In Hawaii, black rat reports concentrate on Oʻahu, clustered around Diamond Head State Monument, Pearl Harbor National Memorial, and the coastal wetlands of James Campbell National Wildlife Refuge on the North Shore. It’s not a native Hawaiian animal. It’s an invasive stowaway that arrived on sailing ships centuries ago and never left port life behind.
Its long tail and climbing build let it move through palm crowns, utility lines, and forest canopy that ground-bound rats can’t reach, which makes it a serious threat to Hawaii’s native birds. Black rats raid nests for eggs and chicks, and they’re one of the main reasons native forest birds and seabirds have disappeared from the state’s lowlands.
Records here run year-round, with reports peaking in April, May, and November. Hawaii’s iNaturalist and GBIF counts show where people have looked and reported, not how many rats actually live on the islands.
Full species profile
