Abstract
Double-crested Cormorants (Phalacrocorax auritus) increased dramatically in North America during the 1990s, providing the opportunity to study the effects of an increase of a top predator on an existing predator–prey system. In Oneida Lake, New York, USA, Double-crested Cormorants were first observed nesting in 1984 and had increased to over 360 nesting pairs by 2000. Concomitant with this increase in piscivorous birds was a decrease in the adult walleye (Stizostedion vitreum) and yellow perch (Perca flavescens) populations. Analysis of a 40-yr data series shows higher mortality of subadults (age 1–2 yr perch and age 1–3 yr walleye) for both species in the 1990s compared to the previous three decades. Cormorant diet was investigated from 1995 to 2000 using a combination of cast pellets, regurgitants, and stomach analysis. Walleye and yellow perch were a major portion of the cormorant diet during these years (40–82% by number). The number of subadult walleye and yellow perch consumed by cormorants suggests...
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
