Refuge use in a killifish: influence of body size and nutritional state

2002 ◽  
Vol 80 (4) ◽  
pp. 782-788 ◽  
Author(s):  
Lisa M Dowling ◽  
Jean-Guy J Godin
Keyword(s):  
Body Size ◽  
Risk Taking ◽  
Control Model ◽  
Nutritional State ◽  
Refuge Use ◽  
Individual Fitness ◽  
Threatening Stimulus ◽  
Energetic State ◽  
Predator Model ◽  
Individual Body

Refuge use by animals provides greater safety from predation. A refuging animal continuously must decide whether to stay in the refuge or to emerge into open habitat. This decision may depend on its energetic state and vulnerability to predation, both of which can vary with individual body size. We experimentally tested the concurrent effects of body size and nutritional (hunger) state on refuge use in the banded killifish (Fundulus diaphanus). Individual killifish were "attacked" in an open laboratory habitat (containing food) by either a trout predator model or a control model that did not resemble a trout. Frightened fish typically fled into a foodless refuge nearby. The amount of time that killifish spent in the refuge before emerging increased significantly with body length, but was not affected by their current nutritional state or the threatening stimulus (type of model). Smaller killifish were thus more risk-prone than larger conspecifics irrespective of their current nutritional state. Such size-mediated risk-taking behaviour has important consequences for individual fitness and implications for population and community composition and dynamics in nature.

scholarly journals Overwintering temperature and body condition shift emergence dates of spring-emerging solitary bees

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4721 ◽  
Author(s):  
Mariela Schenk ◽  
Oliver Mitesser ◽  
Thomas Hovestadt ◽  
Andrea Holzschuh
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Body Condition ◽  
Mechanistic Model ◽  
Life Cycles ◽  
Solitary Bees ◽  
Plant Interactions ◽  
Individual Fitness ◽  
Emergence Date ◽  
Individual Body

Solitary bees in seasonal environments must align their life-cycles with favorable environmental conditions and resources; the timing of their emergence is highly fitness relevant. In several bee species, overwintering temperature influences both emergence date and body weight at emergence. High variability in emergence dates among specimens overwintering at the same temperatures suggests that the timing of emergence also depends on individual body conditions. However, possible causes for this variability, such as individual differences in body size or weight, have been rarely studied. In a climate chamber experiment using two spring-emerging mason bees (Osmia cornuta and O. bicornis), we investigated the relationship between temperature, emergence date, body weight, and body size, the last of which is not affected by overwintering temperature. Our study showed that body weight declined during hibernation more strongly in warm than in cold overwintering temperatures. Although bees emerged earlier in warm than in cold overwintering temperatures, at the time of emergence, bees in warm overwintering temperatures had lower body weights than bees in cold overwintering temperatures (exception of male O. cornuta). Among specimens that experienced the same overwintering temperatures, small and light bees emerged later than their larger and heavier conspecifics. Using a simple mechanistic model we demonstrated that spring-emerging solitary bees use a strategic approach and emerge at a date that is most promising for their individual fitness expectations. Our results suggest that warmer overwintering temperatures reduce bee fitness by causing a decrease in body weight at emergence. We showed furthermore that in order to adjust their emergence dates, bees use not only temperature but also their individual body condition as triggers. This may explain differing responses to climate warming within and among bee populations and may have consequences for bee-plant interactions as well as for the persistence of bee populations under climate change.

scholarly journals Suppression of personality variation in boldness during foraging in three-spined sticklebacks

2021 ◽  
Vol 75 (4) ◽  
Author(s):  
Hannah E. A. MacGregor ◽  
Aislinn Cottage ◽  
Christos C. Ioannou
Keyword(s):  
Negative Feedback ◽  
Risk Taking ◽  
Positive Feedback ◽  
Gasterosteus Aculeatus ◽  
Control Treatment ◽  
Refuge Use ◽  
Individual Level ◽  
Behavioural Type ◽  
State Behaviour

