After spending the winter in the pack ice Adelie penguins arrive at their
breeding colonies on land at the end of October. They return to the same
nest and the same mate as in the previous year if they can. They build nests
out of small rocks then mate and lay two eggs by mid-November.
The male and female take turns incubating the eggs over the next 34 days
until the chicks hatch. Each off-duty bird spends 15-20 days at sea feeding
to regain the weight it has lost during courtship.
Once chicks hatch (December) the parents alternate guard and feeding
duties. They swap over every couple of days. The adult birds catch krill,
fish and amphipods which they regurgitate for the chicks.
When chicks are 3 weeks old (January) they are big enough to be left
alone, allowing both parents to simultaneously collect food for them. The
chicks group together for protection and warmth.
At 7-9 weeks of age (February) the chicks have replaced their down with
adult feathers and are ready to go to sea. Once they depart most will not
return until they are old enough to breed (3 - 5 years of age).
Stomach contents from breeding Adelie penguins are collected each breeding
season to determine annual variations in quantity and proportion of prey
types (krill, fish and amphipods) and to investigate associations between
such variations and the breeding success of the birds.
We have found that the penguins feed at a range of distances from the colony on a variety of food types and that foraging behavior changes as the breeding season progresses.
Brooded chicks are fed an average of 300 g of food per meal. The adults catch fish, amphipods and krill at this time, and frequently feed within 30 km of the colony.
Chicks in creches receive an average of 650 g of food per meal. Most
of the food at this time is krill which the adults catch in large quantities
at the edge of the continental shelf 110 km from the colony.
(Mawson region)
Weight: 3 - 6 kg
Life expectancy: 10 - 20 years
Age of first breeding: 3 - 5 years
Breeding season: October-March
Clutch size: 2 eggs
Chick survival rate: 0.7 - 1.1 per nest
Chick growth rate (av): 80 g per day
Chick age at fledging: 50 - 70 days
Fledging weight: 3.1 kg
Meal size:
brooded chick: 300 g
creched chick: 650 g
Diet:
krill: (30-60%)
fish: (20-60%)
amphipods: (<<10%)
Distance traveled when feeding during:
incubation: 100 - 300 km
brood stage: 5 - 110 km
creche stage: 80 - 120 km
winter: 1,200 km
Walking speed on ice: 2.5 km/hr
Swimming speed: 4 - 7 km/hr
Predators:
skuas (eggs & chicks)
leopard seals & killer whales
Adapted with permission from:
Australian Antarctic Division website
http://www.antdiv.gov.au
Blackline Master #13