Variation in breeding parameters of the Australian magpieGymnorhina tibicenin suburban and rural environments

Abstract

The breeding ecology of the Australian magpie Gymnorhina tibicen in suburban and rural areas was compared as part of a study into the synanthropy of the species in southeast Queensland, Australia. During the two years of the study suburban magpies were found to have significantly advanced breeding dates compared to rural magpies. Suburban magpies typically re-nested when an initial nest failed, although this did not result in greater productivity than that of the rural magpies. Suburban magpies had similar mean numbers of young per breeding pair; they also showed higher mortality between fledging and a final count in February. This study suggests that introduced predators and deaths due to motor vehicles may account for this mortality in suburban areas. Anthropogenic factors present within suburban areas such as the watering of lawns and the widespread provision of food for wildlife are likely to play an important role in the differences in the timing of breeding. In addition, temperature may also have an inhibitory effect on the onset of breeding, an influence lessened in the suburban areas due to higher temperatures.