Predation on heliconia bugs, Leptoscelis tricolor: examining the influences of crypsis and predator color preferences

2010 ◽  
Vol 88 (1) ◽  
pp. 122-128 ◽  
Author(s):  
C. W. Miller ◽  
S. D. Hollander
Keyword(s):  
Natural Populations ◽  
Predation Pressure ◽  
Color Preference ◽  
Color Variation ◽  
Objective Measures ◽  
Potential Prey ◽  
Pressure Potential ◽  
Color Preferences ◽  
Color Saturation ◽  
Avian Predators

Individuals in natural populations commonly vary in color, and such color variation can be important for survival under predation pressure. Potential prey may be more likely to survive when they are cryptic against their backgrounds. Alternatively, individual coloration, regardless of background, may itself best predict predation events. Few studies have simultaneously tested the importance of crypsis and predator color preferences in explaining predation events. In this study we used objective measures of coloration to examine whether heliconia bugs, Leptoscelis tricolor Westwood, 1842 (Hemiptera: Coreidae), resembling their background were less likely to be eaten by avian predators (crypsis hypothesis). Next, we evaluated whether insect color, irrespective of background, best explains predation events (color preference hypothesis). We found the strongest evidence for the crypsis hypothesis; predators chose prey that differed most from their background in color saturation. Some evidence was also found for the color preference hypothesis; predators avoided brightly colored prey. These results suggest that crypsis can be effective in detouring predation. However, when potential prey are detected, predator color preferences may best explain predation events.

scholarly journals Numerical Analysis on Color Preference and Visual Comfort from Eye Tracking Technique

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Ming-Chung Ho ◽  
Jhih-Ming Chen ◽  
Ray-Ying Huang ◽  
Ming-Hsun Shen ◽  
Ming-Chi Lu ◽  
...  
Keyword(s):  
Eye Tracking ◽  
Eye Movement ◽  
Color Preference ◽  
Future Research ◽  
Subjective Feeling ◽  
Visual Comfort ◽  
Color Preferences ◽  
Physiological Indicators ◽  
Movement Data ◽  
Color Assignment

Color preferences in engineering are very important, and there exists relationship between color preference and visual comfort. In this study, there are thirty university students who participated in the experiment, supplemented by pre- and posttest questionnaires, which lasted about an hour. The main purpose of this study is to explore the visual effects of different color assignment with subjective color preferences via eye tracking technology. Eye-movement data through a nonlinear analysis detect slight differences in color preferences and visual comfort, suggesting effective physiological indicators as extensive future research discussed. Results found that the average pupil size of eye-movement indicators can effectively reflect the differences of color preferences and visual comfort. This study more confirmed that the subjective feeling will make people have misjudgment.

Comments on Guimarães & Sawaya. Pretending to be venomous: is a snake's head shape a trustworthy signal to a predator?

2011 ◽  
Vol 28 (1) ◽  
pp. 123-124 ◽  
Author(s):  
Janne K. Valkonen ◽  
Johanna Mappes
Keyword(s):  
Prey Species ◽  
Adaptive Significance ◽  
Predation Pressure ◽  
Olfactory Cues ◽  
Head Shape ◽  
Venomous Snake ◽  
Avian Predators ◽  
Empirical Experiment ◽  
Plasticine Models

Several species of non-venomous snake are known to flatten their heads when disturbed, and this behaviour has been suggested to be a mimicry of vipers (Arnold & Ovenden 2002, Hailey & Davies 1986, Young et al. 1999). Using plasticine models, Guimarães & Sawaya (2011) tested the antipredatory function of a triangular head shape in snakes. Their article presents the first published empirical experiment testing the adaptive significance of vipers' triangular head shape. Guimarães & Sawaya (2011) found no support for the viper mimicry hypothesis. Accordingly, they concluded that ‘the shape of [the] head seemed not to confer advantage itself’. Although the use of plasticine models is a generally accepted method of testing predation pressure on snakes, we argue that the experiment may have failed to find the antipredatory function of triangulation due to the pooling of attacks by mammalian and avian predators. Mammals generally rely on olfactory cues during foraging. Plasticine has a strong odour which does not resemble the odour of any prey species. It is thus unlikely that mammals would treat snake replicas as true snakes.

scholarly journals Ultraviolet Degradation in Carotenoid Patches: Live Versus Museum Specimens of Wood Warblers (Parulidae)

The Auk ◽  
2005 ◽  
Vol 122 (3) ◽  
pp. 793-802 ◽  
Author(s):  
Gabriel D. McNett ◽  
Karen Marchetti
Keyword(s):  
Natural Populations ◽  
Adaptive Significance ◽  
Color Variation ◽  
Museum Specimens ◽  
The Past ◽  
Wood Warblers ◽  
Color Spectrum ◽  
The Difference ◽  
Using Data ◽  
Source Materials

