Biology subjects

Winters, S.

Publications and source records attributed to Winters, S..

7 recordsLinked to original sources

bioRxiv2026

Testing The Protective Function of Flash Coloration Using Wild Avian Predators

Many prey reveal conspicuous color patches during movement that become concealed when they stop. Such abrupt changes in appearance have been proposed to disrupt predator tracking and make prey more difficult to relocate, providing the basis of the flash coloration hypothesis. However, empirical support remains inconsistent and comes largely from experiments using human observers or simplified artificial prey. Here, we used touchscreen-equipped operant chambers to test the flash coloration hypothesis with wild blue tits (Cyanistes caeruleus) searching for moving digital prey modelled on Catocala moths. The digital prey revealed either conspicuous or cryptic hindwings during flight before adopting a cryptic resting appearance. Contrary to predictions, conspicuous hindwings neither increased prey survival nor delayed prey relocation compared to moths with cryptic hindwings. However, conspicuous hindwings also did not incur detectable predation costs. In contrast, background strongly affected prey detection, with moths surviving better on realistic bark than on smooth grey backgrounds. Our results provide no evidence that conspicuous colors revealed during movement enhance prey survival in this context, suggesting that any protective effect attributed to flash coloration may be weak or strongly dependent on ecological conditions.

animal behavior and cognition↗

bioRxiv2026

Independent major-effect loci and limited trait associations characterise warning colour variation across sexes and life stages in the wood tiger moth (Arctia plantaginis)

Variation in warning colouration is common, despite strong positive frequency-dependent selection favouring the most common morph, and may arise from spatially or temporally variable selection or associations with other traits. We investigated the maintenance of warning colour variation in the wood tiger moth, Arctia plantaginis, which shows sexual dimorphism in colouration: two distinct male morphs controlled by a single locus, and continuous variation in female hindwing colour and larval warning signal size. Using whole-genome sequencing of 657 individuals from a laboratory stock derived from a wild polymorphic population, we examined the genetic basis of multiple life-history traits, chemical defence, pheromones, and male activity. We specifically tested for associations with male colour and aimed to identify the genetic basis of female and larval colour variation. We detected separate major-effect loci for female colour and larval signal size, which were different from the male colour locus. Hindwing melanism was the only trait associated with male colour, mapping to a nearby major-effect locus and showing a link to reduced activity at higher temperatures. Female colour was phenotypically correlated with pheromone amount. However, apart from melanism, none of the other traits measured showed an association with any of the loci controlling warning colours and we found no evidence that male colour is part of a supergene or complex co-adapted phenotype. Instead, our results indicate largely independent genetic architectures for warning colours suggesting that variable selection rather than genetic associations may contribute to the maintenance of colour polymorphisms in this species.

evolutionary biology↗

bioRxiv2026

Beyond abstract selection coefficients: Protandry impacts the buildup of heterozygote advantage over the lifespan in a color polymorphic moth

Population genetic models excel at identifying the conditions for polymorphisms based on balancing selection but typically disregard the ecological processes that yield particular values of selection coefficients. We model a system that combines antagonistic pleiotropy, dominance reversal and heterozygote advantage: the wood tiger moth Arctia plantaginis, where alternative haplotypes at a major-effect locus determine male hindwing coloration. Yellow offers better protection against predators, while white is often associated with better mating success. The effects of mortality and reproductive success overlap in time because protandrous males can mate as long as they are alive, but they need to avoid predation for several days before the bulk of females emerge. We show that protandry aids polymorphism maintenance whenever the second-fittest genotype (after the heterozygote) is the poorly surviving but mating advantaged homozygote, while increased protandry harms polymorphism when the second-best fitness is that of the survival advantaged morph. Ecologically plausible protandry times predict that dominance reversal does not have to be strong for polymorphism to be maintained. Our study highlights the importance of timing traits in maintaining polymorphisms in Lepidoptera and showcases the benefits of deriving fitness explicitly in place of abstract selection coefficients that lack temporal components within the life cycle.

