Disentangling thermal from alternative drivers of reflectance in jewel beetles: A macroecological study

Aim

To predict future colour–climate relationships, it is important to distinguish thermal drivers of reflectance from other evolutionary drivers. We aimed to achieve this by comparing relationships between climate and coloration in ultraviolet–visible (UV–Vis) and near-infrared (NIR) light, separately.

Location

Samples were distributed primarily across Australia and North America, with some from Africa and Asia.

Major taxa studied

Coleoptera: Buprestidae.

Methods

We used jewel beetles as models to identify climatic drivers of reflectance, because jewel beetles have highly diverse coloration and a wide distribution and are often active in hot conditions. Specifically, we tested the association between climate, body size and reflectance using a phylogenetic comparative analysis for three wavebands (UV–Vis, NIR and total).

Results

Reflectance of jewel beetles was more strongly predicted by body size than by climate. NIR reflectance and total reflectance were not associated with climate, but larger beetles had higher NIR reflectance. For UV–Vis reflectance, small beetles were darker in warmer and more humid environments, whereas there was no association with climate for large beetles.

Main conclusions

Our study suggests that variation in reflectance of jewel beetles is not driven by thermal requirements and highlights the importance of considering NIR reflectance when evaluating explanations of the effects of colour on thermoregulation.     

Edaphic and climatic history has driven current dung beetle species pool and assemblage structure across a transition zone in central South Africa

We investigate biogeographical, regional and sub‐regional‐scale responses of scarabaeine dung beetles to late Cenozoic changes in edaphic and climatic character that created a Savanna/Karoo transition zone in the Northern Cape, South Africa. Across a 50 200 km² study area, the Northern Cape species pool comprised six biogeographical groups defined from distribution across southern Africa. These species groups contributed in different proportions to five regional assemblages defined from structural differences across the transition zone. Towards transition zone peripheries, regional assemblage structure was more strongly correlated to sandiness dating from Miocene to Pliocene deposition (Kalahari), aridity dating from Pliocene to Pleistocene climatic change (Bushmanland Karoo), or cooler temperatures dating from Miocene to Pliocene uplift (Upper Karoo). Correlates of sub‐regional assemblages trended to intensification of dominant drivers towards regional peripheries. Drivers of central transition zone, regional assemblages (‘Gariep Karoo’, ‘Gariep Stony Karoo’) showed no dominance. Biogeographically, endemism dominates the Northern Cape transition zone: south‐west arid groups in Nama Karoo regions; Kalahari plus north‐east savanna groups in the Kalahari. Regionally, transition drives assemblage structure: unique variance, 60% in the Kalahari, 21–30% in four Nama Karoo regions; shared variance (overlap), 25–65% between Kalahari and warmer Karoo regions, 11–71% between mainly cooler Karoo regions.     

Do trace metals influence visual signals? Effects of trace metals on iridescent and melanic feather colouration in the feral pigeon

Trace metals are chemical pollutants of prime concern nowadays given their implication in several human diseases and their noxious effects on wildlife. Previous studies demonstrated their negative (e.g. lead, cadmium) or positive (e.g. zinc) effects on body condition, immunity and reproductive success in birds. Because of their effects on bird condition, trace metals are likely to influence the production of condition‐dependent plumage colours, that may be used in mate choice. In the feral pigeon Columba livia, we investigated iridescent colouration in response to lead and zinc experimental (i.e. metal supplementation in standardized conditions) and natural exposure (i.e. metal concentrations in feathers of wild urban pigeons), and melanic feather colouration in response to experimental lead and zinc exposure. Both studies (i.e. experimental and correlative) consistently showed that lead exposure decreased iridescent neck feather brightness independently of colour morph. Moreover, lead, when provided alone, decreased melanic feather reflectance in the middle wavelengths while zinc supplementation increased melanic feather reflectance in the violet‐wavelength. In conclusion, our study suggests that the colouration of iridescent and melanic feathers depends on the exposure to pollutants. Whether trace metal exposure affected the ability of birds to produce melanin pigments, to grow the microstructural feather elements required for maximum colour display, or to cope with bacteria that degrade feather microstuctures remains unclear. Future studies should investigate whether these metal‐induced modifications of plumage colouration affect behaviours involved in sexual selection.     

