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Ecology, management and conservation in natural and modified habitats
RESEARCH ARTICLE

The pest status of Australian white ibis (Threskiornis molucca) in urban situations and the effectiveness of egg-oil in reproductive control

John M. Martin A C , Kris French A and Richard E. Major B
+ Author Affiliations
- Author Affiliations

A Institute for Conservation Biology, School of Biological Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.

B Australian Museum, 6 College Street, Sydney, NSW 2010, Australia.

C Corresponding author. Email: john.martin@cp.nsw.gov.au

Wildlife Research 34(4) 319-324 https://doi.org/10.1071/WR07005
Submitted: 8 January 2007  Accepted: 30 May 2007   Published: 28 June 2007

Abstract

The Australian white ibis (Threskiornis molucca) is considered to be an urban pest along the east coast of Australia. The non-specific diet and broad habitat requirements of ibis have facilitated their successful exploitation of the urban environment. Ibis are considered a pest because they pose a threat to aircraft safety, scavenge food at waste-management sites, cafés and parks, and compete with other native species for food and habitat. This study assesses a new ibis-management technique, the application of ‘egg-oil’ to suppress hatching. On other species, egg-oiling has been shown to be environmentally safe and socially preferable to culling adult birds. Approximately 5 mL of food-grade canola oil was sprayed upon each egg, and both incubator and field trials were used to investigate the efficacy of this technique on ibis and to determine the optimal application time and frequency of egg-oil. Treatment eggs were given an application of oil during the 23-day incubation period either once per week, or once early (<7 days), mid (~14 days) or late (>18 days) incubation. All four treatments were observed to be 100% effective at preventing ibis eggs from hatching during the laboratory trial and more than 98% effective during the field trial. These results indicate that applying canola oil to ibis eggs once, at any time, during the 23-day incubation period is sufficient to prevent ibis eggs from hatching. The field trial also showed that 30% of ibis, across the four oiling treatments, continued to incubate the unviable eggs for up to 54 days longer than the normal incubation period. Given that ibis are multibrooded, raising up to three successful clutches in a breeding season, the increased time devoted to incubating oil-treated eggs could reduce the opportunity for multiple broods, compared with conventional egg destruction. The egg-oil technique offers an additional tool for land managers to conduct ibis reproduction control, which should reduce the amount of time required to conduct ibis management, consequently reducing the cost to land managers.


Acknowledgements

Funding for this project came from Fairfield City Council, Waste Services New South Wales, the Centennial Parklands Foundation and the Australian Museum’s Postgraduate Awards. We specifically thank Katie Cabezas of Fairfield City Council, Joan Dawes of Pestat and Geoff Ross of the New South Wales Department of Environment and Conservation (NSW DEC). Thank you also to the two anonymous reviewers. This research was undertaken in accordance with the requirements of the University of Wollongong Animal Ethics Committee and with approval from the NSW DEC (NPWS).


References

Australian Transport Safety Bureau (2002). The hazards posed to aircraft by birds. Unpublished report for the Commonwealth Department of Transport and Regional Services, Canberra, ACT.

Australian Transport Safety Bureau (2003). Bird species information sheet: Ibis. Canberra, ACT.

Bankstown City Council (2004). Survey into local residents’ attitudes towards ibis nesting at Lake Gillawarna, final report. Bankstown City Council Community Research.

Blackwell, F. B. , Seamans, T. W. , Helon, D. A. , and Dolbeer, R. A. (2000). Early loss of herring gull clutches after egg-oiling. Wildlife Society Bulletin 28, 70–75.
Cummings J. L. , Pitzler M. E. , Pochop P. A. , Krupa H. W. , Pugh T. L. , and May J. A. (1992). Field evaluation of white mineral oil to reduce hatching in Canada goose eggs. In ‘Thirteenth Great Plains Wildlife Damage Control Workshop Proceedings’. (Eds C. D. Lee and S. E. Hygnstrom.) pp. 67–72. (Kansas State University.)