evolutionary biology↗

bioRxiv2025

Biologically inspired warning patterns deter birds from wind turbines

Wind power has been at the forefront of investment and innovation in renewable energy. However, bird fatalities from collisions with wind turbines present an ecological and social challenge to the growing deployment of wind power. Increasingly, research has focused on utilising the sensory ecology of animals to provide passive or active cues that minimise collision risk by increasing the detectability and/or aversiveness of the turbine blades and towers. In nature, numerous aposematic species use contrasting colours and striped patterns to warn birds of their unprofitability. These common signal elements are effective due to their salience within a wide range of natural scenes, memorability, generalisability across taxa due to mimicry, and exploitation of the innate colour preferences of birds. This begs the question: might biologically inspired turbine blades that mimic aposematic patterns help protect birds by increasing their avoidance of turbine blades? Here, we used a screen-based game experimental setup to test the behavioural responses of wild-caught great tits (Parus major) to three existing wind turbine patterns (white, red striped, and single black blade) as well as a novel biologically inspired aposematic pattern. Birds were less likely to approach and, when they did approach, took significantly longer to approach patterned compared to uniform white blades. This effect was strongest for our aposematic pattern compared to all other patterns tested, highlighting the utility of our bio-inspired approach. Our work suggests that adding red, black and yellow warning patterns to wind turbine blades could reduce bird collisions with wind turbines.

ecology↗

bioRxiv2024

Exploring mate choice and male strategies in a polymorphic moth

Color polymorphisms in natural populations often reflect the interplay between various selective pressures, such as natural and sexual selection. In this study, we investigate the dynamics of sexual selection operating on color polymorphism in wood tiger moths under different ecological contexts. Wood tiger moths exhibit polymorphism in male hindwing coloration, with individuals possessing one or two dominant W alleles displaying two forms of white coloration that differ in their UV reflectance (WW, Wy), while those with two recessive y alleles exhibit yellow coloration (yy). Females carry the color alleles, but do not express them phenotypically. We performed two mate choice experiments that simulated two ecological conditions: one with limited morph availability and low male encounter rates and the other with all morphs present and high potential for male encounters. We demonstrate that WW males consistently experience higher mating success compared to yy males, irrespective of the presence of Wy males and male encounter rates. Surprisingly, mating with a WW male does not confer direct reproductive benefits to females in terms of lifetime reproductive success; instead, Wy females exhibit overall higher reproductive success regardless of their mating partner. Although the precise mechanism driving the higher mating success of WW males remains unclear, a temporal decline in mating success of WW males suggests potential differences in male mating strategies. Our findings support the hypothesis that sexual selection contributes to the maintenance of polymorphism, revealing a stable mating advantage of a particular color morph that may be offset by other selective forces.

evolutionary biology↗

bioRxiv2023

Diet influences resource allocation in chemical defence but not melanin synthesis in an aposematic moth

For animals that synthesise their chemical compounds de novo, resources, particularly proteins, can influence investment in chemical defences and nitrogen-based wing colouration such as melanin. Competing for the same resources often leads to trade-offs in resource allocation. We manipulated protein availability in the larval diet of the wood tiger moth, Arctia plantaginis, to test how early life resource availability influences relevant life history traits, melanin production, and chemical defences. We expected higher dietary protein to result in more effective chemical defences and a higher amount of melanin in the wings. According to the resource allocation hypothesis, we also expected individuals with less melanin to have more resources to allocate to chemical defences. We found that protein-deprived moths had a slower larval development, and their chemical defences were less unpalatable for bird predators, but the expression of melanin in their wings did not differ from that of moths raised on a high-protein diet. The amount of melanin in the wings, however, unexpectedly correlated positively with chemical defences, irrespective of the diet they were raised on. Our findings demonstrate that the resources available in early life have an important role in the efficacy of chemical defences, but melanin-based warning colours are less sensitive to resource variability than other fitness-related traits.

ecology↗

bioRxiv2019

The structure of species discrimination signals across a primate radiation

Discriminating between conspecifics and heterospecifics potentially challenging for closely related sympatric species. The guenons, a recent primate radiation, exhibit high degrees of sympatry and form multi-species groups in which hybridization is possible but rare in most populations. Guenons have species-specific colorful face patterns hypothesized to function in species discrimination. Here, we apply a novel machine learning approach to identify the face regions most essential for correct species classification across fifteen guenon species. We then demonstrate the validity of these computational results using experiments with live guenons, showing that facial traits identified as critical for accurate classification do indeed influence selective attention toward con- and heterospecific faces. Our results suggest variability among guenon species in reliance on single-trait-based versus holistic facial characteristics when discriminating between species, and differences in behavioral responses to faces can be linked to whether discrimination is based on a single trait or whole-face pattern. Our study supports the hypothesis that guenon face patterns function to promote species discrimination and provides novel insights into the relationship between species interactions and phenotypic diversity.

evolutionary biology↗