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Las VI Jornadas Científicas del Museo Nacional de Ciencias Naturales (MNCN-CSIC) fueron celebradas el 17 y 18 de abril de 2023 en Madrid. En ellas tuvieron lugar 3 sesiones plenarias de 45 minutos, 21 charlas de 15 minutos y 31 charlas de 5 minutos. Finalizaron con mesa redonda sobre "El futuro de la carrera investigadora en el Museo"., Presentamos los resultados de un estudio sobre la diversidad de derméstidos que habitan los nidos de una especie de ave troglodita, el herrerillo común (Cyanistes caeruleus), así como el efecto sobre estos Coleópteros de diversos factores, entre ellos la temperatura y la humedad relativa en el interior del nido. Se identificaron diez taxones, seis como especies reconocidas y cuatro como taxones larvarios identificados a nivel de género. La mayoría de los derméstidos encontrados, en estado larvario, eran derméstidos nidícolas del género Anthrenus. Los ejemplares de derméstidos necrobiontes (aquellos que se alimentan de cadáveres tanto en fase larvaria como adulta) se encontraron en menor proporción, y casi siempre en estado adulto. En los nidos de herrerillo donde se aumentó experimentalmente la temperatura se encontraron más larvas de derméstidos que en los nidos control, y en aquellos nidos donde se registraron valores más altos de temperatura se encontraron más derméstidos adultos necrobiontes del género Dermestes.

La teoría evolutiva de la señalización en animales propone que ciertas coloraciones llamativas pueden haber evolucionado para actuar como señales fiables de la calidad del individuo. Las coloraciones rojas producidas por pigmentos carotenoides pueden depender de transformaciones enzimáticas (oxidaciones) de los carotenoides amarillos obtenidos con la dieta, lo cual parece ocurrir dentro de la membrana mitocondrial. De ese modo, la transformación de los pigmentos y la respiración celular (producida en la mitocondria) podrían compartir un mismo mecanismo bioquímico. Tal coincidencia haría que la intensidad de coloración roja reflejara directamente la eficacia metabólica de cada animal y, por tanto, la calidad del mismo de una manera general e infalsificable. Varios trabajos han descrito que el esfuerzo de vuelo puede producir estrés oxidativo. Un metabolismo oxidativo modificado durante el vuelo podría influenciar la transformación de carotenoides y, en último término, la coloración del individuo. Nosotros intentamos inferir la relación entre la expresión de ornamentos pigmentados por carotenoides rojos y el metabolismo del vuelo mediante un experimento en piquituertos comunes (Loxia curvirostra). Se capturaron para ello 295 machos adultos con redes japonesas en una población Ibérica. Esto se hizo durante el invierno ya que es el periodo en el que más piquituertos pueden ser capturados. Aproximadamente, a la mitad de ellos se les recortó dos plumas primarias de cada ala con la intención de aumentar su esfuerzo de vuelo, y la otra mitad fue dejada como control. Para estimular el crecimiento de plumas en una superficie pequeña durante un periodo corto de tiempo y en invierno-primavera, se desplumó un área del obispillo de todas las aves. Durante las siguientes semanas pudimos capturar 34 de estos individuos. No detectamos sesgos en la tasa de recuperación de cada grupo experimental, ni diferencias morfológicas entre ambos. Sin embargo, entre los recapturados, aquellos cuyas plumas fueron recortadas mostraron una ligera pérdida de peso, mientras los controles tendieron a aumentar éste. Además, los piquituertos de alas recortadas, generaron plumas más rojas en el obispillo que los controles. Los resultados sugieren que el recorte de las plumas indujo un mayor gasto energético que condujo a una pérdida de masa corporal. Pero, además, el hecho de generar plumas más rojas parece apoyar la idea de que el metabolismo asociado al vuelo está relacionado con las reacciones enzimáticas necesarias para convertir carotenoide amarillo en rojo. Se discuten las implicaciones de este resultado en términos evolutivos.

