Register      Login
Emu Emu Society
Journal of BirdLife Australia
Shopping Cart: ( empty )
You are here: Home > Journals > MU > MU08053
RESEARCH ARTICLE
Contents Vol 109(3)

Do Palm Cockatoos (Probosciger aterrimus) have long enough lifespans to support their low reproductive success?

Robert Heinsohn A F , Tanya Zeriga A B , Stephen Murphy C , Paul Igag D , Sarah Legge C and Andrew L. Mack E
+ Author Affiliations
- Author Affiliations

A Fenner School of Environment and Society, Australian National University, Canberra, ACT 0200, Australia.

B Wildlife Conservation Society, PO Box 277, Goroka, EHP, Papua New Guinea.

C Australian Wildlife Conservancy, Suite 5 Hay Street, Subiaco, WA 6008, Australia.

D Papua New Guinea Institute of Biological Research, Goroka, EHP, Papua New Guinea.

E Powdermill Nature Reserve, 1847 Rte 381, Rector, PA 18677, USA.

F Corresponding author. Email: Robert.Heinsohn@anu.edu.au

Emu 109(3) 183-191 https://doi.org/10.1071/MU08053
Submitted: 4 October 2008  Accepted: 16 April 2009   Published: 13 August 2009

Abstract

As an order, Parrots (Psittaciformes) are both the longest lived birds and among the most endangered. Palm Cockatoos (Probosciger aterrimus) have an extremely slow life history, including one of the lowest rates of breeding success reported for parrots. Here we use population viability analysis (PVA) to examine whether populations of Palm Cockatoos are viable in the long term with such low rates of reproduction. We built PVA models for two field sites with robust data on reproductive success and availability of nest-hollows: Iron Range on Cape York Peninsula (Queensland, Australia) and Crater Mountain (Eastern Highlands Province, Papua New Guinea). Our Iron Range models incorporate a fluctuating resource base of nest-hollows resulting from natural losses from fire, wind and tree decay and natural replenishment through tree breakages in tropical cyclones. The number of females allowed to breed each year in the simulations was limited by the availability of hollows. Our Iron Range models suggest that the population is only viable if juvenile and adult mortality rates are very low, and that at least some birds in the population live to 100 years old. Based on known maximum lifespans in the Cacatuidae, we conclude that Palm Cockatoos at Iron Range are unlikely to live for long enough on average to support their low rates of reproduction, and highlight the possibility that the population may be in decline. At Crater Mountain, where nestlings are harvested for food by local people, the models suggest that the reported current rate of 40% of nestlings taken is not sustainable.


Acknowledgements

We thank Naomi Langmore and three anonymous reviewers for helpful comments on the manuscript, and Bob Lacy and Phil Miller for technical assistance with VORTEX. Our research on Palm Cockatoos has been supported by grants from the World Parrot Trust, the Hermon Slade Foundation, and through excellent logistical support from the Fenner School of Environment and Society, Australian National University.


References

Austad, S. N. (1993). The comparative perspective and choice of animal models in aging research. Aging Clinical and Experimental Research 5, 259–267.
Australian Bureau of Meteorology (2009). Tropical cyclones in Queensland: Historical impacts along the east coast. Available at http://www.bom.gov.au/weather/cyclone/about/cyclones-eastern-impacts.shtml [Verified 1 July 2009].

Beissinger, S. R. , and Westphal, M. I. (1998). On the use of demographic models of population viability in endangered species management. Journal of Wildlife Management 62, 821–841.
| Crossref | GoogleScholarGoogle Scholar | BirdLife International (2009). What’s new (2009). Available at http://www.birdlife.org/action/science/species/global_species_programme/whats_new.html [Verified 1 July 2009].

Brook, B. W. , and Whitehead, P. J. (2005). Plausible bounds for maximum rate of increase in magpie geese (Anseranas semipalmata): implications for harvest. Wildlife Research 32, 465–471.
| Crossref | GoogleScholarGoogle Scholar | Igag P. (2002). The conservation of large rainforest parrots: a study of the breeding biology of palm cockatoos, eclectus parrots and Pesquet’s parrots. M.Sc. Thesis, Australian National University, Canberra.

IUCN (2008). ‘2008 IUCN Red List of Threatened Species.’ (International Union for Conservation of Nature.) Available at www.iucnredlist.org [Verified 1 July 2009].

Johnson, A. , Bino, R. , and Igag, P. (2004). A preliminary evaluation of the sustainability of cassowary (Aves : Casuariidae) capture and trade in Papua New Guinea. Animal Conservation 7, 129–137.
| Crossref | GoogleScholarGoogle Scholar | Juniper T. , and Parr M. (1998). ‘Parrots: A Guide to Parrots of the World.’ (Pica Press: Sussex, UK.)

Lacy, R. C. (1993). VORTEX: A computer simulation model for Population Viability Analysis. Wildlife Research 20, 45–65.
| Crossref | GoogleScholarGoogle Scholar | Mack A. L. , and West P. (2005). Ten thousand tonnes of small animals: Wildlife consumption in Papua New Guinea, a vital resource in need of management. Resource Management in Asia-Pacific Working Paper No. 61. Australian National University, Canberra.

Miller P. S. , and Lacy R. C. (2005). ‘Vortex: A Stochastic Simulation of the Extinction Process. Version 9.50 User’s Manual.’ (Conservation Breeding Specialist Group (Species Survival Commission and International Union for Conservation of Nature): Apple Valley, MN.)

Munshi-South, J. , and Wilkinson, G. S. (2006). Diet influences life span in parrots. Auk 123, 108–118.
| Crossref | GoogleScholarGoogle Scholar | Nelder V. , and Clarkson J. (1995). ‘Vegetation Survey of Cape York Peninsula. Cape York Peninsula Land Use Strategy.’ (Department of Environment and Heritage: Brisbane.)

Newton I. (1989). ‘Lifetime Reproduction in Birds.’ (Academic Press: London, UK.)

O’Grady, J. J. , Brook, B. W. , Reed, D. H. , Ballou, J. D. , Tonkyn, D. W. , and Frankham, B. (2006). Realistic levels of inbreeding depression strongly affect extinction risk in wild populations. Biological Conservation 133, 42–51.
| Crossref | GoogleScholarGoogle Scholar | Snyder N. , McGowan P. , Gilardi J. , and Grajal A. (2004). ‘Parrots: Status Survey and Conservation Action Plan 2000–2004.’ (International Union for Conservation of Nature: Gland, Switzerland.)

Walker, J. S. , Cahill, A. J. , and Marsden, S. J. (2005). Factors influencing nest-site occupancy and low reproductive output in the Critically Endangered Yellow-crested Cockatoo Cacatua sulphurea on Sumba, Indonesia. Bird Conservation International 15, 347–359.
| Crossref | GoogleScholarGoogle Scholar |