首页 | 本学科首页   官方微博 | 高级检索  
     


Importance of the Japanese anchovy (Engraulis japonicus) to breeding rhinoceros auklets (Cerorhinca monocerata) on Teuri Island, Sea of Japan
Authors:A. Takahashi  M. Kuroki  Y. Niizuma  A. Kato  S. Saitoh  Y. Watanuki
Affiliation:Department of Polar Science, The Graduate University for Advanced Studies, Itabashi, Tokyo 173-8515, Japan,
Laboratory of Applied Zoology, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan,
National Institute of Polar Research, Itabashi, Tokyo 173-8515, Japan,
Laboratory of Physical Oceanography, Faculty of Fisheries, Hokkaido University, Hakodate 041-0821, Japan,
Abstract:Temporal variation in the diet and chick growth of rhinoceros auklets (Cerorhinca monocerata), on Teuri Island, Sea of Japan, was studied to understand how local marine environmental changes affect the reproduction of this piscivorous seabird. The food delivered by parents to chicks was sampled every 1-2 weeks from late May to July, 1994-1998. Overall, the diet of nestling rhinoceros auklets consisted of (by mass) 61% Japanese anchovy (Engraulis japonicus), 18% Japanese sand lance (Ammodytes personatus), 18% Japan Sea greenling (Pleurogrammus azonus), 2% other fish and 1% squid. Among years, the contribution of anchovy ranged from 16% to 93%. Once anchovy occurred in the diet, it dominated (80% on average) thereafter. Accordingly, when anchovy appeared in the diet early in the chick-rearing season (1994, 1998), the contribution of anchovy overall was large. The first appearance of anchovy in the diet of auklets late in the summer of 1997 was possibly related to negatively anomalous sea-surface temperature. Food loads composed of anchovy (34.0 g) were heavier than those of sand lance (22.5 g) and greenling (28.5 g). The energy density of anchovies also was higher: 6.3 kJ g-1 wet mass compared to 0+ greenling (4.78 kJ g-1) and 0+ sand lance (3.78 kJ g-1). Thus, a high proportion of anchovy in the diet resulted in high food load mass, high daily growth rates of chicks and high fledging success. This study highlighted the importance of the time of arrival of migratory high-lipid prey, which is influenced by local oceanographic conditions, to the reproductive performance of a piscivorous seabird.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号