Australian magpie

Appearance

The adult magpie is a fairly solid, sturdy bird ranging from 37 to 43 cm in length with a 65–85 cm wingspan, and weighing 220–350 g.

Its robust wedge-shaped bill is bluish-white bordered with black, with a small hook at the tip. The black legs are long and strong. The plumage is pure glossy black and white; both sexes of all subspecies have black heads, wings and underparts with white shoulders.

The tail has a black terminal band. The nape is white in the male and light greyish-white in the female. Mature magpies have dull red eyes, in contrast to the yellow eyes of currawongs and white eyes of Australian ravens and crows. The main difference between the subspecies lies in the "saddle" markings on the back below the nape. Black-backed subspecies have a black saddle and white nape. White-backed subspecies have a wholly white nape and saddle. The male Western Australian subspecies "dorsalis" is also white-backed, but the equivalent area in the female is scalloped black.

Juveniles have lighter greys and browns amidst the starker blacks and whites of their plumage; two- or three-year-old birds of both sexes closely resemble and are difficult to distinguish from adult females. Immature birds have dark brownish eyes until around two years of age. Australian magpies generally live to around 25 years of age, though ages of up to 30 years have been recorded. The reported age of first breeding has varied according to area, but the average is between the ages of three and five years.

Well-known and easily recognisable, the Australian magpie is unlikely to be confused with any other species. The pied butcherbird has a similar build and plumage, but has white underparts unlike the former species' black underparts. The magpie-lark is a much smaller and more delicate bird with complex and very different banded black and white plumage. Currawong species have predominantly dark plumage and heavier bills.

Naming

There are currently thought to be nine subspecies of the Australian magpie, although there are large zones of overlap with intermediate forms between the taxa. There is a tendency for birds to become larger with increasing latitude, the southern subspecies being larger than those further north, except the Tasmanian form which is small.

Distribution

The Australian magpie is found in the Trans-Fly region of southern New Guinea, between the Oriomo River and Muli Strait, and across most of Australia, bar the tip of Cape York, the Gibson and Great Sandy Deserts, and southwest of Tasmania.

Behavior

The Australian magpie is almost exclusively diurnal, although it may call into the night, like some other members of the Artamidae.

On the ground, the Australian magpie moves around by walking, and is the only member of the Artamidae to do so; woodswallows, butcherbirds and currawongs all tend to hop with legs parallel. The magpie has a short femur, and long lower leg below the knee, suited to walking rather than running, although birds can run in short bursts when hunting prey.

The magpie is generally sedentary and territorial throughout its range, living in groups occupying a territory, or in flocks or fringe groups. A group may occupy and defend the same territory for many years.

A wide variety of displays are seen, with aggressive behaviours outnumbering pro-social ones. Crouching low and uttering quiet begging calls are common signs of submission.

The "manus flutter" is a submissive display where a magpie will flutter its primary feathers in its wings. A magpie, particularly a juvenile, may also fall, roll over on its back and expose its underparts. Birds may fluff up their flank feathers as an aggressive display or preceding an attack.

Young birds display various forms of play behaviour, either by themselves or in groups, with older birds often initiating the proceedings with juveniles. These may involve picking up, manipulating or tugging at various objects such as sticks, rocks or bits of wire, and handing them to other birds.

A bird may pick up a feather or leaf and flying off with it, with other birds pursuing and attempting to bring down the leader by latching onto its tail feathers. Birds may jump on each other and even engage in mock fighting. Play may even take place with other species such as blue-faced honeyeaters and Australasian pipits.

Reproduction

Magpies have a long breeding season which varies in different parts of the country; in northern parts of Australia they will breed between June and September, but not commence until August or September in cooler regions, and may continue until January in some alpine areas.

The nest is a bowl-shaped structure made of sticks and lined with softer material such as grass and bark. Near human habitation, synthetic material may be incorporated. Nests are built exclusively by females and generally placed high up in a tree fork, often in an exposed position.

The trees used are most commonly eucalypts, although a variety of other native trees as well as introduced pine, "Crataegus", and elm have been recorded.

The Australian magpie produces a clutch of two to five light blue or greenish eggs, which are oval in shape and about 30 by 40 mm. The chicks hatch synchronously around 20 days after incubation begins; like all passerines, the chicks are altricial—they are born pink, naked, and blind with large feet, a short broad beak and a bright red throat.

Their eyes are fully open at around 10 days. Chicks develop fine downy feathers on their head, back and wings in the first week, and pinfeathers in the second week. The black and white colouration is noticeable from an early stage. Nestlings are fed exclusively by the female, though the male magpie will feed his partner.

The Australian magpie is known to engage in cooperative breeding, and helper birds will assist in feeding and raising young. This does vary from region to region, and with the size of the group—the behaviour is rare or nonexistent in pairs or small groups.

Juvenile magpies begin foraging on their own three weeks after leaving the nest, and mostly feeding themselves by six months old. Some birds continue begging for food until eight or nine months of age, but are usually ignored.

Birds reach adult size by their first year. The age at which young birds disperse varies across the country, and depends on the aggressiveness of the dominant adult of the corresponding sex; males are usually evicted at a younger age. Many leave at around a year old, but the age of departure may range from eight months to four years.

Food

The Australian magpie is omnivorous, eating various items located at or near ground level including invertebrates such as earthworms, millipedes, snails, spiders and scorpions as well as a wide variety of insects—cockroaches, ants, beetles, cicadas, moths and caterpillars and other larvae.

Insects, including large adult grasshoppers, may be seized mid-flight. Skinks, frogs, mice and other small animals as well as grain, tubers, figs and walnuts have also been noted as components of their diet.

It has even learnt to safely eat the poisonous cane toad by flipping it over and consuming the underparts. Predominantly a ground feeder, the Australian magpie paces open areas methodically searching for insects and their larvae.

One study showed birds were able to find scarab beetle larvae by sound or vibration. Birds use their bills to probe into the earth or otherwise overturn debris in search of food. Smaller prey are swallowed whole, although magpies rub off the stingers of bees and wasps before swallowing.

Predators

Natural predators of magpies include various species of monitor lizard and the barking owl. Birds are often killed on roads or electrocuted by powerlines, or poisoned after killing and eating house sparrows or mice, rats or rabbits targeted with baiting. The Australian raven may take nestlings left unattended.

Defense

Much energy is spent defending a territory from intruders, particularly other magpies, and different behaviours are seen with different opponents. The sight of a raptor results in a rallying call by sentinel birds and subsequent coordinated mobbing of the intruder.

Magpies place themselves either side of the bird of prey so that it will be attacked from behind should it strike a defender, and harass and drive the raptor to some distance beyond the territory. A group will use carolling as a signal to advertise ownership and warn off other magpies.

In the "negotiating display", the one or two dominant magpies parade along the border of the defended territory while the rest of the group stand back a little and look on. The leaders may fluff their feathers or caroll repeatedly. In a "group strength display", employed if both the opposing and defending groups are of roughly equal numbers, all magpies will fly and form a row at the border of the territory.

The defending group may also resort to an aerial display where the dominant magpies, or sometimes the whole group, swoop and dive while calling to warn an intruding magpie's group.

Cultural

The Australian magpie featured in aboriginal folklore around Australia. The Yindjibarndi people of the Pilbara in the northwest of the country used the bird as a signal for sunrise, frightening them awake with its call. They were also familiar with its highly territorial nature, and it features in a song in their "Burndud", or songs of customs. It was a totem bird of the people of the Illawarra region south of Sydney.