Exploration speed in captivity predicts foraging tactics and diet in free-living red knots.

Autor: Ersoy S; Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands.; Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands., Beardsworth CE; Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands., Dekinga A; Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands., van der Meer MTJ; Department of Marine Microbiology & Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands., Piersma T; Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands.; Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands., Groothuis TGG; Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands., Bijleveld AI; Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands.
Jazyk: angličtina
Zdroj: The Journal of animal ecology [J Anim Ecol] 2022 Feb; Vol. 91 (2), pp. 356-366. Date of Electronic Publication: 2021 Nov 22.
DOI: 10.1111/1365-2656.13632
Abstrakt: Variation in foraging tactics and diet is usually attributed to differences in morphology, experience and prey availability. Recently, consistent individual differences in behaviour (personality) have been shown to be associated with foraging strategies. Bolder or more exploratory individuals are predicted to have a faster pace-of-life and offset the costs of moving more or in risky areas, with higher energetic gains by encountering profitable foraging opportunities and prey. However, the relationship between personality, foraging and diet is poorly understood. We investigated how exploratory behaviour in red knots Calidris canutus is associated with foraging tactics and diet by combining laboratory experiments, field observations and stable isotope analysis. First, we developed a mobile experimental arena to measure exploration speed in controlled settings. We validated the method by repeated testing of individuals over time and contexts. This setup allowed us to measure exploratory personality at the field site, eliminating the need to bring birds into captivity for long periods of time. After releasing birds within days of their capture, we asked whether exploration speed was associated with differences in foraging tactics and diet in the wild. We found that tactile foraging red knots mainly caught hard-shelled prey that are buried in the sediment, whereas visual foraging knots only captured soft preys located close to or on the surface. We also found that faster explorers showed a higher percentage of visual foraging than slower explorers. By contrast, morphology (bill length and gizzard size) had no significant effect on foraging tactics. Diet analysis based on δ 15 N and δ 13 C stable isotope values of plasma and red blood cells confirmed our field observations with slower explorers mainly consumed hard-shelled prey while faster explorers consumed more soft than hard-shelled prey. Our results show that foraging tactics and diet are associated with a personality trait, independent of morphological differences. We discuss how consistent behaviour might develop early in life through positive feedbacks between foraging tactics, prey type and foraging efficiency.
(© 2021 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.)
Databáze: MEDLINE
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