The Rifleman (Acanthisitta chloris) is a species of passerine bird that is native to New Zealand. This bird’s habitat is thinly wooded forests. It is the most widespread species in the genus Acanthisitta. It occurs on the two islands New Zealand, however, it is found rarely north of Te Aroha. The North Island subspecies, A. c. granti, occurs mainly in lowland Tawa forest, while the South Island subspecies is found in high altitude beech forest and sometimes lowland forest with podocarp (a type of coniferous evergreen).

This is the smallest species of bird endemic to new Zealand with the adult reaching a maximum of 3.15 inches in length. The male is bright green on the dorsal side. The female is more brown and her head and back are flecked with orange-yellow. The female weighs about one-quarter of an ounce and the male weighs slightly less. Both adult birds are white underneath and have white eyebrow stripes. Their wings are short and rounded. The tail is also very short. The bill is long and thin and slightly upward turned.

The Rifleman is an insectivore and searches for maggots and small insects on tree trunks and among leaf litter on the forest floor. The search for food begins at the base of a tree and it climbs up it progressively, spiraling up around the trunk. When finished with the search of a particular tree, the bird glides to the foot of a nearby tree and begins the procedure all over again.

The Rifleman builds its nest in rock fissures, tree trunks with holes, or in a cavity in the ground. The entrance to the nest is often so narrow that the bird may struggle to get inside. The nest usually has a dome shape and is finely interwoven with grass, down feathers and other light material. Brooding lasts between 13 to 15 days and the female lays 4 to 5 eggs. There can be two broods per year.