Estas Jornadas tuvieron lugar en Madrid el 28 de octubre de 2022

Este congreso tuvo lugar en Estocolmo (Suecia) del 28 de julio al 2 de agosto., The animal signaling theory posits that conspicuous colorations exhibited by many animals have evolved as reliable signals of individual quality. Red carotenoid-based ornaments may depend on enzymatic transformations (oxidation) of dietary yellow carotenoids, which could occur in the inner mitochondrial membrane (IMM). Thus, carotenoid ketolation and cell respiration could share the same biochemical pathways. Accordingly, the level of trait expression (redness) would directly reveal the efficiency of individuals¿ metabolism and, hence, the bearer quality in an unfalsifiable way. Different avian studies have described that the flying effort may induce oxidative stress. A redox metabolism modified during the flight could thus influence the carotenoid conversion rate and, ultimately, animal coloration. Here, we aimed to infer the link between red carotenoid-based ornament expression and flight metabolism by increasing flying effort in wild male common crossbills Loxia curvirostra (Linnaeus). In this order, 295 adult males were captured with mist nets in an Iberian population during winter. Approximately half of the birds were experimentally handicapped through wing feather clipping to increase their flying effort, the other half being used as a control group. To stimulate the plumage regrown of a small surface during a short time-lapse, we also plucked the rump feathers from all the birds. A fraction of the birds with fully grown rump feathers (34 individuals) could be recaptured during the subsequent weeks. We did not detect any significant bias in recovery rates and morphological variables in this reduced subsample. However, among recaptured birds, individuals with experimentally impaired flying capacity showed body mass loss, whereas controls showed a trend to increase their weight. Moreover, clipped males showed redder feathers in the newly regrown rump area compared to controls. The results suggest that wing-clipped individuals could have endured higher energy expenditure as they lost body mass. Despite the small sample size, the difference in plumage redness between the two experimental groups would support the hypothesis that the flying metabolism may influence the redox enzymatic reactions required for converting yellow dietary carotenoids to red ketocarotenoids.

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Giessen (Germany) One-day online conference: March 15, 2022 (https://conference.eounion.org/2022/), Ornaments can evolve to reveal individual quality when their production/maintenance costs make them reliable as `signals¿ or if their expression level is intrinsically linked to condition by some unfalsifiable mechanism (indices). The latter has been mostly associated with traits constrained by body size. In red ketocarotenoid-based colorations, that link could, instead, be established with cell respiration at the inner mitochondrial membrane (IMM). The production mechanism could be independent of resource (yellow carotenoids) availability, thus discarding costs linked to allocation trade-offs. A gene coding for a ketolase enzyme (CYP2J19) responsible for converting dietary yellow carotenoids to red ketocarotenoids has recently been described. We treated male Zebra Finches with an antioxidant designed to penetrate the IMM (mitoTEMPO) and a thyroid hormone (triiodothyronine) with known hypermetabolic effects. Among hormone controls, MitoTEMPO downregulated CYP2J19 in the bill (a red ketocarotenoid-based ornament), supporting the mitochondrial involvement in ketolase function. Both treatments interacted when increasing hormone dosage, indicating that mitochondria and thyroid metabolisms could simultaneously regulate coloration. Moreover, CYP2J19 expression was positively correlated to redness but also to yellow carotenoid levels in the blood. However, treatment effects were not annulated when controlling for blood carotenoid variability, which suggests that costs linked to resource availability could be minor.

Sexual and social selections promote the evolution of many conspicuous colorations in animals. These traits would act as individual quality signals when they transmit reliable information. Reliability should be assured by production costs unaffordable for low-quality trait bearers or guaranteed if trait expression is tightly linked to individual quality and cannot be falsified (“index signals”). It has been suggested that colored ornaments produced by red ketocarotenoid pigments could meet the latter. These ketocarotenoids are often obtained by enzymatic transformation of dietary yellow carotenoids. Recently, the first enzyme performing this transformation has been described: CYP2J19. This enzyme, belonging to the cytochrome p450 superfamily, is presumably located in the inner mitochondrial membrane, thus linking color expression with cell respiration efficacy. However, it remains to be clarified if the tissue where this intracellular mechanism acts could influence signal reliability and trait evolution. CYP2J19 expression data are now available for different species and tissues. Here, we review current data in birds and hypothesize that CYP2J19 activity could have evolved in some species by being relocated from the liver tissue to the ornaments (epidermis), a pattern more strongly observed in those birds where the red is expressed in non-feathered bare parts (e.g. bill, legs). One potential explanation is that bare parts, unlike feathers, require a constant carotenoid mobilization to maintain color throughout the year. We propose that tissue relocation allows for avoiding production costs derived from potential CYP2J19 interference on vital liver functions. Implications for signal reliability in ornamental evolution are discussed.

International audience; The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change).To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)—a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting.SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language).The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration.

The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Further, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-terms studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org) – a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within a year of the establishment, SPI-Birds counts 120 members working on more than 80 populations, with data concerning breeding attempts of almost a million individual birds over a 1700 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration, and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by of Findable, Accessible, Interoperable, and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration.

Additional methods and complementary analyses, tables and figures