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Immunological surveillance against cancer across mammals
No full textInternational audienceContrary to expectations based on their higher cell numbers, larger and longer-lived species do not face dramatically increased risk of cancer. This strongly suggests that evolution has fashioned natural cancer resistance mechanisms, yet our knowledge remains limited on what these mechanisms might be. The cancer immunological surveillance hypothesis, proposed by Burnet and Thomas in the 1950s, highlights immunity as a key factor determining species-specific cancer resistance. Here we address the original, evolutionary interpretation of this hypothesis by investigating the relationship between cancer mortality risk and markers of efficient antigen presentation. Our results show that the expansion of the MHC class I gene complex, as well as increased selection for diversity at these genes is associated with sharply decreasing cancer mortality risk across mammals. This suggests that the efficient presentation of diverse peptides in somatic cells is important for cancer suppression across mammals, providing pioneering evidence that supports the cancer immunosurveillance hypothesis across species
Functional profiles and organochlorine degradation potential in microbial communities of tropical epilithic biofilms: a case study in Guadeloupe (Lesser Antilles)
No full textInternational audienceThis study investigates the composition, structure, and predictive associated functions of epilithic bacteria living in the biofilms of a freshwater (FWR) and a mixed-saline (MSR) tropical river. High-throughput sequencing revealed a 69% overlap in species richness between the two sites. Cyanobacteria were dominant in freshwater, while heterotrophic classes like Alphaproteobacteria and Betaproteobacteria were prevalent in the mixed-saline biofilm. Predictive functional analysis (FAPROTAX) indicated greater diversity in MSR, favoring organic matter degradation and nutrient cycling, with more bacterial OTUs involved in chemoheterotrophy and hydrogen oxidation (Wilcoxon, p > 0.001). In contrast, FWR had a higher abundance of OTUs linked to phototrophy and degradation of aromatic compounds and plastics (Wilcoxon, p > 0.001). Key microbial interactions were revealed between phototrophic cyanobacteria and heterotrophs such as Fulvivirga (Cytophagia), suggesting a pivotal role for this genus in the carbon cycle. Additionally, bacterial species known for their ability to remove chlorine from pollutants, such as Acidovorax, Acinetobacter, Comamonas, Curvibacter, Sediminibacterium, or bacterial species belonging to the Sphingomonadaceae family were more diverse and abundant in FWR site. These findings point to promising bioremediation potential driven by biofilm community activities, particularly in tropical freshwater environments impacted by organochlorine contaminants
La légende du “Petit Colibri” au prisme des sciences de la conservation: Propos introductifs
No full textInternational audienceDiese einführende Rede, gehalten von Jean-Raphaël Gros-Desormeaux (CNRS), eröffnet das Kolloquium zur Bildung und Sensibilisierung für Wasser und aquatische Lebensräume im Kontext des Klimawandels in Martinique. Nach einem Dank an das Office de l’Eau de la Martinique stützt sich der Redner auf die Naturschutzwissenschaften, um eine kontextualisierte Interpretation der amerindischen Legende vom „kleinen Kolibri“ zu entwickeln, die häufig mit ökologischem Engagement in Verbindung gebracht wird. Er passt ihre Bedeutung an den martinikanischen Kontext an: Das Feuer und der Wald stehen für die physischen Auswirkungen des Klimawandels auf die Wasserressourcen; das Gürteltier symbolisiert soziale und psychologische Verwundbarkeiten; und der Kolibri verweist auf individuelle und kollektive Handlungsmöglichkeiten zur Abschwächung und Anpassung.Anschließend stellt der Vortrag die Klimaprojektionen für die Kleinen Antillen gemäß dem RCP-8.5-Szenario vor (Temperaturanstieg, Veränderungen der Winde und Niederschläge, Entwicklung der tropischen Wirbelstürme) und betont die künftigen hydrologischen und sozio-hydro-ökologischen Herausforderungen. Der Redner erinnert an drei zentrale Prinzipien der Naturschutzwissenschaften: die Abhängigkeit des Lebens vom Wasser, die wesentliche Rolle ökologischer Nischen und die Gefahr biologischer Aussterbeereignisse bei zu schnellen Umweltveränderungen.Die Analyse wird durch eine Reflexion über die Bürgerbeteiligung in der Wasserverwaltung in Frankreich ergänzt, basierend auf jüngsten wissenschaftlichen Veröffentlichungen. Drei wichtige Entwicklungen werden hervorgehoben: eine verstärkte Demokratisierung seit der Verordnung von 2016, eine wachsende Bürgerbeteiligung insbesondere bei Fragen der Wasserqualität sowie eine allmählich zunehmende Offenheit der kommunalen Entscheidungsträger für direkte Beteiligungsformen – wenn auch regional unterschiedlich. Gleichzeitig werden bestehende Grenzen deutlich: unzureichende Ressourcen, politische Diskontinuität, lokale Widerstände und die geringe Umsetzung öffentlicher Konsultationen in konkrete Maßnahmen.Abschließend stellt der Redner den Aufbau des Kolloquiums vor, das zwei Podiumsdiskussionen umfasst – eine zu institutionellen Sensibilisierungspolitiken und eine zu einer neuen Generation engagierter Bürgerinnen und Bürger sowie Fachkräfte – sowie drei thematische Workshops zu Innovationen, Kunst als Instrument der Sensibilisierung und aquatischen Lebensräumen als pädagogischen Lernorten.