Behavioural innovation and the evolution of cognition in birds

Cognition shapes the interactions of an animal with its environment. Species vary greatly in all aspects of cognition, and studying the relationship between this variation and ecology is crucial for understanding how intelligence has evolved. In this thesis, I approach questions about the ecology and evolution of cognition that are often ignored because cognition is difficult to quantify. I use innovation rate as an operational measure and residual brain size as a correlate of general cognition in birds. I first examine the link between cognition and ecology through comparative analyses of the relationships between residual brain size, innovativeness, and measures of ecological generalism across a broad sample of the avian phylogeny, and within a single clade (Icteridae). I find that innovation is positively correlated with habitat breadth but not diet generalism, and that neither measure of generalism is associated with residual brain size. Although residual brain size and innovation rate are strongly correlated with one another, they each appear to have different relationships to a species' ecology. Further analysis finds that the relationship between innovativeness and residual brain size is driven by innovations that involve the use of novel foraging techniques and not the ingestion of new food items. Comparative studies use the traits of extant species to infer their evolutionary history, but can only speculate on the forces driving changes in a trait. The latter half of my thesis focuses on these underlying forces and behavioural mechanisms. Using a game theory model, I show that unpredictable food availability might drive both behavioural flexibility and sociality, two traits strongly associated with cognitive complexity. Finally, I focus on innovativeness at the intraspecific level and examine foraging innovation in a large-brained grackle species, Quiscalus lugubris. I find that this gregarious species is slower to innovate when conspecifics are nearby, and that individuals differ in their ability to solve novel problems. I use these differences to describe the process of innovation, and show that novelty responses, attention, persistence, and flexibility are all important factors underlying individual variation in the ability to innovate.La cognition dirige les interactions d'un animal avec son environnement. Les espèces varient énormément dans tous les aspects de la cognition, et étudier les relations entre ces variations, l'écologie et l'évolution est crucial pour comprendre comment l'intelligence a évolué. Dans cette thèse, j'aborde les questions de l'écologie et l'évolution de la cognition souvent ignorées, la cognition étant difficile à évaluer quantitativement. J'ai utilisé le taux d'innovation comme une mesure opérationnelle, et la taille résiduelle du cerveau comme un corrélat de la capacité cognitive générale des oiseaux. J'ai d'abord examiné le lien entre la cognition et l'écologie en procédant à des analyses comparatives des relations entre la taille résiduelle du cerveau, la capacité innovatrice, et des mesures du généralisme écologique à travers un large échantillon de la phylogénie aviaire, et dans un clade unique (Icteridae). J'ai trouvé que la capacité innovatrice est corrélée positivement avec l'étendue de l'habitat, mais non avec le régime généraliste, et qu'aucune mesure du généralisme n'est associée avec la taille résiduelle du cerveau. Bien que la taille résiduelle du cerveau et le taux d'innovation soient fortement corrélés entre eux, chacun d'eux semble avoir des relations différentes avec l'écologie de l'espèce. Une analyse plus poussée a montré que la relation entre la capacité innovatrice et la taille résiduelle du cerveau est déterminée par les innovations impliquant l'utilisation de nouvelles techniques d'approvisionnement, et non l'ingestion de nouveaux types d'aliments. Les études comparatives utilisent les traits d'espèces existantes pour en déduire leur évolution, mais peuvent seulement spéculer sur les forces conduisant les changements d'un trait. La seconde moitié de ma thèse se concentre sur ces forces sous-jacentes et les mécanismes comportementaux. En utilisant un modèle de théorie des jeux, j'ai montré que l'imprévisibilité de la disponibilité alimentaire peut mener tant à la flexibilité comportementale qu'à la socialité, deux traits fortement associés à la complexité cognitive. Enfin, je me suis concentrée sur la capacité innovatrice au niveau interindividuel et j'ai étudié l'innovation lors de l'approvisionnement chez le Quiscale merle, Quiscalus lugubris, une espèce possédant un gros cerveau. J'ai trouvé que cette espèce grégaire est moins rapide à innover lorsque des congénères sont à proximité, et que les individus diffèrent dans leur capacité à résoudre de nouveaux problèmes. J'ai utilisé ces différences pour décrire le processus de l'innovation, et montré que la réponse à la nouveauté, l'attention, la persistance et la flexibilité sont d' importants facteurs sous-jacents de la variation interindividuelle de la capacité à innover

