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

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 δ15 N and δ13 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.

The role of scientific reasoning and religious beliefs in use of complementary and alternative medicine.

BACKGROUND: While previous research has shown that trust in complementary and alternative medicine (CAM) is linked with other unfounded beliefs (e.g. paranormal phenomena or pharmaceutical conspiracies) and that analytic thinking can help alter these beliefs, the role of the ability to evaluate evidence as a protective factor has not been established yet. METHODS: A cross-sectional design with a hundred participants was used with self-report data from questionnaires and performance test. The dependent variables were the belief in CAM and use of CAM. Predictor variables were scientific reasoning (measured by Scientific Reasoning Scale), critical thinking dispositions (measured by Critical Thinking Disposition Instrument; UF-EMI), religious beliefs (measured by Santa Clara Strength of Religious Faith Questionnaire), gender and age. RESULTS: Scientific reasoning and religious faith independently predicted belief in alternative medicine, while the role of scientific reasoning in actual reported use of CAM diminished after religious faith, gender and age were introduced to the model. CONCLUSION: The results highlight the fact that it is not enough to appeal to the general critical thinking of people, but we need to teach them some practical skills that would help them to evaluate evidence in other, health-unrelated, contexts as well.