Females show greater changes in wing colour with latitude than males in the green‐veined white butterfly,Pieris napi (Lepidoptera: Pieridae)

In butterflies, wing colour may simultaneously be under sexual selection in the context of mating selection and natural selection in the context of thermoregulation. In the present study, we collected mated females of the green‐veined white butterfly (Pieris napi) from locations spanning 960 km of latitude across Fennoscandia, and investigated sex‐specific latitudinal wing colour variation in their offspring raised under identical conditions. We measured wing colour characteristics, including reflectance at wavelengths 300–700 nm and the degree of wing melanization. At all latitudes, females reflected more light in the short wavelengths (< 400 nm) and less in the long wavelengths (> 450 nm), and they were more melanized than males. However, female wing colour varied more with latitude than that of males. Among females, long wavelength reflectance decreased, whereas short wavelength reflectance and melanization increased, towards the north. By contrast, among males, latitudinal variation was found only in the ventral hindwing melanization. These results are consistent with the idea that the balance between natural and sexual selection acting on wing colour changes with latitude differently in males than females. The dark wing colour of females in the north may be a thermoregulatory adaptation, although males may be constrained from evolving the dark dorsal wing colour favoured by natural selection because of constant sexual selection across latitudes. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Responses of the blister beetle Hycleus apicicornis to visual stimuli

Insect attraction to host plants may be partly mediated by visual stimuli. In the present study, the responses of adult Hycleus apicicornis (Guér.) (Coleoptera: Meloidae) to plant models of different colours, different combinations of two colours, or three hues of blue of different shapes are compared. Single‐colour models comprised the colours sky blue, bright green, yellow, red, white and black. Sky blue (reflecting light in the 440–500 nm region) is the most attractive, followed by white, which reflects light over a broader range (400–700 nm). On landing on sky blue targets, beetles exhibit feeding behaviour immediately. When different hues of blue (of different shapes) are compared, sky blue is preferred over turquoise, followed by dark blue, indicating that H. apicicornis is more attracted to lighter hues of blue than to darker ones. No significant differences are found between the three shapes (circle, square and triangle) tested, suggesting that reflectance associated with colour could be a more important visual cue than shape for host location by H. apicicornis. The preference of H. apicicornis for sky blue can be exploited in designing an attractive trap for its management.     

Climate change and breeding parameters of great and blue tits throughout the western Palaearctic

Increasing evidence suggests that climate change has consequences on avian breeding phenology. Here, variations in laying date and clutch size of great tit Parus major and blue tit Parus caeruleus within and between breeding populations through the western Palaearctic are examined in relation to climatic fluctuations, measured by the winter North Atlantic Oscillation (NAO) index. Within and across breeding sites, laying date was related to winter‐NAO index such that great and blue tit females lay earlier after warmer, moister winters (positive values of winter NAO‐index). The present study shows that for most populations there is an advancement of laying date, but the rate of change with respect to NAO significantly differed geographically across the western Palaearctic and did not differ between species. However, clutch size of great and blue tits was not affected by climatic fluctuations, presumably because the whole season is being shifted, but not in relation to food supplies. These combined analyses for the two species controlled for potentially confounding variables such as latitude, longitude, elevation and habitat of each study site.     

QUANTITATIVE GENETIC DIVERGENCE AND STANDING GENETIC (CO)VARIANCE IN THERMAL REACTION NORMS ALONG LATITUDE

Although the potential to adapt to warmer climate is constrained by genetic trade‐offs, our understanding of how selection and mutation shape genetic (co)variances in thermal reaction norms is poor. Using 71 isofemale lines of the fly Sepsis punctum, originating from northern, central, and southern European climates, we tested for divergence in juvenile development rate across latitude at five experimental temperatures. To investigate effects of evolutionary history in different climates on standing genetic variation in reaction norms, we further compared genetic (co)variances between regions. Flies were reared on either high or low food resources to explore the role of energy acquisition in determining genetic trade‐offs between different temperatures. Although the latter had only weak effects on the strength and sign of genetic correlations, genetic architecture differed significantly between climatic regions, implying that evolution of reaction norms proceeds via different trajectories at high latitude versus low latitude in this system. Accordingly, regional genetic architecture was correlated to region‐specific differentiation. Moreover, hot development temperatures were associated with low genetic variance and stronger genetic correlations compared to cooler temperatures. We discuss the evolutionary potential of thermal reaction norms in light of their underlying genetic architectures, evolutionary histories, and the materialization of trade‐offs in natural environments.     