{https://youtu.be/jsEppxt3vIw?si=As4kDW0Ct3MFZ82v}This introductory address, delivered by Jean-Raphaël Gros-Desormeaux (CNRS), opens the colloquium dedicated to education and awareness-raising on water and aquatic environments in the context of climate change in Martinique. After acknowledging the Office de l’Eau de la Martinique, the speaker draws on conservation science to propose a contextualized interpretation of the Amerindian legend of the “little hummingbird,” often associated with environmental engagement. He adapts its meaning to the Martinican context: the fire and the forest symbolize the physical impacts of climate change on water resources; the armadillo reflects social and psychological vulnerabilities; and the hummingbird represents the individual and collective capacities to act, mitigate, and adapt.The presentation then outlines climate projections for the Lesser Antilles under the RCP 8.5 scenario (temperature rise, changes in winds and precipitation, evolution of cyclonic activity), highlighting upcoming hydrological and socio–hydro–ecological challenges. The speaker recalls three key principles from conservation science: the dependence of life on water, the essential role of ecological niches, and the risks of biological extinction when environmental changes occur too rapidly.The analysis extends to a reflection on citizen participation in water governance in France, drawing on recent scientific literature. Three major trends are emphasized: increased democratization since the 2016 ordinance, growing civic mobilisation around water quality issues, and the gradual openness of elected officials to more direct participation—though uneven across territories. Remaining limitations are also identified, including insufficient resources, political discontinuities, local resistance, and weak translation of public consultations into tangible action.Finally, the speaker presents the structure of the colloquium, organised around two roundtables — one on institutional policies for awareness-raising, the other on fostering a new generation of engaged citizens and professionals — along with three thematic workshops on innovation, art as a tool for water awareness, and aquatic environments as in situ educational resources.{https://youtu.be/jsEppxt3vIw?si=As4kDW0Ct3MFZ82v}Esta intervención introductoria, pronunciada por Jean-Raphaël Gros-Desormeaux (CNRS), abre el coloquio dedicado a la educación y la sensibilización sobre el agua y los medios acuáticos en el contexto del cambio climático en Martinica. Tras agradecer al Office de l’Eau de Martinique, el ponente recurre a las ciencias de la conservación para proponer una interpretación contextualizada de la leyenda amerindia del “pequeño colibrí”, a menudo asociada al compromiso ambiental. Adapta su significado al contexto martiniqueño: el fuego y el bosque simbolizan los impactos físicos del cambio climático sobre los recursos hídricos; el tatú refleja las vulnerabilidades sociales y psicológicas; y el colibrí representa la capacidad individual y colectiva para actuar, mitigar y adaptarse.La presentación expone a continuación las proyecciones climáticas para las Antillas Menores según el escenario RCP 8.5 (aumento de temperaturas, cambios en los vientos y precipitaciones, evolución de la actividad ciclónica), subrayando los futuros desafíos hidrológicos y socio–hidro–ecológicos del territorio. El ponente recuerda tres principios fundamentales de las ciencias de la conservación: la dependencia de la vida respecto al agua, el papel esencial de los nichos ecológicos y los riesgos de extinción biológica cuando los cambios ambientales son demasiado rápidos.El análisis continúa con una reflexión sobre la participación ciudadana en la gobernanza del agua en Francia, a partir de publicaciones científicas recientes. Se destacan tres tendencias principales: una mayor democratización desde la ordenanza de 2016, una creciente movilización ciudadana en torno a la calidad del agua y una apertura progresiva de los cargos electos hacia una participación más directa, aunque con variaciones territoriales. También se señalan las limitaciones persistentes: falta de recursos, discontinuidad política, resistencias locales y escasa traducción de las consultas públicas en acciones concretas.Por último, el ponente presenta la estructura del coloquio, organizado en torno a dos mesas redondas —una sobre políticas institucionales de sensibilización y otra sobre la construcción de una nueva generación de ciudadanos y profesionales comprometidos— junto con tres talleres temáticos dedicados a la innovación, al arte como herramienta de sensibilización sobre el agua y a los medios acuáticos como espacios pedagógicos in situ.