Breeding of the Gull-billed Tern in the Sahara and an update on its distribution in Algeria

Abstract

The breeding distribution of the Gull-billed Tern Gelochelidon nilotica in Algeria is poorly known as the species is mainly associated with highly unstable habitats. We conducted a survey of the distribution of the species across all major Algerian wetlands and monitored a breeding colony at El Goléa during 2009. The species is usually described as a passage migrant in the Sahara, but its status may have to be reconsidered following our discovery of a small colony nesting on an islet in Sebkhet El Maleh, El Goléa. The colony consisted of 25 birds which built nine nests and foraged exclusively in and around the salt lake. Laying of eggs began in mid-April, in synchrony with high temperatures and strong evaporation. Clutches varied between 1 and 3 eggs but none was successful. The gradual drop in water level and subsequent drying of the Sebkha coincided with the first hatchings, exposing the first hatchlings to mammalian predation arising from the intrusion of jackals Canis aureus, which entirely destroyed the colony.