Abstract Consistent inter-individual variation in behaviour within a population, widely referred to as personality variation, can be affected by environmental context. Feedbacks between an individual’s behaviour and state can strengthen (positive feedback) or weaken (negative feedback) individual differences when experiences such as predator encounters or winning contests are dependent on behavioural type. We examined the influence of foraging on individual-level consistency in refuge use (a measure of risk-taking, i.e. boldness) in three-spined sticklebacks, Gasterosteus aculeatus, and particularly whether changes in refuge use depended on boldness measured under control conditions. In the control treatment trials with no food, individuals were repeatable in refuge use across repeated trials, and this behavioural consistency did not differ between the start and end of these trials. In contrast, when food was available, individuals showed a higher degree of consistency in refuge use at the start of the trials versus controls but this consistency significantly reduced by the end of the trials. The effect of the opportunity to forage was dependent on behavioural type, with bolder fish varying more in their refuge use between the start and the end of the feeding trials than shyer fish, and boldness positively predicted the likelihood of feeding at the start but not at the end of the trials. This suggests a state-behaviour feedback, but there was no overall trend in how bolder individuals changed their behaviour. Our study shows that personality variation can be suppressed in foraging contexts and a potential but unpredictable role of feedbacks between state and behaviour. Significance statement In this experimental study, we examined how foraging influences consistency in risk-taking in individual three-spined sticklebacks. We show that bolder individuals become less consistent in their risk-taking behaviour than shyer individuals during foraging. Some bolder individuals reinforce their risk-taking behaviour, suggesting a positive feedback between state and behaviour, while others converge on the behaviour of shyer individuals, suggesting a negative feedback. In support of a role of satiation in driving negative feedback effects, we found that bolder individuals were more likely to feed at the start but not at the end of the trials. Overall, our findings suggest that foraging can influence personality variation in risk-taking behaviour; however, the role of feedbacks may be unpredictable.

scholarly journals Guppies prefer to follow large (robot) leaders irrespective of own size

2018 ◽  
Author(s):  
David Bierbach ◽  
Hauke J. Mönck ◽  
Juliane Lukas ◽  
Marie Habedank ◽  
Pawel Romanczuk ◽  
...  
Keyword(s):  
Body Size ◽  
Risk Taking ◽  
Poecilia Reticulata ◽  
Direct Evidence ◽  
Behavioral Patterns ◽  
Behavioral Differences ◽  
Leaders And Followers ◽  
Biomimetic Robotic Fish ◽  
Risk Taking Behavior ◽  
Swimming Capacity

AbstractBody size is often assumed to determine how successful an individual can lead others with larger individuals being more likely to lead than smaller ones. However, direct evidence for such a relation is scarce. Furthermore, even if larger individuals are more likely to lead, body size correlates often with specific behavioral patterns (e.g., swimming capacity) and it is thus unclear whether larger individuals are more often followed than smaller ones because they are larger or because they behave in a certain way. To control for behavioral differences among differentially-sized leaders, we used biomimetic robotic fish – Robofish – of different sizes. Robofish is accepted as a conspecific by live guppies (Poecilia reticulata) and provides standardized behaviors irrespective of its size. We specifically asked whether larger leaders are preferentially followed when behavior is controlled for and whether the preferences of followers depend on their own body size or their risk taking behavior (‘boldness’). We found that live guppies followed larger Robofish leaders closer than smaller ones and this pattern was independent of the followers’ own body size as well as risk-taking behavior. This is the first study that shows a ‘bigger is better’ pattern in leadership in shoaling fish that is fully independent of behavioral differences between differentially-sized leaders and followers’ own size and personality.

