Breeding in a postulated wintering site: first evidence for the breeding of Baillon's Crake Porzana pusilla in Senegambia, West Africa

We report the discovery of the first breeding population of Baillon's Crake Porzana pusilla in Senegambia, West Africa. From winter 2007-2010, 278 Baillon's Crakes were caught within and immediately north of Parc National des Oiseaux du Djoudj in the Senegal delta, as well as in a wetland in The Gambia at Pakali Ba. The records included 169 juvenile Baillon's Crakes, 23 of which were not fully fledged and were undoubtedly hatched in the area. The distribution of five assigned age intervals revealed that two consecutive broods were probably hatched within the breeding period, which is estimated to extend from September until February. During that period, the shallow Scirpus- and Sporobolus-marshes are still flooded and offer optimal habitat. The high number of captures suggests that a large population occurs in the Senegal delta. Furthermore, the species may be more abundant in Sahelian wetlands than was previously assumed. Sub-Saharan populations of P. pusilla are usually considered resident. However, due to limited seasonal availability of favourable habitats, the Senegambian population is probably migratory, but where this population occurs during the dry season is unknown.