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 > WR06116
RESEARCH ARTICLE
Contents Vol 35(2)

Home range and movements of radio-tracked estuarine crocodiles (Crocodylus porosus) within a non-tidal waterhole

Matthew L. Brien A E , Mark A. Read B , Hamish I. McCallum C and Gordon C. Grigg D
+ Author Affiliations
- Author Affiliations

A University of Florida, Fort Lauderdale Research and Education Center, 3205 College Avenue, Davie, FL 33314, USA.

B Great Barrier Marine Park Authority, PO Box 1379, Townsville, Qld 4810, Australia.

C School of Zoology, University of Tasmania, Private Bag 5, Hobart, Tas. 7001, Australia.

D Department of Zoology and Entomology, School of Integrative Biology, The University of Queensland, Brisbane, Qld 4072, Australia.

E Corresponding author. Email: mbrien@ufl.edu

Wildlife Research 35(2) 140-149 https://doi.org/10.1071/WR06116
Submitted: 24 August 2006  Accepted: 15 February 2008   Published: 21 April 2008

Abstract

We radio-tracked five male and eight female estuarine crocodiles (Crocodylus porosus) in a non-tidal waterhole in Lakefield National Park in northern Queensland during the late dry/mid-wet season (2003–04) and the following dry season (2004). Individual crocodiles occupied larger home ranges (River Channel Areas (RCA) during the late dry/mid-wet season (10.64 ± 2.86 ha) than in the dry season (3.20 ± 1.02 ha), and males occupied larger home ranges (23.89 ± 2.36 ha) than females (5.94 ± 1.34 ha) during the late dry/mid-wet season. There were no obvious differences in home range between sexes during the dry season. During the late dry/mid-wet season, adult males often travelled long distances along the waterhole while females moved less. During the dry season, movement patterns were quite variable, with no clear difference between sexes. All crocodiles were most active from late afternoon (1500–1800 hours) until midnight. Individual home ranges (RCA) overlapped considerably during the late dry/mid-wet season. The extent of home-range overlap between three adult males and the number of times they either passed each other or were located near each other was particularly striking. Previous research has come to conflicting conclusions about the extent of territoriality in wild estuarine crocodiles, although it has been widely believed that males are highly territorial. The findings imply that large adult male estuarine crocodiles are not highly territorial in non-tidal freshwater systems that are geographically confined.


Acknowledgements

This project was partly funded by the Queensland Parks and Wildlife Service through the Australia Zoo Crocodile Research Fund. All field work involving crocodiles was approved by the University of Queensland Animal Ethics Committee, which follows National Health and Medical Research Council of Australia guidelines. Australia Zoo staff, Lakefield rangers, Annabelle Olsen and Rosemary Read provided support and assistance during the project. Michael Cherkiss and Valerie Johnson edited an early draft of the paper. We thank the three anonymous reviewers for their valuable comments and editing. Most importantly, we thank Jemeema Carrigan, who was an integral part of all the field work; without her this project would not have been possible.


References

Australian Bureau of Meteorology (1989). ‘Climate of Australia.’ (Department of Administration Services: Melbourne.)

Bustard, H. R. , and Choudhury, B. C. (1980). Long distance movement by a salt water crocodile (Crocodylus porosus). British Journal of Herpetology 6, 87.
Chabreck R. H. (1965). The movement of alligators in Louisiana. Proceedings of the Annual Conference of the Southeastern Association of Game and Fish Commissioners 19, 102–110.

Cohen K., Cook M., and Pearce H. (2001). ‘Heritage Trails of the Tropical North.’ (Queensland Environmental Protection Agency: Brisbane.)

Cott, H. B. (1961). Scientific results of an inquiry into the ecology and economic status of the Nile crocodile (Crocodylus niloticus) in Uganda and northern Rhodesia. Transactions of the Zoological Society of London 29, 211–356.
Hardy A. R., and Taylor K. D. (1980). Radio tracking of Rattus norvegicus on farms. In ‘A Handbook on Biotelemetry and Radio Tracking: Proceedings of an International Conference on Telemetry and Radio Tracking in Biology and Medicine, Oxford, 20–22 March 1979’. (Eds C. J. Amlaner, Jr and D. W. Macdonald.) pp. 657–665. (Pergamon Press: Oxford.)

