Assessments of range-wide distribution of six African storks and their relationships with protected areas

Abstract

Species range maps provided by the IUCN and BirdLife International are recognised to sometimes mischaracterise distribution and have resulted in inaccurate status assessments. In this study we assessed distribution trends and relationships with protected area extent for six African storks, the African Openbill Anastomus lamelligerus, Abdim’s Stork Ciconia abdimii, African Woolly-necked Stork C. microscelis, Saddlebilled Stork Ephippiorhynchus senegalensis, Marabou Stork Leptoptilos crumenifer and Yellow-billed Stork Mycteria ibis. Each of these species is understudied and assumed to be ubiquitous throughout sub-Saharan Africa and therefore considered Least Concern on the IUCN Red List. We developed empirically based distribution maps for the six African stork species using a plethora of data sources from >150 years. We found all six species were widespread from East to Southern Africa, but had highly fragmented ranges in West Africa. West African populations have either declined or been extirpated since the 1960s. Countries that require better field coverage include Angola, the Democratic Republic of Congo, Somalia, South Sudan, Sudan and Zimbabwe. For each species, there was a positive relationship between occurrence and protected area extent, suggesting either protected habitat is important for storks or unprotected areas are poorly covered in the field. We evaluate species status based on the new collated information and recommend uplisting the global status of the Saddle-billed Stork to Near Threatened and West African populations of the Saddle-billed Stork, Marabou Stork and Yellowbilled Stork to Threatened status.

Keywords: conservation assessments; fragmentation; population trend; surveys; wetlands; waterbirds