Monopolization of food by zebrafish (Danio rerio) increases in risky habitats

2002 ◽  
Vol 80 (12) ◽  
pp. 2164-2169 ◽  
Author(s):  
Ian M Hamilton ◽  
Lawrence M Dill
Keyword(s):  
Danio Rerio ◽  
Coefficient Of Variation ◽  
Perceived Risk ◽  
Open Habitat ◽  
Risk Of Predation ◽  
Resource Monopolization

Dominant zebrafish (Danio rerio) previously have been shown to reduce their monopolization of food when foraging in structurally complex habitats compared with open habitats. Complex habitats may be more difficult to defend but may also be safer. To decouple these effects, we compared aggression and monopolization of food in groups of zebrafish foraging in an open habitat and one with overhead cover, as well as in an open habitat and a complex (vegetated) habitat. Covered and open habitats should have been equally defendable. In our experiments, fish used covered habitats more than open ones, suggesting that the perceived risk of predation was lower in covered habitats. There was no difference in use of vegetated and open habitats, suggesting that these habitats, which should differ in defendability, did not differ in safety. We found that the degree of food monopolization (expressed in the coefficient of variation within groups) at risky feeders was significantly greater in open habitats than in covered, but not vegetated, habitats. We did not find a difference in aggression between habitats. These results indicate that resource monopolization in groups of zebrafish is greater in risky habitats and support the hypothesis that the lower monopolization of food in complex habitats could result from greater safety in those habitats rather than, or in addition to, the reduction in defendability.

An increase in habitat complexity reduces aggression and monopolization of food by zebra fish (Danio rerio)

1998 ◽  
Vol 76 (4) ◽  
pp. 770-772 ◽  
Author(s):  
Seán P Basquill ◽  
James WA Grant
Keyword(s):  
Danio Rerio ◽  
Coefficient Of Variation ◽  
Habitat Complexity ◽  
Structural Complexity ◽  
Zebra Fish ◽  
Resource Monopolization ◽  
Dominant Fish ◽  
The Relationship ◽  
Complex Habitat

We tested the predictions that an increase in the structural complexity of a habitat causes both a decrease in aggression and the monopolization of resources. Groups of three zebra fish (Danio rerio) were allowed to compete for food in a complex habitat with simulated vegetation and in a simple habitat with no vegetation. As predicted, both the levels of aggression by the dominant fish (P = 0.050) and the coefficient of variation of the amount of food eaten within a group (P = 0.020), a measure of food monopolization, were lower in the complex habitat than in the simple one. Fish that chased competitors more frequently ate more food in both habitats, but the relationship was stronger in the simple than in the complex habitat. Our results suggest that aggression is less useful as a mode of competition in habitats with greater structural complexity. Manipulating the structural complexity of the habitat may be a practical way of controlling the intensity of aggression and resource monopolization in groups of animals.

scholarly journals Effects of a New Pedestrian Pathway in Grand Teton National Park on Breeding Sagebrush Songbirds

2008 ◽  
Vol 31 ◽  
pp. 3-7
Author(s):  
Anna Chalfoun
Keyword(s):  
Perceived Risk ◽  
Breeding Habitat ◽  
Energy Budgets ◽  
Human Presence ◽  
Wildlife Species ◽  
Fitness Consequences ◽  
Risk Of Predation ◽  
Natural Landscapes ◽  
Wildlife Populations ◽  
Induced Changes

Human-induced changes to natural landscapes have become ubiquitous, resulting in exposure of wildlife populations to novel stressors (Munns 2006). While it is clear that changes such as habitat loss can directly impact wildlife species, less clear is the extent to which human presence itself functions as a disturbance that influences wildlife behaviors with important fitness consequences. Animals clearly respond to perceived risk of predation by natural predators via, for example, fleeing, or altering foraging and/or breeding habitat selection (Marzluff 1988, Hakkarainen et al. 2001, Frid and Dill2002, Blumstein 2006, Borkowski et al. 2006, Fontaine and Martin 2006). Such responses can alter access to important resources, energy budgets, and therefore attributes such as body condition (Bechet et al. 2004) with potential impacts to survival and reproductive output. Of critical importance to the management of wildlife populations is therefore to determine 1) whether wildlife species perceive human presence as predation risk, 2) how individuals respond to such risk, and 3) how such responses influence fitness consequences and therefore population dynamics and community structure.

