 Penguins
weigh in.
British
Antarctic Survey
The British Antarctic
Survey (BAS) is testing a newly developed, high-tech penguin weigh-bridge
at Banham Zoo in Norfolk before taking it for field trials in a penguin
colony on the subantarctic island of Bird Island, South Georgia. 
Information collected
from the new weigh-bridge will help researchers understand why the number
of Macaroni penguins have declined in recent years. By testing the system
out with captive African penguins in the zoo, the BAS can get an idea
of how the system is working and make some final adjustments before the
full field trials begin in November. Researchers from BAS worked with
a consultant design engineer to produce the automated system that identifies
and weighs individual penguins in the wild as they come and go from their
colonies. Penguins are fitted with a small tag on an ankle bracelet that
gives each an individual identification number that works like a bar code.
Each time a tagged penguin walks across the weigh-bridge, either on its
way out of the colony to go to sea or on its way back to bring food to
its chick, its identity and weight is recorded on a data-logger.
British Antarctic
Survey Dr Kate Barlow says, "It is a challenge to design a device that
can record the weight of a moving object. The weigh-bridge is painted
to blend in with its surroundings so that the birds will hop onto it.
They need to stay in one position long enough to make an accurate measurement
so a small hop onto a step makes them stop before making a decision on
what to do next. At the zoo we’ve been able to test the equipment in a
fairly controlled environment, but the behaviour of Macaroni penguins
in a large colony is bound to give us a few technical adjustments to make
later."
With a world population
of around 5-6 million breeding pairs Macaroni penguins are one of the
most important predators in the Scotia Sea. There are around 2.5 million
pairs breeding at South Georgia. The BAS long-term monitoring studies
at Bird Island show that population may have halved since 1976 and scientists
are keen to understand why this has happened. Dr Barlow continues, "We
want to find out what factors affect the penguin populations and how the
numbers of penguins relate to environmental changes, whether these be
natural or influenced by human activities in the Southern Ocean. For example,
we want to know how much food parents bring back to their chicks in the
colony, how often they feed them and so on. Our current technique for
weighing the birds involves catching them, putting them in a bag then
using a hand-held balance hooked to the bag. The development of an automatic
weighing system will minimise the disturbance to the penguin populations
in our study colony."
More about the Antarctic:
Antarctica and the
subantarctic region have a long history of exploitation of marine resources
starting with sealing in the last century followed by whaling. Since the
1960s large-scale catches of fish, krill and squid have been made. The
international body CCAMLR (the Commission for the Conservation of Marine
Living Resources) is charged with the evaluation of fishing activity in
the Southern Ocean. It depends on fundamental scientific research conducted
by organisations like British Antarctic Survey to enable it to recommend
catch levels for commercial fisheries. The research carried out by BAS
at Bird Island on seals, albatross and penguins form the basis for monitoring
the Southern Ocean ecosystem.
Bird Island lies
at the northern tip of the island of South Georgia. South Georgia is a
UK Overseas Territory in the Southern Ocean about 8,000 miles from Britain,
between latitudes 53° 56’, 54° 55’S and longitudes 34° 45’ and 38° 15’W.
Macaroni penguins
are 71 cm (2’4") tall. They arrive from their breeding colony in the same
week, in late October, each year. They lay two eggs, only one of which
hatches, and both the male and female share the incubation period that
lasts 35 days. On average only one third of the breeding pairs will successfully
rear a chick to fledging in each year. Although young birds return to
the colony the following summer they will not breed until they are 5-7
years old.
The British Antarctic
Survey (BAS) is responsible for almost all of the British Government's
scientific research in the Antarctic, South Georgia, and the South Sandwich
Islands. Financial support comes through NERC from the Office of Science
and Technology. All aspects of the research programme are organised from
the BAS headquarters in Cambridge.
More information on penguins:
Penguins
of the World
Distribution
of Penguins on the Antarctic Peninsula and Islands of the Scotia Sea
Penguins;
A Worldwide Guide
The
Penguins; Spheniscidae
Distribution
and Abundance of Antarctic and Subantarctic Penguins
Penguins;
Ecology and Management
Videos on antarctic wildlife:
Antartic
Wildlife Adventure
Don't forget to check out our travel
site for wildlife and advanture holidays in the Antarctic region.
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