Can North Island regain some of its lost seabirds?

On North Island’s west coast is a narrow plateau on which Sunset Beach and Honeymoon Beach stand (the latter also called Anse Bonnen Kari, the Creole name for the Barringtonia trees that dominate the beach crest’s woodland). Inland of these beaches is it possible to find broken pieces of sandstone rock, very different from the granite that forms the bulk of the island’s structure. This sandstone, and the soils that surround it on this plateau, are rich in phoshate and derived from many years of deposition of seabird droppings. In the early 20th century some of this guano was exported from North Island, during a period when guano was one of Seychelles’ major exports and two of Seychelles’ islands, Assumption and St Pierre, were devastated by the process.

It is also highly likely that the plateau was at one time forested with a tree called Bwamapou (Pisonia grandis). Chemicals from its decaying leaves combined with the seabirds’ droppings to harden the underlying sand into the phosphatic sandstone. But where are the seabirds now? There appears to be no written record of their occurrence, suggesting that they disappeared before man’s arrival on the island or that, more likely, man was responsible for their disappearance when he first settled. The latter has happened elsewhere on seabird islands, where the seabirds, probably mainly boobies, were used as a source of food, and the trees were cut down as Bwamapou timber is useless for construction. Boobies have disappeared from many of Seychelles’ seabird islands and re-establishing them is likely to be a long process. However, other seabirds are waiting in the wings.

White Terns: it might be possible to encourage them to nest on North Island
White Terns: it might be possible to encourage them to nest on North Island

On boat journeys between Mahe and North Island several seabird species are commonly seen: White-tailed Tropicbird, Wedge-tailed Shearwater, Tropical Shearwater, Brown Noddy, Lesser Noddy, White Tern, and between May and October Sooty Tern. Of these, only the first two species currently nest on North Island and these only in small numbers. The cat and rat eradications undertaken 10 years ago, and the current myna eradication, open the possibility that some of these seabirds, perhaps especially White Tern and Lesser Noddy, could eventually arrive (or return) as breeding species, further diversifying North Island’s animal life. White Terns would add another level of beauty to these wonderful beaches. These birds might even be encouraged to return by placing models resembling them in trees along the western plateau.

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