120 | Chapter 6
patterns is slight. That potential expands when the bird is making loops
of thousands of kilometres from colony to food and back to colony.
In Chapter 5, I made mention of the 15,000 km journeys undertaken
by Murphy’s Petrels during spells of about 19– 20 days when they are
excused incubation duties because their mate is attending to the egg.
These travels can take the birds over 4,000 km north- east from Hen-
derson Island, in the bluest, emptiest expanses of the South Pacific,
towards South America. Remarkably, our GPS tracking showed how,
during the first day of the journey, the petrels head approximately
southward from Henderson (24°S) to latitudes around 35– 40°S. Once
that far south, they start to turn left towards the east, benefitting from
the west winds of these higher latitudes. The pattern is set for an anti-
clockwise loop that extends towards South America, and then contin-
ues during the homeward journey. (See Map 7.) When compared to the
outbound leg, returning birds follow a more northern track (15– 20°S),
relishing the helping impetus of the south- east trades of these lower
latitudes.
Not all Southern Hemisphere loops are anti- clockwise like those of
Murphy’s Petrels of both sexes. In other species, clear route differences
between males and females have been discovered. While an entire book
was required to describe how men hail from Mars and women from
Venus, I can report on the clockwise tendencies of male Wandering Al-
batrosses and the anti- clockwise predilections of females in a single
paragraph.
The Wanderers nesting on the Crozets (46°S) in the Southern Ocean
find themselves in one of the windiest parts of the world. Fiercely the
west wind blows day after stormy day. When embarking on foraging
trips during breeding, the albatrosses normally leave their colonies in
a downwind direction, towards the east.^14 Journeys that go north of the
archipelago, most commonly undertaken by breeding females, are then
anti- clockwise, while those to the south, habitually made by males, are
clockwise. These strategies, respectively involving return journeys
around 30 and 55°S, mean that the birds return to the longitude of the
Crozets at latitudes where the easterly component of the wind is stron-
ger than in the Roaring Forties. There are, however, some shorter jour-
neys, for example during the chick- guard phase, when birds remain close