Australian Magpie

Australian Magpie

Description

The Australian magpie (Cracticus tibicen) is a medium-sized black and white passerine bird native to Australia and southernNew Guinea. Although once considered to be three separate species, it is now considered to be one, with nine recognisedsubspecies. A member of the Artamidae, the Australian magpie is classified in the butcherbird genus Cracticus and is most closely related to the black butcherbird (C. quoyi). It is not, however, related to the European magpie, which is a corvid. The adult Australian magpie is a fairly robust bird ranging from 37 to 43 cm (14.5–17 in) in length, with distinctive black and white plumage, gold brown eyes and a solid wedge-shaped bluish-white and black bill. The male and female are similar in appearance, and can be distinguished by differeAustralian_Magpie 2nces in back markings. With its long legs, the Australian magpie walks rather than waddles or hops and spends much time on the ground.

Described as one of Australia’s most accomplished songbirds, the Australian magpie has an array of complex vocalisations. It is omnivorous, with the bulk of its varied diet made up of invertebrates. It is generally sedentary and territorial throughout its range. Common and widespread, it has adapted well to human habitation and is a familiar bird of parks, gardens and farmland in Australia and New Guinea. This species is commonly fed by households around the country, but in spring a small minority of breeding magpies (almost always males) become aggressive and swoop and attack those who approach their nests. Magpies were introduced into New Zealand in the 1860s but have subsequently been accused of displacing native birds and are now treated as a pest species.[2] Introductions also occurred in the Solomon Islands and Fiji, where the birds are not considered aninvasive species. The Australian magpie is the mascot of several Australian sporting teams, most notably the Collingwood Magpies.

 

Distribution and habitat

Australian_Magpie_-_distributionThe Australian magpie is found in the Trans-Fly region of southern New Guinea, between the Oriomo River and the Princess Mariane Strait, and across most of Australia, bar the tip of Cape York,[46] the Gibson and Great Sandy Deserts, and southwest of Tasmania.[47] Birds taken mainly from Tasmania and Victoria were introduced into New Zealand by local Acclimatisation Societies of Otago and Canterbury in the 1860s, with the Wellington Acclimatisation Society releasing 260 birds in 1874. White-backed forms are spread on both the North and eastern South Island, while black-backed forms are found in the Hawke’s Bay region.[48] Magpies were introduced into New Zealand to control agricultural pests, and were therefore a protected species until 1951.[49] They are thought to affect native New Zealand bird populations such as the tui and kererū, sometimes raiding nests for eggs and nestlings,[49] although studies by Waikato University have cast doubt on this,[50] and much blame on the magpie as a predator in the past has been anecdotal only.[51] Introductions also occurred in the Solomon Islands and Sri Lanka, although the species has failed to become established. It has become established in western Taveuni in Fiji, however.[48]

The Australian magpie prefers open areas such as grassland, fields and residential areas such as parks, gardens, golf courses, and streets, with scattered trees or forest nearby. Birds nest and shelter in trees but forage mainly on the ground in these open areas.[52] It has also been recorded in mature pine plantations; birds only occupy rainforest and wet sclerophyll forest in the vicinity of cleared areas.[46] In general, evidence suggests the range and population of the Australian magpie has increased with land-clearing, although local declines in Queensland due to a 1902 drought, and in Tasmania in the 1930s have been noted; the cause for the latter is unclear but rabbit baiting, pine tree removal, and spread of the masked lapwing (Vanellus miles) have been implicated.[53]

Behaviour

The Australian magpie is almost exclusively diurnal, although it may call into the night, like some other members of the Artamidae.[54] Natural predators of magpies include various species of monitor lizard and the barking owl.[55] 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.[56] The Australian raven may take nestlings left unattended.[57]

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 (thigh bone), and long lower leg below the knee, suited to walking rather than running, although birds can run in short bursts when hunting prey.[58]

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.[56] 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.[59] 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.[60] 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.[61]

A wide variety of displays are seen, with aggressive behaviours outnumbering pro-social ones.[62] Crouching low and uttering quiet begging calls are common signs of submission.[63] The manus flutter is a submissive display where a magpie will flutter its primary feathers in its wings.[64] A magpie, particularly a juvenile, may also fall, roll over on its back and expose its underparts.[64] Birds may fluff up their flank feathers as an aggressive display or preceding an attack.[65] 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.[66]

