Peter completed his PhD in 2002, the same year he started work at Taronga Zoo as the manager of the Herpetofauna Division (reptiles and amphibians). His PhD was on the distribution and evolution of temperature-dependent sex determination in Australian dragon lizards. Before joining Taronga he worked as a research assistant at Sydney University for many years, studying aspects of the biology and ecology of a diverse range of reptile and amphibian species, including salt water crocodiles, lizards, snakes and turtles. As well as extensive field work in Australia, his work took him to Southern Africa, Canada, Indonesia and Fiji where he started research projects on the conservation of Fijian Iguanas. With his Fijian collaborators, research partners and students he has surveyed over 90 islands in Fiji for presence / absence of iguanas, described two new species of Fijian iguana, and has been involved in a 19 year conservation project to save the Monuriki Island crested iguanas from extinction by captive breeding and reintroduction after goats and rats were eradicated from the island.
In 2016 he joined the Research and Science group at Taronga as a Terrestrial Biologist. Today his work involves co-ordinating and genetic management of captive breeding programs for two species of Christmas Island lizards that are extinct in the wild, encouraging native species back to the Taronga site by bandicoot monitoring, improving fox control, on-site microbat surveys and designing and installing bat roost boxes in the zoo grounds, and a citizen science project with Macquarie and Sydney universities into antibiotic resistance in native animals, through DNA testing of possum scats. His research interests include invasive species ecology, in situ conservation, restoration ecology, captive breeding, and reintroduction.