Abstract Accurate assessment of color is essential in testing the adaptive significance of color variation in avian plumage. Over the past decade, use of objective methods for assessing color has increased, with particular emphasis on ultraviolet (UV) wavelengths. Researchers have used various source materials, most notably museum specimens, to extend or represent color measurements of individuals in natural populations. Here, we address whether the colors seen in museum specimens accurately represent the colors seen in natural populations. We focus on UV wavelengths and carotenoid-derived colors across 10 species of wood-warblers (Parulidae). Our results indicate an uneven decrease in brightness across the color spectrum, with greater relative decrease in shorter wavelengths in museum specimens. That decrease leads to differences in both hue and chroma between living and museum specimens. The difference from live specimens appears to increase with the museum specimen's age. Our results suggest that caution is needed when using data from museum specimens to test hypotheses on plumage coloration, particularly those involving communication. Degradación Ultravioleta en Parches de Carotenoides: Especímenes Vivos versus Especímenes de Museo de Especies de la Familia Parulidae

Color Preference as a Function of Background and Illumination

1971 ◽  
Vol 33 (3_suppl) ◽  
pp. 1083-1088 ◽  
Author(s):  
Julie Hopson ◽  
Rosemary Cogan ◽  
Carole Batson
Keyword(s):  
Visual Field ◽  
Color Vision ◽  
Short Wave ◽  
Color Preference ◽  
Illumination Intensity ◽  
Background Illumination ◽  
Color Preferences ◽  
Normal Color Vision ◽  
Preference Orders ◽  
Background Brightness

90 students with normal color vision reported color preferences for 10 3-in. X 5-in. Munsell papers with a Munsell value/chroma of 5/6 on white, gray, or black backgrounds with a 5-in. X 7-in. visual field exposed for 2-sec. intervals. Colors of short wave lengths tended to be preferred. Preferences for colors were less extreme when colors were viewed on a black background. Illumination intensity did not reliably affect color preferences. The importance of evaluating the extent of preference differences between colors adjacent in preference orders was discussed. Background brightness and illumination did not clearly resolve differences in preference orders found in earlier studies, and the possible influence of other stimulus variables was discussed.

A Psychometric Approach to the Measurement of Color Preference

1981 ◽  
Vol 53 (1) ◽  
pp. 163-174 ◽  
Author(s):  
Elaine P. Gelineau
Keyword(s):  
Phase 1 ◽  
Color Preference ◽  
Color Preferences ◽  
Reliable Technique ◽  
Personality Research ◽  
Color Vision Test ◽  
Components Analysis ◽  
Stability Of Preferences ◽  
Q Sort ◽  
Effect Of Surface

A three-part investigation was conducted to explore the meaning of color preferences. Phase 1 used a Q-sort technique to assess intra-individual stability of preferences over 5 wk. Phase 2 used principal components analysis to discern the manner in which preferences were being made. Phase 3 used canonical correlation to evaluate a hypothesized relationship between color preferences and personality, with five scales of the Personality Research Form serving as the criterion measure. Munsell standard papers, a standard light source, and a color vision test were among control devices applied. There were marked differences in stability of color preferences. Sex differences in intra-individual stability were also apparent among the 90 subjects. An interaction of hue and lightness appeared to underlie such judgments when saturation was kept constant. An unexpected breakdown in control pointed toward the possibly powerful effect of surface finish upon color preference. No relationship to five manifest needs was found. It was concluded that the beginning steps had been taken toward psychometric development of a reliable technique for the measurement of color preference.

scholarly journals Tail regeneration after autotomy revives survival: a case from a long-term monitored lizard population under avian predation

2017 ◽  
Vol 284 (1847) ◽  
pp. 20162538 ◽  
Author(s):  
Jhan-Wei Lin ◽  
Ying-Rong Chen ◽  
Ying-Han Wang ◽  
Kuen-Chih Hung ◽  
Si-Min Lin
Keyword(s):  
Cost Benefit ◽  
Predation Pressure ◽  
Natural Conditions ◽  
Tail Regeneration ◽  
Tail Loss ◽  
Avian Predators ◽  
Predatory Birds ◽  
The Cost ◽  
Caudal Autotomy

Caudal autotomy in lizards has intrigued scientists for more than 100 years. Because of the relative lack of literature under natural conditions, the complicated association among field autotomy rate, real predation pressure, the long-term cost of tail loss, and the benefit of regeneration remains equivocal. In this study, we conducted a 7-year capture–mark–recapture (CMR) programme with a wild population of a sexually dichromatic lizard, Takydromus viridipunctatus . We used autotomy indexes and a contemporary bird census mega-dataset of four predatory birds as predictors to examine the association between tail loss and predation pressure. We further estimated the survival cost of tail loss and alleviation by regeneration under natural conditions through CMR modelling. We found that large and small avian predators affect lizard survival through the following two routes: the larger-sized cattle egret causes direct mortality while the smaller shrikes and kestrels are the major causes of autotomy. Following autotomy, the survival rate of tailless individuals over the next month was significantly lower than that of tailed individuals, especially males during the breeding season, which showed a decline of greater than 30%. This sex-related difference further demonstrated the importance of reproductive costs for males in this sexually dichromatic species. However, the risk of mortality returned to baseline after the tails were fully grown. This study indicates the benefit of tail regeneration under natural conditions, which increases our understanding of the cost–benefit dynamics of caudal autotomy and further explains the maintenance of this trait as an evolutionarily beneficial adaption to long-term predator–prey interactions.

