Abstract
Nest-site selection and nest success for Red-breasted Mergansers (Mergus serrator) breeding on a barrier island complex (Tern Islands) with >10,000 Common Terns (Sterna hirundo) in eastern New Brunswick, Canada, were studied in 2005 and 2006. Concealment was the most important feature for nest placement as 153 of 156 nests were in dense stands of Marram Grass (Ammophila breviligulata), and overhead concealment, vegetation density and vegetation height were all greater at nests than at random locations. Apparent success for all nests was 57% and was similar between years. Few nests were depredated (N = 3), but abandonment was responsible for 95% of nest losses and was most common early in the season. Nest success was <45% for nests initiated before 25 May but >75% for nests initiated after 10 June. Nest abandonment was influenced by intraspecific nest parasitism and investigator activity. Red-breasted Mergansers selected nest sites adaptively on Tern Islands because: 1) nests were more concealed than random sites; 2) avian predation at nests in the Common Tern colony was lower than at nests on nearby islands without terns; 3) nests were not exposed to mammalian predators; and 4) nest success and nest densities were high.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.