Haynes C. D., Ridpath M. G., and Williams M. A. J. (1991). ‘Monsoonal Australia: Landscape, Ecology and Man in the Northern Lowlands.’ (A.A. Balkema: Rotterdam.)

Henschel, J. R. , and Skinner, J. D. (1991). Territorial behaviour by a clan of spotted hyaenas Crocuta crocuta. Ethology 88, 223–235.
Hooge P. N. (2002). Animal movement analysis extension. Alaska Biological Science Center, USGS, Anchorage. Available online at http://www.absc.usgs.gov/glba/gistools/animal_mvmt.htm [Verified April 2008].

Hooge P. N., and Eichenlaub B. (2001). Animal movement extension to Arcview, ver 2.2. Alaska Biological Science Center, USGS, Anchorage.

Horner, M. A. , and Powell, R. A. (1990). Internal structure of home ranges of black bears and analyses of home range overlap. Journal of Mammalogy 71, 402–410.
| Crossref | GoogleScholarGoogle Scholar | Jenkins W. G., and Forbes M. A. (1985). Seasonal variation in abundance and distribution of Crocodylus porosus in the tidal East Alligator River, northern Australia. In ‘Biology of Australasian Frogs and Reptiles’. (Eds G. Grigg, R. Shine and H. Ehmann.) pp. 63–69. (Royal Zoological Society of NSW: Sydney.)

Joanen, T. , and McNease, L. (1970). A telemetric study of nesting female alligators on Rockefeller Refuge, Louisiana. Proceedings of the Annual Conference of the Southeastern Association of Game and Fish Commissioners 24, 175–193.
Kenward R. E. (2001). ‘A Manual for Wildlife Radio Tagging.’ (Academic Press: London.)

Kernohan B. J., Gitzen R. A., and Millspaugh J. J. (2001). Analysis of animal space use and movements. In ‘Radio Tracking and Animal Populations’. (Eds J. J. Millspaugh and J. M. Marzluff.) pp. 125–166. (Academic Press: San Diego, CA.)

Kushlan, J. A. , and Mazzotti, F. J. (1989). Population biology of the American crocodile. Journal of Herpetology 23, 7–21.
| Crossref | GoogleScholarGoogle Scholar | Lang J. W. (1987). Crocodilian behaviour: implications for management. In ‘Wildlife Management: Crocodiles and Alligators’. (Eds G. J. W. Webb, S. C. Manolis and P. J. Whitehead.) pp. 273–294. (Surrey Beatty: Sydney.)

Magnusson, W. E. , and Lima, A. P. (1991). The ecology of a cryptic predator, Paleosuchus trigonatus, in a tropical rainforest. Journal of Herpetology 25, 41–48.
| Crossref | GoogleScholarGoogle Scholar | McCullagh P., and Nelder J. A. (1989). ‘Generalized Linear Models.’ (Chapman and Hall: London.)

Melquist, W. E. , and Hornocker, M. G. (1983). Ecology of river otters in west central Idaho. Wildlife Monographs 83, 1–60.
Messel H., and Vorlicek G. C. (1987). population model for Crocodylus porosus in the tidal waterways of northern Australia: management implications. In ‘Wildlife Management: Crocodiles and Alligators’. (Eds G. J. W. Webb, S. C. Manolis and P. J. Whitehead.) pp. 189–198. (Surrey Beatty: Sydney.)

Messel H., Vorlicek A. G., Wells A. G., and Green W. J. (1980). ‘The Blyth–Cadell River System Study and the Status of Crocodylus porosus in Tidal Waterways of Northern Australia.’ (Pergamon Press: Sydney.)

