Migration stopover behaviour of Sooty Falcons (Falco concolor) during their southward journey

Five (2 juvenile, 3 adult) Sooty Falcons (Falco concolor) were tracked in 2021 and 2022 on their southward migration. Falcons made stopovers along their migratory route where food may have been abundant, but potentially exposed themselves to heightened risks associated with those locations. Juveniles made inland and (SE African) coastal stopovers. Adults did not make inland stopovers, but two did stopover at the coast before crossing to Madagascar. Inland stopovers (n=6) constituted up to 51.4% of migration time of juveniles. Inland and coastal stopovers (n=10) were 42.9–79.4% of southward migration time. Mean duration of inland stopovers was 9.3±7.7 days, 18.0±8.5 days for coastal stopovers. 50% utilization distribution isopleths of inland stops covered 8,437±8,674 km², and 53,638±18,672 km² for coastal stops. The most important habitats were Shrubland, Tree cover, and Grassland. We found no link between weather and stopover behaviour, whether inland or on the coast. The data identify the location of stopovers, and suggest their relative importance for feeding and potential for heightened risks, at least in the years of tracking. Analysing data from a larger sample over more years, coupled with information on prey (e.g. locusts and Quelea) and threats (e.g. pesticide use) would clarify the ecological role of migratory stopovers, potential areas of risk, and enable targeted conservation action.