Biology subjects

Uiterwaal, S. F.

Publications and source records attributed to Uiterwaal, S. F..

4 recordsLinked to original sources

bioRxiv2026

Individual-level social associations and social information use predict foraging success in winter mixed-species flocks

The acquisition of social information to improve foraging efficiency is considered one of the primary drivers of mixed-species flocks (MSFs). This flow of social information occurs among individuals of multiple species, but analyses of MSFs at the level of species fail to capture the nuances of this dynamic. We investigated how individual-level social associations in North American MSFs impact discovery of novel feeders presented alongside vocal cues. We used radio-frequency identification (RFID) data loggers to track arrivals of individually tagged black-capped chickadees (Poecile atricapillus), white-breasted nuthatches (Sitta carolinensis), and downy woodpeckers (Dryobates pubescens) at fixed feeders, and during novel feeder trials paired with chickadee, nuthatch, or white noise playbacks. For chickadees, a higher number of total associations and conspecific playbacks improved novel feeder discovery. The foraging benefits in nuthatches and woodpeckers were predicted by their individual-level associations with chickadees and these benefits only manifested during chickadee playbacks. We demonstrate that the advantages of mixed-species flocking are not uniformly distributed across species; rather, they are contingent upon individually maintained social associations and the presence of social information. These findings highlight the necessity of quantifying individual variation to accurately assess the evolutionary drivers and fitness consequences of species interactions.

animal behavior and cognition↗

bioRxiv2026

The OS-Prey (Omnibus Study of Prey) database: A compilation of diet records for birds of prey.

MotivationThe diet composition of a predator is a direct reflection of its role in a food web, resulting from interactions with prey species. Raptors (including hawks, owls, and falcons) are ubiquitous predators with diverse diets, yet there is no comprehensive database of raptor diet composition. We present a database of over 3500 raw raptor diet records, compiled from more than 1000 studies and representing 173 raptor species from across the world. Our dataset complements existing qualitative summaries of species diets by compiling thousands of quantitative diet "samples" over time and space to present diet data at a uniquely fine resolution. Main types of variable containedThe database comprises published records of raptor diets from pellets, prey remains, direct or photographic observations, prey DNA, and raptor gut or gullet contents. For each diet, we present the taxonomic identity and amounts of consumed prey. We additionally present various metadata for each diet such as location, habitat, and season. Spatial location and grainThe study incorporates diet records collected worldwide, with each record assigned geographic coordinates corresponding to the location where the diet information was obtained. Time period and grainThe database includes diet records from 1893 to 2025. We report a year for each diet record. Major taxa and level of measurementWe recorded raptor diet at the species level, including raptors from three orders: Strigiformes, Falconiformes and Accipitriformes excluding vultures. Most prey are identified to species, but prey taxonomic level varies depending on the extent to which they could be identified. Software formatDiet records and metadata are provided in two files with comma-separated value (.csv) format.

ecology↗

bioRxiv2021

Quantifying predator functional responses under field conditions reveals interactive effects of temperature and interference with sex and stage.

O_LIPredator functional responses describe predator feeding rates and are a core component of predator-prey theory. Although originally defined as the relationship between predator feeding rates and prey densities, it is now well known that predator functional responses are shaped by a multitude of factors. Unfortunately, how these factors interact with one another remains unclear, as widely used laboratory methods for measuring functional responses are generally logistically constrained to examining a few factors simultaneously. Furthermore, it is also often unclear whether laboratory derived functional responses translate to field conditions. C_LIO_LIOur goal was to apply an observational approach for measuring functional responses to understand how sex/stage differences, temperature, and predator interference interact to influence the functional response of zebra jumping spiders on midges under natural conditions. C_LIO_LIWe used field feeding surveys of jumping spiders to infer spider functional responses. We applied a Bayesian model averaging approach to estimate differences among sexes and stages of jumping spiders in their feeding rates and their dependencies on midge densities, temperature, and predator interference. C_LIO_LIWe find that females exhibit the steepest functional responses on midges, followed by juveniles, and then males, despite males being larger than juveniles. We also find that sexes and stages differ in the temperature dependence of their space clearance (aka attack) rates. We find little evidence of temperature dependence in females, whereas we find some evidence for an increase in space clearance rate at high temperatures in males and juveniles. Interference effects on feeding rates were asymmetric with little effect of interference on male feeding rates, and effects of interference on females and juveniles depending on the stage/sex from which the interference originates. C_LIO_LIOur results illustrate the multidimensional nature of functional responses in natural settings and reveal how factors influencing functional responses can interact with one another through behavior and morphology. Further studies investigating the influence of multiple mechanisms on predator functional responses under field conditions will provide an increased understanding of the drivers of predator-prey interaction strengths and their consequences for communities and ecosystems. C_LI

ecology↗

bioRxiv2018

Data paper: FoRAGE (Functional Responses from Around the Globe in all Ecosystems) database: a compilation of functional responses for consumers and parasitoids

Functional responses - the relationships between consumer foraging rate and resource (prey) density - provide key insights into consumer-resource interactions and predation mechanics while also being a major contributor to population dynamics and food web structure. We present a global database of standardized functional response parameters extracted from the published literature. We refit the functional responses with a Type II model using standardized methods and report the fitted parameters along with data on experimental conditions, consumer and resource taxonomy and type, as well as the habitat and dimensionality of the foraging interaction. The consumer and resource species covered here are taxonomically diverse, from protozoans filtering algae to wasps parasitizing moth larvae to wolves hunting moose. The FoRAGE database (doi:10.5063/F17H1GTQ) is a living data set that will be updated periodically as new functional responses are published.

ecology↗