Intra-population variability of the non-breeding distribution of southern giant petrels Macronectes giganteus is mediated by individual body size

2018 ◽  
Vol 30 (5) ◽  
pp. 271-277
Author(s):  
Lucas Krüger ◽  
Vitor H. Paiva ◽  
Julia V.G. Finger ◽  
Elisa Petersen ◽  
José C. Xavier ◽  
...  
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
Population Level ◽  
Total Body Length ◽  
South Shetland Islands ◽  
Latitudinal Distribution ◽  
The North ◽  
Wing Load ◽  
Breeding Distribution ◽  
Individual Body

AbstractLiterature reports that body size can be associated with latitudinal distribution, for instance larger animals inhabit higher latitudes and colder habitats. This rule can be applied for species and populations within a species. The potential influence of body size on non-breeding distribution and habitat use at the intra-population level was investigated for southern giant petrels Macronectes giganteus (Gmelin) from Elephant Island, South Shetland Islands. The non-breeding distribution of 23 individuals was tracked, and total body length, culmen length, wing length, wing load and body mass were measured. Positions of core areas were used to estimate the latitudinal distribution of each individual. Smaller individuals were found to be associated more with lower latitudes, where warmer conditions and more coastal and productive waters prevail, whereas large males were associated more with higher latitudes, with colder conditions near sea ice caps, presumably feeding on carrion or preying on penguins. This association reflects a latitudinal gradient, with smaller individuals positioning themselves towards the north, and larger individuals towards the south. In this case, body size, individual distribution and habitat use were found to be associated, highlighting the importance of studying potential effects of individual body size on the ecology of seabirds.

scholarly journals Phenology of hatching, emergence, and end-of-season body size in young-of-year coho salmon in thermally contrasting streams draining the Copper River Delta, Alaska

2019 ◽  
Vol 76 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Emily Y. Campbell ◽  
Jason B. Dunham ◽  
Gordon H. Reeves ◽  
Steve M. Wondzell
Keyword(s):  
Body Size ◽  
Environmental Variability ◽  
Coho Salmon ◽  
Growing Season ◽  
Early Life History ◽  
Growth And Survival ◽  
Individual Fitness ◽  
Marked Variability ◽  
Thermal Regimes ◽  
Body Sizes

Phenology can be linked to individual fitness, particularly in strongly seasonal environments where the timing of events has important consequences for growth, condition, and survival. We studied the phenology of coho salmon (Oncorhynchus kisutch) hatching and emergence in streams with contrasting thermal variability but in close geographic proximity. Following emergence, we tracked body sizes of cohorts of young-of-year fish until the end of the growing season. Hatch and emergence occurred at the same time among streams with marked variability in thermal regimes. We demonstrate that this can be explained in part by the thermal units accumulated during embryo development. At the end of the first growing season, there were some differences in body size, but overall fish size was similar among streams despite strong differences in thermal regimes. Collectively, these results provide novel insights into the interactions between environmental variability and the early life-history stages of coho salmon, furthering our understanding of the consequences of phenology on growth and survival for individuals within the critical first summer of life.

scholarly journals Nutrition Labeling Usage Influences Blood Markers in Body-Size Self-Conscious Individuals: The Korean National Health and Nutrition Examination Survey (KNHANES) 2013–2018

2020 ◽  
Vol 17 (16) ◽  
pp. 5769
Author(s):  
Su Yeon Kye ◽  
Kyu-Tae Han ◽  
Sung Hoon Jeong ◽  
Jin Young Choi
Keyword(s):  
Body Mass Index ◽  
Body Image ◽  
Body Size ◽  
National Health ◽  
Size Perception ◽  
Nutrition Labeling ◽  
Nutrition Examination Survey ◽  
Health And Nutrition ◽  
Body Size Perception ◽  
Individual Body