{https://youtu.be/jsEppxt3vIw?si=As4kDW0Ct3MFZ82v}Cette intervention introductive, prononcée par Jean-Raphaël Gros-Desormeaux (CNRS), ouvre le colloque consacré à l’éducation et à la sensibilisation à l’eau et aux milieux aquatiques dans le contexte du changement climatique en Martinique. Après avoir remercié l’Office de l’Eau de la Martinique, l’auteur mobilise les sciences de la conservation pour proposer une relecture contextualisée de la légende amérindienne du « petit colibri », souvent associée à l’engagement environnemental. Il en propose une interprétation adaptée au territoire martiniquais : le feu et la forêt renvoient aux impacts physiques du changement climatique sur la ressource en eau ; le tatou symbolise les vulnérabilités sociales et psychologiques ; et le colibri évoque les capacités individuelles et collectives à agir, à atténuer et à s’adapter.L’intervention présente ensuite les projections climatiques pour les Antilles selon le scénario RCP 8.5 (hausse des températures, modification des vents et des précipitations, évolution de l’activité cyclonique), mettant en évidence les futurs enjeux hydrologiques et socio-hydro-écologiques du territoire. L’auteur rappelle trois enseignements fondamentaux des sciences de la conservation : la dépendance de la vie à l’eau, l’importance des niches écologiques et les risques d’extinction liés à des changements environnementaux trop rapides.L’analyse se prolonge par une réflexion sur la participation citoyenne dans la gouvernance de l’eau en France, à partir d’un état des lieux issu de la littérature scientifique. Trois évolutions structurantes sont mises en avant : la démocratisation accrue depuis l’ordonnance de 2016, la mobilisation croissante des citoyens sur les enjeux de qualité de l’eau, et l’ouverture progressive des élus à une participation plus directe, malgré des disparités territoriales. Les limites persistantes sont également soulignées : manque de moyens, discontinuités politiques, résistances locales et faible transformation des consultations en actions effectives.Enfin, l’auteur présente la structuration du colloque autour de deux tables rondes — l’une sur les politiques institutionnelles de sensibilisation, l’autre sur l’engagement citoyen et professionnel — ainsi que trois ateliers thématiques consacrés aux innovations, à l’art comme outil de sensibilisation et aux milieux aquatiques comme supports pédagogiques.{https://youtu.be/jsEppxt3vIw?si=As4kDW0Ct3MFZ82v}Esta palestra introdutória, proferida por Jean-Raphaël Gros-Desormeaux (CNRS), abre o colóquio dedicado à educação e à sensibilização sobre a água e os ambientes aquáticos no contexto das mudanças climáticas na Martinica. Após agradecer ao Office de l’Eau de la Martinique, o autor recorre às ciências da conservação para propor uma interpretação contextualizada da lenda ameríndia do “pequeno beija-flor”, frequentemente associada ao engajamento ambiental. Ele adapta seu significado ao contexto martinicano: o fogo e a floresta simbolizam os impactos físicos das mudanças climáticas sobre os recursos hídricos; o tatu representa vulnerabilidades sociais e psicológicas; e o beija-flor evoca as capacidades individuais e coletivas de agir, mitigar e se adaptar.A apresentação segue com as projeções climáticas para as Pequenas Antilhas segundo o cenário RCP 8.5 (aumento das temperaturas, mudanças nos ventos e nas precipitações, evolução da atividade ciclônica), destacando os futuros desafios hidrológicos e socio-hidro-ecológicos do território. O autor relembra três princípios fundamentais das ciências da conservação: a dependência da vida em relação à água, o papel essencial dos nichos ecológicos e os riscos de extinção biológica quando as mudanças ambientais ocorrem de forma muito rápida.A análise se estende a uma reflexão sobre a participação cidadã na governança da água na França, com base na literatura científica recente. Três tendências principais são destacadas: a democratização ampliada desde o decreto de 2016, a crescente mobilização cidadã em torno da qualidade da água e a abertura gradual de representantes eleitos para formas mais diretas de participação — ainda que com diferenças entre os territórios. Também são identificadas limitações persistentes, como a falta de recursos, a descontinuidade política, resistências locais e a fraca tradução das consultas públicas em ações concretas.Por fim, o autor apresenta a estrutura do colóquio, organizado em torno de duas mesas-redondas — uma sobre políticas institucionais de sensibilização e outra sobre a construção de uma nova geração de cidadãos e profissionais engajados — além de três oficinas temáticas dedicadas à inovação, à arte como ferramenta de sensibilização sobre a água e aos ambientes aquáticos como espaços pedagógicos in situ.{https://youtu.be/jsEppxt3vIw?si=As4kDW0Ct3MFZ82v
