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

Challenges in freshwater organism conservation in West Africa are worsened by significant knowledge gaps, even for charismatic species like crocodiles. This study addresses these gaps by assessing crocodile diversity, distribution, and conservation threats in Guinea-Bissau, where existing data is outdated. We used visual surveys, inquiries, molecular barcoding, camera trapping, and bibliographic reviews to investigate crocodile populations. Notably, we found evidence suggesting the Nile crocodile (Crocodylus niloticus), previously thought extinct in West Africa since about 200 years, may persist in Guinea-Bissau’s Cacheu region. We also confirmed the presence of the West African crocodile (Crocodylus suchus) in 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, informing evolutionary studies and conservation planning. Conservation efforts should prioritize habitat protection through community-managed reserves and restoration initiatives. Additionally, engaging local communities to raise awareness and develop conflict mitigation strategies is crucial, particularly in areas with human-crocodile interactions.