Fig 1 - uploaded by Annette Aiello
Content may be subject to copyright.
Examples of putative false boundary disruptive coloration across taxa (Cott, 1940). From top left clockwise: Giant Anteater (Myrmecophaga tridactyla), Common Snipe (Gallinago gallinago), Common Field Grasshopper (Chorthippus brunneus), White Admiral (Limenitis arthemis arthemis), two-striped Grass Frog (Hylarana taipehensis). Images courtesy of Wikimedia.
Source publication
There is a recent surge of evidence supporting disruptive coloration, in which patterns break up the animal's outline through false edges or boundaries, increasing survival in animals by reducing predator detection and/or preventing recognition. Though research has demonstrated that false edges are successful for reducing predation of prey, researc...
Similar publications
Reproductive timing often affects reproductive success. Plants and animals in a multitude of habitats time reproduction to coincide with environmental conditions that are conducive to fertilization or offspring growth and survival. Many marine organisms time the release of planktonic larvae with large amplitude nocturnal tides. These conditions swe...
Nest-site fidelity is associated with previous reproductive success in birds but is thought to be rare among territorial, open-cup nesting passerines. I investigated nest reuse decisions by Spotted Antbirds (Hylophylax naevioides) in central Panama. A quarter of all nest attempts were located at a previously used nest site, often within an extant n...
Camouflage is a widespread strategy to avoid predation and is of particular importance for animals with reduced mobility or those in exposed habitats. Camouflage often relies on matching the visual appearance of the background, and selecting fine-scale backgrounds that complement an individual’s appearance is an effective means of optimising camouf...
We quantified foraging rates and foraging visibility metrics for four Neotropical warblers—Slate-throated Redstart (Myoborus miniatus), Golden-crowned Warbler (Basileuterus culicivorus), Wilson's Warbler (Wilsonia pusilla), and Black-and-White Warbler (Mniotilta varia)—under flocking and solitary conditions in western Panama to test hypotheses rega...
Colour polymorphism is a recurrent feature of natural populations, and its maintenance has been studied in a range of taxa in their native ranges. However, less is known about whether (and how) colour polymorphism is maintained when populations are removed from their native environments, as in the case of introduced species. We here address this is...
Citations
... No cockroaches with colour patterns are recorded from strata of definitive Hettangian to Pliensbachian (Lower Jurassic) age. However, in the Toarcian, one species of cockroach from the family Raphidiomimidae (Liadoblattina blakei Scudder, 1886) has been recorded with irregular bands (Vr sansk y & Ansorge, 2007) that, by comparison with extant insects (Joron 2009;Simmons 2009;Seymoure & Aiello 2015) and based on Hinkelman's (2023) analysis of cockroach colouration, is here interpreted as disruptive colouration. Like the new taxa described here, Liadoblattina blakei is also specifically from the T-OAE interval. ...
We describe the seventh valid species of cockroach , Alderblattina simmsi gen. et sp. nov., from insect-rich strata recording the Toarcian Oceanic Anoxic Event (T-OAE). The T-OAE represents a period of extreme global warming and environmental change that drove palaeoecological pressures and evolutionary changes in marine and terrestrial ecosystems. Here, for the first time, we present evidence that this event may also be the driver for the evolution of aposematic colouration, a predator deterrent, in cockroaches. The specimen , an isolated compressed tegmen, was collected at Alder-ton Hill, Gloucestershire, UK, and is assigned to a new genus and species, based on the following unique combination of characteristics: small forewing; 15 branches of R and 11 branches of M + CuA; strong cross-vein between R and M; intercalaries; and two well-defined subspherical maculae (spots) and colouration at the wing tip. Alderblattina simmsi is assigned to the family Rhipidoblattinidae Rohdendorf, primarily based on its small size and the presence of branched anal veins in the clavus. The colouration present on A. simmsi represents the first recorded likely occurrence of aposematism in cockroaches, and provides evidence for the evolution of colour patterning in Blattodea.