scholarly journals Size-selective mortality fosters ontogenetic changes in collective risk-taking behaviour in zebrafish, Danio rerio

2021 ◽  
Author(s):  
Tamal Roy ◽  
Robert Arlinghaus
Keyword(s):  
Danio Rerio ◽  
Risk Taking ◽  
Direct Selection ◽  
Small Fish ◽  
Control Line ◽  
Selective Mortality ◽  
Predation Threat ◽  
Size Selection ◽  
Risk Of Predation ◽  
The Impact

AbstractSize-selective mortality is common in fish populations and can operate either in a positive size-selective fashion or be negatively size-selective. Through various mechanisms (like genetic correlations among behaviour and life-history traits or direct selection on behaviour co-varying with growth rate or size-at-maturation), both positive- and negative size-selection can result in evolutionary changes in behavioural traits. Theory suggests that size-selection alone favours boldness, but little experimental evidence exists about whether and to what extent size-selection can trigger its evolution. Here we investigated the impact of size-selective mortality on boldness across ontogeny using three experimental lines of zebrafish (Danio rerio) generated through positive (large-harvested), negative (small-harvested) and random (control line) size-selective mortality for five generations. We measured risk-taking during feeding (boldness) under simulated aerial predation threat and in presence of a live cichlid. We found that boldness decreased with ontogenetic age under aerial predation threat, and the small-harvested line was consistently bolder than controls. Collective personality emerged post larval stages among the selection lines. In presence of a cichlid, the large-harvested line was bolder at the highest risk of predation. The large-harvested line showed higher variability and plasticity in boldness across life stages and predation risks. Collectively, our results demonstrate that size-selective harvesting may evolutionarily alter risk-taking tendency. Size-selection alone favours boldness when selection acts on small fish. Selection typical of fisheries operating on large fish favours boldness at the highest risk of predation and increases behavioural variability and plasticity. There was no evidence for positive size-selection favouring evolution of shyness.

Female mouthbrooders adjust incubation duration to perceived risk of predation

2004 ◽  
Vol 68 (6) ◽  
pp. 1275-1281 ◽  
Author(s):  
Barbara Taborsky ◽  
Katharina Foerster
Keyword(s):  
Perceived Risk ◽  
Risk Of Predation ◽  
Incubation Duration

Effect of Turbidity on the Predator Avoidance Behaviour of Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

1993 ◽  
Vol 50 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Robert S. Gregory
Keyword(s):  
Chinook Salmon ◽  
Perceived Risk ◽  
Predator Avoidance ◽  
Oncorhynchus Tshawytscha ◽  
Avoidance Behaviour ◽  
Fish Predator ◽  
Juvenile Chinook Salmon ◽  
Risk Of Predation ◽  
Juvenile Chinook ◽  
Predator Risk

The effect of turbidity on the predator avoidance behaviour of juvenile chinook salmon (Oncorhynchus tshawytscha) was determined in controlled laboratory experiments. Bird and fish models were used to simulate predator risk. In the absence of risk, juvenile chinook were distributed randomly within an experimental arena in turbid conditions (≈23 NTU), but in clear conditions (<1 NTU) they associated with the bottom. When introduced to bird and fish predator models, the chinook altered their distribution and occupied deeper parts of the arena regardless of turbidity level. However, their responses in turbid conditions were less marked and of shorter duration. Turbidity apparently reduced the perceived risk of predation in juvenile chinook.

Foraging Response to Risks of Predation and Competition in Artificial Pools

2010 ◽  
Vol 56 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Gil Stav ◽  
Burt P. Kotler ◽  
Leon Blaustein
Keyword(s):  
Perceived Risk ◽  
Foraging Activity ◽  
Left Behind ◽  
Similar Tendency ◽  
Green Toad ◽  
Risk Of Predation ◽  
Giving Up Density ◽  
Culiseta Longiareolata ◽  
The Rich ◽  
Resource Patches

