American white pelicans reveal their presence by their large webbed tracks and guano-stained (whitewashed) landscapes. Other than fish losses and the presence of B. damnificus, direct observation is the only way to determine if pelicans have been in an area.
Evaluation of Predation
Fish losses at harvest, the presence of B. damnificus, and direct observation are the only ways to determine if pelicans have foraged on aquaculture ponds. Direct observation of pelican predation may not always be possible because pelicans will forage at night, especially on aquaculture facilities with active daytime harassment programs.
Trampling of vegetation is characteristic of pelican damage agricultural crops (e.g., rice).