... We acquired four male E. auxiliaris specimens from the C. P. Gillette Museum of Arthropod Diversity at Colorado State University in fall 2017. We then developed artificial models following the methods of Seymoure and Aiello (2015) and Seymoure et al. (2018). As E. auxiliaris perch with wings hooded over the abdomen, we scanned the dorsal surface of the moth specimens in perching posture using a Brother MFC-J4510DW Scanner (Brother Industries; Fig. 1). ...
... Plasticine models of insects, as well as other animals, have been a productive method for measuring predation rates across species, as well as how predation varies with traits and biogeography (Niskanen & Mappes, 2005;Saporito et al., 2007;Roslin et al., 2017). The plasticine clay remains malleable for weeks and thereby allows assessment of beak marks from avian predators as well as teeth marks from mammalian predators (e.g., bats; Merrill et al. 2012, Seymoure and Aiello 2015). ...
... We restricted our survival analysis to only attacks and missing models that occurred at night. Missing models were incorporated into the Kaplan-Meier survival analysis as censored individuals (Seymoure & Aiello, 2015). ...
... On the other side, having partly colored wings and with 'transparent elements breaking at least one prey border seems to be the most effective mechanism for reducing detectability of prey and subsequent predation' (Arias et al., 2021(Arias et al., : 1844. Also, Seymoure & Aiello (2015: 1623 showed on a butterfly that 'an internal conspicuous band on a wing surface increases survival more than marginally located discontinuous patterns (false edges) or a marginally located ban'. The transverse colored bands of the Liassic Heterophlebia spp. ...
Wing coloration is a very ancient feature among insects. Even the wings of the oldest known Pterygota showed transverse colored bands involved in a putative disruptive function. However, no evidence of wing coloration in the representatives of the superorder Odonatoptera is recorded before the latest Triassic. These were the only insect flying- predators until the pterosaurs began their diversification. Here we argue that the situation dramatically changed in the Early Jurassic, with the simultaneous appearance of Odonata with patterns of coloration in phylogenetically distant clades. It is especially the case in the Heterophlebiidae, a small family closely related to the Anisoptera, in which we could record no less than five different patterns of coloration in the same rather small area of North-Western Europe. At the same time and in the same area, small potentially insectivorous pterosaurs greatly diversified. The increase of the predation pressure on the Odonata is the most probable cause of the appearance of patterns of colored spots and bands on the dragonfly wings at that time. In the period between the Middle Jurassic to Early Cretaceous, the number of Odonata with spots and bands of color on wings dramatically increased, we assume in relation to the predation pressure due to an increasing diversification of insectivorous pterosaurs, but also small feathered dinosaurs and birds.
... In polymorphic salamanders (Plethodon spp.), dorsal stripes have been linked to avoidance of frequency-dependent predation (Fitzpatrick et al., 2009). Disruptive colouration works to conceal the body shape or silhouette by breaking up an organism's outline with a false high contrast boundary (Seymoure & Aiello, 2015;Stevens & Merilaita, 2009). It has been found to be effective at reducing predation risk when compared to nondisruptively patterned or unpatterned controls (Stevens et al., 2006). ...
In mammals, colouration patterns are often related to concealment, intraspecific communication, including aposematic signals, and physiological adaptations. Slow lorises (Nycticebus spp.) are arboreal primates native to Southeast Asia that display stark colour contrast, are highly territorial, regularly enter torpor, and are notably one of only seven mammal taxa that possess venom. All slow loris species display a contrasting stripe that runs cranial-caudally along the median sagittal plane of the dorsum. We examine whether these dorsal markings facilitate background matching, seasonal adaptations, and intraspecific signaling. We analyzed 195 images of the dorsal region of 60 Javan slow loris individuals (Nycticebus javanicus) from Java, Indonesia. We extracted greyscale RGB values from dorsal pelage using ImageJ software and calculated contrast ratios between dorsal stripe and adjacent pelage in eight regions. We assessed through generalized linear mixed models if the contrast ratio varied with sex, age, and seasonality. We also examined whether higher contrast was related to more aggressive behavior or increased terrestrial movement. We found that the dorsal stripe of N. javanicus changed seasonally, being longer and more contrasting in the wet season, during which time lorises significantly increased their ground use. Stripes were most contrasting in younger individuals of dispersal age that were also the most aggressive during capture. The dorsal stripe became less contrasting as a loris aged. A longer stripe when ground use is more frequent can be related to disruptive colouration. A darker anterior region by younger lorises with less fighting experience may allow them to appear larger and fiercer. We provide evidence that the dorsum of a cryptic species can have multimodal signals related to concealment, intraspecific communication, and physiological adaptations.
