Nile Crocodiles in Lake Nasser, Egypt, Are Found Close to Fishermen's Camps, Indicating Potential Conflicts

Conflict between wildlife and humans is one of the main causes of wildlife decline. Numerous studies have investigated environmental and anthropogenic variables determining the distribution of large carnivores to predict and mitigate the risks of such conflicts. However, for aquatic carnivores, such as crocodiles, little is known about which variables explain their distribution. Yet, human-crocodile conflicts are on the rise. A better understanding of such variables will potentially prevent conflicts or even promote coexistence between crocodiles and humans. Here, we analyze which environmental and anthropogenic variables determine the distribution of Nile crocodiles (Crocodylus niloticus) in Lake Nasser, Egypt. As apex predators, Nile crocodiles are often perceived to be responsible for the declining fish populations, and proximity to fishermen could lead to conflicts and killing of crocodiles. Since both crocodiles and fishermen hunt fish, we expected to find Nile crocodiles close to fishermen's camps. To analyze the crocodile distribution, we surveyed 1880 km of Lake Nasser's shoreline and collected 192 sightings of Nile crocodiles. We used readily available spatial data for 23 environmental and anthropogenic variables, including ambient temperature, the slope of the shoreline, and the distance to fishermen's camps. We used MaxEnt species distribution modeling to quantify which variables were correlated with Nile crocodile locations. Our analyses revealed a higher probability to find Nile crocodiles closer to fishermen's camps. Additionally, crocodile presence was positively associated with flat shorelines. The findings that crocodiles are not driven away by fishing activities reflect a conflict between fishermen and crocodiles. This study contributes to an understanding of which environmental and anthropogenic variables determine the distribution of Nile crocodiles, a key conservation point to promote human-crocodile coexistence.