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- Metcalfe, N. B., et al.
(författare)
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Solving the conundrum of intra-specific variation in metabolic rate: A multidisciplinary conceptual and methodological toolkit New technical developments are opening the door to an understanding of why metabolic rate varies among individual animals of a species
- 2023
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Ingår i: Bioessays. - 0265-9247. ; 45:6
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Tidskriftsartikel (refereegranskat)abstract
- Researchers from diverse disciplines, including organismal and cellular physiology, sports science, human nutrition, evolution and ecology, have sought to understand the causes and consequences of the surprising variation in metabolic rate found among and within individual animals of the same species. Research in this area has been hampered by differences in approach, terminology and methodology, and the context in which measurements are made. Recent advances provide important opportunities to identify and address the key questions in the field. By bringing together researchers from different areas of biology and biomedicine, we describe and evaluate these developments and the insights they could yield, highlighting the need for more standardisation across disciplines. We conclude with a list of important questions that can now be addressed by developing a common conceptual and methodological toolkit for studies on metabolic variation in animals.
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- Norin, Tommy, et al.
(författare)
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Predator presence affects activity patterns but not food consumption or growth of juvenile corkwing wrasse (Symphodus melops)
- 2021
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer. - 0340-5443 .- 1432-0762. ; 75:1
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Tidskriftsartikel (refereegranskat)abstract
- Indirect effects of predators can manifest themselves as changes in prey behaviour and physiology. Given that digestion requires energy, it has been suggested that prey will choose to eat smaller meals under predation risk to reserve a larger portion of the aerobic metabolic scope they have available for energetically demanding tasks more critical than digestion, such as escape. To test this prediction, we quantified food consumption and growth of juvenile corkwing wrasses (Symphodus melops) over 11 days in the presence or absence of a predator (Atlantic cod, Gadus morhua). We then quantified behaviour and food consumption of the same wrasses in behavioural arenas with a predator. All food consumption was examined in the context of the aerobic scope that would have been available during the digestive period. Overall, there was no effect of predator exposure on food consumption or growth, yet predator-exposed wrasses were more consistent in their daily food consumption, lending some support to our prediction of prey bet-hedging on meal size under predation risk. The lack of a clear pattern may have resulted from a relatively low percentage of aerobic scope (similar to 20-27%) being occupied by digestion, such that fish retained ample capacity for activities other than digestion. In the subsequent behavioural trials, predator-exposed wrasses were more active and spent more time near the cod than predator-naive wrasses, suggesting the former had habituated to predation threat and were more risk-taking. Our results highlight the complex and often counter-intuitive effects that predator presence can have on prey populations beyond direct consumption. Significance statement Predators affect the behaviour of prey species by simply being present in the environment. Such intimidation by predators can change activity patterns of prey and be as important as direct predation for ecosystem dynamics. However, compared to behavioural changes, we know little about how predators indirectly affect prey physiology. We investigated if fish deliberately eat less food when a predator is present, in order to retain sufficient physiological capacity for avoiding a potential attack, on top of the energetically costly process of digesting. While our study confirms that predator encounters reduce prey activity, prey fish appeared to rapidly habituate to predator presence and we did not see reduced food consumption in predator-exposed fish; these were, however, more consistent than unexposed fish in their daily food consumption, suggesting that fish may still be mindful about protecting their aerobic capacity under predation risk.
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- Roche, Dominique G., et al.
(författare)
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Behavioural lateralization in a detour test is not repeatable in fishes
- 2020
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 167, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- Behavioural lateralization, the asymmetric expression of cognitive functions, is reported to enhance key fitness-relevant traits such as group coordination, multitasking and predator escape. Therefore, studies reporting negative effects on lateralization in fish due to environmental stressors such as ocean acidification, hypoxia and pollutants are worrisome. However, such studies tend to use a detour test and focus on population level measures, without validating whether lateralization is consistent within individuals across time. We conducted a multispecies, international assessment of the repeatability (R) of lateralization in four previously studied fish species using a detour test (T-maze), a common method for testing lateralization. We also reanalysed a published data set on a fifth species using new statistical methods. We expected the three shoaling species to exhibit greater within-individual consistency in lateralization than their nonshoaling counterparts given previous reports of stronger lateralization in group-living fishes. Absolute and relative lateralization scores were highly nonrepeatable in all five species (0.01<R<0.08), irrespective of their shoaling status. We carefully reviewed 31 published studies in which the detour test was employed to examine lateralization in fish and identified statistical issues in all of them. We develop and propose new statistical analyses to test for population and individual level lateralization. The commonly used detour test does not appear to be appropriate for quantifying behavioural lateralization in fishes, calling into question functional inferences drawn by many published studies, including our own. Potential fitness benefits of lateralization and anthropogenic effects on lateralization as a proxy for adaptive brain functioning need to be assessed with alternative paradigms.
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