Colour choice behaviour in the pollen beetle Meligethes aeneus (Coleoptera: Nitidulidae)

The pollen beetle Meligethes aeneus Fabricius (Coleoptera, Nitidulidae), a pest of oilseed rape (Brassica napus), is known to respond to coloured stimuli; however, current understanding of the underlying mechanisms of colour choice in this species is limited. In the present study, physiological and behavioural experiments are conducted to determine the response of the pollen beetle to colours in the field. Spectral sensitivity is measured in 10 animals using the electroretinogram technique. Light flashes (100 ms) at varied wavelengths (340–650 nm, 10‐nm steps) and at different light intensities are applied to the eye after dark adaptation. In behavioural experiments in the field, 100 water traps of varying colours (from yellow to green to blue with varying amounts of white and black added, and with known spectral reflectance) are set out on a bare soil field in May 2008. The mean spectral sensitivity curve of M. aeneus peaks at 520 nm; however, a model template fitted to the long wavelength tail of the observed curve reveals a peak at approximately 540 nm (green). A secondary sensitivity peak is observed in the ultraviolet (UV) range (370 nm). A total of 2482 pollen beetles are captured in the coloured traps. The results show that the pollen beetles' preference for yellow over other colours can be modelled as a colour opponent mechanism (green versus blue); however, further experiments are needed to specify responses to colours with higher UV reflectance. These findings may be used to optimize trap colours for monitoring to help develop integrated pest management strategies for pollen beetle control.     

Colour, fat and social status in male damselflies, Calopteryx maculata

In the black-winged damselfly, Calopteryx maculata, younger males challenge and displace older males from mating territories. Fatter males tend to win fights. These fights were initially interpreted as wars of attrition based on fat reserves, but the distributions of fat at the end of fights suggests at least some assessment of the opponent's condition. Alternatively, new models have been developed that show how the observed pattern could result without assessment. We show that there is a subtle but reliable cue to fat reserves: colour. Females are a relatively drab brown-black. Males are a strikingly iridescent blue-green colour, resulting from a multilayer constructive interference reflector system in the epicuticle. In fatter males the lamellae are more compressed and the peak reflectance is at shorter wavelengths (blue). Leaner, greener males have greater spacing between lamellae and reflect longer wavelengths. The peak reflectance is as predicted from transmission electron micrograph measurements of the lamellar spacing. The rate of change in spacing over time can be manipulated experimentally by manipulating the diet. Individuals on a higher food diet remained blue longer and at the end of the experiment were fatter and bluer. In our studies, colour is a better predictor of territorial status than fat. Copyright 2000 The Association for the Study of Animal Behaviour.     

Floral colour variation of Nicotiana glauca in native and non-native ranges: Testing the role of pollinators' perception and abiotic factors

• Invasive plants displaying disparate pollination environments and abiotic conditions in native and non-native ranges provide ideal systems to test the role of different ecological factors driving flower colour variation.
• We quantified corolla reflectance of the ornithophilous South American Nicotiana glauca in native populations, where plants are pollinated by hummingbirds, and in populations from two invaded regions: South Africa, where plants are pollinated by sunbirds, and the Balearic island of Mallorca, where plants reproduce by selfing. Using visual modelling we examined how corolla reflectance could be perceived by floral visitors present in each region. Through Mantel tests we assessed a possible association between flower colour and different abiotic factors.
• Corolla reflectance variation (mainly along medium to long wavelengths, i.e. human green-yellow to red colours) was greater among studied regions than within them. Flower colour was more similar between South America and South Africa, which share birds as pollinators. Within invaded regions, corolla reflectance variation was lower in South Africa, where populations could not be distinguished from each other by sunbirds, than in Spain, where populations could be distinguished from each other by their occasional visitors. Differences in corolla colour among populations were partially associated with differences in temperature.
• Our findings suggest that shifts in flower colour of N. glauca across native and invaded ranges could be shaped by changes in both pollination environment and climatic factors. This is the first study on plant invasions considering visual perception of different pollinators and abiotic drivers of flower colour variation.

