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Gillian Bryant   BSc. (Hons), Zoology UWA

Doctor of Philosophy Thesis

The southwest carpet python (Morelia spilota imbricata): Thermal biology, conservation and mesopredator release response in a threatened snake species in coastal woodland and jarrah forest of southwest Western Australia

Supervisors:

  • Dr Trish Fleming BSc (Hons), MSc, PhD
  • Dr Kris Warren BSc. BVMS (Hons) PhD, Murdoch University
  • Paul de Tores BSc. Dip.Nat.Res., Department of Environment and Conservation (WA)

My PhD research has focused on ecological aspects of the southwest carpet python (Morelia spilota imbricata) in two habitat types in southwest Western Australia, the swan coastal plain, north of Bunbury, and in the jarrah forest surrounding Dwellingup. 

The research has been part of two distinct wider research groups.  Pythons were included in a program run by The Department of Environment and Conservation (DEC) and funded by the Australian Research Council, to determine factors that affect the translocation outcomes of the endangered western ringtail possum (Pseudocheirus occidentalis).  Pythons, being efficient predators, seemed to be playing a significant role in reducing the possums’ success of translocation!  Drs Judy Clarke and Helen Grimm, PhD researchers at Murdoch University have focussed their research on the possums.  The second research program, also managed by DEC researches and funded by the Invasive Animals CRC, has been examining the mesopredator release hypothesis across many areas in Western Australia.  A reduction or elimination of apex (top-order) predators will undoubtedly destabilise the food web present in the ecosystem to some extent (Prugh, Stoner, Epps et al., 2009, Soulé, Bolger, Alberts et al., 1988). In this instance, there may be an increase in abundance of smaller, lower-order predators, ‘mesopredators’, through mesopredator release.  I researched pythons, as a mesopredator, in response to the DEC fox baiting program.

In order to monitor the ecology of this threatened species I was trained by Dr Paul Eden from Perth Zoo and my co-supervisor Dr Kristin Warren to surgically implant radiotransmitters into the python’s coelomic cavities.  The radiotransmitters can last up to three years, depending on their size, allowing long-term monitoring of these magnificent animals in their natural environment.  Additionally, each radiotransmitter was equipped with temperature loggers that recorded the python’s internal body temperature every hour.  I also collected blood from pythons during the implanting procedure and following surgery which assessed the health implications of implanting the radiotransmitters into the pythons.  Through weekly radiotelemetry of each implanted python, I collected data on their thermal biology, foraging behaviour, diet, habitat use and their mating system. 

Through this research I have several different research papers in press or under review (see below for details) with the collaboration of my supervisors, Trish, Kris and Paul, and research colleagues I have made along the way, Dr Bill Bateman (University of Pretoria, South Afric), Dr Paul Eden (Perth Zoo), Shannon Dundas (Murdoch University) and Dr Leanne Twomey (Vet Path).  I hope that my PhD research will provide additional knowledge on this unique West Australian species of python which will aid in the species’ long-term conservation.

Literature cited:

Prugh, L., et al. (2009). The rise of the mesopredator. Bioscience, 59: 779.
Soulé, M. E., et al. (1988). Reconstructed dynamics of rapid extinctions of chaparral-requiring birds in urban habitat islands. Conservation Biology, 2: 75-92.

Publications:

Bryant, G.L., Eden, P., de Tores, P.J. & Warren, K. In Press. Development of an improved procedure for implanting radiotransmitters into the coelomic cavities of snakes. Australian Veterinary Journal
Bryant, G.L., de Tores, P.J., Warren, K. & Fleming, P.A. In review. Does size matter? The influence of body size and thermal biology on the diet of a threatened python species (Morelia spilota imbricata).
Bryant, G.L., Dundas, S. & Fleming, P.A. In review. Are tree hollows providing a cosy nest for carpet pythons?
Bryant, G.L., Bateman, P.W. & Fleming, P.A. In review. Tantalising Tongues: male carpet pythons use chemoreception to differentiate between females.
Bryant, G.L., Fleming, P.A., Twomey, L, & Warren, K. In prep. Haematology and serum biochemistry of the southwest carpet python (Morelia spilota imbricata): factors that affect blood values.

