Proceedings of the Vertebrate Pest Conference

Nest predation is pervasive and debatably the most vital factor limiting avian productivity. Studies have shown that avian and mammalian predator control programs for the protection of shorebirds have been successful in increasing overall nesting success. Our work focused on the management of both native and non-native predator populations at Naval Base Coronado (NBC) in an effort to minimize predation pressure upon the California least tern and western snowy plover populations during the breeding season. We had a total of 580 tern and plover egg and non-egg predation events on NBC between 2012 and 2015. Predation by corvids was responsible for 63% of total predations, raptors 24%, mammals 7%, and other animals 6%. We captured 60% (n = 93) of the corvids with modified goshawk traps and 90% (n = 17) of the raptors with Bal-chatri traps. Our predator management program focused on the control of corvids, rather than mammals and raptors, as corvids were historically responsible for the greatest loss of tern nests compared to other taxa. We used a variety of trapping and hunting techniques over the years and, through trial and error, have enhanced our removal success and overall predator management program on Naval Base Coronado.