Penguins, Krill and Sheathbills

February 2018 Quest Nature Tours – Universities Alumni expedition in to Antarctica

VIDEO: Chinstrap Penguin feeds two chicks. Feeding two chicks is a challenge. Hungry chicks stimulate their parents to regurgitate by tapping bills and poking the adults. Half Moon Island, Antarctica. February 2018.

On our February 2018 Quest Nature Tours – Universities Alumni expedition to Antarctica, we watched Chinstrap and Gentoo Penguins raise their young. Many were already as large as the adults, having grown rapidly during the two previous months. Imagine how much food each chick needs to grow before the Antarctic winter returns.

Krill

Breeding success depends on food availability, in particular Antarctic Krill, a shrimp-like crustacean. This "superfood" is the foundation of the Antarctic food chain. Chinstrap Penguins feed almost exclusively on Antarctic Krill and mostly at night, whereas Gentoos supplement their diet of large amounts of krill with small fish and squid. Observing penguins feed their young made us think about the energy needed to stay alive and healthy.

Antarctic Krill (Euphausia superb) is a small shrimp-like crustacean about 6 cm long and weighing up to 2 grams. One of the most abundant animals on earth, it gathers in huge swarms and is vital food for penguins.

Chinstrap and Gentoo Penguins Feeding Behaviour

Chinstrap and Gentoo Penguins lay two eggs. Both parents take turns feeding their offspring. Finding food is a challenge and involves travelling long distances. Gentoos hunt close to shore and up to about 25 km from shore, whereas Chinstraps hunt farther out.

Toothless, penguins swallow their prey whole. To help them swallow, they have strong jaws and fleshy spines on their tongues and throats. Since penguins don’t have pouches to bring back food to hungry young waiting on shore, inside their bodies is a complex stomach system that digests and stores krill and other food from the sea. Later, adult penguins regurgitate the food in a form that chicks can swallow. In some cases it will be like an oily milk, in others it’s more solid. 

VIDEO: Gentoo Chick Feeding and Getaway. This parent has stored digested food and regurgitates it. The young sticks its bill inside the adult’s. Chicks always want more and don’t want the parent to leave. Port Lockroy, Antarctica. February 2018.

Snowy Sheathbills

Snowy Sheathbill is the only species of landbird on the Antarctic Continent. Except for a pink warty face, its plumage is pure white. Sheathbills cannot swim or dive and do not have webbed feet, all adaptations needed to feed in the ocean. However, as proficient scavengers on land, they eat spilled seafood, birds’ eggs, chicks, fresh droppings, still births, seal placentas, and more. We were captivated by their tactics as they wandered through a penguin colony and grabbed morsels from adults feeding young.

VIDEO Gentoo Feeding Chick and Sheathbill: The white chicken-like birds in the video are Snowy Sheathbills, the only species of landbird on the Antarctic continent  It is a clever scavenger in penguin colonies. Port Lockroy, Antarctica. February 2018.

Chinstrap Penguins were wary of Snowy Sheathbills as they wander around looking to scavenge. Half Moon Island in Antarctica on 14 February 2018.