Calving / Farrowing Onset Alert

Before giving birth, an animal grows restless: pacing, lying down and standing up over and over, and a slow rhythm of contractions. Each of those movements stirs the signal in its own way. Together they form a pattern that builds for hours before labor — enough warning to be there when it matters.

In the physics: Pre-parturition behavior produces a distinctive escalating pattern: increased low-frequency locomotion micro-Doppler, frequent lying-standing posture transitions (large RTI silhouette changes), and rhythmic abdominal contractions in a narrow sub-Hz band that differ from normal breathing.