... The second approach informed of the progression of predation rates during the 4 days that the experiment lasted, and potentially could also inform of changes in the predator response to the different replicas during the course of the experiment. These two analyses, used independently or in combination, are commonplace to evaluate avian predation on artificial butterfly prey in the tropics with similar experimental designs(Dell'Aglio et al., 2016;Finkbeiner et al., 2012Finkbeiner et al., , 2014Finkbeiner et al., , 2017Finkbeiner et al., , 2018Seymoure & Aiello, 2015).We assessed differences in predation between treatments using a GLMM with a log-link Poisson distribution. The predated number of replicas of each species and colouration treatment were entered as count numbers per site. ...
Imperfect mimicry may be maintained when the various components of an aposematic signal have different salience for predators. Experimental laboratory studies provide robust evidence for this phenomenon. Yet, evidence from natural settings remains scarce.
We studied how natural bird predators assess multiple features in a multicomponent aposematic signal in the Neotropical ‘clear wing complex’ mimicry ring, dominated by glasswing butterflies.
We evaluated two components of the aposematic signal, wing colouration and wing morphology, in a predation experiment based on artificial replicas of glasswing butterflies (model) and Polythoridae damselflies (mimics) in their natural habitat. We also studied the extent of the colour aposematic signal in the local insect community. Finally, we inspected the nanostructures responsible for this convergent colour signal, expected to highly differ between these phylogenetically distinct species.
Our results provide direct evidence for a stronger salience of wing colouration than wing morphology, as well as stronger selection on imperfect than in perfect colour mimics. Additionally, investigations of how birds perceive wing colouration of the local insect community provides further evidence that a UV‐reflective white colouration is being selected as the colour aposematic signal of the mimicry ring. Using electron microscopy, we also suggest that damselflies have convergently evolved the warning colouration through a pre‐adaptation.
These findings provide a solid complement to previous experimental evidence suggesting a key influence of the cognitive assessment of predators driving the evolution of aposematic signals and mimicry rings.
... The presence of bands along the wing margin in another butterfly species, Anartia fatima, while of a different color and position on the wing compared with the Banded Swallowtail, also serves to reduce predation, through creating a false boundary (Seymoure & Aiello, 2015). Variants where the band was shifted to form an outline of the wings of A. fatima, or as a discontinuous edge along the wing boundary, both resulted in lower survivorship compared with wildtype models. ...
Abstract Butterflies have evolved a diversity of color patterns, but the ecological functions for most of these patterns are still poorly understood. The Banded Swallowtail butterfly, Papilio demolion demolion, is a mostly black butterfly with a greenish‐blue band that traverses the wings. The function of this wing pattern remains unknown. Here, we examined the morphology of black and green‐blue colored scales, and how the color and banding pattern affects predation risk in the wild. The protective benefits of the transversal band and of its green‐blue color were tested via the use of paper model replicas of the Banded Swallowtail with variations in band shape and band color in a full factorial design. A variant model where the continuous transversal green‐blue band was shifted and made discontinuous tested the protective benefit of the transversal band, while grayscale variants of the wildtype and distorted band models assessed the protective benefit of the green‐blue color. Paper models of the variants and the wildtype were placed simultaneously in the field with live baits. Wildtype models were the least preyed upon compared with all other variants, while gray models with distorted bands suffered the greatest predation. The color and the continuous band of the Banded Swallowtail hence confer antipredator qualities. We propose that the shape of the band hinders detection of the butterfly's true shape through coincident disruptive coloration; while the green color of the band prevents detection of the butterfly from its background via differential blending. Differential blending is aided by the green‐blue color being due to pigments rather than via structural coloration. Both green and black scales have identical structures, and the scales follow the Bauplan of pigmented scales documented in other Papilio butterflies.
