136 | Chapter 7
Australia and arrival in the south-west Atlantic were 10 August and 13
October in 2002, and 12 August and 9 October in 2003!^7 Sixty- four
days to beat into wind halfway round the world one year, a mere 58 days
the next.
Migration takes birds to non- breeding areas, most commonly in
winter – and here again evidence for consistent choices emerges. Some
of the evidence comes from traditional hard work and, more specifi-
cally, from scouring the east coast of Scotland on bleak winter days for
European Shags bearing colour rings applied during the summer at the
colony on the Isle of May. Well wrapped up, Hannah Grist’s team accu-
mulated 3,797 winter resightings of 882 individuals, up to 486 km north
and 136 km south of the colony.^8 Individual Shags tended to be sighted
the same distance from the colony, not only in the short term, when
sightings were mere days apart, but from one winter to the next. They
evidently developed an affiliation for a stretch of coastline.
To discover whether offshore species are also faithful to wintering
areas, modern devices such as geolocators are needed. On Skomer Is-
land, Wales, adult Atlantic Puffins have delighted the island’s many day-
visitors for decades. Only recently have the winter movements of the
Puffins begun to become clearer, thanks to the research of the OxNav
group, presaged in Chapter 4. In winter Skomer Puffins essentially
make one of four possible migratory journeys: remain in local, north-
east Atlantic waters,* remain in local waters and then head into the
Mediterranean before returning to Wales, cross the Atlantic and then
loop northwards to Icelandic waters before the return, and reach the
central Atlantic before entering the Mediterranean in advance of the
return to Wales. (See Map 9.) When the Oxford group had accumulated
up to six years of geolocator data for some birds, it was striking how
individuals were consistent from year to year despite the diversity
among the whole population.^9 Such a variety of complex routes seems
unlikely to be programmed genetically, nor, remembering that the baby
‘puffling’ fledges unaccompanied at night, is it likely that the route is
learnt by following parents.
- (^) I am obviously using ‘local’ quite loosely!