Australian magpie

Gymnorhina tibicen (Latham, 1802)

Order: Passeriformes

Family: Artamidae

New Zealand status: Introduced

Conservation status: Introduced and Naturalised

Other names: magpie, white-backed magpie, black-backed magpie, makipae

Geographical variation: Eight subspecies recognised in Australia, of which perhaps three were introduced to, and persist in, New Zealand. White-backed forms are assigned to two subspecies: the larger tyrannica (introduced from south-east Australia to the North Island), and the smaller hypoleuca (introduced from Tasmania to parts of the South Island). The black-backed form is assigned to the subspecies tibicen.

Australian magpie. Female black-backed magpie. North Shore Auckland, September 2007. Image © Peter Reese by Peter Reese

Australian magpie. Female black-backed magpie. North Shore Auckland, September 2007. Image © Peter Reese by Peter Reese

The black-and-white Australian magpie is a common and conspicuous inhabitant of open country throughout much of New Zealand. It was introduced from Australia and Tasmania by Acclimatisation Societies between 1864 and 1874, mainly to control insect pests. There are three subspecies; the black-backed, and two white-backed forms, with white-backed birds predominating in most parts of New Zealand.

Identification

This familiar large songbird is similar in size to a crow or a New Zealand pigeon. The white-backed form tyrannica is the largest of the sub-species. The male has a white hind-neck, mantle, rump and shoulder patches. The upper two-thirds of the tail and under-tail coverts are also white. The rest of the plumage is black, with a blue iridescence. The female is similar, but the mantle is grey, and the black parts of the plumage are less iridescent. Both sexes have a blue-grey bill with a dark tip, and red eyes. The male takes several years to attain full adult plumage; after the second moult it resembles an adult female. Some white appears on the mantle after the third moult, and the remainder after the fourth moult. The juvenile is mottled grey on the under-surface. The black-backed magpie is similar to the white-backed forms, but with a black mantle. The female can be identified by the presence of some grey on the lower hind-neck. The two subspecies interbreed, resulting in offspring with a varying amount of black on the mantle, ranging from a few feathers to a narrow band.

Both sexes have a distinctive carolling song; “quardle oodle ardle wardle doodle”.

With its large size and strikingly pied plumage, the Australian magpie is not readily confused with any other species.

Distribution and habitat

The magpie is found throughout the North Island. In the South Island it is most common from Kaikoura to Southland. It is uncommon in Nelson and inland Marlborough, and is largely absent from Westland, except for the area between Harihari and Westport. The white-backed forms predominate except in Hawke’s Bay and North Canterbury, where black-backed birds make up around 95% of the population.

The white-backed forms originate from south-eastern Australia and Tasmania, and the black-backed from northern Australia and southern New Guinea. Australian magpies were also introduced to Fiji.

Magpies are most abundant on farmland with shelterbelts of pines, macrocarpas and gums. They inhabit both lowland and hill-country farming districts, and are frequently found in urban habitats such as parks and golf-courses.

Population

Australian magpies are common in much of the North Island and the east of the South Island south of Kaikoura. They have declined in some areas, e.g. Wellington, as a result of control programmes.

Ecological and economic impacts

The Australian magpie has been widely implicated in the predation of native birds and their nests, but much evidence is anecdotal. However, magpies do occasionally kill other birds, mostly smaller species. One was seen to pursue, capture and kill a juvenile goldfinch, and another took 3 newly-hatched banded dotterel chicks from a nest. Most attacks appear to be opportunistic, involving young or weak victims. Many of the attacks by magpies against larger birds are directed towards harriers, and generally cease when the target leaves the territory. This harassment of harriers may even have a protective effect on other species breeding in a magpie’s territory.

A study in the Waikato whereby nests of a range of species were monitored by cameras revealed only one instance of magpie predation. The vast majority of predation events involved mammalian predators or harriers. The conclusion reached was that magpies were not an important predator of the nests of rural birds. Likewise a study by several regional councils and Landcare Research found little evidence that magpies affected the populations of other species of birds. Magpies were removed from a number of blocks of land, and other blocks were left untouched as controls. The bird species were surveyed before commencement of control in the “kill” blocks, and then again after the operations had been completed. Little change in numbers of other species was found afterwards, or in comparison with the populations in the control blocks. However the visibility of other species was affected; without magpies some were more frequently seen.

