Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats
Shopping Cart: ( empty )
You are here: Home > Journals > WR > WR06059
RESEARCH ARTICLE
Contents Vol 34(1)

A morphological model for sexing nestling peregrine falcons (Falco peregrinus macropus) verified through genetic analysis

Victor G. Hurley A , Fiona Hogan A B , John G. White A and Raylene Cooke A C
+ Author Affiliations
- Author Affiliations

A School of Life and Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, Vic. 3125, Australia.

B Population and Evolutionary Genetics Unit, Museum Victoria, GPO Box 666E, Melbourne, Vic. 3001, Australia.

C Corresponding author. Email: raylene.cooke@deakin.edu.au

Wildlife Research 34(1) 54-58 https://doi.org/10.1071/WR06059
Submitted: 29 May 2006  Accepted: 5 January 2007   Published: 27 February 2007

Abstract

Adult peregrine falcons (Falco peregrinus macropus) have monotypic plumage and display strong reversed sexual dimorphism, with females significantly larger than males. Reversed sexual dimorphism is measurable among nestlings in the latter stages of their development and can therefore be used to differentiate between sexes. In the early stages of development, however, nestlings cannot be sexed with any degree of certainty because morphological differentiation between the sexes is not well developed. During this study we developed a model for sexing younger nestlings based on genetic analysis and morphometric data collected as part of a long-term banding study of this species. A discriminant function model based on morphological characteristics was developed for determining the sex of nestlings (n = 150) in the field and was shown to be 96.0% accurate. This predictive model was further tested against an independent morphometric dataset taken from a second group of nestlings (n = 131). The model correctly allocated sex to 96.2% of this second group of nestlings. Sex can reliably be determined (98.6% accurate) for nestlings that have a wing length of at least 9 cm using this model. Application of this model, therefore, allows the banding of younger nestlings and, as such, significantly increases the period of time over which banding can occur. Another important implication of this model is that by banding nestlings earlier, they are less likely to jump from the nest, therefore reducing the risk of injury to both the brood and the bander.


Acknowledgements

Thanks must first and foremost go to the volunteers of the Victorian Peregrine Project, in particular those that assisted in collecting morphometric data, namely: M. Manhal, P. Wignell, D. McKinty, J. Cashin, D. Hay, F. Cross, S. Moore and the various students especially M. Boulet, M. Awasthy, N. Wagner, B. Denis and S. Gelinet. Our heartfelt thanks go to Jim and Sherry Watson. We thank the following sponsors whose generous support made this project possible: Ford Motor Co. Australia, Boral Resources, the R. E. Ross Trust, Joyce W. Vickery Trust, Australian Geographic, Optus Communications, Readymix, Parks Victoria and Southern Cement and CMIL (owners of 367 Collins Street) and the postgraduate support program of Deakin University and the Holsworth Wildlife Research Endowment. Museum Victoria is thanked for providing validation samples and three anonymous referees for their comments on the paper. Birds Australia, in particular Chris Tzaros and Mike Weston, are thanked for providing assistance. This research was conducted under research permit number 10003190 and ABBBS Banding Authority No. 1705.


References

Arroyo, B. E. , DeCornulier, T. , and Bretagnolle, V. (2000). Sex and age determination of short-eared owl nestlings. Condor 102, 216–219.
| Crossref | GoogleScholarGoogle Scholar | Brown L., and Amadon D. (1989). ‘Eagles, Hawks and Falcons of the World.’ (Spring Books: Hong Kong.)

Cade T. J., Enderson J. H., Thelander C. G., and White C. M. (1988). ‘Peregrine Falcon Populations, their Management and Recovery.’ (The Peregrine Fund Inc: Boise, ID.)

Delgado, M. D. M. , and Penteriani, V. (2004). Gender determination of Eurasian eagle-owls (Bubo bubo) by morphology. Journal of Raptor Research 38, 375–377.
Lowe K. W. (1989). ‘The Australian Bird Bander’s Manual.’ (Australian National Parks and Wildlife Service, Commonwealth of Australia: Canberra.)

Marchant S., and Higgins P. J. (Eds) (1993). ‘Handbook of Australian, New Zealand and Antarctic birds. Volume 2, Raptors to Lapwings.’ (Oxford University Press: Melbourne.)

McDonald, P. G. (2003). Nestling growth and development in the brown falcon, Falco berigora: an improved ageing formula and field-based method of sex determination. Wildlife Research 30, 411–418.
| Crossref | GoogleScholarGoogle Scholar | Mooney N. J., and Brothers N. (1993). Dispersion, nest and pair fidelity of peregrine falcons Falco peregrinus in Tasmania. In ‘Australian Raptor Studies’. (Ed. P. D. Olsen.) pp. 33–42. (RAOU: Currumbin, Qld.)

Mueller, H. C. (1990). Can saw-whet owls be sexed by external measurements? Journal of Field Ornithology 61, 339–346.
Nisbet I. C. T. (1988). Summary. In ‘Peregrine Falcon Populations: Their Management and Recovery’. (Eds T. J. Cade, J. H. Enderson, C. G. Thelander and C. M. White.) pp. 851–855. (The Peregrine Fund Inc: Boise, ID.)

Olendorf, R. R. (1972). Weighing and measuring raptors. Journal of Raptor Research 6, 53–56.
Olsen P. D. (1995). ‘Australian Birds of Prey.’ (University of New South Wales Press: Sydney.)

Olsen, P. D. , and Cockburn, A. (1991). Female-biased sex allocation in peregrine falcons and other raptors. Behavioural Ecology and Sociobiology 28, 417–423.
| Crossref | GoogleScholarGoogle Scholar | Porter R. D., Jenkins A. M., and Gaski A. L. (Eds) (1987). ‘Working Bibliography of the Peregrine Falcon.’ (Institute for Wildlife Research, National Wildlife Federation: Washington DC.)

White C. M. (1987). The peregrine: systematics and evolution. In ‘Working Bibliography of the Peregrine Falcon’. (Eds R. D. Porter, A. Jenkins and A. Gaski.) National Wildlife Federation Science Technical Series No. 9. (Institute for Wildlife Research, National Wildlife Federation: Washington, DC.)

White C. M., and Boyce D. A. (1988). An overview of peregrine falcon subspecies. In ‘Peregrine Falcon Populations: Their Management and Recovery’. (Eds T. J. Cade, J. H. Enderson, C. G. Thelander and C. M. White.) pp. 789–810. (The Peregrine Fund Inc: Boise, ID.)

White C. M., Parrish J. R., Brimm D. J., and Longmire J. L. (1993). Aspects of variation between peregrine falcons (Falco peregrinus); a review with emphasis on Southern Hemisphere populations. In ‘Australian Raptor Studies’. (Ed. P. D. Olsen.) pp. 13–24. (RAOU: Currumbin, Qld.)