Genetic colour variation visible for predators and conspecifics is concealed from humans in a polymorphic moth

The definition of colour polymorphism is intuitive: genetic variants express discretely coloured phenotypes. This classification is, however, elusive as humans form subjective categories or ignore differences that cannot be seen by human eyes. We demonstrate an example of a 'cryptic morph' in a polymorphic wood tiger moth (Arctia plantaginis), a phenomenon that may be common among well-studied species. We used pedigree data from nearly 20,000 individuals to infer the inheritance of hindwing colouration. The evidence supports a single Mendelian locus with two alleles in males: WW and Wy produce the white and yy the yellow hindwing colour. The inheritance could not be resolved in females as their hindwing colour varies continuously with no clear link with male genotypes. Next, we investigated if the male genotype can be predicted from their phenotype by machine learning algorithms and by human observers. Linear discriminant analysis grouped male genotypes with 97% accuracy, whereas humans could only group the yy genotype. Using vision modelling, we also tested whether the genotypes have differential discriminability to humans, moth conspecifics and their bird predators. The human perception was poor separating the genotypes, but avian and moth vision models with ultraviolet sensitivity could separate white WW and Wy males. We emphasize the importance of objective methodology when studying colour polymorphism. Our findings indicate that by-eye categorization methods may be problematic, because humans fail to see differences that can be visible for relevant receivers. Ultimately, receivers equipped with different perception than ours may impose selection to morphs hidden from human sight.Peer reviewe

Multimodal Aposematic Defenses Through the Predation Sequence

Aposematic organisms warn predators of their unprofitability using a combination of defenses, including visual warning signals, startling sounds, noxious odors, or aversive tastes. Using multiple lines of defense can help prey avoid predators by stimulating multiple senses and/or by acting at different stages of predation. We tested the efficacy of three lines of defense (color, smell, taste) during the predation sequence of aposematic wood tiger moths (Arctia plantaginis) using blue tit (Cyanistes caeruleus) predators. Moths with two hindwing phenotypes (genotypes: WW/Wy = white, yy = yellow) were manipulated to have defense fluid with aversive smell (methoxypyrazines), body tissues with aversive taste (pyrrolizidine alkaloids) or both. In early predation stages, moth color and smell had additive effects on bird approach latency and dropping the prey, with the strongest effect for moths of the white morph with defense fluids. Pyrrolizidine alkaloid sequestration was detrimental in early attack stages, suggesting a trade-off between pyrrolizidine alkaloid sequestration and investment in other defenses. In addition, pyrrolizidine alkaloid taste alone did not deter bird predators. Birds could only effectively discriminate toxic moths from non-toxic moths when neck fluids containing methoxypyrazines were present, at which point they abandoned attack at the consumption stage. As a result, moths of the white morph with an aversive methoxypyrazine smell and moths in the treatment with both chemical defenses had the greatest chance of survival. We suggest that methoxypyrazines act as context setting signals for warning colors and as attention alerting or "go-slow" signals for distasteful toxins, thereby mediating the relationship between warning signal and toxicity. Furthermore, we found that moths that were heterozygous for hindwing coloration had more effective defense fluids compared to other genotypes in terms of delaying approach and reducing the latency to drop the moth, suggesting a genetic link between coloration and defense that could help to explain the color polymorphism. Conclusively, these results indicate that color, smell, and taste constitute a multimodal warning signal that impedes predator attack and improves prey survival. This work highlights the importance of understanding the separate roles of color, smell and taste through the predation sequence and also within-species variation in chemical defenses.Peer reviewe

Context-dependent coloration of prey and predator decision making in contrasting light environments

A big question in behavioral ecology is what drives diversity of color signals. One possible explanation is that environmental conditions, such as light environment, may alter visual signaling of prey, which could affect predator decision-making. Here, we tested the context-dependent predator selection on prey coloration. In the first experiment, we tested detectability of artificial visual stimuli to blue tits (Cyanistes caeruleus) by manipulating stimulus luminance and chromatic context of the background. We expected the presence of the chromatic context to facilitate faster target detection. As expected, blue tits found targets on chromatic yellow background faster than on achromatic grey background whereas in the latter, targets were found with smaller contrast differences to the background. In the second experiment, we tested the effect of two light environments on the survival of aposematic, color polymorphic wood tiger moth (Arctia plantaginis). As luminance contrast should be more detectable than chromatic contrast in low light intensities, we expected birds, if they find the moths aversive, to avoid the white morph which is more conspicuous than the yellow morph in low light (and vice versa in bright light). Alternatively, birds may attack first moths that are more detectable. We found birds to attack yellow moths first in low light conditions, whereas white moths were attacked first more frequently in bright light conditions. Our results show that light environments affect predator foraging decisions, which may facilitate context-dependent selection on visual signals and diversity of prey phenotypes in the wild. Light environments are constantly changing and may alter visual appearance of prey, but also bias predators' decision making. Our findings using blue tits in visual search tasks and the wood tiger moth prey under two light environments demonstrate that birds show context-dependent predatory behavior. This suggests that light environments can play a major selective role and influence visual signaling in the wild.Peer reviewe