An exceptional network of diploic veins in pangolins: implications for brain drainage and placental mammal phylogeny
No full textInternational audienc
Influence of phylogenetic proximity on children’s empathy towards other species
No full textInternational audienceEmpathy is an essential social skill that develops progressively during childhood. Although mainly studied in the context of human intra-specific interactions, it also extends towards other species. Various factors influence the strength of empathy towards other species, including phylogenetic distance. The present study aimed to examine if this parameter also affects children’s empathy towards other species. Three hundred and eight children - aged 5 to 12 years old- were given an empathic choice test on an extended photographic sample of organisms, followed by a scale measuring their empathic tendencies towards human peers. Results highlighted that children’s empathy towards other living beings decreased with phylogenetic distance, and that this trend strengthened as age increased. Interestingly, presence of animals in the household tended to be positively related to children’s empathy towards their peers. Comparison with data collected in previous studies revealed that although the effect of phylogenetic distance was stronger in adults than in children, no difference was observed compared to adults with autism spectrum disorder (ASD), except for human beings. This research sheds new light on children’s empathy towards other species and provides elements to consider for their sensitization to animal welfare and wildlife protection, as well as new insights on the specific status that animals can have for people with ASD
IA et éducation : une même révolution, des visions multiples
No full textNational audience"This conference entitled 'AI and Education: One Revolution, Multiple Visions' presents the results of an international exploratory survey conducted among 129 future education professionals distributed across Alsace (France), Quebec (Canada), Martinique, and Guadeloupe. Grounded in a constructivist and inductive approach (Charmaz, 2014; Strauss, 1987), the study analyzes the knowledge, perceptions, and representations of generative artificial intelligence among future teachers through three questions:What do they know about AI?How do they perceive its pedagogical usefulness?How do they envision the transformation of the teaching role in the AI era?The theoretical framework articulates activity theory (Engeström, 2001), enabling understanding of the tensions generated by the introduction of new tools, and AI literacy (UNESCO, 2024), focused on developing technical, critical, and ethical skills. The three studied contexts reveal contrasting representations: a technical and functional vision in Alsace, a strategic and experiential perspective in Quebec, and a pragmatic and inclusive approach in the Caribbean, particularly around Creole language learning.The results highlight a convergence on AI's usefulness for time-saving, structuring ideas, and supporting pedagogical design, but also differentiated concerns across territories, notably regarding the redefinition of professional identity and risks of dehumanization. The analysis ultimately underscores major challenges: transformation of pedagogical practices, ethical appropriation of AI, workload, and reconfiguration of teaching work.This study invites us to rethink AI appropriation in light of cultures, territories, and systemic tensions, and contributes to renewed reflection on the evolution of education professions in a context of rapid socio-technical transformations."Cette conférence intitulée « IA et éducation : une même révolution, des visions multiples » présente les résultats d’une enquête exploratoire internationale menée auprès de 129 futurs professionnels de l’éducation répartis entre l’Alsace (France), le Québec (Canada), la Martinique et la Guadeloupe.Inscrite dans une démarche constructiviste et inductive (Charmaz, 2014 ; Strauss, 1987), l’étude analyse les connaissances, perceptions et représentations de l’intelligence artificielle générative chez de futurs enseignants à travers trois questions :Que savent-ils de l’IA ?Comment perçoivent-ils son utilité pédagogique ?Comment envisagent-ils la transformation du rôle enseignant à l’ère de l’IA ?Le cadre théorique articule la théorie de l’activité (Engeström, 2001), permettant de comprendre les tensions générées par l’introduction de nouveaux outils, et la littératie en IA (UNESCO, 2024), centrée sur le développement de compétences techniques, critiques et éthiques. Les