Setting our sights on infectious diseases

In May 2019, the Wellcome Centre for Anti-Infectives Research (WCAIR) at the University of Dundee, UK, held an international conference with the aim of discussing some key questions around discovering new medicines for infectious diseases and a particular focus on diseases affecting Low and Middle Income Countries. There is an urgent need for new drugs to treat most infectious diseases. We were keen to see if there were lessons that we could learn across different disease areas and between the preclinical and clinical phases with the aim of exploring how we can improve and speed up the drug discovery, translational, and clinical development processes. We started with an introductory session on the current situation and then worked backward from clinical development to combination therapy, pharmacokinetic/pharmacodynamic (PK/PD) studies, drug discovery pathways, and new starting points and targets. This Viewpoint aims to capture some of the learnings

Technical innovations drive the relationship between innovativeness and residual brain size in birds

The hypothesis that large brains allow animals to produce novel behaviour patterns is supported by the correlation between brain size, corrected for body size, and the frequency of foraging innovations reported in the literature for both birds and primates. In birds, foraging innovations have been observed in over 800 species, and include behaviours that range from eating a novel food to using tools. Previous comparative studies have quantified innovativeness by summing all reports of innovative behaviour, regardless of the nature of the innovation. Here, we use the variety of foraging innovations recorded for birds to see which of two classic hypotheses best accounts for the relationship between innovativeness and brain size: the technical intelligence hypothesis or the opportunistic-generalism intelligence hypothesis. We classified 2182 innovation cases into 12 categories to quantify the diversity of innovations performed by each of 76 avian families. We found that families with larger brains had a greater repertoire of innovations, and that innovation diversity was a stronger predictor of residual brain size than was total number of innovations. Furthermore, the diversity of technical innovations displayed by bird families was a much better predictor of residual brain size than was the number of food type innovations, providing support for the technical intelligence hypothesis. Our results suggest that the cognitive capacity required to perform a wide variety of novel foraging techniques underpins the positive relationship between innovativeness and brain size in birds. We include a summary of innovation data for 803 species as Supplementary Material. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.</p

Technical innovations drive the relationship between innovativeness and residual brain size in birds

The hypothesis that large brains allow animals to produce novel behaviour patterns is supported by the correlation between brain size, corrected for body size, and the frequency of foraging innovations reported in the literature for both birds and primates. In birds, foraging innovations have been observed in over 800 species, and include behaviours that range from eating a novel food to using tools. Previous comparative studies have quantified innovativeness by summing all reports of innovative behaviour, regardless of the nature of the innovation. Here, we use the variety of foraging innovations recorded for birds to see which of two classic hypotheses best accounts for the relationship between innovativeness and brain size: the technical intelligence hypothesis or the opportunistic-generalism intelligence hypothesis. We classified 2182 innovation cases into 12 categories to quantify the diversity of innovations performed by each of 76 avian families. We found that families with larger brains had a greater repertoire of innovations, and that innovation diversity was a stronger predictor of residual brain size than was total number of innovations. Furthermore, the diversity of technical innovations displayed by bird families was a much better predictor of residual brain size than was the number of food type innovations, providing support for the technical intelligence hypothesis. Our results suggest that the cognitive capacity required to perform a wide variety of novel foraging techniques underpins the positive relationship between innovativeness and brain size in birds. We include a summary of innovation data for 803 species as Supplementary Material. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.</p