Feeding

The Australian magpie is omnivorous, eating various items located at or near ground level including invertebrates such asearthworms, millipedes, snails, spiders and scorpions as well as a wide variety of insects—cockroaches, ants, beetles, moths and caterpillars and other larvae. Insects, including large adult grasshoppers, may be seized mid-flight 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.[67] It has even learnt to safely eat the poisonous cane toad by flipping it over and consuming the underparts.[68] Predominantly a ground feeder, the Australian magpie paces open areas methodically searching for insects and their larvae.[69] One study showed birds were able to find scarab beetle larvae by sound or vibration.[70] Birds use their bills to probe into the earth or otherwise overturn debris in search of food.[71] Smaller prey are swallowed whole, although magpies rub off the stingers of bees and wasps before swallowing.[72]

Breeding

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.[73] 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.[74] Nests are built exclusively by females and generally placed high up in a tree fork, often in an exposed position.[75] 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.[76] Other bird species, such as the yellow-rumped thornbill (Acanthiza chrysorrhoa), willie wagtail (Rhipidura leucophrys), Southern Whiteface (Aphelocephala leucopsis), and (less commonly) noisy miner (Manorina melanocephala), often nest in the same tree as the magpie. The first two species may even locate their nest directly beneath a magpie nest, while the diminutivestriated pardalote (Pardalotus striatus) has been known to make a burrow for breeding into the base of the magpie nest itself. These incursions are all tolerated by the magpies.[77] The channel-billed cuckoo (Scythrops novaehollandiae) is a notable brood parasite in eastern Australia; magpies will raise cuckoo young, which eventually outcompete the magpie nestlings.[78]

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 (1.2 by 1.6 in).[79] 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.[80] Nestlings are fed exclusively by the female, though the male magpie will feed his partner.[81] The Australian magpie is known to engage incooperative breeding, and helper birds will assist in feeding and raising young.[33] 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.[33]

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.[82] 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.[83]

Relationship with humans

Swooping

Magpies are ubiquitous in urban areas all over Australia, and have become accustomed to people. A small percentage of birds become highly aggressive during breeding season from late August to early October, and will swoop and sometimes attack passersby. The percentage has been difficult to estimate but is significantly less than 9%.[84] Almost all attacking birds (around 99%) are male,[85] and they are generally known to attack pedestrians at around 50 m (150 ft) from their nest, and cyclists at around 100 m (300 ft).[86] There appears to be some specificity in choice of attack targets, with the majority of individuals specializing on either pedestrians or cyclists.[87] Attacks begin as the eggs hatch, increase in frequency and severity as the chicks grow, and tail off as the chicks leave the nest.[88]

These magpies may engage in an escalating series of behaviours to drive off intruders. Least threatening are alarm calls and distant swoops, where birds fly within several metres from behind and perch nearby. Next in intensity are close swoops, where a magpie will swoop in from behind or the side and audibly “snap” their beaks or even peck or bite at the face, neck, ears or eyes. More rarely, a bird may dive-bomb and strike the intruder’s (usually a cyclist’s) head with its chest. A magpie may rarely attack by landing on the ground in front of a person and lurching up and landing on the victim’s chest and peck at the face and eyes.[89]

Magpie attacks can cause injuries, typically wounds to the head,[90] and being unexpectedly swooped while cycling can result in loss of control of the bicycle, which may cause injury.[91][92][93]

If it is necessary to walk near the nest, wearing a broad-brimmed or legionnaire’s hat or using an umbrella will deter attacking birds, but beanies and bicycle helmets are of little value as birds attack the sides of the head and neck.[94]

Magpies prefer to swoop at the back of the head; therefore, keeping the magpie in sight at all times can discourage the bird. Using a basic disguise to fool the magpie as to where a person is looking, such wearing sunglasses on the back of the head. Eyes painted on hats or helmets will deter attacks on pedestrians but not cyclists.[95]

Cyclists can deter attack by attaching a long pole with a flag to a bike is an effective deterrent,[96] and the use of cable ties on helmets has become common and appears to be effective.[97]

Magpies are a protected native species in Australia, so it is illegal to kill or harm them. However, this protection is removed in some Australian states if a magpie attacks a human, allowing for the bird to be destroyed if it is considered particularly aggressive (such a provision is made, for example, in section 54 of the South Australian National Parks and Wildlife Act).[98] More commonly, an aggressive bird will be caught and relocated to an unpopulated area.[99] Magpies have to be moved some distance as almost all are able to find their way home from distances of less than 25 km (15 mi).[100] Removing the nest is of no use as birds will breed again and possibly be more aggressive the second time around.[101]

It is claimed by some that swooping can be prevented by hand-feeding magpies. Magpies will become accustomed to being fed by humans, and although they are wild, will return to the same place looking for handouts. The idea is that humans thereby appear less of a threat to the nesting birds. Although this has not been studied systematically, there are reports of its success.

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