Geographic mosaic of selection by avian predators on hindwing warning colour in a polymorphic aposematic moth

Warning signals are predicted to develop signal monomorphism via positive frequency-dependent selection (+FDS) albeit many aposematic systems exhibit signal polymorphism. To understand this mismatch, we conducted a large-scale predation experiment in four countries, among which the frequencies of hindwing warning coloration of the aposematic moth,Arctia plantaginis,differ. Here we show that selection by avian predators on warning colour is predicted by local morph frequency and predator community composition. We found +FDS to be the strongest in monomorphic Scotland and lowest in polymorphic Finland, where the attack risk of moth morphs depended on the local avian community. +FDS was also found where the predator community was the least diverse (Georgia), whereas in the most diverse avian community (Estonia), hardly any models were attacked. Our results support the idea that spatial variation in predator communities alters the strength or direction of selection on warning signals, thus facilitating a geographic mosaic of selection.Peer reviewe

Multimodal Aposematic Signals and Their Emerging Role in Mate Attraction

Chemically defended animals often display conspicuous color patterns that predators learn to associate with their unprofitability and subsequently avoid. Such animals (i.e., aposematic), deter predators by stimulating their visual and chemical sensory channels. Hence, aposematism is considered to be "multimodal." The evolution of warning signals (and to a lesser degree their accompanying chemical defenses) is fundamentally linked to natural selection by predators. Lately, however, increasing evidence also points to a role of sexual selection shaping warning signal evolution. One of the species in which this has been shown is the wood tiger moth, Arctia plantaginis, which we here put forward as a promising model to investigate multimodality in aposematic and sexual signaling. A. plantaginis is an aposematic diurnal moth which exhibits sexually dimorphic coloration as well as sex-limited polymorphism in part of its range. The anti-predator function of its coloration and, more recently, its chemical defenses (even when experimentally decoupled from the visual signals), has been well-demonstrated. Interestingly, recent studies have revealed differences between the two male morphs in mating success, suggesting a role of coloration in mate choice or attraction, and providing a possible explanation for its sexual dimorphism in coloration. Here, we: (1) review the lines of evidence showing the role of predation pressure and sexual selection in the evolution of multimodal aposematic signals in general, and in the wood tiger moth in particular; (2) establish gaps in current research linking sexual selection and predation as selective pressures on aposematic signals by reviewing a sample of the literature published in the last 30 years; (3) highlight the need of identifying suitable systems to address simultaneously the effect of natural and sexual selection on multimodal aposematic signals; and (4) propose directions for future research to test how aposematic signals can evolve under natural and sexual selection.Peer reviewe

Antipredatory Function of Head Shape for Vipers and Their Mimics

Most research into the adaptive significance of warning signals has focused on the colouration and patterns of prey animals. However, behaviour, odour and body shape can also have signal functions and thereby reduce predators' willingness to attack defended prey. European vipers all have a distinctive triangular head shape; and they are all venomous. Several non-venomous snakes, including the subfamily Natricinae, commonly flatten their heads (also known as head triangulation) when disturbed. The adaptive significance of this potential behavioural mimicry has never been investigated

