The Least Tern breeding season was a special occasion this year. Cargill, in cooperation with STINAPA Bonaire, IMARES and DROB, constructed an artificial island in an area to the south of Bonaire which is very important for the migratory birds that visit Bonaire. The artificial island had wooden decoys placed to attract the terns and also rocks and pipe shelters for the chicks to hide from predators.
The annual breeding season is from May to the end of August. The Least Terns made very good use of the newly built island. STINAPA researchers registered a total of 243 nests on the island which produced 219 chicks. Around the rest of the Cargill area, another 991 nests of a variety of terns that breed on our island were registered, 561 of which were Least Tern nests.
A big challenge for nesting Least Terns are the predators that eat the eggs and hunt the chicks. There are a lot of predators for the birds to be wary of, such as feral cats, crabs, hermit crabs, laughing gulls, lizards and other sea- and water birds. The Least Terns on the artificial island were better protected from most of these predators thanks to the water surrounding the nesting island. It was noted that the survival rate of the chicks on the artificial island was much higher than the rest of the colonies in the area.
On August 29th one last Least Tern chick that was still learning to fly was spotted. The bird decoys, specially built by Cargill staff, to attract the Least Terns to the artificial island, were removed and stored away until next year’s breeding season.