Biology subjects

Straw, A. D.

Publications and source records attributed to Straw, A. D..

8 recordsLinked to original sources

bioRxiv2026

Low-latency multicamera 3D tracking of insects with Braid

Advances in camera technology and computer vision techniques have allowed researchers to track animals in 3D in ways which previously were difficult or impossible. Many such 3D tracking tools make use of multiple cameras, but unfamiliarity with the principles and technology involved can make it difficult to employ such techniques. In this protocol, we describe Braid, open-source software for live, multi-camera 3D tracking of insects. Using background-subtraction, Braid performs detection of objects without requiring the use of physical markers affixed to the insect. Braid constructs low-latency 3D position estimates using Kalman filtering and nearest neighbor data association. We document in detail the process of tracking freely flying bees within a flight arena using Braid. This protocol includes instructions on installation, configuration of cameras, setup, calibration, and operation. Within the system described here, we demonstrate that Braid can achieve position estimates accurate to <1 millimeter (within a 0.3 cubic meter volume). These factors make Braid suitable for tracking small, fast-flying animals like insects. Braid's low latency allows live tracking, removing the necessity to collect large video files and making it suitable for integration in closed loop systems such as virtual reality. Code is available at https://github.com/strawlab/strand-braid

animal behavior and cognition↗

bioRxiv2025

Precise, individualized foraging flights in honey bees revealed by multicopter drone-based tracking

Honey bees routinely fly hundreds or thousands of meters between their hive and established foraging locations [1-3]. To navigate these long distances, they are known to combine both landmark use [4-7] and path integration [8-11] and have been hypothesized to build a cognitive map [12-14]. Due to technical challenges inherent in tracking these small insects, obtaining three-dimensional, high-resolution measurements of individual navigational precision, and thus a detailed understanding of their strategies, has been difficult. Here, we utilize a novel multicopter drone-based tracking system [15] to measure the individual flight paths of honey bees in a structured agricultural landscape at unprecedented spatial and temporal resolution. Although bees could choose from multiple routes, we discovered that individual bees follow idiosyncratic paths with striking and repeatable precision. Flight path variability was highest over visually sparse regions and lowest near prominent proximal landmarks. Furthermore, individual strategies differed: some bees flew directly toward the hive before maneuvering around a specific tree, while others flew directly to a gap between a hedgerow and the tree. Thus, each animal varies in how it uses visual information and selects between behavioral strategies. The level of precision exhibited by their flight paths exceeds that reported in the waggle dance, implying that dance variability does not reflect a limit in the bees underlying spatial representation. Our results demonstrate the remarkable precision of individual bee navigation and illustrate the potential of this new drone-based tracking method to illuminate fine-scale behavioral mechanisms across a spectrum of honey bee ecology and cognition. HighlightsO_LIIndividual honey bees follow strikingly precise, idiosyncratic flight paths, revealing personalized strategies for navigating complex, obstacle-rich landscapes. C_LIO_LIVariability in individual bee flight paths was lower near conspicuous landmarks, but greater when further from such features, as a consequence variability in bee flights was not uniform along a route. C_LIO_LINavigational precision far exceeds waggle dance variability, showing that dance imprecision is not constrained by limits in spatial representation. C_LIO_LIMulticopter drone-based tracking method enables new investigations of 3D flight control and visual navigation in structurally complex realistic environments. C_LI

neuroscience↗

bioRxiv2025

A low-cost immersive Virtual Reality system to study social interactions and collective behavior in fish

1This study introduces a low-cost, open-source, immersive Virtual Reality (VR) system designed to investigate real-time social interactions and collective behaviors in fish. Understanding collective animal behaviors, such as schooling in fish, presents significant observational challenges due to rapid and complex interactions. To address these difficulties, we developed an innovative closed-loop VR environment allowing precise control and measurement of interactions between real and virtual fish. This setup incorporates high-speed 3D tracking, real-time visual feedback, and automated data processing, creating realistic and interactive scenarios. We present experimental results, obtained with rummy-nose tetras (Hemigrammus rhodostomus ), showing that freely moving real fish consistently adjusted their speed, depth, and spatial positioning to follow virtual fish effectively. Fish matched moderate virtual speeds comfortably, struggled slightly at higher speeds, and actively maintained vertical positioning to sustain group cohesion. The implementation of this VR system provides critical insights into sensory and cognitive processes underlying collective movement and decision-making in fish. By revealing both flexibility and constraints in fish behavior, our findings underscore the potential of VR technology to study social interactions in controlled yet realistic settings. Ultimately, this VR system advances our understanding of collective animal behavior, providing a foundation for cross-species studies linking neural processes, behavioral interactions, and group dynamics.

animal behavior and cognition↗

bioRxiv2024

Contradictory behavioral effects of neuronal perturbations on behavioral responses to linearly polarized light in freely walking Drosophila

