Seasonal Occurrence and Daytime Behaviour of Eurasian Spoonbills Platalea leucorodia leucorodia in Senegal's Atlantic Coastal Areas

Abstract. Senegal hosts hundreds of wintering Eurasian Spoonbills Platalea leucorodia every year. To contribute to the paucity of knowledge on their distribution and ecology, this study aimed to compare the occurrence and behaviour of spoonbills at the three most important sites in Senegal: Djoudj National Park, Technopôle of Dakar and Palmarin Reserve. Based on monthly counts in 2017 and 2018, Djoudj reached peak numbers of more than 2500 birds in April. The number in Palmarin peaked at 500 birds in October. In both cases this well exceeds the 1% threshold for the East Atlantic Flyway population, but Djoudj can hold up to a sixth of the population. Technopôle is an intermediate site that rarely hosts more than 50 individuals. Based on the scanning of behaviours throughout the day, we show that foraging activity was high early in the morning and decreased towards noon. At Palmarin, Spoonbills spent more time resting (68%) than at Djoudj (50%), allocating less time to foraging (16%) compared with Djoudj (29%). If this indicates favourable wintering habitat at Palmarin, the growing population of Eurasian Spoonbills from Europe may increasingly rely on the Palmarin site during the coming decade.