the clash | 183is wholly predictable and so tells us when this mysterious species breeds
(see Chapter 1).
Light pollution is an especial hazard for the Cory’s Shearwaters of
Tenerife. The largest of the Canary Islands, Tenerife, with a human pop-
ulation of about 900,000, is a destination for some 4.5 million tourists
annually, and provides nesting space for at least 2,500 shearwater pairs.
Possibly as many as half the fledglings reared each year are grounded by
light attraction as they leave their burrows and head to sea by night.
This first journey tends to be made in the first three hours after sunset,
the very time when residents and holidaymakers are most likely to be
wining and dining under artificial light. Twelve youngsters GPS- tracked
from colony to touch- down all came to earth within 10 km of the col-
ony but the tracks revealed that some had overflown the sea before re-
turning to land.^3 Thus the young shearwater is not secure from the lure
of light once it is over the sea. To reduce the problem, light levels need
to be brought down, not only in the vicinity of colonies, but along the
Tenerife shoreline.
Thanks to rescue campaigns, usually conducted by volunteers, over
130,000 birds worldwide are given a second opportunity to reach the
sea after tumbling out of the sky. But I fear the problem will persist for
many years. The several Save Our Shearwater campaigns, a name* that
has gained traction in various parts of the world for very obvious rea-
sons, will need to remain active.
Another onshore hazard is posed by power lines. The scale of the
collision problem is immense. Every year, there may be as many as 25
million bird/line collisions in Canada. And the problem is exacerbated
for seabirds because many of the species nesting a few kilometres from
the sea journey to and from the colony in darkness when, of course, the
collision risk escalates. For millennia, Newell’s Shearwaters and Hawai-
ian Petrels have crossed the dissected volcanic coastline of Kauai at dusk
and headed inland, gaining height and crossing green steep- sided valleys
on the last leg of their trek to the colony. Nowadays power lines may
- (^) The equivalent, Sauvons les Pétrels, on the Francophone island of La Réunion lacks a certain
je ne sais quoi.