Messel H., Vorlicek G. C., Wells A. G., Green W. J., Curtis H. S., Roff C. R. R., Weaver C. M., and Johnson A. (1981). ‘Surveys of Tidal Waterways on Cape York Peninsula, Queensland, Australia and their Crocodile Populations. Monograph 16. South Western Cape York Peninsula (Nassau, Staaten and Gilbert River Systems and Duck Creek System) and Northern Cape York Peninsula (Port Musgrave: Wenlock and Ducie River Systems, Palm, Dulcie and Namaleta Creeks, Escape River).’ (Pergamon Press: Sydney.)

Millspaugh J. J., and Marzluff J. M. (2001). Radio tracking and animal populations: past trends and future needs. In ‘Radio Tracking and Animal Populations’. (Eds J. J. Millspaugh and J. M. Marzluff.) pp. 383–393. (Academic Press: San Diego, CA.)

Minns, C. K. (1995). Allometry of home range size in lake and river fishes. Canadian Journal of Fisheries and Aquacultural Science 52, 1499–1508.
Powell R. A. (1989). Effects of resource productivity, patchiness and predictability on mating and dispersal strategies. In ‘Comparative Socioecology of Mammals and Humans’. (Eds V. Standen and R. A. Foley.) pp. 101–123. (Blackwell Scientific: Oxford.)

Powell R. A. (1994). Structure and spacing of Martens populations. In ‘Sables and Fishers: Biology and Conservation’. (Eds S. W. Buskirk, A. S. Harestad, M. G. Raphael and R. A. Powell.) pp. 101–121. (Cornell University Press: New York.)

R Development Core Team (2006). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. Available online at http://www.R-project.org [Verified March 2008].

Read, M. A. , Grigg, G. C. , Irwin, S. R. , Shanahan, D. , and Franklin, C. E. (2007). Satellite tracking reveals long distance coastal travel and homing by translocated estuarine crocodiles. PLos One 2, e949.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Taplin L. E. (1987). The management of crocodiles in Queensland, Australia. In ‘Wildlife Management: Crocodiles and Alligators’. (Eds G. J. W. Webb, S. C. Manolis and P. J. Whitehead.) pp. 129–140. (Surrey Beatty: Sydney.)

Taylor, D. (1984). Management implications of an adult female alligator telemetry study. Proceedings of the Annual Conference of the Southeastern Association of Fish and Wildlife Agencies 38, 222–227.
Webb G. J. W. (1991). The influence of season on Australian crocodiles. In ‘Monsoonal Australia: Landscape, Ecology and Man in the Northern Lowlands’. (Eds C. D. Haynes, M. G. Ridpath and M. A. J. Williams.) pp. 125–131. (A.A. Balkema: Rotterdam.)

Webb G. J. W., and Manolis S. C. (1989). ‘Australian Crocodiles: a Natural History.’ (New Holland Publishers: Sydney.)

Webb, G. J. W. , and Messel, H. (1978). Movement and dispersal patterns of Crocodylus porosus in some rivers of Arnhem Land, northern Australia. Australian Wildlife Research 5, 263–283.
| Crossref | GoogleScholarGoogle Scholar |

Webb, G. J. W. , Messel, H. , and Magnusson, W. E. (1977). The nesting biology of Crocodylus porosus in Arnhem Land, northern Australia. Copeia 1977, 238–249.
| Crossref | GoogleScholarGoogle Scholar |

Webb, G. J. W. , Messel, H. , Crawford, J. , and Yerbury, M. (1978). Growth rates of Crocodylus porosus (Reptilia: Crocodilia) from Arnhem Land, northern Australia. Australian Wildlife Research 5, 385–399.
| Crossref | GoogleScholarGoogle Scholar |

Welch, B. L. (1947). The generalization of ‘student’ problems when several different population variances are involved. Biometrika 34, 28–35.


Worton, B. J. (1989). Kernel methods for estimating the utility distribution in home range studies. Ecology 70, 164–168.
| Crossref | GoogleScholarGoogle Scholar |

Worton, B. J. (1995). Using Monte Carlo simulation to evaluate kernel-based home range estimators. Journal of Wildlife Management 59, 794–800.
| Crossref | GoogleScholarGoogle Scholar |