Range: Kauaʻi

Region of origin: Continental United States (Oregon)

Date of first introduction: 1961 (35 individuals introduced to Kauaʻi)

Average size: Female - 35 to 45kg, Male - 45 to 65kg

Litter frequency: 1 litter per year

Litter size: 1 to 2 (twinning common, triplets rare)

Home range: 0.3 km to 138.5 km

Diet: Opportunistic grazer on broadleafs, ferns, and fruits

2

References: Tomich 1986, Innes 2013

Black-tailed Deer (Odocoileus hemionus)

Identifying Markers

Physical Appearance: Reddish-brown coat, a short, wide tail with a black top and white underside, and large, mule-like ears (pictured).

Tracks: Two-toed cloven hoof prints, shaped like an upside-down heart, about 2–3 inches long.

Scat: Small, oval, dark brown or black, pellets, left in scattered clusters, typically found along trails, bedding areas, and near browse zones.

Browse Lines: Feeds on leaves, shrubs, and saplings up to 5 feet high

Environmental Impacts

Black-tailed deer in Hawaiʻi cause significant environmental damage by browsing on native shrubs and saplings, which hinders forest regeneration and reduces plant diversity. Their preference for high elevation forests and shrublands throughout the Alakaʻi plateau puts pressure on rare and fragile ecosystems. Unlike axis deer, which graze in large herds, black-tailed deer are more cryptic and seemingly more solitary in dense forested areas throughout Kauaʻi. Their current range has a significant overlap with some of the last remaining critical habitat for many endemic flora and fauna.