tied to home | 87That time is often of the essence is neatly illustrated by the migrant
Common Terns returning with implanted PIT tags to Peter Becker’s
artificial German islands (Chapter 1). The tags yield robust information
on the precise date of a bird’s return. When a male and a female that had
previously bred together both survived the winter at sea and reached
the colony in Germany, reuniting was the norm. When reuniting, the
two members of pairs typically arrived back within two days of each
other. But around one-fifth of pairs that survived divorced, and their
return dates typically differed by a week. If the two erstwhile mates ar-
rived 16 or more days apart, they always split. Possibly the time pressure
is such that the first- arriving tern starts seeking a mate as soon as s/he
arrives at the colony. If the former mate returns within that search win-
dow, they reunite, If s/he does not... well, too bad. It is better for the
first- arriving bird to establish a new partnership than to forgo breeding
altogether by waiting for too long.^2
As breeding approaches, penguins, too, return to their colonies, sleek
and plump. Once ashore, the species that have dispersed far outside the
breeding season, for example Macaroni* and Rockhopper Penguins, re-
main ashore until laying. The female has come ashore with sufficient
body reserves to form the egg before she heads back to sea immediately
after laying. Likewise her mate has sufficient reserves to remain ashore,
initially during the pre- laying period, and latterly during his incubation
stint, the clutch’s first.
Arguably the pattern of pre- laying attendance shows most variation
among the petrels and albatrosses. There is a batch of non- migratory
species, including the Northern Fulmar, some prions, Kerguelen Petrel
and Blue Petrel, which begin to visit the colony once the post- nuptial
moult is completed. This may be as little as 2– 3 months after the previous
chick has fledged. More commonly seen is a progressive increase in num-
bers attending the colony in the months prior to breeding, with males
often arriving a little earlier than females. However the peak in numbers
is not seen immediately before laying. Rather, it occurs significantly
- (^) As I wrote that, I was aware that extravagantly- plumed Macaroni Penguins were named after
macaronis, extravagantly- dressed eighteenth century dandies. Then the question arose of what
might be the connection between a dandy and those familiar tubes of pasta. The answer seems
to be that the founders of the Macaroni Club wished to celebrate their exotic fashion sense by
alluding to a food that was exotically novel in England 250 years ago, namely macaroni.