Population Changes, Breeding Cycles and Breeding Success over Six Years in a Seabird Colony at Michaelmas Cay, Queensland
Population Changes, Breeding Cycles and Breeding Success over Six Years in a Seabird Colony at Michaelmas Cay, Queensland
复制标题
昆士兰州迈克尔马斯岛海鸟栖息地六年来的种群变化、繁殖周期和繁殖成功率
作者：
B. R. King;J. Hicks;J. Cornelius
从1984年5月到1990年4月，每个月的米迦勒节都要清点海鸟。在研究期间培育了7个物种。主要繁殖种为褐乌燕鸥、褐乌燕鸥、柏氏凤头燕鸥和小凤头燕鸥。银鸥新荷兰松鸦、苏门答腊黑枕燕鸥、黑枕燕鸥，数年少量繁殖。灰燕鸥的半年繁殖周期为8.6个月，在繁殖高峰之间进行测量，而其他种类为一年生繁殖，夏季5个，冬季1个（银鸥）。在连续的繁殖周期中，黑燕鸥和白头翁的繁殖种群规模波动较大。凤头燕鸥数量先增加后减少，小凤头燕鸥数量先增加后减少。在研究期间，银鸥的平均数量保持相当稳定。灰燕鸥、白头燕鸥和凤头燕鸥在不同的繁殖周期中，羽化成功率差异很大。小冠燕鸥在三个周期内成功繁殖，并在研究期间显示出越来越多的羽化成功率。气候对黑燕鸥和白头翁的繁殖种群有重要影响。共录得三个气旋；一种改变了黑燕鸥繁殖周期的周期性，二种影响了其繁殖数量和繁殖成功率。年中，长时间的强风导致了黑燕鸥和白头翁的繁殖失败。土壤的侵蚀也造成了巢穴的损失。人为干扰对繁殖种群影响不大。
Seabirds were counted on Michaelmas Cay every month from May 1984 to April 1990. Seven species bred during the study. The major breeding species were Sooty Tern Sterna fuscata, Common Noddy Anous stolidus, Crested Tern S. bergii and Lesser Crested Tern S. bengalensis. Silver Gull Larus novaehollandiae, Black-naped Tern S. sumatrana and Bridled Tern S. anathaetus bred in some years in small numbers. Sooty Terns had a sub-annual breeding cycle of 8.6 months duration, measured between peaks of breeding numbers, while the other species were annual breeders, five in summer and one (Silver Gull) in winter. In successive breeding cycles, the sizes of breeding populations of Sooty Tern and Common Noddy both fluctuated strongly. Crested Tern numbers increased slightly then decreased, and Lesser Crested Tern numbers increased strongly then decreased again. Average Silver Gull numbers remained fairly stable over the study period. Fledging success varied considerably among breeding cycles of Sooty Tern, Common Noddy and Crested Tern. Lesser Crested Terns bred successfully in three cycles and showed increasing fledging success over the study period. Climate had a major influence on breeding populations of Sooty Tern and Common Noddy. Three cyclones were recorded; one altered the periodicity of Sooty Tern breeding cycles and two affected its breeding numbers and success. In mid-year, prolonged periods of strong winds caused breeding failures in Sooty Tern and Common Noddy. Erosion of the cay also caused nest losses. Human disturbance had little effect on breeding populations.