Many insects can use the polarization of the skylight as a navigational cue. As shown previously, freely walking Drosophila orient along the e-vector of linearly polarized UV light presented both dorsally and ventrally. We are interested in the neuronal mechanisms leading to this behavior, and specifically how the central complex and its inputs are involved. We investigated the behavior of flies exposed to linearly polarized near-UV light (400 nm) presented dorsally. Flies walked freely in a circular, flat arena surrounded by a heat barrier. Using the GAL4-UAS genetic system, we drove the expression of the potassium inward rectifier KIR2.1 to perturb each of several different neuron types of the polarization vision pathway. Perturbing EPG compass neurons in the central complex slightly weakened average alignment and increased its variability. On the other hand, when two different GAL4 lines driving expression in the ER4m ring neurons, identified by connectomics as the major polarization inputs to the fly central complex, were perturbed, the alignment strength increased. A similar effect was observed when the inputs to ER4m, the TuBua neurons, were perturbed. We did not predict EPG and ER4m perturbations to cause opposite effects. Further investigation would be required to understand the physiological mechanisms of these contradictory behavioral effects.

neuroscience↗

bioRxiv2023

High Resolution Outdoor Videography of Insects Using Fast Lock-On Tracking

Insects have significant global impacts on ecology, economy, and health and yet our understanding of their behavior remains limited. Bees, for example, use vision and a tiny brain to find flowers and return home, but understanding how they perform these impressive tasks has been hampered by limitations in recording technology. Here we present Fast Lock-On (FLO) tracking. This method moves an image sensor to remain focused on a retroreflective marker affixed to an insect. Using paraxial infrared illumination, simple image processing can localize the sensor location of the insect in a few milliseconds. When coupled with a feedback system to steer a high magnification optical system to remain focused on the insect, a high spatial-temporal resolution trajectory can be gathered over a large region. As the basis for several robotic systems, we show FLO is a versatile idea which can be employed in combination with other components. We demonstrate that the optical path can be split and used for recording high-speed video. Furthermore, by flying a FLO system on a quadcopter drone, we track a flying honey bee and anticipate tracking insects in the wild over kilometer scales. Such systems have the capability of providing higher resolution information about insects behaving in natural environments and as such will be helpful in revealing the biomechanical and neuroethological mechanisms used by insects in natural settings. One-Sentence SummaryFast Lock-On tracking enables recording trajectories and high-speed videos of insects behaving over large areas in the wild.

animal behavior and cognition↗

bioRxiv2022

Displacement experiments provide evidence for path integration in Drosophila

Like many other animals, insects are capable of returning to previously visited locations using path integration. Recently, Drosophila has been added to the list of insects thought capable of this navigational memory. Existing experimental evidence, however, has a potential confound. Here we show that pheromones deposited at the site of reward might enable flies to find previously rewarding locations even without memory. Thus, we designed an experiment to determine if flies can use path integration memory despite potential pheromonal cues by displacing the flies shortly after an optogenetic reward. We found that rewarded flies returned to the location predicted by a memory-based model. Several analyses are consistent with path integration as the mechanism by which flies returned to the reward. We conclude that while pheromones may often be important in fly navigation and must be carefully controlled in future experiments, Drosophila may indeed be capable of performing path integration.

neuroscience↗

bioRxiv2021

The olfactory gating of visual preferences to human skin and colors in mosquitoes

Mosquitoes track odors, locate hosts, and find mates visually. The color of a food resource, such as a flower or warm-blooded host, can be dominated by long wavelengths of the visible light spectrum (green to red for humans) and is likely important for object recognition and localization. However, little is known about the hues that attract mosquitoes or how odor affects mosquito visual search behaviors. We used a real-time 3D tracking system and wind tunnel that allowed careful control of the olfactory and visual environment to quantify the behavior of more than 1.3 million mosquito trajectories. We found that CO2 induces a strong attraction to specific hues, including those that humans perceive as cyan, orange, and red. Sensitivity to orange and red correlates with mosquitoes strong attraction to the color spectrum of human skin, which is dominated by these wavelengths. Attraction was eliminated by filtering the orange and red bands from the skin color spectrum and by introducing mutations targeting specific long-wavelength opsins or CO2 detection. Collectively, our results show that odor is critical for mosquitoes wavelength preferences and that the mosquito visual system is a promising target for inhibiting their attraction to human hosts.

neuroscience↗

bioRxiv2018

A unifying model to predict multiple object orienting behaviors in tethered flies

Individual visual processing circuits for Drosophila locomotor control have been studied in detail, but contributions of specific pathways to multiple behaviors remain unclear. To address how both flexible and stereotyped visual object response behaviors potentially share neural circuit components, we investigated models of asymmetric motion responses. Such models have predicted that object fixation without explicit neural encoding of position is possible. Here we investigated what neural circuits and behaviors are consistent with such models. In behavioral experiments on tethered flying flies, we found close correspondence between T4/T5-neuron dependent turning responses to objects and model output for high frequency perturbations. Furthermore, we found that the model predicts key results from several published accounts of stereotyped object tracking. The concurrence of experiment and theory suggests a neural substrate and algorithmic basis for stereotyped object tracking and informs future studies of flexible visual behaviors and their neural bases.

neuroscience↗