Epstein J. , Shaw P. , McKee J. , and Kaufman G. (2001). Assessing the potential for disease transmission from Australian white ibis (Threskiornis molucca) to humans and food-production animals: a behavioural and epidemiologic survey. In ‘Proceedings of the American Association of Zoo Veterinarians, American Association of Wildlife Vets, Association of Reptilian & Amphibian Vets, National Association of Zoo & Wild Vets, Joint Conference Orlando, Florida’. (Eds C. K. Baer and M. M. Willette.) pp. 185–187.

Feare C. J. (1991). Control of bird pest populations. In ‘Bird Population Studies’. (Eds C. M. Perrins, J.-D. Lebreton and G. J. M. Hirons.) pp. 463–478. (Oxford University Press: Oxford.)

Freeman B. M. , and Vince M. A. (1974). ‘Development of the Avian Embryo.’ (Chapman and Hall: London.)

Gross A. O. (1951) The herring gull–cormorant control project. In ‘Proceedings of the 10th International Ornithological Congress’. (Ed. S. Hörstadius.) pp. 532–536. (Uppsala, Sweden.)

Kingsford, R. T. , and Johnson, W. (1998). Impact of water diversions on colonially-nesting waterbirds in the Macquarie marshes of arid Australia. Colonial Waterbirds 21, 159–170.
Crossref | GoogleScholarGoogle Scholar | Kingsford R. T. , Porter J. L. , and Ahern A. D. (2002). Aerial survey of wetland birds in eastern Australia – October 2000–2002. NSW National Parks and Wildlife Service Occasional Paper No. 33.

Kopij, G. (1999). Breeding ecology of the sacred ibis Threskiornis aethiopicus in the Free State, South Africa. South African Journal of Wildlife Research 29, 25–30.
Legoe C. (2002). A health survey of Australian white ibis (Threskiornis molucca) in the Sydney region for disease of avian and public health importance. M.Sc. Thesis, University of Sydney.

Le Souëf, W. H. D. (1917). Australian ibises. Emu 17, 94–95.
Low T. (2003). ‘The New Nature: Winners and Losers in Wild Australia.’ (Penguin Books: Australia.)

Lowe K. W. (1984). The feeding and breeding biology of the sacred ibis Threskiornis aethiopicus in southern Victoria. Ph.D. Thesis, University of Melbourne.

Lowe, K. W. , and Richards, G. C. (1991). Morphological variation in the sacred ibis Threskiornis aethiopicus superspecies complex. Emu 91, 41–45.
Martin J. , and Dawes J. (2005). Egg oil: A tool for the management of pest bird populations. In ‘13th AustralasianVertebrate Pest Management Conference’. (Ed. J. Parks.) p. 234. (Wellington, New Zealand.)

Mayfield, H. F. (1975). Suggestions for calculating nest success. Wilson Bulletin 87, 456–466.
Pochop P. A. , Cummings J. L. , Steuber J. E. , and Yoder C. A. (1998 b). Comparison of white mineral oil and corn oil to reduce hatchability in ring-billed gull eggs. In ‘Proceedings of the 18th Vertebrate Pest Conference’. (Eds R. O. Baker and A. C. Crabb.) pp. 411–412. (University of California: Davis, CA.)

Porter J. L. , Kingsford R. T. , and Hunter S. J. (2006). Aerial survey of wetland birds in eastern Australia – October 2003–2005. NSW National Parks and Wildlife Service Occasional Paper No. 37.

Ross G. A. (2004). Ibis in urban Sydney: a gift from Ra or a pharaoh’s curse? In ‘Urban Wildlife: More than Meets the Eye’. (Eds D. Lunney and S. Burgin.) pp. 148–152. (Royal Zoological Society of New South Wales: Sydney.)

Shaw P. (1999). Integrated management systems for Australian white ibis Threskiornis molucca on the Gold Coast, Queensland, Australia. In ‘Bird 1999 Committee – USA/Canada Proceedings, First Joint Annual Meeting’. (Ed. B. Mackinnon.) pp. 139–147. (Vancouver, BC.)

Symonds S. (1999). ‘Healesville Sanctuary: a Future for Australian Wildlife.’ (Australian Scholarly Publishing: Melbourne.)

Underwood, M. , and Bunce, A. (2004). The breeding biology of the white-faced storm petrel (Pelagodroma marina) on Mud Island, Port Phillip Bay, Victoria. Emu 104, 213–220.
Crossref | GoogleScholarGoogle Scholar |