156
B. STONEHOUSE
Antarctic Peninsula, in Eastern Antarctica between longitudes 90" and
llO"E, and in the southwestern corner of the Ross Sea. The eastern side
of the Antarctic Peninsula, much of Eastern Antarctica between 60"W
and 90"E, and most of Western Antarctica, present ice cliffs and floating
tongues of land ice, with only occasional exposed islands, rocky cliffs or
headlands. Pack ice drifts offshore forming a semi-continuous belt
around the continent throughout the year. Although generally driven
out by offshore winds in summer, it remains close to land in certain
areas (e.g. Weddell Sea, Dronning Maud Land, Marie Byrd Land),
creating cold summer conditions which appear to discourage penguin
colonization.
Eastern Antarctica and the Antarctic Peninsula lie in the path of
depressions, which bring strong winds, low cloud and heavy snow to peripheral coastal areas. Coasts farther south (e.g. southern Graham Land
and Victoria Land) are colder, but have clearer and more stable summer
weather. In Eastern Antarctica cyclonic easterlies are often masked by
violent catabatic winds, which pour off glaciers and shelf ice and often
help to maintain a wide channel of open water close to the coast. Addie
and Emperor penguins, which have a circumpolar distribution on the
continent, breed successfully in both the windiest and the coldest coast,al
areas. Temperature frequency curves for Antarctic coastal stations
(Fig. Sc-e) show a remarkable uniformity during the summer, irrespective of latitude. The most frequently occurring temperatures lie within
a few degrees of freezing point, and summer curves are both steeper and
more negatively skewed than those of other seasons.
Addie penguins are generally present wherever snow-free beaches or
islands, and open water (if only in the form of inshore leads or polynyas),
are available between late October and late February. Chinstraps and
Southern Gentoos breed in separate or mixed colonies on the Antarctic
Peninsula, but not elsewhere on mainland Antarctica. Emperor penguins
breed on sea ice or (rarely) on islands, in places where currents and tidal
movements ensure open water close at hand from September onward.
For a discussion of colony biotopes see Budd (1961).
3. Population Numbers
The greatest variety of penguin species occurs between latitudes 43"s
and 62"s (Fig. 6). Four species in varying abundance breed on Marion,
Heard, South Georgia and Macquarie, and three or four (with a possible
fifth) on the Falklands. New Zealand's South Island has very much
smaller and more scattered populations of five species (Northern and
Southern Blue, White-flippered, Fjordland, Yellow-eyed) and the New
Zealand area, including the cold temperate islands, can muster seven
full species and a variety of subspecies.
B. STONEHOUSE
Antarctic Peninsula, in Eastern Antarctica between longitudes 90" and
llO"E, and in the southwestern corner of the Ross Sea. The eastern side
of the Antarctic Peninsula, much of Eastern Antarctica between 60"W
and 90"E, and most of Western Antarctica, present ice cliffs and floating
tongues of land ice, with only occasional exposed islands, rocky cliffs or
headlands. Pack ice drifts offshore forming a semi-continuous belt
around the continent throughout the year. Although generally driven
out by offshore winds in summer, it remains close to land in certain
areas (e.g. Weddell Sea, Dronning Maud Land, Marie Byrd Land),
creating cold summer conditions which appear to discourage penguin
colonization.
Eastern Antarctica and the Antarctic Peninsula lie in the path of
depressions, which bring strong winds, low cloud and heavy snow to peripheral coastal areas. Coasts farther south (e.g. southern Graham Land
and Victoria Land) are colder, but have clearer and more stable summer
weather. In Eastern Antarctica cyclonic easterlies are often masked by
violent catabatic winds, which pour off glaciers and shelf ice and often
help to maintain a wide channel of open water close to the coast. Addie
and Emperor penguins, which have a circumpolar distribution on the
continent, breed successfully in both the windiest and the coldest coast,al
areas. Temperature frequency curves for Antarctic coastal stations
(Fig. Sc-e) show a remarkable uniformity during the summer, irrespective of latitude. The most frequently occurring temperatures lie within
a few degrees of freezing point, and summer curves are both steeper and
more negatively skewed than those of other seasons.
Addie penguins are generally present wherever snow-free beaches or
islands, and open water (if only in the form of inshore leads or polynyas),
are available between late October and late February. Chinstraps and
Southern Gentoos breed in separate or mixed colonies on the Antarctic
Peninsula, but not elsewhere on mainland Antarctica. Emperor penguins
breed on sea ice or (rarely) on islands, in places where currents and tidal
movements ensure open water close at hand from September onward.
For a discussion of colony biotopes see Budd (1961).
3. Population Numbers
The greatest variety of penguin species occurs between latitudes 43"s
and 62"s (Fig. 6). Four species in varying abundance breed on Marion,
Heard, South Georgia and Macquarie, and three or four (with a possible
fifth) on the Falklands. New Zealand's South Island has very much
smaller and more scattered populations of five species (Northern and
Southern Blue, White-flippered, Fjordland, Yellow-eyed) and the New
Zealand area, including the cold temperate islands, can muster seven
full species and a variety of subspecies.