Black rats didn’t originate in New Mexico, or anywhere in North America. They arrived on ships centuries ago and still favor buildings, farms, and other human-altered ground over open wild country, which fits the sparse, scattered pattern of just 15 confirmed state records.
Bosque del Apache National Wildlife Refuge and the Rio Grande corridor show up among the record locations, places where irrigated farmland and river towns sit close together, exactly the kind of mixed human and river-edge setting this species tends to use elsewhere.
Every dated sighting falls between June and November, with a clear cluster in July and August. Black rats are active at night and easy to miss, so that summer bump likely reflects more people outdoors and reporting rather than a true seasonal rise in numbers.
Full species profile
