Search results for " Color"
showing 10 items of 770 documents
Multiple modalities in insect warning displays have additive effects against wild avian predators
2019
Allocation to different components of defence has been suggested as an explanation for the existence of multiple aposematic morphs in a single population. We tested whether there are trade-offs between warning colouration and chemical defence or whether these have an additive effect when combined, using blue tits (Cyanistes caeruleus) as predators and the polymorphic wood tiger moth (Arctia plantaginis) as prey. We used artificial edible models (with and without the moths’ defensive fluids) with paper wings whose colour and pattern properties matched those of real moths. When the models were presented sans defensive fluids or when the fluids were presented without colour cues, we detected n…
Safety in Numbers: How Color Morph Frequency Affects Predation Risk in an Aposematic Moth
2021
Polymorphic warning signals in aposematic systems are enigmatic because predator learning should favor the most common form, creating positive frequency-dependent survival. However, many populations exhibit variation in warning signals. There are various selective mechanisms that can counter positive frequency-dependent selection and lead to temporal or spatial warning signal diversification. Examining these mechanisms and their effects requires first confirming whether the most common morphs are favored at both local and regional scales. Empirical examples of this are uncommon and often include potentially confounding factors, such as a lack of knowledge of predator identity and behavior. …
Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability
2022
The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection because drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance, are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths, we show that the presence of o…
Sole coloration as an unusual aposematic signal in a Neotropical toad
2019
Many animals have evolved remarkable strategies to avoid predation. In diurnal, toxic harlequin toads (Atelopus) from the Amazon basin, we find a unique colour signal. Some Atelopus populations have striking red soles of the hands and feet, visible only when walking. When stationary, the toads are hard to detect despite their yellow-black dorsal coloration. Consequently, they switch between high and low conspicuousness. Interestingly, some populations lack the extra colour display of the soles. We found comprehensive support that the red coloration can act as an aposematic signal directed towards potential predators: red soles are significantly more conspicuous than soles lacking red colora…
The impact of life stage and pigment source on the evolution of novel warning signal traits
2021
Our understanding of how novel warning color traits evolve in natural populations is largely based on studies of reproductive stages and organisms with endogenously produced pigmentation. In these systems, genetic drift is often required for novel alleles to overcome strong purifying selection stemming from frequency-dependent predation and positive assortative mating. Here, we integrate data from field surveys, predation experiments, population genomics, and phenotypic correlations to explain the origin and maintenance of geographic variation in a diet-based larval pigmentation trait in the redheaded pine sawfly (Neodiprion lecontei), a pine-feeding hymenopteran. Although our experiments c…
Influence of colour, smell and taste on the survival of the wood tiger moth (Arctia plantaginis) adults during predation event
2021
Saalistajien torjumiseksi saalis voi käyttää erilaisia puolustusmekanismeja, jotka stimuloivat useita eri aisteja (ts. multimodaalista signalointia). Esimerkiksi aposemaattiset eliöt puolustautuvat varoitussignaalin lisäksi sekundaarisella puolustuksella. Tässä tutkimuksessa keskityttiin siihen, kuinka täpläsiilikkään (Arctia plantaginis) väritys (genotyypit WW, Wy ovat valkoisia ja yy keltaisia), haju (metoksipyratsiinista) ja maku (pyrrolitsidiinialkaloidista) toimivat puolustuksena lintusaalistajien hyökkäyksiä vastaan. Linnuille tarjottiin kummankin värisiä eläviä siilikkäitä, joita oli manipuloitu niin, että niillä oli joko hajua, makua tai molempia näistä. Näin pystyttiin tutkimaan ku…
The complete mitochondrial genome of the wood tiger moth (Arctia plantaginis) and phylogenetic analyses within Arctiinae
2021
We report the assembly and annotation of the complete mitochondrial genome of the warningly-coloured wood tiger moth (Arctia plantaginis) and investigate its phylogenetic position within Arctiinae. The A.plantaginis mitogenome is 15,479 bp long with 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNA genes, and an A + T-rich region (D-loop). The phylogenetic analyses based on 13 protein-coding genes showed A.plantaginis clustering within a clade of species with white wings and yellow or red bodies. This result can be useful in understanding the evolution of coloration in Arctiid moths. Peer reviewed
Factores de riesgo de infección de la herida quirúrgica en cirugía electiva de cáncer de sigma y recto. Implantación de un programa de vigilancia
2014
Objetivos: Conocer la tasa de infección de la herida quirúrgica (SSI), laparotómica y perineal, en cirugía oncológica electiva colorrectal y determinar sus respectivos factores de riesgo independientes. Expresar el riesgo o probabilidad de sufrir dicha infección, a través de la incidencia acumulada (IA) y la densidad de incidencia (DI). Evaluar las diferencias entre la cirugía preservadora de esfínteres (CPE) y la amputación abdominoperineal (AAP) en cuanto a la infección de la laparotomía en el cáncer de recto. Conocer la morbilidad no infecciosa de la herida perineal tras AAP y sus factores de riesgo. Valorar el efecto de medidas correctoras aplicadas en el tiempo para disminuir la SSI y …
¿Una nueva vertiente en el Volcán Copahue?: El caso del río Colorado.
El volcán Copahue (37°51′08″S–71°10′03″O) ha sido uno de los más estudiados del cinturón volcánico Argentino-Chileno, desarrollándose numerosos trabajos desde el punto de vista geoquímico, y en particular abarcando el estudio de las aguas del sistema. Dichos trabajos se concentran en su mayoría en las nacientes del sistema volcánico hidrotermal (SVH) (Agusto et al, 2012). Sin embargo, existen varios afluentes que alimentan al rio Caviahue de los cuales no se tiene mayor información. El objetivo de este trabajo es dterminar el origen de uno de ellos, el río Colorado. Desde el flanco E del volcán emanan dos vertientes ácidas (pH 1-2,5) y calientes (35-45°C) que se unen para formar el río Agri…
Seeing red? Colour biases of foraging birds are context dependent.
2020
Funder: Suomen Kulttuurirahasto; doi: http://dx.doi.org/10.13039/501100003125