trois contextes étudiés révèlent des représentations contrastées : vision technique et fonctionnelle en Alsace, perspective stratégique et expérientielle au Québec, approche pragmatique et inclusive dans les Antilles, notamment autour de l’apprentissage du créole.Les résultats mettent en lumière une convergence sur l’utilité de l’IA pour le gain de temps, la structuration des idées et l’aide à la conception pédagogique, mais aussi des inquiétudes différenciées selon les territoires, notamment sur la redéfinition de l’identité professionnelle et les risques de déshumanisation. L’analyse souligne enfin des défis majeurs : transformation des pratiques pédagogiques, appropriation éthique de l’IA, charge de travail et reconfiguration du travail enseignant.Cette étude invite à repenser l’appropriation de l’IA à l’aune des cultures, des territoires et des tensions systémiques, et contribue à une réflexion renouvelée sur l’évolution des métiers de l’éducation dans un contexte de transformations socio-techniques rapides
Les métamorphoses chez les poissons et leurs régulations endocriniennes
No full textInternational audienceThe most emblematic metamorphoses in the animal kingdom remain those of the caterpillar into a butterfly and the tadpole into a frog. However, some other vertebrates also present, at one or more steps of their biological cycle, drastic changes in their morphology, physiology and behavior, allowing them to adapt to a new environment (habitat) and way of life, and thus considered as metamorphoses. This is the case within fish, for some representatives of teleosts (the largest group among vertebrates) and of cyclostomes (the most ancient group among vertebrates). Thus, a larval (or primary) metamorphosis takes place, as for amphibians, in pleuronectiformes ( e.g. flatfish), elopomorphs ( e.g. eels) and also in cyclostomes ( e.g. lamprey). This larval metamorphosis is controlled, in all cases, by thyroid hormones. However, this regulation is remarkably opposite, stimulatory in teleosts as in amphibians, and inhibitory in the lamprey. These opposing regulations, as well as the presence of metamorphoses only in certain groups or even certain species, suggest that the recruitment of thyroid hormones for the control of metamorphoses would have occurred repeatedly and independently during the evolution of vertebrates. The neuroendocrine control of the production of thyroid hormones during larval metamorphosis is ensured in amphibians by the stimulatory control of pituitary thyrotropin, itself under the stimulatory control of hypothalamic corticotropin-releasing hormone instead of the thyrotropin-releasing hormone classically involved in the thyrotropic control of metabolism. A similar neuroendocrine control would also occur for teleost larval metamorphosis, but investigations are yet limited. Data are still lacking concerning the neuroendocrine control of the production of thyroid hormone which exerts an inhibitory control on lamprey metamorphosis. In some amphidromous migratory fishes, a so-called secondary metamorphosis, because it occurs at the juvenile stage, allows the passage from the freshwater (river) to the seawater (ocean). These are silvering in eels and smoltification in salmons. Salmon smoltification is a transition between two phases of juvenile body growth, under the positive control of thyroid hormones, as the larval metamorphosis of amphibians and teleosts. In contrast, eel silvering marks the end of the feeding and body growth phase as well as the initiation of the reproductive phase, and is controlled by the gonadotropic axis with sex steroids. The additional involvement of other hormones, such as cortisol for larval and secondary metamorphosis and growth hormone for smoltification, has also been demonstrated in the control of vertebrate metamorphoses. Overall, the larval (primary) and secondary metamorphoses observed in various vertebrates, and the recruitment of thyroid hormones and different neuroendocrine axes for their triggering, have contributed to the evolution of complex life cycles adapted to diverse habitats.Les métamorphoses les plus emblématiques du règne animal restent celles de la chenille en papillon et du têtard en grenouille. Cependant, au sein des poissons, certains téléostéens et les cyclostomes présentent, à un ou plusieurs moments de leur cycle biologique, des changements drastiques de leurs morphologie, physiologie et comportement, leur permettant de s’adapter à un nouveau milieu (habitat) et mode de vie. Ainsi, une métamorphose larvaire (ou primaire) va avoir lieu, comme pour les amphibiens, chez les pleuronectiformes (poissons plats e.g. la sole), chez les élopomorphes ( e.g. l’anguille) ou encore chez les cyclostomes ( e.g. la lamproie). Cette métamorphose larvaire est contrôlée, dans tous les cas, par les hormones thyroïdiennes. Cependant, cette régulation est remarquablement opposée, stimulatrice