     

Sex‐specific floral attraction traits in a sequentially hermaphroditic species

• ● Many angiosperms are hermaphroditic and produce bisexual flowers in which male (pollen export) and female (stigma receptivity) functions are separated temporally. This sequential hermaphroditism may be associated with variation in flower size, color, or pattern, all of which may influence pollinator attraction. In this study, we describe variation in these traits across discrete functional sex stages within and between 225 greenhouse‐grown individuals of Clarkia unguiculata (Onagraceae). In addition, to identify the effects of floral phenotype on pollinator attraction in this species, we examine the effects of these floral traits on pollen receipt in ~180 individuals in an experimental field array.
• ● Petal area, ultraviolet (UV)‐absorbing nectar guide area, and blue and green mean petal reflectance differ significantly across the functional sex stages of C. unguiculata. Male‐ and female‐phase flowers display significantly different pollinator attraction traits. Petal and UV nectar guide area increase as flowers progress from male phase to female phase, while blue reflectance and green reflectance peak during anther maturation.
• ● In field arrays of C. unguiculata, female‐phase flowers with large UV nectar guides receive more pollen than those with small nectar guides, and female‐phase flowers with high mean blue reflectance values are more likely to receive pollen than those with low blue reflectance. Female‐phase flowers with green mean reflectance values that differ most from background foliage also receive more pollen than those that are more similar to foliage. These findings indicate that components of flower color and pattern influence pollen receipt, independent of other plant attributes that may covary with floral traits. We discuss these results in the context of hypotheses that have been proposed to explain sex‐specific floral attraction traits, and we suggest future research that could improve our understanding of sexual dimorphism in sequentially hermaphroditic species and the evolution of features that promote outcrossing.

     

Species‐dependent microarchitectural traits of iridescent scales in the triad taxa of Ornithoptera birdwing butterflies

Ornithoptera birdwing butterflies have blue, green, or orange iridescent scales in different species or subspecies. To understand the species‐ or subspecies‐dependent scale color differences, we performed comparative morphometric analyses of iridescent scales from three closely related taxa: O. priamus priamus (green), O. priamus urvillianus (blue), and O. croesus (orange). The three types of Ornithoptera wings exhibited reversible color changes to longer wavelengths with different kinetics upon immersion in methanol, suggesting that their color differences are at least partly based on differences in the size of air cavities made by nanostructures. Cover scales of all three color types were visually semi‐transparent glass scales that exhibited color when placed on a dark background. The dorsoventral differences in coloration were observed in single scales, suggesting the optical importance of scale surfaces. Scanning electron microscopy of cover scales in cross section revealed that all color types exhibited finely sculpted tapered ridges and thick, irregular basal multilayers containing tandemly clustered granular objects and air cavities. Scale thickness, ridge height, and multilayer thickness were significantly different among the three color types, and granular object size was significantly different between orange scales and blue and green scales. We conclude that each of the three taxa of Ornithoptera butterflies possesses unique quantitative size values on tapered ridges and irregular multilayers with granular objects and air cavities to express unique structural color. These species‐ or subspecies‐dependent structural colors might have evolved via quantitative shifts in these microarchitectural traits rather than via changes in the basic developmental or architectural plan for color expression.     

Warning Signal Efficacy: Assessing the Effects of Color,Iridescence, and Time of Day in the Field

Warning coloration deters predators from attacking distasteful or toxic prey. Signal features that influence warning color effectiveness are not well understood, and in particular, we know very little about how effective short‐wavelength and iridescent colors are as warning color elements in nature and how warning signal effectiveness changes throughout the day. We tested the effect of these factors on predation risk in nature using specimens of the distasteful pipevine swallowtail butterfly, Battus philenor. B. philenor adults display both iridescent blue and diffusely reflecting orange components in their warning signal. We painted B. philenor wings to create five different model types: all‐black, only‐iridescent‐blue, only‐orange, iridescent‐blue‐and‐orange (intact signal), and matte‐blue‐and‐orange. We placed 25 models in each of 14 replicate field sites for 72 h and checked for attacks three times each day. Model type affected the likelihood of attack; only‐orange models were, the only model attacked significantly less than the all‐black model. Iridescence did not enhance or decrease warning signal effectiveness in our experiment because matte‐blue‐and‐orange models were attacked at the same rate as iridescent‐blue‐and‐orange models. Time of day did not differentially affect model type. Video recordings of attacks revealed that insectivorous birds were responsible. The results of this experiment, when taken with previous work, indicate that the response to blue warning coloration is likely dependent on predator experience and context, but that iridescence per se does not affect warning signals in a natural context.     

