Relationships of Settlement Date and Body Size with Reproductive Success in Male Oriental Great Reed Warbler Acrocephalus Orientalis

with reproductive success in male Oriental Great Reed Warbler Acrocephalus orientalis. Zoological Studies 49(3): 398-404. Relationships of the settlement date and body size with the reproductive success of Oriental Great Reed Warbler Acrocephalus orientalis males was studied at Yangsu-ri, Yangpyeong-gun, and Gyeonggi-do, Korea during 4 breeding seasons (1998-2001). Although most males were monogamous (50.6%), some were polygynous (25.9%), and others were unmated (23.5%). Males that settled earlier were more likely to mate with females earlier, were likely to be polygynous, and consequently had higher reproductive success. Early-settling males had longer wings and tails, and greater mass than later-settling ones. However, although body size was an important factor affecting the settlement date in males, it did not directly affect reproductive success. This study showed that the settlement date is an important factor predicting reproductive success in males.