New Zealand Wrens: Acanthisittidae

Physical characteristics: Riflemen are the smallest living bird species in New Zealand. They have greenish upperparts and whitish undersides with yellow wash on the sides. Females are generally duller than males and are brown striped. Males have a bright yellow-green back while females have a back that is striped with darker and lighter browns and flecked with red-brown spots. Both sexes have a slightly upturned bill, with the female bill being a little more upturned. They have white bellies and white markings above the eyes. Their wings have a yellow bar with a white spot at the end of the bar and yellowish rumps and flanks. Males are generally smaller than females, Riflemen have been able to adapt to environments with non-native plants, allowing them to remain successful as humans have introduced new plants to New Zealand. (Illustration by Barbara Duperron. Reproduced by permission.) with adults about 3 inches (8 centimeters) in length and weighing between 0.2 and 0.3 ounces (6.3 and 9.0 grams).

Geographic range: Riflemen are found on both main islands (North Island and South Island) of New Zealand, except for the northern portion of the North Island. They are also found on Stewart Island, just off the southeastern coast of South Island, and the Great Barrier and Little Barrier Islands.

Habitat: Riflemen are located in various habitats including forests, scrublands, farmlands, and disturbed and regenerating habitats. They adapt easily to new environments composed of plant species not native to their normal habitats.

Diet: Their diet consists of insects, spiders, and other small invertebrates, animals without backbones. Males take prey from tree leaves while females find food within tree bark. The female's slightly more upcurved bill helps the female pry and loosen bark away from trees. They often work their way up and around tree trunks in a spiral route that takes them from the base of a tree up to 20 to 30 feet (6 to 9 meters) off the ground.

Behavior and reproduction: Riflemen are lively, diurnal, active during the day, birds. Their call is a sharp, high-pitched, cricket-like "zipt" or "zsit" that is sounded either singly or in a rapid series of separate notes. Most of their activity consists of foraging in trees, going from one tree to another, usually in an established route. Riflemen are not very strong fliers, so, they limit their flights to short ones from tree to tree, and rarely go out of their small familiar territory. They rarely go to the ground. Sometimes when perching on a branch, riflemen will quickly flick their wings.

Riflemen are monogamous birds, forming long-lasting pair bonds. Their breeding season is from August to January. Males do most of the construction of the nest. The typical nest is a rather complex structure in a tree crevice, sometimes with a dome-like roof and inside lined with spider webs and mosses. Females lay two to four white eggs. About ten days before and during the egg laying process, males will bring food to females up to nine times an hour. Both parents usually raise two broods, young birds that are born and raised together, each year. The incubation period, time that it takes to sit on eggs before they hatch, is nineteen to twenty-one days. The nestling period, time necessary to take care of young birds unable to leave nest, is twenty-three to twenty-five days, but can last up to sixty days. Eggs weigh about 20 percent of the female's weight, and are laid every other day. Males incubate during the day and females incubate at night. Hatchlings are born in an undeveloped condition, so they take longer than most birds to develop into a stage where they can fly away.

Parents often use one to three adult or juvenile helpers to help feed nestlings and fledged offspring, those able to fly. For a first clutch, group of eggs hatched together, helpers are not usually related to the parents. They help to feed and defend the chicks, and to clean the nest. Some helpers only help with one nest, but others divide their time between several nests. With helpers, parents often have less work to do. Fledged young birds from the first brood often help to feed the chicks of the second brood. The nest for the second brood is often started before the first brood has left the first nest. This nest is smaller, loosely built, and unlined. Males do not bring food to females before and during the second egg-laying period. The second clutch of eggs is usually one egg less than the first clutch.

Riflemen and people: There is no known significance between riflemen and people.

Conservation status: Riflemen are fairly common and protected by New Zealand laws and a strong conservation program. They are the most successful species of the New Zealand wrens. ∎