chez les téléostéens comme chez les amphibiens, et inhibitrice chez la lamproie. Ces régulations opposées, de même que la présence de métamorphoses seulement chez certains groupes voire certaines espèces, suggèrent que le recrutement des hormones thyroïdiennes pour le contrôle des métamorphoses se serait produit de façon répétée et indépendante au cours de l’évolution des vertébrés. Le contrôle neuroendocrine de la production des hormones thyroïdiennes lors de la métamorphose larvaire est assuré par l’axe thyréo-/corticotrope chez les amphibiens, ce qui serait le cas également chez les téléostéens. Chez certains grands migrateurs amphidromes, une métamorphose dite secondaire, car se produisant au stade juvénile, permet le passage de l’eau douce (rivière) à l’eau de mer (océan). Il s’agit de l’argenture chez l’anguille et la smoltification chez le saumon. La smoltification est une transition entre deux phases de croissance corporelle, sous le contrôle positif des hormones thyroïdiennes, comme la métamorphose larvaire des amphibiens et des téléostéens. Par contre, l’argenture marque la fin de la phase d’alimentation et de croissance corporelle ainsi que l’initiation de la phase de reproduction, et est contrôlée par l’axe gonadotrope avec les stéroïdes sexuels. Ainsi, les métamorphoses larvaires et secondaires, observées chez certains vertébrés, et le recrutement d’axes neuroendocrines différents, ont contribué à l’évolution de cycles de vie complexes adaptés à des habitats diversifiés
Approximate controllability of a non-local hyperbolic coupled system
No full textInternational audienceWe analyse the interior approximate controllability of a non-local coupled system of damped wave equations, involving the fractional Laplacian. The single control is located in one of the equations. The other one depends on a non-negative parameter that makes the system converge to an integrodifferential parabolic–elliptic system, as it goes to zero. To obtain the main result, we first transformed the system into an abstract equation, revealing the main operator. Then, using the spectral properties of this operator and the semigroup theory, we established well-posedness results for the latter system and for its adjoint. Finally, we stated the approximate controllability of the initial system as a result of a strong unique continuation property for the fractional Laplacian
Agathis vs. Hymenaea—trapping biases to interpret arthropod assemblages in ambers
No full textInternational audienceThese findings confirm different resin trapping patterns between Agathis and Hymenaea, with significant implications for interpreting the amber record. The fauna trapped by Hymenaea resin closely resembles the arthropod biocoenosis that live in and around the trunks, indicating autochthony and close relationship with the forest ecosystem, unlike Agathis resin. These results improve our understanding of arthropod trapping biases in resin and lead us to reconsider previously proposed interpretations of Cretaceous forest biocoenoses
Quantifying the success of prey crypsis, aposematism and evasiveness in avoiding predators’ attack
No full textAbstract Antipredator defences typically act at distinct stages of the predation sequence—encounter, identification, approach, and subjugation. However, their effectiveness has rarely been quantified and compared simultaneously in wild predator-prey systems. We conducted a study in Peru, where we installed aviaries at two localities and recorded the responses of wild avian predators to three types of antipredator defences—crypsis, aposematism, and evasiveness—expressed by three butterfly species. The study included both immature and adult birds from insectivorous species in forest and urban environments. We tested the theoretical expectations that cryptic butterflies (Nymphalidae: Euptychiina) were rarely detected, aposematic Heliconius (Nymphalidae: Heliconiinae) were often sighted but seldom attacked, and evasive Spicauda (Hesperiidae: Eudaminae) were frequently detected and attacked but evaded capture at higher rates. Despite these distinct defensive strategies, mortality rates among prey types were largely similar, but predator life stage strongly influenced defence effectiveness. Immature birds were more likely to attack Heliconius , possibly reflecting a lack of learned avoidance for aposematic signals. Additionally, predator family influenced predation patterns, with more skilled insectivores (e.g., Vireonidae) showing higher capture success against defended prey. These findings illuminate the evolutionary pressures that shape predator behaviour and prey defences in tropical ecosystems, where high predator diversity possibly maintains the coexistence of multiple defensive strategies. The observed similar mortality rates underscore the adaptive value of these defences, as they collectively distribute the total predation pressure across prey species