This study analyzed the effects of nutrition labeling and examined whether nutrition labeling usage influences the levels of blood markers, such as high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) in body-size self-conscious individuals. The dependent variables were HDL-C and TG; the independent variables were the respondents’ awareness of nutrition labeling use, sociodemographic factors, perceived health status, stress, lifestyle, frequency of eating out, family history of hyperlipidemia, survey year, body mass index, total energy intake, and cholesterol levels. Body-size perception was assessed by matching body mass index with subjective body-shape recognition using data from the Korean National Health and Nutrition Examination Survey (2013–2018). Differences were observed in HDL-C and TG levels according to nutrition labeling usage and body-image perception. The group that recognized body image correctly showed high HDL-C and low TG levels when they actively used nutrition labeling, whereas the group that recognized body image incorrectly showed no significant changes in HDL-C and TG levels even when actively using nutrition labeling. The standard nutritional information, which does not consider individual body-size perceptions, has a restrictive effect. Policies should be developed towards tailored intervention strategies considering individual body-size perception.

scholarly journals Determinants of life-history traits in a fish ectoparasite: a hierarchical analysis

Parasitology ◽  
2011 ◽  
Vol 138 (7) ◽  
pp. 848-857 ◽  
Author(s):  
G. LOOT ◽  
N. POULET ◽  
S. BROSSE ◽  
L. TUDESQUE ◽  
F. THOMAS ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Egg Size ◽  
Life History Traits ◽  
Abiotic Factors ◽  
Individual Characteristics ◽  
Trade Off ◽  
Individual Fitness ◽  
Parasite Number ◽  
Egg Number

SUMMARYObjective. Unravelling the determinants of parasite life-history traits in natural settings is complex. Here, we deciphered the relationships between biotic, abiotic factors and the variation in 4 life-history traits (body size, egg presence, egg number and egg size) in the fish ectoparasite Tracheliastes polycolpus. We then determined the factors affecting the strength of the trade-off between egg number and egg size. Methods. To do so, we used 4-level (parasite, microhabitat, host and environment) hierarchical models coupled to a field database. Results. Variation in life-history traits was mostly due to individual characteristics measured at the parasite level. At the microhabitat level (fins of fish hosts), parasite number was positively related to body size, egg presence and egg number. Higher parasite number on fins was positively associated with individual parasite fitness. At the host level, host body size was positively related to the individual fitness of the parasite; parasites were bigger and more fecund on bigger hosts. In contrast, factors measured at the environmental level had a weak influence on life-history traits. Finally, a site-dependent trade-off between egg number and egg size existed in this population. Conclusion. Our study illustrates the importance of considering parasite life-history traits in a hierarchical framework to decipher complex links between biotic, abiotic factors and parasite life-history traits.

Effects of temperature and salinity on survival of young-of-the-year Hudson River striped bass (Morone saxatilis): implications for optimal overwintering habitats

2002 ◽  
Vol 59 (5) ◽  
pp. 787-795 ◽  
Author(s):  
Thomas P Hurst ◽  
David O Conover
Keyword(s):  
Body Size ◽  
Low Temperature ◽  
Striped Bass ◽  
Low Temperatures ◽  
Morone Saxatilis ◽  
Hudson River ◽  
Temperature Tolerance ◽  
Low Temperature Tolerance ◽  
Energetic State ◽  
Young Of The Year

We examined the role of salinity, body size, and energetic state in determining low temperature tolerance of young-of-the-year (YOY) striped bass (Morone saxatilis) and used this information to map optimal overwintering habitat in the Hudson River estuary. A long-term experiment compared survival at 15 ppt and 30 ppt. In additional experiments, winter-acclimated fish were exposed to temperature declines (2.3°C·day–1 to 1°C·week–1) at salinities from 0 ppt to 35 ppt. Highest survival at low temperatures was consistently observed at intermediate salinities. These results suggest that the observed distribution of overwintering striped bass is related to physiological constraints on osmo regulatory ability at low temperatures. Low temperature tolerance appeared unrelated to body size and energetic state. Salinity profiles were used to describe the location and extent of optimal wintering habitats under various hydrographic regimes. The location of optimal habitats was displaced by over 27 km along the river axis because of variation in salinity regime. Changes in the availability of optimal habitat may be responsible for variation in recruitment to the Hudson River population. These results demonstrate the need to consider a holistic approach encompassing all seasons of the year in assessing habitat requirements of fishes.

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