Anxiety and Color Saturation Preference

1992 ◽  
Vol 75 (2) ◽  
pp. 545-546 ◽  
Author(s):  
Susan R. Ireland ◽  
Yvonne M. Warren ◽  
Lawrence G. Herringer
Keyword(s):  
Anxiety Scale ◽  
Color Preference ◽  
Personality Characteristics ◽  
Color Saturation ◽  
The Mean ◽  
The Relationship

The relationship between personality characteristics and color preference was investigated. Of 49 women and 17 men, 30 individuals scoring above the mean on an anxiety scale preferred significantly less saturated colors than 36 individuals scoring below the mean.

scholarly journals Variation in context dependent foraging behavior across pollinators

2017 ◽  
Author(s):  
Heather M. Briggs ◽  
Stuart Graham ◽  
Callin M. Switzer ◽  
Robin Hopkins
Keyword(s):  
Foraging Behavior ◽  
Plant Traits ◽  
Flower Color ◽  
Color Preference ◽  
Field Conditions ◽  
Floral Traits ◽  
Floral Display ◽  
Floral Trait ◽  
Color Preferences ◽  
Natural Field

Pollinator foraging behavior has direct consequences for plant reproduction and has been implicated in driving floral trait evolution. Exploring the degree to which pollinators exhibit flexibility in foraging behavior will add to a mechanistic understanding of how pollinators can impact selection on plant traits. Although plants have evolved suites of floral traits to attract pollinators, flower color is a particularly important aspect of the floral display. Some pollinators show strong innate color preference, but many pollinators display flexibility in preference due to learning associations between rewards and color, or due to variable perception of color in different environments or plant communities. This study examines the flexibility in flower color preference of two groups of native butterfly pollinators under natural field conditions. Our study reveals that pipevine swallowtails and skippers, the predominate pollinators of the two native Texas Phlox species, display distinct patterns of color preferences across different contexts. Pipevine swallowtails exhibit highly flexible color preferences and likely utilize other floral traits to make foraging decisions. In contrast, skippers have consistent color preferences and likely use flower color as a primary cue for foraging. As a result of this variation in color preference flexibility, the two pollinator groups impose concordant selection on flower color in some contexts but discordant selection in other contexts. This variability could have profound implications for how flower traits respond to pollinator-mediated selection. Our findings suggest that studying dynamics of behavior in natural field conditions is important for understanding plant-pollinator interactions.

Note on Color Preference and Color Vision Test Performance

1989 ◽  
Vol 69 (3-1) ◽  
pp. 1039-1042
Author(s):  
L. W. Buckalew ◽  
Nancy Maits Buckalew ◽  
Sherman Ross
Keyword(s):  
Sex Differences ◽  
Color Vision ◽  
Test Performance ◽  
Normal Group ◽  
Color Preference ◽  
Color Preferences ◽  
Color Vision Test

The incidence of color deficient vision was investigated using the Pseudo-Isochromatic Plates on a relatively large and representative group. in the sample of 112 adults aged 20 to 80 yr. and comprised of 53% women and 12% minorities, 8% of men and 3% of women were color deficient. Over-all performance indicated no effects for sex or race. Nearly half of the plates were nondiscriminating among sex, minority/majority, and ”normal” and ”defective” color vision groups. Named color preferences within the ”normal” group strongly favored blues and reflected no sex differences.

scholarly journals How do predators generalize warning signals in simple and complex prey communities? Insights from a videogame

2020 ◽  
Vol 287 (1921) ◽  
pp. 20200014
Author(s):  
Mónica Arias ◽  
John W. Davey ◽  
Simon Martin ◽  
Chris Jiggins ◽  
Nicola Nadeau ◽  
...  
Keyword(s):  
Natural Populations ◽  
Computer Game ◽  
Butterfly Species ◽  
Warning Signals ◽  
Identical Stimulus ◽  
Toxic Species ◽  
Avian Predators ◽  
Colour Patterns

The persistence of distinct warning signals within and between sympatric mimetic communities is a puzzling evolutionary question because selection favours convergence of colour patterns among toxic species. Such convergence is partly shaped by predators' reaction to similar but not identical stimulus (i.e. generalization behaviour), and generalization by predators is likely to be shaped by the diversity of local prey. However, studying generalization behaviour is generally limited to simple variations of prey colour patterns. Here, we used a computer game played by humans as surrogate predators to investigate generalization behaviours in simple (4 morphs) and complex (10 morphs) communities of unprofitable (associated with a penalty) and profitable butterflies. Colour patterns used in the game are observed in the natural populations of unprofitable butterfly species such as Heliconius numata . Analyses of 449 game participants' behaviours show that players avoided unprofitable prey more readily in simple than in complex communities. However, generalization was observed only in players that faced complex communities, enhancing the protection of profitable prey that looked similar to at least one unprofitable morph. Additionally, similarity among unprofitable prey also reduced attack rates only in complex communities. These results are consistent with previous studies using avian predators but artificial colour patterns and suggest that mimicry is more likely to evolve in complex communities where increases in similarity are more likely to be advantageous.

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