36 | Chapter 2
Once a seabird has the flying powers to quit the immediate nesting
area, it is faced with a choice. One possibility is to explore the local re-
gion, loosely interpreted. This tactic potentially tells the explorer about
the whereabouts of the best feeding areas. Presumably remaining with
parents facilitates this process. However, even in the absence of parents,
following members of one’s own species could be a useful pointer to
feeding zones and migratory routes.
Fifty years ago, Mike Harris, working on the Welsh island of Skok-
holm, swapped eggs between the nests of Herring Gulls which routinely
remain close to the colony through the winter, and the nests of Lesser
Black- blacked Gulls which, at least in the 1960s, then spent the winter
in Iberia.^10 The young Lesser Black- backs were barely affected by the
treatment; they still went to Iberia. But the young Herring Gulls, raised
by migratory Lesser Black- backed foster parents, moved further south
through France than ‘normal’ young Herring Gulls. Carried out before
the advent of modern electronics, and indeed around the time man first
stepped on the moon, these results could indicate that young birds fol-
low the species they perceive as their own as a means of finding their
way in the world.
Shortly after becoming independent of its mother,
a juvenile Great Frigatebird may cruise the Indian Ocean,
remaining continuously in flight for up to two months.