Synopsis

In the Sydney region, the Powerful Owl (Ninox strenua) is a large predator of folivores such as ringtail and brushtail possums (Trichosurus spp.). Together possums and owls have increased markedly over the last 50 years, and now occupy rainforest gullies close to urban areas.
Lead (Pb) is a major environmental pollutant and bioaccumulates in the food chain as it concentrates in animal bones, where it remains for extended periods. Analysing lead concentration in bones can give us an indication of past levels of lead exposure and potentially, environmental lead concentrations. Because lead concentrates in bones, it can be assessed in the scats and pellets of carnivores. The Georges River Group of the Powerful Owl Project has been analysing the composition of prey items collected in bolus from roosting sites on both sides of the Georges River between 2012 and 2017. The bones of more than 250 prey animals have been collected from ten separate owl territories. The Georges River provides a natural boundary between the earlier European settlement, and therefore motor vehicles use, on the northern side of the Georges River and the more recently settled southern side of the river. These two sites may differ in lead (Pb) levels as the more recently settled areas were mainly urbanised in an era of lead-free fuel after 1986.

Aims

• examine differences in prey items in Powerful Owl scats and pellets from 10 sites in southern Sydney
• examine Pb levels in the bones and feathers of vertebrate prey
• explore potential differences in Pb levels that might account for differences in environmental Pb between areas with long and short histories of usage of fuel-based Pb.

Student Benefits

This is a multi-disciplinary project that will expose the student to a range of disciplines. You will:
• work on a high priority conservation project
• gain skills in laboratory and data analytical techniques
• work with a community group (Powerful Owl Project)
• undertake a mixture of microscope, laboratory and community-based work
• get access to a large existing database