Australian Magpie Gymnorhina tibicen
This is the most consistently present species. It is well suited to
suburbs (Jones 2002). In a short study Davey (1995) demonstrated how dense the
population of this species can be in Canberra. It is conspicuous, bold
and abundant. It feeds on invertebrates on lawns and open ground. They will
become tame and accept hand feeding. They vigorously attack most raptors at all
times and will also chase other birds. This is the only species that has been
recorded from every site and is the one recorded and breeding on the most
charts. Only seven out of 1316 charts have not included this species, five of
those are from Sites 73 & 219. Its omnipresence makes the annual variation
quite noticeable, even though the amplitude is minimal. There is a slight dip in
numbers from July to September, then a rise to November. From November to July
it is almost constant. This spring dip is probably due to the count being down
slightly when females are on nests. The long-term abundance has barely
perceptible changes, although overall a small increase. This species
demonstrates best, the closeness of the average A value in the two graphs.
In the breeding season some individuals are very aggressive in
defence of their nest and they will swoop at people. Mostly this is annoying or
gives a fright, sometimes this results in injury to people. Although they
aggressively defend their nests, they do not defend dependent young. Nest building commences and peaks in July and is finished by
October. Nests with eggs or young commence in July, peaks in September
and is finished by January. First dependent young in September, peaking in
November and last in May. There are many records that appear to show a complete
breeding event and the duration is generally close to 15 weeks. The frequency of
breeding has been quite stable over the years (was very low in Year
2).
Graphs on page: 103, Rank: 1, Breeding Rank:
1, Breeding graph on page: 107, A = 2.71793, F = 99.47%,
W = 52.0, R = 84.861%,
G = 3.20.
Philip
