Diversity, distribution and conservation of crocodiles (Order: Crocodylia) in Guinea-Bissau, West Africa

Challenges in freshwater organisms’ conservation in West Africa are exacerbated by the significant knowledge shortfalls on various biological groups, including charismatic species such as crocodiles. This study addresses these gaps by assessing crocodile diversity, distribution, and conservation threats in Guinea-Bissau (West Africa), where existing data is outdated. We combined visual surveys, inquiries, molecular barcoding, camera trapping and bibliographic review to study crocodile diversity and distribution, and conservation threats in Guinea-Bissau. After 222 years, we recorded evidence of the current presence of the Nile crocodile (Crocodylus niloticus) in West Africa, possibly restricted to the Cacheu region (Guinea-Bissau). We also recorded the West African crocodile (Crocodylus suchus) in most of Guinea-Bissau’s major river basins and coastal lagoons (including the Bijagós Archipelago), and the West African dwarf crocodile (Osteolaemus cf tetraspis) in the southern mainland and the Bijagós Archipelago. Habitat loss and deliberate killings were identified as major threats. Standardized surveys and genetic sampling are essential to assess population size, connectivity, and genetic diversity, aiding in evolutionary studies and conservation planning. Conservation measures should prioritize habitat protection through community-managed reserves and restoration efforts. Additionally, engaging local communities to raise awareness and develop conflict mitigation strategies is crucial, particularly in areas with human-crocodile interactions.