Noio are an endemic subspecies of black noddy and are present year-round in Hawaiʻi. They are often observed near sea cliffs when breeding. Their breeding season is variable, but many birds begin to nest on ocean cliff ledges and caves in late spring. Noio are 14 inches long with a 28 inch wingspan. Their feathers are a dark charcoal black, with a white “cap” on the top of the birds head.