Conservation Programs

A charismatic species on our doorstep is helping rare pelican species around the world.
 
Australian Pelicans at Outer Harbour have been the focus of a long-term protection and research effort which has provided information on fluctuations in population size, dispersal and breeding behaviour.

The information gained from this study can help management of this species, as well as other, rarer species of pelican, such as the extremely rare Dalmatian Pelican in eastern Europe and the Spot-billed Pelican in south-east Asia.

Location in wild
The study colony is at Outer Harbour, Adelaide

Numbers in wild
Only 5 of 18 known breeding sites in SA have active breeding colonies

Threats
Fox predation

Our involvement
Since 1990

Type of involvement
Research, fox control

Partners
University of Adelaide  Flinders University, South Australian Aquatic Science Centre , University of Western Australia
Funding from Australian Research Council , BIOCITY: Centre for Urban Habitats at the University of Adelaide

Australian pelicans were once numerous in South Australia with eighteen known breeding sites, but have since declined from these earlier highs with only five breeding sites currently active.

Dredging at Outer Harbour in 1978 created an artificial island, and this was colonised by Australian pelicans. This ‘new’ colony has been the focus of studies to better understand the biology of this and other pelican species, such as the extremely rare Dalmatian pelican in eastern Europe and the Spot-billed Pelican in south-east Asia.

The long term nature of this work has allowed information to be collected on fluctuations in colony size, dispersal and to determine the age at which specific life events occur. Banding of birds has found that animals born at Outer Harbour at Adelaide disperse throughout south-eastern Australia. Information has also been collected on the breeding behaviour of pelicans, including seasonality, clutch size and survivorship. Other colonies, especially those in SW Qld are based around irregular rainfall events and hence information gained from this stable population can provide a foundation for conservation of these irregular, but important breeding populations.

A particular focus of this project has been to understand the factors associated with chick mortality. Pelicans belong to a group of birds that lay more eggs than normally survive to leave the nest, with eggs laid asynchronously which reduces the likelihood of the last hatchling surviving. This asynchrony has been found to be related to food availability, with low fish stocks resulting in eggs being laid further apart than when fish stocks are abundant. As pelicans incubate their eggs from the time the first is laid, asynchrony in laying means that but the time the last egg hatches there can be a large size difference in nestlings due to the age difference. A combination of hatch order, sex, size and hormone levels affect survivorship of nestlings, and the impact of these factors on survivorship after leaving the nest is being assessed as part of the long term study.

Nestling mortality is a major limiting factor to population growth of many bird species that show brood reduction. By understanding the mechanisms that result in chick mortality, it is possible to develop methods to increase nestling survival, aiding population growth of threatened species. The ability to harvest nestlings for conservation purposes without affecting the source population and to increase the survival of nestlings in the field and captivity has important implications for conservation of bird species. The knowledge gained from this research has been used increase the size of an isolated population of yellow-tailed black cockatoos on the Eyre Peninsula, South Australia.

Removal of foxes from Section bank Island has resulted in breeding again, following a couple of years where breeding success was very low (non-existent in 2007).  Weekly monitoring of breeding colonies has shown that foxes are the major cause of low breeding success.

There are now over 600 pelican nests in the colony, and white ibis, silver gulls, and royal spoonbills are also nesting.

If you see a pelican with a wing tag, please report the sighting here.