Feeding behavior of juvenile and adult Reddish Egrets (Egretta rufescens) in Guerrero Negro, Baja California Sur, Mexico

The Reddish Egret (Egretta rufescens) is the least well-studied species of heron in North America, and even less is known for Mexican populations. In Guerrero Negro, Baja California Sur, the artificial wetland Salitrales 1A is an important feeding area for this species. During winter (December 2013-February 2014), we studied the feeding behavior and efficiency by age class (adults >= 1 year and juveniles < 1 year). We observed a decrease in the abundance and in the proportion of adults from December to February, associated with a reduction in the water level. Feeding attempts per minute by juveniles were higher than adults (1.28 and 1.03, respectively), the number of successful prey captures per minute was similar between both age classes (0.53 and 0.48), which resulted in greater feeding efficiency of adults (39% and 47% successful capture attempts). The lower efficiency of the juveniles is likely due to incipient visual-motor coordination and the lack of experience to identify the prey.