... We also found that light areas accounted for about 20% of the fore wing area and about 29% of the hind wing area. However, some studies indicate that light areas have high spectral reflectance and they could be used as information for intraspecies identification or for detecting the opposite sex in butterflies (Emmel, 1972;Taylor, 1973;Seymoure & Aiello, 2015). The role of the light areas on butterfly wings in heat absorption will be addressed in our future research. ...
Butterflies can directly absorb heat from the sun via their wings to facilitate autonomous flight. However, how is the heat absorbed by the butterfly from sunlight stored and transmitted in the wing? The answer to this scientific question remains unclear. The butterfly Tirumala limniace (Cramer) is a typical heat absorption insect, and its wing surface color is only composed of light and dark colors. Thus, in this study, we measured a number of wing traits relevant for heat absorption including the thoracic temperature at different light intensities and wing opening angles, the thoracic temperature of butterflies with only one right fore wing or one right hind wing; In addition, the spectral reflectance of the wing surfaces, the thoracic temperature of butterflies with the scales removed or present in light or dark areas, and the real-time changes in heat absorption by the wing surfaces with temperature were also measured. We found that high intensity light (600-60,000 lx) allowed the butterflies to absorb more heat and 60-90 was the optimal angle for heat absorption. The heat absorption capacity was stronger in the fore wings than the hind wings. Dark areas on the wing surfaces were heat absorption areas. The dark areas in the lower region of the fore wing surface and the inside region of the hind wing surface were heat storage areas. Heat was transferred from the heat storage areas to the wing base through the veins near the heat storage areas of the fore and hind wings.
... Cryptic coloration is thought to reduce the likelihood of detection and recognition by predators (Endler, 1991;Ruxton et al., 2004;Stevens & Merilaita, 2009). Several recent experiments involving artificial butterflies in nature have demonstrated the efficiency of cryptic coloration in preventing predator attacks (Seymoure & Aiello, 2015;Cheng et al., 2018;Seymoure et al., 2018). However, we found no information on the ability of cryptic species to escape predators after detection and attack, or on how escape ability differs between flying and resting butterflies in nature. ...
1. This article reports the responses of wild, adult jacamars to butterflies with distinct coloration types in central Brazil. Fully aposematic species, i.e. those exhibiting bright and/or contrasting colours on both wing surfaces (= A/A), were predominantly sight‐rejected by birds and, with one exception, the few butterflies attacked and captured were taste‐rejected afterwards.
2. Aposematic and cryptic butterflies, i.e. those exhibiting bright and/or contrasting colours on the upper and cryptic colours on the underwings (= A/C) were sight‐rejected while flying, when they show their conspicuous colours to predators. This suggests that birds associate butterfly colours with their difficulty of capture, as in the case of Morpho and several Coliadinae species. These butterflies, however, were heavily attacked at rest, when they are cryptic.
3, Fully cryptic butterflies, i.e. those exhibiting cryptic colours on both wing surfaces (= C/C) did not elicit sight rejections by birds. Comparisons involving the number of attacks and the capture success of flying and resting individuals showed no significant differences in species more frequently observed like some cracker butterflies (Hamadryas feronia and H. februa) and Taygetis laches. Compared with the A/C Coliadinae, these butterflies showed a lesser, although not significantly different, ability to escape while flying, but a greater and significantly different ability to escape while at rest.
4, A hunting tactic of jacamars, which consists of following flying A/C and C/C butterflies on sight, and waiting until they perch to locate and attack them, is described for the first time.
... Past work matching artificial prey items to Lepidopteran models has also tended to ensure that matches of colour are based on targets falling within the range of photon catch values of the real animal model 25 . Our work most closely follows other recent work on butterfly coloration 63,65 , which used a visual discrimination model to create matches to the real butterflies, with matches chosen when colours fell within 1-3 JNDs. Our approach is in fact even more detailed in that, unlike past studies, we did not create all targets per treatment as identical and simply matching an average model coloration, but instead we included individual variation by matching different individual targets to 100 unique individual moth models (see below). ...