Too hot to die? The effects of vegetation shading on past,present, and future activity budgets of two diurnal skinks from arid Australia

Behavioral thermoregulation is an important mechanism allowing ectotherms to respond to thermal variations. Its efficiency might become imperative for securing activity budgets under future climate change. For diurnal lizards, thermal microhabitat variability appears to be of high importance, especially in hot deserts where vegetation is highly scattered and sensitive to climatic fluctuations. We investigated the effects of a shading gradient from vegetation on body temperatures and activity timing for two diurnal, terrestrial desert lizards, Ctenotus regius, and Morethia boulengeri, and analyzed their changes under past, present, and future climatic conditions. Both species’ body temperatures and activity timing strongly depended on the shading gradient provided by vegetation heterogeneity. At high temperatures, shaded locations provided cooling temperatures and increased diurnal activity. Conversely, bushes also buffered cold temperature by saving heat. According to future climate change scenarios, cooler microhabitats might become beneficial to warm‐adapted species, such as C. regius, by increasing the duration of daily activity. Contrarily, warmer microhabitats might become unsuitable for less warm‐adapted species such as M. boulengeri for which midsummers might result in a complete restriction of activity irrespective of vegetation. However, total annual activity would still increase provided that individuals would be able to shift their seasonal timing towards spring and autumn. Overall, we highlight the critical importance of thermoregulatory behavior to buffer temperatures and its dependence on vegetation heterogeneity. Whereas studies often neglect ecological processes when anticipating species’ responses to future climate change the strongest impact of a changing climate on terrestrial ectotherms in hot deserts is likely to be the loss of shaded microhabitats rather than the rise in temperature itself. We argue that conservation strategies aiming at addressing future climate changes should focus more on the cascading effects of vegetation rather than on shifts of species distributions predicted solely by climatic envelopes.     

Pterin pigments amplify iridescent ultraviolet signal in males of the orange sulphur butterfly, Colias eurytheme

Animal colouration is typically the product of nanostructures that reflect or scatter light and pigments that absorb it. The interplay between these colour-producing mechanisms may influence the efficacy and potential information content of colour signals, but this notion has received little empirical attention. Wing scales in the male orange sulphur butterfly (Colias eurytheme) possess ridges with lamellae that produce a brilliant iridescent ultraviolet (UV) reflectance via thin-film interference. Curiously, these same scales contain pterin pigments that strongly absorb wavelengths below 550 nm. Given that male UV reflectance functions as a sexual signal in C. eurytheme, it is paradoxical that pigments in the wing scales are highly UV absorbing. We present spectrophotometric analyses of the wings before and after pterin removal that show that pterins both depress the amplitude of UV iridescence and suppress a diffuse UV reflectance that emanates from the scales. This latter effect enhances the directionality and spectral purity of the iridescence, and increases the signal's chromaticity and potential signal content. Our findings also suggest that pterins amplify the contrast between iridescent UV reflectance and scale background colour as a male's wings move during flight.     

Geographic variation for colour in the sandburrowing beetle Chaerodes trachyscelides White (Goleoptera: Tenebrionidae) on New Zealand beaches analysed using CIELAB L * values

Chaerodes trachyscelides White is a highly specialized, flightless burrowing beetle confined to the narrow strip of sand at and just above high water level on sandy marine beaches in New Zealand. Although the ventral surface of the beetle is always pale, the dorsal surface varies from pale to almost black. Large samples of this beetle were taken, together with the sand, from 11 beaches on New Zealand's three main islands. The colour of the dorsal surface of each individual beetle and that of the sand samples was measured using reflectance spectroscopy and expressed as CIE L*,a*,b* (CIELAB) values. The L* values, which are objective, quantitative measures of the degree of lightness of the beetles, were subjected to statistical and frequency analysis. Although the species was very variable in colour and the variation appeared to be continuous, a highly significant correlation was obtained between the mean of the L* values for the samples on each beach and that of the sand, the correlation coefficient being 0.961. This close association between the lightness of the beetles and that of the sand suggests the variable melanism functions as cryptic colouration. On most beaches, the distribution oflightness among the beetles sampled conformed to a normal curve. For beetles from sites where the sand was relatively uniform, such as the black Taranaki beaches, the L* frequency distribution curves were narrow and the coefficient of variation of mean beetle colour was relatively small indicating low colour variability. In contrast, the greatest within-site variability occurred on the two Stewart Island beaches sampled, where in each case there was less uniformity in the colour of the sand. At one of these sites, Maori Beach, darker sand present below the high water level is often deposited on the zone occupied by the beetles after storms. On Lonneker's Beach, the distribution of L* values among the beetles sampled was actually bimodal. On this small beach, there was an area of intensely black sand in the zone occupied by the beetles, but most of the rest was covered with light golden sand. These results are interpreted as evidence that the variability of colour of Chaerodes beetles has the effect of populations being able to match the colour of the sand of their home beaches, presumably as a consequence of the differential survival of individuals.     

