Amerikaanse Dwergstern (Least Tern) Sternula antillarum


Use of artificial nesting island and decoys prove promising for tern restoration in Bonaire

Gepubliceerd op
15 mei 2014

Terns are iconic birds of shores and the sea throughout the world’s oceans. Bonaire has traditionally been a critical island for Caribbean nesting populations of several tern species, but nesting numbers have plummeted in recent decades due to human disturbance, invasive predators and habitat loss. Terns typically nest in large colonies on or close to the ground. Consequently, they are easy prey to ground-dwelling predators (like rats, cats and dogs) and human disturbance.

Photo: (Least Tern) Sternula antillarum

An egg of a Least Tern (may 2014, © P. Bertuol).
An egg of a Least Tern (may 2014, © P. Bertuol).

The creation of artificial nesting islands and the deployment of decoys and sound recordings to re-establish endangered tern breeding populations has been and continues to be successfully used in many areas around the world. It is now being used for the first time in the Dutch Caribbean, on the island of Bonaire.

The project in question is taking place in the 6,200 hectare “Important Bird Area” (IBA) area of southern Bonaire centered around the Cargill Salt Bonaire N.V. solar salt works. This area is also the main southern Caribbean breeding site of the West-Indian Flamingo, Bonaire’s trademark bird. Parts of the extensive area also carry international legal protected status as a Ramsar-treaty wetland.

The Cargill bulldozer starts work. (Nov 2013, © Cargill Salt Bonaire NV.)
The Cargill bulldozer starts work. (Nov 2013, © Cargill Salt Bonaire NV.)

Based on conversations held in June 2013, between IMARES, Cargill, the Bonaire National Parks Foundation (STINAPA) and the government planning department, the decision was reached to jointly develop a Tern Nesting Improvement Plan. Groundwork to rebuild the first new nesting island, free from introduced predators and industrial disturbance was begun in November. At the end of April 2014, the first decoys were deployed and 6 Least Terns settled on the island on the first afternoon. In the meantime, two weeks further, the island had 90 Least Tern nests and two Common Tern nests. The collaborating parties have grand plans to continue and expand the project. Aside from introducing a new management approach to the region, the project also represents a public-private partnership others might learn from.

”This plan is a solid start upon which we can build an on-going Tern Nesting Improvement Plan.  We do not intend for this to be a one-time effort, but instead, an on-going effort to increase the tern population on Bonaire”, said Gary Rimmey, manager of the Bonaire salt works.