I wondered what I would put in this area but on reflection have decided to include a great interest and passion of mine:
1 Magpies – our personal study and record 1992-2005
General Information on Magpies
All magpies are glossy black-and-white birds. However, there are many variations in the patterning of their feathers that distinguish the various subspecies. The common east-coast black-backed magpie has a distinctive white collar separating its black head form those on its back. In contrast, the whole back of the white-backed magpie is the male has a white back, and the female has mottled gray. The fledglings initially covered with light gray fluffy down, which was then replaced with mottled light gray feathers for a few months, before becoming darker in colour. Juveniles are a year old, and have black feathers on their wings, but still a mottled grey back until the feathers turn white after a couple of years for the male, and a darker mottled gray for the female.
There are two different races of magpie in Australia. Generally, white-backs are found in southern Australia while black-backs are found in to the north. Another races which lives in the western side of the continent, has white-backed males and black backed females.
Magpies are highly territorial with each territory, approximately 2 hectares, occupied by 2-20 birds and all adults in a group defend the boundaries of the territory. Much of the defense is passive – the sight and sound of magpies in a territory is usually enough to keep others away – but the birds are not averse to a little physical contact. Any transgression of the boundary is usually the signal for the occupying group to swoop en masse on an intruder.
Magpies that have not joined a family group stay together in loose flocks of up to 100 birds.
Several members of the family group, including the mother, father and older siblings, care for magpie chicks. The young leave the nest after a month or so. Eggs range from pale blue to green and are sometimes patterned with brown. Three to six eggs are laid in a nest made of twigs, leaves, and sometimes man made items such as wire and newspaper. The eggs hatch in about three weeks. It is extremely rare for any more than 3 eggs to hatch, and the third chick is usually the runt of the nest, and may not survive any length of time. Usually two chicks become healthy adults.
It has long been assumed that among magpies, as with other territorial birds that live in pairs or have larger family groups, the dominant male fathers almost all of the chicks. Perhaps other males in the group father the occasional chick, but the essence of this isn’t only the defense of space, but the defense of “mating rights”. Recent DNA analysis challenges this – it’s shown that extraterritorial matings are common: up to 50 per cent of fledglings are fathered by males outside the group. Also, a female magpie sitting on an egg and raising a chick is not necessarily its mother. It’s probable that some female magpies lay their eggs in other magpies’ nests.
The implications of these latest results have caused quite a stir among ornithologists and biologists. For many years, the accepted wisdom among evolutionary theorists has been that social animals, especially those whose earlier offspring remain in the family group to help raise later young, are being genetically ‘selfish’.
I hope you find this info interesting and look forward to any feedback you may have.