Passive acoustics reveal low-latitude distribution of North Atlantic minke whales

Substantial knowledge gaps exist regarding the migratory patterns of many whale species. Recent meta-analyses of passive acoustic sensor networks have provided critical information on the distribution of several baleen whale species across the western North Atlantic Ocean. However, of the baleen whales known to regularly inhabit this region, knowledge of common minke whales Balaenoptera acutorostrata remains scarce, particularly at lower latitudes. A large passive acoustic monitoring (PAM) data set from the Wider Caribbean Region, comprising 92 PAM recorder deployments and over 11900 recording days between 2001 and 2025, was analyzed using a convolutional neural network-based minke whale pulse train detector. Results provide novel insights into the spatial and temporal distribution of the common minke whale in the tropics and subtropics of the western North Atlantic Ocean. Our findings reveal pronounced spatial and seasonal occurrence patterns, with detections concentrated between 14° and 18°N during winter months (December-March). This includes the first acoustic evidence of common minke whales in the US Virgin Islands, Dominican Republic, Montserrat, and Guadeloupe. Summer detections at some sites suggest the presence of non-migratory individuals, challenging previous assumptions that their presence at lower northern latitudes is limited to winter months. Despite considerable recording effort in the Gulf of Mexico, only one pulse train was detected, providing limited evidence of the species in this region. Results from this broad-scale analysis refine the known winter range and potential breeding grounds of North Atlantic common minke whales and underscore the value of PAM in data-poor and logistically challenging environments.