Week 5
31 July 2006

Penguins - Part I

Introduction to Penguins

Most of the approximately 17 species of penguins are found in the northern cool temperate area of the Southern Ocean. The highest penguin diversity is found in the Sub-antarctic islands. The penguins described in the next two sections, Adélies, Chinstraps, Gentoos, and Emperors, can all be found in the area of the South Shetland Islands and the Antarctic Peninsula, the region where the Nathaniel B. Palmer is traveling.

Question: What are some of the differences between temperate and tropical zones? Name two countries in a temperate zone and two countries in a tropical zone.

Adélie Penguin Link	Chinstrap Penguin Link
Gentoo Penguin Link	Emperor Penguin Link

Question: On which of the following continents are penguins found: a) South America b) Africa  c) Antarctica

Penguins are closely related to petrels and albatrosses. Today’s penguins are flightless, but they evolved from a small-sized ancestor that was able to fly. This ancestor was also a strong swimmer, like the present day diving petrel.

Penguin physiology has developed to withstand the extremely low land and sea temperatures. Adaptations have been made in body insulation, circulation and metabolism as well as in behavior.

Question: What is the difference between the study of anatomy and the study of physiology?

The feet, and in some species the facial region, are featherless. The under flippers are sparsely feathered. These areas have an abundant blood supply that is used to dissipate heat.

Penguin feathers are short and densely packed in order to trap warm air next to the skin. These feathers also waterproof the body. The penguin body is packed in blubber. Its wings have become flippers with flat bones and fused joints. The flippers work like propulsion paddles.

Swimming Emperor penguins Link

All except 3 species of penguins “porpoise.”  They leap out of the water to breathe without slowing their swimming speed. Emperor and Adélie penguins are the only species that actually breed on the continent.

Adélie Penguin

Adélies at Palmer Station. Research ship Lawrence Gould in background.

Adélie out for a stroll

Description and Distribution: The Adélie Penguin is medium-sized with white and black or bluish-black feathers. It has a tiny head and an angular bill. These penguins have a conspicuous white eye ring. Their size ranges from 70-71 centimeters and weight from 3.8-8.2 kg. They can be found along coastal Antarctica and the South Shetland Islands among other areas. In the 1990’s, the population was estimated at 2.4 million breeding pairs.

Voice: The colonies are very noisy. The display call sounds like: arr-rar-rar-raah followed by kug-gu-gu-gu-gs –aaa, with head and neck fully extended and with head waving and flipper beating.  The common contact call is a guttural barking aark.*

Diet: Adélies eat crustaceans, some fish, and cephalopods. They catch their prey by pursuit-diving. Most food is caught between 20-40 meters under the surface, but dives have been recorded as deep as 175 meters. Krill is a favorite food around the peninsula.

Behavior: Adélies are gregarious year round. They are usually monogamous, but this may vary according to locality. The breeding season is from October to February. The female lays two eggs which are incubated for 32-37 days. Both parents incubate and provide food for the young.

Chinstrap Penguin

Chinstrap penguin and chicks (closeup) Photo from: National Oceanic & Atmospheric Adminstration (NOAA), NOAA Central Library Link

Description and Distribution: The Chinstrap Penguin is a medium-sized black and white penguin. It has a black line across a white chin and sides of the head. The white around the face reaches just above the eye. The black area of the head is limited to the crown and neck. Their size ranges from 68-76 cm, and weight between 3.2-5.3 kg.  The birds can be found from the Antarctic peninsula though the subantarctic oceans. They principally live in the Scotia Sea. The total estimated breeding pairs number 7.5 million.

Voice: The display call is a loud cackling with bill open, soft humming, and ah, kauk, kauk with head swinging and flipper beating. The contact call consists of low barking.*

Diet: They eat crustaceans and some fish by pursuit diving.

Behavior: They are highly gregarious. They are monogamous and believed to form long-lasting pair-bonds.

Chinstrap takes a peck at a Gentoo after getting crowded on the trail Link
Adélie find a good rock! Link	Chinstrap with eggs Link

Bonus Question: Why don’t Polar Bears eat penguins? a) The penguins taste fishy. b) The bears can’t catch them. c) The bears have run out of salsa.

* Do not attempt at home. Penguin calls should be reproduced by trained professionals only.