Greater temperature sensitivity of plant phenology at colder sites: implications for convergence across northern latitudes

Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance at colder sites. To test this hypothesis, we examined up to 20 years of phenology data for 47 tundra plant species at 18 high‐latitude sites along a climatic gradient. Across all species, the timing of leaf emergence and flowering was more sensitive to a given increase in summer temperature at colder than warmer high‐latitude locations. A similar pattern was seen over time for the flowering phenology of a widespread species, Cassiope tetragona. These are among the first results highlighting differential phenological responses of plants across a climatic gradient and suggest the possibility of convergence in flowering times and therefore an increase in gene flow across latitudes as the climate warms.     

Tundra and boreal forest of interior Alaska during terminal MIS 6 and MIS 5e

Two sites within the boreal forest of interior Alaska shed light on the climate and vegetation of terminal marine isotope stage (MIS) 6 (ca. 140–130 kyr ago) and MIS 5e (125–116 kyr ago). The Birch Creek and Koyukuk localities are river-cut exposures with sediments dating from the penultimate glaciation (at least) to the present. Plant macrofossils, pollen, and beetles were analyzed at these sites. Terminal MIS 6-aged samples indicate a cooler than modern climate and the presence of shrub tundra. During MIS 5e, boreal forest grew at the sites and temperatures were similar to modern times. However, the forest may also have been more mesic than today, as indicated by relatively abundant ferns. Winters may have been warmer than today, as suggested by beetle-based climatic reconstructions as well as the presence of two extralimital taxa that today live in regions where winter temperatures are up to 15 °C warmer than at the site localities.     

Reduced sexual dichromatism,mutual ornamentation,and individual quality in the monogamous Zenaida dove Zenaida aurita

Although variation in plumage coloration is known to occur both between and within sexes, its study remains limited to a few bird families. The Zenaida dove Zenaida aurita is a socially monogamous tropical columbid bird species, characterized by an overall cinnamon‐brownish plumage and structural colorations on the head and neck. The species has been described as sexually dichromatic for plumage, although color differences between males and females are not obvious in the field. We investigated variation in the presumably melanin‐based color of the crown, mantle, breast, and belly, in the iridescent dark‐blue streaks on the head, and in the symmetric iridescent patches on the neck, over the whole spectrum visible to birds. Further, unlike most previous studies, we assessed covariation between plumage color and phenotypic traits in both males and females in relation to the putative signaling function of ornaments. Zenaida doves appeared to be slightly sexually dichromatic for the hue of pigment‐based colored areas, with males being on average more reddish than females. However, this difference was not discernible when considering the avian visual system. Conversely, although the reflectance spectra of iridescent plumage did not significantly differ between sexes in brightness, chroma or spectral position of the peaks, color discrimination analyses showed that individuals should be able to perceive between‐ or within‐sex differences in the color of the iridescent patch. In addition, several color parameters of brown and iridescent feathers were significantly related to territorial status, body condition, wing chord, and, albeit weakly, to individual multilocus heterozygosity. Overall, our results thus suggest that plumage color might be a reliable signal of quality in individuals of both sexes in this species. Further studies are needed to test the potential implication of plumage coloration in mate choice and mating patterns in the Zenaida dove.     

Dispersal response to climate change: scaling down to intraspecific variation

Range shift, a widespread response to climate change, will depend on species abilities to withstand warmer climates. However, these abilities may vary within species and such intraspecific variation can strongly impact species responses to climate change. Facing warmer climates, individuals should disperse according to their thermal optimum with consequences for species range shifts. Here, we studied individual dispersal of a reptile in response to climate warming and preferred temperature using a semi‐natural warming experiment. Individuals with low preferred temperatures dispersed more from warmer semi‐natural habitats, whereas individuals with higher preferred temperatures dispersed more from cooler habitats. These dispersal decisions partly matched phenotype‐dependent survival rates in the different thermal habitats, suggesting adaptive dispersal decisions. This process should result into a spatial segregation of thermal phenotypes along species moving ranges which should facilitate local adaptation to warming climates. We therefore call for range shift models including intraspecific variation in thermal phenotype and dispersal decision.