... Artificial moth targets modelled to avian visual systems were used as a proxy for peppered moths to determine morph survival rate through a field predation experiment. This approach is well tested and closely follows a range of past work [25][26][27][29][30][31][32][33][34][63][64][65] . Data collection was conducted in June 2017 to coincide with peppered moth emergence between May and August 2017. ...
Animal defensive coloration has long provided many important examples of evolution and adaptation. Of these, industrial melanism in the peppered moth is the classic textbook example of evolution in action, whereby dark and pale morphs suffer differential predation in polluted and unpolluted woodland based on their camouflage. Despite extensive work, a striking gap remains in that no study has ever objectively quantified their camouflage or related this directly to predation risk. Here we use image analysis and avian vision models to show that pale individuals more closely match lichen backgrounds than dark morphs. Artificial predation experiments in unpolluted woodland show 21% higher survival rates of pale than melanic individuals. Overall, we provide the strongest direct evidence to date that peppered moth morph frequencies stem from differential camouflage and avian predation, providing key support for this iconic example of natural selection. Olivia Walton and Martin Stevens revisit the classic example of the peppered moth, objectively quantifying moth camouflage and predation risk. With bird vision models, pale individuals more closely match lichen backgrounds, and survive better, providing support for this iconic example of natural selection.
... These experiments allow for precise manipulation of artificial models in order to test specific hypotheses about how mimicry phenotypes, or parts thereof, may experience differential predation. The artificial prey method has been implemented in diverse butterfly systems to address the relationship between wing patterning and predation (Dell'Aglio, Stevens, & Jiggins, 2016;Finkbeiner, Briscoe, & Mullen, 2017;Finkbeiner, Briscoe, & Reed, 2012Finkbeiner, Fishman, Osorio, & Briscoe, 2017;Ho, Schachat, Piel, & Monteiro, 2016;Merrill et al., 2012;Seymoure & Aiello, 2015;Wee & Monteiro, 2017). In this study, we applied the artificial prey method to study how female-limited Batesian mimicry operates in wild populations. ...
... Predator psychology is complex and acts as the selective agent in Batesian mimicry systems (Speed, 2000). Over 100 years ago, Fryer (1913) (Finkbeiner et al., 2012), studying the relative contributions of wing color versus pattern to predator deterrence (Finkbeiner et al., 2014), uncovering how eyespot size and number influence predation (Ho et al., 2016;Stevens, Hardman, & Stubbins, 2008), analyzing the evolution of novel colors in warning signals (Dell'Aglio et al., 2016;Finkbeiner, Fishman, et al., 2017;Wee & Monteiro, 2017), and dissecting the importance of white bands (false boundaries) and disruptive coloration for protection from predators (Seymoure & Aiello, 2015). ...
The swallowtail butterfly Papilio polytes is known for its striking resemblance in wing pattern to the toxic butterfly Pachliopta aristolochiae and is a focal system for the study of mimicry evolution. Papilio polytes females are polymorphic in wing pattern, with mimetic and nonmimetic forms, while males are monomorphic and nonmimetic. Past work invokes selection for mimicry as the driving force behind wing pattern evolution in P. polytes. However, the mimetic relationship between P. polytes and P. aristolochiae is not well understood. In order to test the mimicry hypothesis, we constructed paper replicas of mimetic and nonmimetic P. polytes and P. aristolochiae, placed them in their natural habitat, and measured bird predation on replicas. In initial trials with stationary replicas and plasticine bodies, overall predation was low and we found no differences in predation between replica types. In later trials with replicas mounted on springs and with live mealworms standing in for the butterfly's body, we found less predation on mimetic P. polytes replicas compared to nonmimetic P. polytes replicas, consistent with the predator avoidance benefits of mimicry. While our results are mixed, they generally lend support to the mimicry hypothesis as well as the idea that behavioral differences between the sexes contributed to the evolution of sexually dimorphic mimicry.
