Climate-Forced Seasonal Mismatch Between the Hatching of Rhinoceros Auklets and the Availability of Anchovy
Vol. 393: 259–271, 2009 MARINE ECOLOGY PROGRESS SERIES Published October 30 doi: 10.3354/meps08264 Mar Ecol Prog Ser Contribution to the Theme Section ‘Marine ecosystems, climate and phenology: impacts on top predators’ OPENPEN ACCESSCCESS Climate-forced seasonal mismatch between the hatching of rhinoceros auklets and the availability of anchovy Yutaka Watanuki1,*, Motohiro Ito1, Tomohiro Deguchi2, Shoshiro Minobe3 1Graduate School of Fisheries Sciences, Hokkaido University, Minato-cho 3-1-1, Hakodate 041-8611, Japan 2Yamashina Institute for Ornithology, Takanoyama 115, Abiko, Chiba 270-1145, Japan 3Graduate School of Sciences, Hokkaido University, Kit-10 Nishi-8, Kita-ku, Sapporo 060-0810, Japan ABSTRACT: Predator–prey relationships are key to understanding complex marine ecosystem dynamics. The match–mismatch hypothesis posits that predators time energy-intensive activities, such as reproduction, to periods of high food availability. However, predators may be constrained by various ecological or physiological processes, leading to mistimed activities relative to prey availabil- ity. We investigated inter-annual variation in the timing of breeding for a piscivorous seabird (rhinoc- eros auklet Cerorhinca monocerata) in relation to availability of a preferred prey item, Japanese anchovy Engraulis japonicus, using data collected over 18 yr between 1984 and 2006 at Teuri Island in the northern Japan Sea. Our primary goals were (1) to identify the climatic factors that affect the seabirds’ timing of breeding, proxied by hatching date, and anchovy seasonal availability, and (2) to quantify the fitness effects of predator–prey matches and mismatches relative to climate variability. Hatching date was later in years with lower spring air temperatures. Auklets switched their feeding from sandlance and juvenile greenling to anchovy when it was transported into the birds’ foraging range with the seasonal northern expansion of 13°C warm water from the south.
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