Analysis of Barn Owl (Tyto alba) Diet at CSU Channel Islands and Their Potential to Control Rodents, an Alternative to the Application of Second-Generation Anticoagulant Rodenticide.
Authors:Ivett Plascencia, Erika Sanchez
Mentor:Sean Anderson, Associate Professor and Director Pacific Institute for Restoration Ecology, California State University Channel Islands
Today rodent control poisons are used far beyond their original intent of wildlife conservation and have become abundant for urban and agricultural use. Recently the movement and effects of rodenticides throughout the food chain are beginning to be observed and have been found widely distributed throughout non-target taxa. The main rodent control method used on CSU Channel Islands (CSUCI) campus is the application of second-generation anticoagulant rodenticide and raises concern on the effects to non-target wildlife including, birds of prey, bobcats (Lynx rufus) and mountain lions (Pumas concolor). As our CSUCI campus lies within the Santa Monica Mountains National Recreational Area and we are committed to sustainability, we seek to encourage campus use of alternative methods of rodent control. This study explores the potential use of barn owls (Tyto alba) for the control of rodents through an owl-based integrated pest management program. Through a better understanding of current T. alba prey in their diet at CSUCI we may begin to piece together key components of an alternative rodent control method strategy. As a primary assessment we analyze the content of 104 T.alba pellets (collected from May 2011 through May 2012) and compared differences in the diversity (number of species) and the number of individual prey per pellet between collections sites. There was a significant difference in diversity and number of prey between roosting sites (ANOVA P>.05). In addition to our prey studies, we have mounted four artificial nest boxes on the CSUCI campus to encourage nesting and roosting of T. alba. Our results show that T. alba diets vary between roosting sites and their diverse prey base demonstrates potential to control rodents on CSUCI campus through a well-rounded integrated pest management program.