Activity of predators in seabird colonies decreases during the darkest compared to the brightest phase of the diel cycle below, but not above, the Arctic circle
Predator activity can structure communities temporally and influence the spatial distribution of prey. Yet, despite the influence that this may have on prey species’ activity or geographic persistence, our understanding of whether diel predator activity changes geographically remains limited. Here,...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Taylor & Francis
2024
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| Summary: | Predator activity can structure communities temporally and influence the spatial distribution of prey.
Yet, despite the influence that this may have on prey species’ activity or geographic persistence, our
understanding of whether diel predator activity changes geographically remains limited. Here, we
conduct a case study to test whether predator activity during the darkest phase of the diel cycle
increases with the duration of daylight (i.e. photoperiod) at high latitudes during summer, aligning
with the photoperiod constraint hypothesis. Using both observations and experiments at one
seabird colony above and one below the northern polar (Arctic) circle, we compared predator
activity between the brightest and darkest phases of the diel cycle. Avian predator counts were
greater and nest predation events were more common during the brightest phase of the diel cycle
below the Arctic circle (i.e. where the sun goes below the horizon), but similar across phases during
polar summer (i.e. when the sun does not set above the Arctic circle). Our results highlight the
potential influence of light on activity of predator communities and suggest a possible latitudinal
limit to the advantage gained by dark active strategies for avoidance of visually hunting predators.
Keywords: chronoecology; diel activity; light-dark cycle; photoperiod constraint hypothesis; polar
latitude; predator activity |
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