’s when you’re really emerges, with breeding populations at else on Earth.
fresh circular nest from pebbles, and, once together, obscuring their stony abodes. ticking along.” about half their historic numbers. “There Chinstraps are part of a group known
the eggs have hatched, the parents take it “It is the most focused, exhausting and It takes two weeks to survey and get a first is no safe haven,” says Steve. as the brush-tails, which includes gentoos
in turns to hunt and mind the chicks. They exhilarating thing you can do outdoors,” says estimate for the whole of Elephant Island, According to Heather Lynch, director of (easily identified by their carrot-orange bills),
return to the same nest site each year to Steve. “You have to hold statuesque poses, and the emerging numbers confirm the the penguin lab at Stony Brook University, and Adélies (the classic tuxedoed penguin
Skuas try to
breed, which makes them monogamous take young
balanced on one toe on a slope greased with scientists’ suspicions: the chinstrap colonies the problem for these charismatic birds is of the cartoon world). Brush-tails have some
by default. “It’s more a case of shared penguins and guano. You have to ignore the wind, the here have also crashed. There are now just that they exist in a sweet spot in offshore commonalities, including a love of cold water
often succeed.
62 BBC Wildlife September 2020 September 2020 BBC Wildlife 63
CHINSTRAP PENGUINS CHINSTRAP PENGUINS
and a habit of building nests from stones. territories. But there is evidence of another declines in chinstrap populations around
Main image: Yva Momatiuk & John Eastcott/Minden/NPL; chicks: Abbie Trayler-Smith/Greenpeace; leopard seal: Christian Åslund/Greenpeace;
But warming temperatures are sending invader – humans. Up to 20 nations fish the Livingston and King George Islands. “Fishing
these species down very different paths. Southern Ocean. The most efficient vessels is tightly concentrated in areas where
Chinstraps and Adélies are stalwart krill can now harvest up to almost 1,000 tonnes predators forage,” he says. “So, the amount
swimming: Adam Cropp/Getty; king: Ben Cranke/Getty; emperor: David Merron/Getty; fur seal: Michael Grant/Alamy; whale: Getty
feeders. These tiny shrimps thrive where of krill in a day. of catch being taken is actually not a small
there is plentiful sea-ice, feasting on the Scientists are divided on how much of amount of what’s available – it’s enormous.”
thick layers of nutritious algae that blanket a problem this poses for chinstraps. “The Phil agrees that if fishers harvest intensely
its undersides. As the sea-ice surrounding amount of krill that is allowed to be harvested offshore of a particular penguin colony, those
the Antarctic Peninsula has receded is small in relation to consumption by birds could be affected.
southwards, so too have the krill, emptying penguins and whales,” says Phil Trathan, Some scientists feel that fishers should not
the larder for the penguins that specialise an ecologist at the British Antarctic Survey. be allowed to compete directly with wildlife
on them. For gentoos, who’ve increased “So, the fishery will not affect the krill stock struggling to cope with a changing climate.
in number and range, a broader diet gives at the current level of harvesting.” “Regardless of whether fishing is the cause, a
them a more competitive edge. But most krill fishing is concentrated 50 per cent reduction in chinstraps certainly
around the maritime islands of Antarctica, suggests that a big change in management is
Food fight where mammals and birds, including needed,” says Steve Forrest.
But there may be other factors at play, also chinstrap penguins, live. And that could be Whatever the cause of the chinstrap’s
relating to chinstraps’ restricted diet. One a problem, says Jefferson Hinke, a penguin decline, the demise of these creatures signals
theory is that, in recent years, there’s been biologist with the US National Oceanic and that something is severely amiss. “There
an increase in competition for krill, and Atmospheric Administration in La Jolla, used to be a lot more chinstraps, and that
that chinstraps are being squeezed out of California, whose own work has shown steep means that the ocean is now functioning in a
the buffet by their rivals. The humpback different way,” says Heather Lynch. “We need
whale could be one such competitor. These to understand this, because we depend on
voracious krill consumers were nearly the ocean as much as the penguins do.”
hunted to extinction, but their numbers
have recovered and are now close to pre- OLIVE HEFFERNAN is a marine
whaling levels. biologist and science writer. She
There’s no hard evidence that humpbacks travelled to Antarctica on research
are specifically invading traditional chinstrap vessels Esperanza and Arctic Sunrise,
provided by Greenpeace.
FIND OUT MORE Facts about penguins:
discoverwildlife.com/penguin-facts
Clockwise: chinstraps stop them getting
can swim at speeds airborne above the
up to 30kph; these
birds typically have
waves; a leopard seal
preys on a penguin – WARMING ANTARCTICA THE WINNERS & LOSERS
two chicks per brood; shaking it to separate Antarctica is experiencing climate change faster than anywhere else on Earth, with profound impacts.
they might not be able the flesh from the skin
to fly but that doesn’t – off Elephant Island.
WINNERS LOSERS
King penguin Emperor penguin
Kings are adept swimmers, The largest of penguins, emperors
routinely diving over 100m in need ice for protection against
search of fish and squid. Preferring predators, but too much ice is
to forage in open waters, they equally perilous, leaving them further
are expected to benefit from away from their feeding grounds.
Antarctica’s retreating sea-ice. If climate change continues at its
Already, these elegant birds are current pace, more than 80 per cent
moving south, turning up in places of emperor colonies will have too few
such as Elephant Island. adults to successfully breed by 2100.
Southern right whale Antarctic fur seal
These large baleen whales feed Committed krill eaters, these fur seals
on tiny copepod plankton. Once are expected to be particularly hard
hunted to near extinction, their hit by the loss of sea-ice in Antarctic
numbers are now on the rise and waters. A fur seal can eat more than
Chinstraps are being could rebound further still, As the 900kg of krill a year. Their changing
squeezed out of the
waters around Antarctica warm environment is, however, taking a
and the sea-ice melts, conditions toll – fur seals are already showing
buffet by their rivals. will ripen for plankton blooms,
creating a veritable feast for these
signs of food stress, including females
being born with a low birth weight and
ocean giants. having their pups later in life.
64 BBC Wildlife September 2020 September 2020 BBC Wildlife 65
You can also read
