Dynamic vibration-driven feedback shapes predator-prey interactions in an orb-weaving spider

Animals flexibly adjust their movements in real time to capture prey using environmental sensory cues. While sensorimotor transformations have been extensively studied in visual and somatosensory systems, their structure remains poorly understood in substrate-borne vibration sensing. Here, we combined high-resolution web vibration recordings, capable of resolving micrometer-scale displacements, with fine-scale behavioral tracking in the orb-weaving spider Uloborus diversus to investigate how vibration sensing guides prey capture. Using unsupervised modeling, we identified distinct behavioral states and their typical temporal sequence during capture. Predictive generalized linear models revealed reciprocal predator-prey dynamics: when Drosophila vibrations weakened, spiders often switched to actions such as crouching or shaking that enhanced signal detectability. These active phases were followed by static phases marked by increased pure fly-induced vibration power, consistent with an active sampling strategy. Conversely, flies tended to freeze during spider movement and struggled when the spider was still. Spiders also reliably oriented toward the web radius with the highest vibrational amplitude, indicating an amplitude-based strategy for prey localization. Together, our findings reveal a structured sensorimotor transformation linking external vibration cues to the spider's behavioral choices, forming a dynamic feedback loop between vibratory stimulus and movement. This work uncovers general principles of active sensing and closed-loop control in a non-visual invertebrate and suggests that similar strategies may underlie sensorimotor control across diverse animal systems.