Although ecologists have learned much about the influence of competitors and perceived risk of predation on foraging in terrestrial systems by measuring giving-up density (GUD, the amount of food left behind in a resource patch following exploitation), GUDs have rarely been used in aquatic environments. Here we use foraging activity (proportion foraging) and GUDs to assess the effects that two periphyton consumers and potential competitors, green toad (Bufo viridis) tadpoles and mosquito (Culiseta longiareolata) larvae, have on each other. We also examine the effects of perceived risk of predation imposed by a dragonfly nymph (Anax imperator). To do so, we conducted an artificial pool experiment and developed a food patch appropriate for measuring GUDs for periphyton grazers. MoreCulisetaindividuals foraged in rich food patches than in poor patches.Bufoshowed a similar tendency. FewerBufoforaged in both patch types in the presence of cagedAnax. Culisetashowed a similar tendency. However, in the rich patches, onlyBuforeduced foraging activity when the caged predator was present. BothBufoandCulisetadepleted food patches through exploitation, resulting in lower GUDs. Both competitors together resulted in lower GUDs than did food depletion of each species alone. However, the presence of cagedAnaxhad little or no effects on GUDs. Overall, bothBufoandCulisetarespond to food and safety. They are able to direct foraging effort to richer patches and devote more time to those patches, and they respond to predation risk by choosing whether or not to exploit resource patches.

scholarly journals The strength of a female mate preference increases with predation risk

2008 ◽  
Vol 276 (1657) ◽  
pp. 775-780 ◽  
Author(s):  
Tae Won Kim ◽  
John H Christy ◽  
Stefan Dennenmoser ◽  
Jae C Choe
Keyword(s):  
Sexual Selection ◽  
Predation Risk ◽  
Perceived Risk ◽  
General Pattern ◽  
Visual Orientation ◽  
Relative Preference ◽  
Avian Predators ◽  
Risk Of Predation ◽  
Courtship Signals ◽  
Perceived Predation Risk

When females search for mates and their perceived risk of predation increases, they less often express preferences for males that use conspicuous courtship signals, relaxing sexual selection on production of these signals. Here, we report an apparent exception to this general pattern. Courting male fiddler crabs Uca beebei sometimes build pillars of mud at the openings to their burrows in which crabs mate. Females visit several males before they choose a mate by staying and breeding in their burrows, and they preferentially visit males with pillars. Previous studies suggested that this preference is based on a visual orientation behaviour that may reduce females' risk of predation while searching for a mate. We tested this idea by determining whether the female preference for males with pillars increases with perceived predation risk. We attracted avian predators to where crabs were courting and measured the rates that sexually receptive females visited courting males with and without mud pillars. Under elevated risk, females continued to search for mates and they showed a stronger relative preference for males with pillars. Thus, when predation risk is high, females may continue to express preferences that are under natural selection because they help females avoid predation, strengthening sexual selection for use of the preferred signal.

scholarly journals Perceived Risk of Predation Affects Reproductive Life-History Traits in Gambusia holbrooki, but Not in Heterandria formosa

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e88832 ◽  
Author(s):  
Shomen Mukherjee ◽  
Michael R. Heithaus ◽  
Joel C. Trexler ◽  
Jayanti Ray-Mukherjee ◽  
Jeremy Vaudo
Keyword(s):  
Life History ◽  
Perceived Risk ◽  
Life History Traits ◽  
Gambusia Holbrooki ◽  
Risk Of Predation ◽  
Reproductive Life ◽  
Heterandria Formosa ◽  
Reproductive Life History

Do long-tailed macaques avoid large heterospecific carcasses?

Behaviour ◽  
2021 ◽  
pp. 1-12
Author(s):  
Jeffrey V. Peterson ◽  
Agustín Fuentes
Keyword(s):  
Predation Risk ◽  
Nonhuman Primate ◽  
Perceived Risk ◽  
Macaca Fascicularis ◽  
Future Research ◽  
Tree Line ◽  
Risk Of Predation ◽  
Vigilance Behaviour ◽  
Pathogen Avoidance

Abstract This anecdotal observation details the response of long-tailed macaques (Macaca fascicularis) to a heterospecific carcass. The subgroup of macaques we were following abruptly changed their direction of travel upon reaching a tree line while displaying silent vigilance behaviour. We later discovered a dog carcass in the area and concluded their behaviour may have been in response to the smell of that carcass. The carcass was not visible from the response point at the tree line due to its distance from that point (approximately 30 meters) and the uneven and densely vegetated terrain between. The macaques were therefore most likely responding to scent cues from the carcass. We suggest the observed vigilance behaviour is excessive under a strictly pathogen-avoidance explanation and may be understood as a response to a cue of potential predation risk. We review alternative explanations and suggest future research on nonhuman primate heterospecific carcass avoidance is necessary to fully assess the potential relation to perceived risk of predation.

Sign in / Sign up

Export Citation Format

Share Document