Interannual variation in foraging decisions in chick-rearing black-legged kittiwakes

Long-lived species must balance allocation between reproduction and self-maintenance, and such a trade-off is expected to affect their foraging behaviour. A bimodal foraging strategy, where individuals alternate between long trips for self-maintenance and short trips for offspring provisioning, may reflect this compromise. Using tracking data collected over three breeding seasons, we investigated the occurrence of a bimodal foraging strategy and inter-annual variation in foraging decisions among black-legged kittiwakes (Rissa tridactyla) breeding in Kongsfjorden, Svalbard. Kongsfjorden, a glacial fjord with six tidewater glacier fronts, provides close foraging opportunities to breeding sites. The continental shelf break outside the fjord offers another foraging area but involves higher commuting costs. We tested the hypothesis that breeding adults perform foraging trips outside the fjord for self-maintenance. We predicted that 1) adults were more likely to undertake foraging trips outs..., , , # Interannual variation in foraging decisions in chick-rearing black-legged kittiwakes

[https://doi.org/10.5061/dryad.0cfxpnwcj](https://doi.org/10.5061/dryad.0cfxpnwcj)

**Overview**

This dataset contains summarised GPS tracking data of black-legged kittiwakes (Rissa tridactyla), collected in Kongsfjorden, Svalbard, between 2016 and 2018. It provides detailed information on individual trips, distances travelled, and various biometric measurements. The dataset has been used in \"Interannual variation in foraging decisions in chick-rearing black-legged kittiwakes\" by Bertrand et al. 2025, published in Behavioral Ecology.

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