An inventory of Sooty Terns (Sterna fuscata) in the western Indian Ocean with special reference to threats and trends

  • Chris J Feare WildWings Bird Management, 2 North View Cottages, Grayswood Common, Haslemere, Surrey GU27 2DN, UK; University of Leeds, Leeds LS2 9JT, UK
  • Sébastien Jaquemet Laboratoire ECOMAR, Université de la Réunion, 15 avenue René Cassin, BP 7151, 97715 Saint Denis messag cedex, Réunion Island, France
  • Matthieu Le Corre Laboratoire ECOMAR, Université de la Réunion, 15 avenue René Cassin, BP 7151, 97715 Saint Denis messag cedex, Réunion Island, France

Abstract

The western Indian Ocean supports over 6 200 000 pairs of Sooty Terns, some in very large colonies. During the past two centuries colonies have exhibited increase, stability, decline and extinction. The main drivers of these trends have been habitat change and unregulated human exploitation, especially of adults; introduced predators appear to have little effect at the population level but may have prevented re-colonisation following habitat restoration. Regulated harvesting of eggs, based on increasing knowledge of Sooty Tern demography, appears to be sustainable. Some colonies now receive protection but it will be logistically difficult to extend this to all colonies. The main future threats are likely to be climate change and over-exploitation of tuna, on which Sooty Terns depend to feed. Sooty Terns should be monitored to provide insights into these and other perturbations of the marine ecosystem.

Ostrich 2007, 78(2): 423–434
Section
Articles

eISSN: 1727-947X