Moulting season at
Stony Point

by CapeNature

The summer months at the Stony Point African Penguin colony are moulting season, a time that the African Penguin must endure and outlast alone.

This annual ‘feathering’ process is often misunderstood and overlooked, and on occasion the public has been heard to exclaim ‘look at the fluffy chick’ or point out the ‘poorly conditioned’ bird, yet this highly sensitive moulting phase is a natural annual occurrence which equips each penguin with the essentials required to survive in both the marine and terrestrial environment during their natural life.

Understanding moulting season and the moulting cycle

Moulting season moulting birds

African Penguins in the moulting stage

Moulting is the process during which the feathers on a bird are replaced. It is necessary because penguin feathers, which form an insulating barrier between the bird and its cold marine environment; aid in the incubational processes of eggs and in the survivorship of newly hatched chicks at nest sites, deteriorate with time and cease to perform these vital functions. Like an ill-kept wetsuit that has been damaged by the sun and the salt of the ocean – it must be replaced.

Moulting season fattened bird

A fattened up African Penguin, in preparation for the moulting stage, when it cannot enter the water to find food

The dedicated pre-moult fattening period lasts about 35 days – a penguin must build up sufficient fat reserves (leading to an approximately 30% weight increase) to be prepared to cater for metabolic requirements during the moult cycle. Depending on the food resource availability most penguins will overnight at feeding grounds offshore during this pre-moult period. Penguins arrive back to the colony to moult, fat and clumsy. About five days later their feathers suddenly stand up. This marks the beginning of the shedding phase of the moult cycle.

During the synchronized moult season at Stony Point, which peaks in mounting numbers during December, each penguin is land-bound for approximately 21 days, and only once the new feathers form an effective insulation can penguins return back to sea long enough to replenish lost reserves.

During this fasting period the metabolizing of fat reserves results in rapid weight loss, and by the time a penguin returns to sea it weighs only 46% of what it did compared to when it came ashore.

Moulting penguins usually congregate and remain motionless at the shoreline or landing stages at the colony during this summer occurrence. The coolness of the air that comes off the ocean’s surface helps manage metabolic rates at a sustainable level.

Initially a penguin loses muscular control over its old feathers and these fall out to be replaced by the new feathers. Once the moult phase is complete the penguin leaves the shoreline and has to return to the ocean and compete for dwindling food resources. They are absent from the colony for a period of about six weeks at sea recovering from the moult fast.

Moulting season new tuxedo

A healthy African Penguin, with it’s distinctive ‘tuxedo’ markings visible

Penguins that have completed the moult phase are now dressed in clean ‘starched’ tuxedos. Any unnecessary disturbance of moulting penguins during this highly sensitive period may jeopardise their future survival.

Therefore it is imperative that all visitors who come to the colony during the summer period exercise a sustainable level of respect for these little creatures of the ocean so that they can prosper well into the future.

By Cuan McGeorge, Marine Ranger at Stony Point Nature Reserve

About Stony Point Nature Reserve 

Located in the quaint coastal town of Betty’s Bay in the Overberg, the Stony Point Nature Reserve is home to a unique colony of African penguins. Stony Point offers the public the chance to see these wonderful flightless birds up close, via the boardwalk through the colony, which allows the public to observe the penguins go about their daily activities in their natural habitat, without disturbing or disrupting them.
Operating hours: 08:00 – 17:00 (last permits issued at 16:30, gates close at 17:00 sharp)

Reserve office phone number: +27 (0) 28 272 9829

Moulting season thank you

Published in Care for Nature

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