Työhyvinvoinnin tukeminen mielenterveys- ja riippuvuuspalveluiden integraatiossa

Työelämä elää jatkuvassa muutoksessa. Muutosten avulla organisaatiot pyrkivät tule-vaisuuden olemassaolonsa turvaamiseen ja ulkoisiin muutoksiin sopeutumiseen. Muutoksien myötä työntekijän arkipäivän tapa tehdä työtä muuttuu uusien työtehtävien, toimintatapojen, työyhteisön ja lähijohtajien vaihtumisen vuoksi. Myös työhyvinvoinnin tarpeet sekä keinot kehittää ja ylläpitää työhyvinvointia muuttuvat samalla. Jotta työntekijä voi hyvin töissä, kykenee käsittelemään muutoksen aiheuttamia tunteita sekä vastaamaan uusiin haasteisiin, tulee organisaatiomuutos toteuttaa mielekkäästi. Tämän opinnäytetyön tarkoituksena oli kuvata, mitkä tekijät ovat tukeneet mielenterveys- ja riippuvuuspalveluiden työntekijöiden työhyvinvointia palveluiden integraation aikana. Tavoitteena on tuottaa tietoa mielenterveys- ja riippuvuuspalveluiden työntekijöiden työhyvinvoinnista sekä Itä-Savon sairaanhoitopiirille keinoja työhyvinvoinnin tukemiseen. Opinnäytetyö toteutettiin Wepropol-kyselynä mielenterveys- ja riippuvuuspalveluissa integraation aikaan sekä tällä hetkellä työskenteleville työntekijöille (n=41) toukokuussa 2021. Vastausprosentti oli 64 %. Aineisto analysoitiin Wepropolin Insight ja Professional Statistics-ominaisuuksien avulla. Vastauksia tarkasteltiin prosenttien, keskiarvojen ja -hajontojen sekä korrelaatiokertoimien avulla. Tulokset osoittivat keskeisimmiksi työhyvinvointia tukeviksi tekijöiksi integraation ai-kana sekä tällä hetkellä yksilötasolla toteutettavia hyvinvointia tukevia tekijöitä ja psykologisen pääoman vahvuuksia. Integraation aikaan yksilötasolla muutokseen liittyi ahdistuneisuuden tunnetta. Työyhteisön keskusteluissa esiintyi epävarmuutta, kysymyksiä sekä huolta tulevaisuudesta. Muutosviestintä ei ollut ymmärrettävää. Vastaajat eivät kokeneet muutoksen aikana olevansa tietoisia tulevasta tai siitä, kuinka muutos tulee vaikuttamaan käytännön työntekemiseen. Osaamista ei kartoitettu eikä koulutussuunnitelmia tehty uuden työnkuvan hallitsemiseksi. Vastaajat kokivat, etteivät saaneet vaikuttaa päätöksentekoon tulevasta työnkuvasta eikä heidän mielipiteitään kuunneltu muutoksen aikana. Tällä hetkellä työhyvinvointia heikentävistä tekijöistä nousi esiin kysymykset kiireen tunteesta, positiivisen palautteen saamista työstään, työyhteisöiden työn vastuun jakautumisesta tasapuolisesti sekä yhteisten pelisääntöjen luomisesta ja noudattamisesta. Organisaation työhyvinvoinnin tukemisen strategiset keinot eivät ole tavoittaneet työntekijöitä. Jatkotutkimusehdotuksena tulisi vahvistaa muutosvalmennuksen ja -johtamisen osaamista sekä tutkia niiden vaikuttavuutta työhyvinvoinnin kokemukseen muutostilanteissa. Asiasanat: työhyvinvointi, työhyvinvointi muutoksessa, organisaatiomuuto

Supplementary data to: Context-dependent coloration of prey and predator decision making in contrasting light environments

A big question in behavioural ecology is what drives diversity of colour signals. The dataset covers the testing of the context-dependent predator selection on prey coloration. In the first experiment, detectability of artificial visual stimuli to blue tits (Cyanistes caeruleus) was tested by manipulating stimulus luminance and chromatic context of the background. In the second experiment, the effect of two light environments on the survival of aposematic, colour polymorphic wood tiger moth (Arctia plantaginis) was tested. For detailed description of the material, methods, and results of the study, see the article

Predator selection on phenotypic variability of cryptic and aposematic moths.

Natural selection generally favours phenotypic variability in camouflaged organisms, whereas aposematic organisms are expected to evolve a more uniform warning coloration. However, no comprehensive analysis of the phenotypic consequences of predator selection in aposematic and cryptic species exists. Using state-of-the-art image analysis, we examine 2800 wing images of 82 moth species accessed via three online museum databases. We test whether anti-predator strategy (i.e., camouflage or aposematism) explains intraspecific variation in wing colour and pattern across northern hemisphere moths. In addition, we test two mutually non-exclusive, ecological hypotheses to explain variation in colour pattern: diel-activity or dietary-niche. In this work, taking into account phylogenetic relationships, moth phenotypic variability is best explained by anti-predator strategy with camouflaged moths being more variable in wing patterning than aposematic species