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Seabirds that consume more than one prey type may adjust their foraging to maintain provisioning rates for their chicks. How energetically effective are these strategies, and what are the implications for the management of seabirds and their marine habitat?, A multi-species functional response links consumption rates to the availability of multiple prey types, but fitting multi-species functional responses to field data can be difficult, requiring consumption measurements over a range of different prey abundances. Such detailed data may be especially difficult to obtain in marine ecosystems., We used annual time-series data on chick provisioning for the common guillemot Uria aalge together with abundance indices for its two main prey (lesser sandeel Ammodytes marinus and sprat Sprattus sprattus) to parameterize a multi-species functional response for parents provisioning chicks at a major North Sea colony from 1992 to 2005., The fitted model reproduced changes in diet and consumption rate which were consistent with changes in local prey abundance including a long-term decline in sandeels., The model predicted that energy intake by chicks would be more sensitive to changes in sprat abundance than sandeel abundance. Guillemots appeared able to adjust their foraging tactics over a wide range of prey abundances to maintain a consistent energetic intake rate for chicks., Synthesis and applications. Our results suggest guillemot chicks obtain adequate calorific intake from their parents despite fluctuating prey abundances, conferring some resilience in the face of environmental variation. The parameterized multi-species functional response model can be used to estimate levels of severe prey shortage that compromise provisioning. It also enables us to interpret predator consumption rates so that these can be used as a metric of prey availability. Further, quantifying trophic links between marine prey and apex predators is needed to support the development of multi-species models in which the predators can be included. Such models are needed as tools to effectively manage the marine ecosystem, taking into account the objectives of fishing, conservation and the need to maintain Good Environmental Status. [ABSTRACT FROM AUTHOR]

Most seabirds die outside the breeding season, but understanding the key factors involved is hampered by limited knowledge of nonbreeding distributions. We used miniature geolocating loggers to examine the movements between breeding seasons of Atlantic puffins Fratercula arctica from a major North Sea colony where numbers have declined in recent years, apparently due to increased overwinter mortality. The most intensively used region was the northwestern North Sea but most puffins also made excursions into the east Atlantic in the early winter. Ringing recoveries previously indicated that adults from British east coast colonies remained within the North Sea and hence were spatially segregated from those breeding on the west throughout the year. Updated analyses of ringing recoveries support results from geolocators suggesting that usage of Atlantic waters is a recent phenomenon. We propose that the increased adult mortality is related to changes in distribution during the nonbreeding period and reflects worsening conditions in the North Sea. [ABSTRACT FROM AUTHOR]

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Breeding at the right time is essential for animals in seasonal climates in order to ensure that the energy demands of reproduction, particularly the nutritional requirements of growing young, coincide with peak food availability. Global climate change is likely to cause shifts in the timing of peak food availability, and in order to adapt successfully to current and future climate change, animals need to be able to adjust the time at which they initiate breeding. Many animals use environmental cues available before the breeding season to predict the seasonal peak in food availability and adjust their phenology accordingly. We tested the hypothesis that regulation of breeding onset should reflect the scale at which organisms perceive their environment by comparing phenology of three seabird species at a North Sea colony. As predicted, the phenology of two dispersive species, black-legged kittiwake ( Rissa tridactyla) and common guillemot ( Uria aalge), correlated with a large-scale environmental cue (the North Atlantic Oscillation), whereas a resident species, European shag ( Phalacrocorax aristotelis), was more affected by local conditions (sea surface temperature) around the colony. Annual mean breeding success was lower in late years for European shags, but not for the other two species. Since correlations among climate patterns at different scales are likely to change in the future, these findings have important implications for how migratory animals can respond to future climate change. [ABSTRACT FROM AUTHOR]

The article reports on snake pipefish Entelurus aequoreus as poor food for seabirds. It is stated that the population of snake pipefish Entelurus aequoreus has increased in the northeast Atlantic and the North Sea starting in 2003. It is said that since 2003, records show that the said species has been included to the diet of both adult and young seabirds. It is further stated that birds are having difficulty in swallowing the long thin fish making an assumption that the fish is a low-quality food and were perhaps only eaten by the birds when other prey were in short supply.