In a groundbreaking effort to unravel the complexities of animal behavior, the largest study conducted to date on neophobia—defined as the fear of novelty—has shed light on the ecological and evolutionary factors that drive some bird species to exhibit pronounced caution in the presence of unfamiliar objects. This unprecedented global study, published in PLOS Biology, analyzed the behavior of 1,439 birds across 136 species, providing a comprehensive examination of how neophobia manifests on a broad taxonomic scale and what biological and environmental factors govern its variability.
Neophobia has long been recognized as a critical behavioral trait that influences how animals negotiate the precarious balance between risk and reward. While an avoidance of novelty can shield birds from potential hazards, such as toxins or predators, it can also constrain their ability to capitalize on new food resources or adapt to altered habitats. Given the accelerating pace of environmental change worldwide, understanding this behavior is crucial for anticipating species resilience and ecosystem dynamics.
The innovative study mobilized a massive collaborative network comprising 129 researchers from 82 institutions spanning 24 countries on six continents, including field sites, laboratories, and zoological settings. The international team deployed standardized experimental protocols designed to assess neophobia reliably across diverse ecological contexts. Each bird was presented with its familiar, highly preferred food alone and then paired with a novel object specifically tailored in size, color, and texture to match each species’ morphology. This careful standardization ensured that responses reflected inherent species differences rather than experimental artifacts.
Behavioral quantification centered on latency to approach and engage with food. An extended delay in the presence of the novel object, relative to the control condition, served as a quantitative proxy for neophobic inclination. The dataset revealed striking interspecies contrasts: grebes and flamingos emerged as notably neophobic, hesitating markedly before feeding, whereas falcons and pheasants demonstrated minimal fear responses, rapidly approaching food despite the unfamiliar stimulus.
Crucially, this extensive dataset enabled identification of two major ecological predictors of neophobia—dietary specialization and migratory behavior. Dietary specialists, which rely on a narrow range of foods, showed heightened neophobic tendencies, presumably due to limited exposure to environmental variation and the increased risks associated with untested items in their diet. In contrast, dietary generalists exhibited lower neophobia, consistent with their evolutionary history of exploiting a diverse array of resources. Similarly, migratory species displayed elevated neophobia compared to resident counterparts, likely reflecting adaptive strategies to navigate the heightened perils linked to new environments and potentially hazardous novel stimuli encountered during their journeys.
Further dissection of the data highlighted neophobia as a consistent, repeatable trait within individuals. Birds assessed across multiple trials maintained stable behavioral profiles, reinforcing the concept that neophobia is a fixed aspect of personality or temperament rather than a transient state. This has significant implications for ecological and evolutionary models incorporating individual variability in behavioral syndromes and survival strategies.
Interestingly, the study revealed that social context modulates neophobia in unexpected ways. Contrary to expectations that the presence of conspecifics would alleviate fear by distributing risk across individuals, birds tested in groups demonstrated increased neophobic responses. This heightened group neophobia may stem from social cues amplifying cautiousness or individuals deferring risky exploration until others have validated safety, shedding light on the complex interplay between social dynamics and individual decision-making in non-human animals.
Dr. Rachael Miller, who spearheaded the project during her tenure at Anglia Ruskin University and currently holds positions at the University of Cambridge and the University of Exeter, emphasized the dual-edged nature of neophobia. While protective against unknown dangers, these cautious tendencies could hamper species’ ability to exploit opportunities presented by environmental change—such as the colonization of novel habitats or adaptation to anthropogenic changes like urbanization and climate shifts.
The study also stands as a testament to the power of collaborative, large-scale “big team” science. Through the ManyBirds Project, the research brought together expertise and data from around the world, moving beyond single-species or localized studies to generate evolutionary-scale insights into behavior. This collaborative framework not only accelerates discovery but democratizes research opportunities across geographic and institutional boundaries.
Dr. Megan Lambert, co-founder of the ManyBirds Project and a researcher at the University of Veterinary Medicine in Vienna, underscored the conservation implications of these findings. Behavioral traits such as neophobia can critically influence the success of species reintroductions and recovery programs for endangered birds by informing tailored management interventions that consider species-specific risk tolerance and adaptability.
Complementing the core leadership team’s interdisciplinary expertise, contributors from prominent institutions including the University of Lausanne, Heinrich-Heine-University Düsseldorf, University of Buenos Aires, University of Lincoln, Lund University, and Liverpool John Moores University ensured that the research integrated perspectives from evolutionary biology, animal psychology, and conservation science.
The integration of standardized novel-object testing across a spectrum of taxa—from penguins to parrots—establishes a robust behavioral assay for future ecological and evolutionary investigations. Moreover, elucidating the ecological drivers behind fear of novelty advances our understanding of how cognitive and personality traits evolve and influence species’ interactions within rapidly changing ecosystems. This knowledge not only enriches fundamental science but can directly inform conservation strategies aimed at mitigating biodiversity loss in the Anthropocene.
In conclusion, the study’s comprehensive exploration of avian neophobia highlights the nuanced behavioral ecology underlying responses to novelty and opens avenues for further research into the adaptive significance of personality traits. As environmental unpredictability intensifies, such behavioral insights will be ever more critical in guiding effective biodiversity preservation and understanding the evolutionary trajectories of animal populations.
Subject of Research: Ecological and evolutionary drivers of neophobia in birds
Article Title: A large-scale study across the avian clade identifies ecological drivers of neophobia
News Publication Date: 14-Oct-2025
Web References: http://dx.doi.org/10.1371/journal.pbio.3003394
Image Credits: Photo by Jimena Lois-Milevicich
Keywords: Birds, Animal psychology, Wildlife, Zoo animals, Animal learning, Evolutionary biology, Evolutionary ecology, Conservation biology, Endangered species, Conservation ecology
Tags: adaptability of bird speciesavian neophobiabird behavior studiescollaborative research in ecologyecological factors in animal behaviorevolutionary psychology in birdsglobal study on animal behaviorimpacts of environmental change on wildlifeneophobia in different bird speciesresilience of bird populationsrisk and reward in animal behaviorstandardized protocols in behavioral research
