Fish-Eating Birds on Catfish Ponds in the Mississippi Delta

Catfish acreage in the Mississippi Delta has significantly declined in the past two decades, but cormorant density on catfish ponds has remained the same. One possible explanation is that there are fewer cormorants in the region, and this is supported with decreasing roost counts. Cormorant roost harassment can be even more effective today than in the past, because there is less aquaculture acreage to protect and fewer cormorants to move. Roost harassment is important over the entire winter, but even more so around mid-January when cormorant abundance is greatest and when cormorants are more focused on aquaculture ponds. The addition of limited lethal management on ponds and roosts may make dispersal efforts more effective. Understanding which ponds fish-eating birds decide to use is important for effective management at catfish farms. Many pond characteristics influence use by cormorants, herons, and egrets. What is in the pond and what is around the pond are things these birds take into consideration. From this work, it is possible to produce a “heat map” of farms showing the probability that each bird species will use a given pond (Figure 6). Paying more attention to ponds with higher probabilities of damage may help bird harassment efficiency on the farm and reduce depredation