MURRES, CAPELIN AND OCEAN CLIMATE 1 1 Running head: MURRES, CAPELIN AND OCEAN CLIMATE 2 3 Murres, Capelin and Ocean Climate: Inter-annual Associations across a MURRES, CAPELIN AND OCEAN CLIMATE 2
Abstract To ensure energy demands for reproduction are met, it is essential that marine 1 birds breed during periods of peak food availability. We examined associations of the 2 breeding chronology of common murres (Uria aalge) with the timing of the inshore 3 arrival of their primary prey, capelin...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1055.6406 http://play.psych.mun.ca/%7Emont/pdfs/Regular_et_al_EMAS.pdf |
| Summary: | Abstract To ensure energy demands for reproduction are met, it is essential that marine 1 birds breed during periods of peak food availability. We examined associations of the 2 breeding chronology of common murres (Uria aalge) with the timing of the inshore 3 arrival of their primary prey, capelin (Mallotus villosus) from 1980-2006 across a period 4 of pervasive change in the Northwest Atlantic ecosystem. We also assessed the influence 5 of ocean temperature and the North Atlantic Oscillation (NAO; an index of winter 6 climate and oceanography) on these interactions. We found a lagged linear relationship 7 between variations in murre breeding chronology and the timing of capelin arrival in the 8 previous year. On a decadal level, we found a non-linear threshold relationship between 9 ocean temperature and the timing of capelin arrival and murre breeding. Centennially 10 anomalous cold water temperatures in 1991 generated a marked shift in the timing of 11 capelin spawning inshore and murre breeding, delaying both by more than 2 weeks. By 12 the mid-1990s, ocean temperatures returned to pre-perturbation levels, whereas the 13 temporal breeding responses of capelin and murres were delayed for a decade or more. 14 Oceanographic conditions (temperature, NAO) were poor predictors of the timing of 15 capelin arrival inshore in the current year compared to the previous one. Our findings 16 suggest that knowledge of the timing of capelin availability in the previous year provides 17 a robust cue for the long-lived murres, allowing them to achieve temporal overlap 18 between breeding and peak capelin availability. 19 20 |
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