Breeding

Magpies breed early, commencing nest-building in late July, and are normally single brooded. The bulky nest is built of twigs, roots, and man-made materials including wire, and lined with hair and wool. It is usually located in the crown or side-branches of tall trees, especially pines, macrocarpas and gums. Native trees such as tawa and beech are also frequently used. The usual clutch consists of 3-4 eggs, and the resulting chicks are fed by both parents for 4-5 weeks until fledging. They rely on their parents for a further 2 months or so afterwards. Usually only one or two chicks survive, as in most cases it takes one parent per chick to provide sufficient food.

Behaviour and ecology

Magpies have a complex social organisation; pairs or groups defend a territory year round. New Zealand groups seem to consist mainly of single pairs, or pairs with young from the previous season. In most cases juveniles remain with their parents until the winter, but are evicted before the onset of the next breeding season. Other groups consist of a varying number of adult birds, some of which may be previous offspring which have been allowed to remain. Usually only one female breeds successfully. Non-territorial flocks consist of evicted juveniles and sub-adults, numbering up to 80 or more individuals.

Magpies are well-known for their propensity for attacking people by dive-bombing during the breeding season. However, this usually only lasts until shortly after the chicks fledge. Also, as anyone who has kept a pet magpie will attest, they can be playful, especially when young. This often involves rolling on the ground on their backs with their siblings and occasionally also with their parents, in a similar manner to that practised by keas. Various objects may be used as playthings.

Food

Australian magpies mainly feed on invertebrates, taken mostly from the ground. A large proportion of the diet consists of earthworms in winter, but at other times of the year they feed mainly on insects, including pest species. They particularly favour the caterpillars of the porina moth, which are extracted from their tunnels in the ground. Other invertebrates eaten include army worm caterpillars, crickets, wasps, spiders, stick insects and snails. In late summer magpies frequently feed on large cicadas when these are available. As with owls, they eject pellets consisting of the hard parts of these insects. Occasionally magpies consume carrion, lizards, mice, small birds and their eggs and chicks. Seeds and grain may be taken occasionally.

Weblinks

http://en.wikipedia.org/wiki/Australian_Magpie

http://ibc.lynxeds.com/species/australian-magpie-cracticus-tibicen

References

Crossland, A.C. 2008. Aerial pursuit and predation of European goldfinch (Carduelis carduelis) by Australian magpie (Gymnorhina tibicen). Notornis 55: 212-213.

Heather, B.D.; Robertson, H. A. 1996. The field guide to the birds of New Zealand. Viking, Auckland.

Higgins,P.J.; Peter, J.M.; Cowling, S.J. (eds.) 2006. Handbook of Australian, New Zealand and Antarctic birds. Vol. 7, boatbill to starlings. Oxford University Press, Melbourne.

Innes, J.; Morgan, D.; Waas, J.R. 2006. The relative importance of Australian magpies as nest predators of rural birds in New Zealand. New Zealand Journal of Zoology 33: 17-29.

Keedwell, R.; Sanders, M.D. 1999. Australian magpie preys on banded dotterel chicks. Notornis 46: 499-501.

Landcare Research media release, 14 August 2003; No ‘black and white’ case against magpies.

Recommended citation

Angus, D.J. 2013. Australian magpie. In Miskelly, C. M. (ed.) New Zealand Birds Online.

www.nzbirdsonline.org.nz

Australian magpie

Social structure
co-operative breeding groups
Breeding season
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Nest type
woven cup
Nest description
Bulky-cup shaped nest of twigs, sticks, roots and wire, lined with wool, hair, rootlets and fine grass.
Nest height (mean)
10.3 m
Nest height (min)
1 m
Nest height (max)
80 m
Maximum number of successful broods
2
Clutch size (mean)
3.5
Clutch size (min)
2
Clutch size (max)
5
Mean egg dimensions (length)
40.4 mm
Mean egg dimensions (width)
28.1 mm
Egg colour
Highly variable; ground colour various shades of grey, green, brown or blue or combinations of these colours. Marked with spots, streaks, blotches, smudges and hair-lines of various shades or brown or black. Can be unmakred.
Egg laying dates
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Interval between eggs in a clutch
1 days days
Incubation behaviour
female only
Incubation length (mean)
20.5 days
Incubation length (min)
20 days
Incubation length (max)
21 days
Nestling type
semi-precocial
Nestling period (mean)
32.5 days
Nestling period (min)
30 days
Nestling period (max)
35 days
Age at fledging (mean)
32.5 days
Age at fledging (min)
30 days
Age at fledging (max)
35 days
Age at independence (mean)
About 90 days
Age at first breeding (typical)
3 years
Maximum longevity
19 years
Maximum dispersal
358 km in Australia, unknown in New Zealand