Conference Presentations:

Bryant, G.L., Warren, K., deTores, P., and Fleming, P.A. Australasian Management Society – oral presentation, 2009.Title: Is Bigger Better? The influence of body size and thermal biology on the diet of a threatened python species (Morelia spilota imbricata)
Bryant, G. L. and Fleming Patricia .A. Australian New Zealand society for comparative physiology and biochemistry – oral presentation, 2009. Title: Thermal biology of free-ranging southwest carpet pythons (Morelia spilota imbricata)
Bryant, G. L., Bateman, P.W. and Fleming P.A. Australian New Zealand society for comparative physiology and biochemistry – poster presentation, 2009.Title: Sniffing out sex: male carpet pythons use chemosensory information to find sexually attractive females.
Bryant, G.L., deTores, P., and Fleming, P.A. Combined Biological Sciences Meeting Conference - oral presentation, 2009. Title: Size Does Matter: The influence of body size on the diet of a threatened python species Morelia spilota imbricata.
Bryant, G.L., Bateman, P.W., and Fleming, P.A.Second Meeting of the Australian Societies for Herpetology - oral presentation, 2009. Title: Tantalising tastes: Male carpet pythons use chemoreception to differentiate between females.
Bryant, G.L. and Fleming, P.A.Second Meeting of the Australian Societies for Herpetology - oral presentation, 2009.Title: Winter retreats: Are tree hollows providing a cosy nest for carpet pythons?
Bryant, G.L. and Fleming, P.A.Australian Wildlife Management Society (AWMS) Conference - oral presentation, 2008.Title: The role of a hole: how important are tree hollows for pythons?
Bryant, G.L., Fleming, P.A., Warren, K. and deTores, P. Australian Wildlife Management Society (AWMS) Conference - poster presentation, 2008. Title: Pythons, foxes and possums.:
Bryant, G.L., Fleming, P.A., Warren, K. and deTores, P. Combined Biological Sciences Meeting Conference - poster presentation, 2008. Title: Haematological characteristics of blood cells in the south-west carpet python (Morelia spilota imbricata): Some factors that affect blood values.
Bryant, G.L., Fleming, P.A., Warren, K. and deTores, P.Australian Society of Herpetologists (ASH) Conference - oral presentation, 2007. Title: Comparisons of behavioural thermal regulation of the south west carpet python (Morelia spilota imbricata) in different habitats: are foxes an influence?
Bryant, G.L., Fleming, P.A., Warren, K. and deTores, P.Wildlife Disease Association (WDA) Conference - oral presentation, 2007. Title: Haematological characteristics of the south-west carpet python (Morelia spilota imbricata): factors that affect blood values.
deTores, P., Marlow, N., Morris, K., Algar, D., Glen, A., Sutherland, D., Bryant, G.L., Cruz, J. Ecological Society of Australia (ESA) Conference - poster presentation, 2007. Title: Mesopredator release – a response to 1080 control of foxes in WA. What is the evidence and what are we doing?

Awards:

  • 2009       Best student talk on a conservation topic. - 22nd Australasian Management Society Annual Conference, Napier, New Zealand
  • 2009       Best poster. - 26th Annual Meeting of the Australian New Zealand Society for Comparative Physiology and Biochemistry, Geelong University, Victoria.
  • 2008       Best poster on: Getting back to Nature: Wildlife biology. - School of Veterinary and Biomedical Sciences, Murdoch University Research Poster Day 2008.
  • 2006       Best poster on:  Wildlife biology or welfare. - School of Veterinary and Biomedical Sciences, Murdoch University Research Poster Day 2006.

Acknowledgements:

I wish to thank all the fantastic volunteers (too many to mention here) who have helped me with field work and surgery.  Without their help my research would have been considerably more difficult.  This research was undertaken with financial support provided by the Australian Research Council, the Western Australian Department of Environment and Conservation and the School of Veterinary and Biomedical Sciences Murdoch University. The Invasive Animals CRC provided in-kind support for this project.

Photos provided by Gillian Bryant.

Department of Environment and ConservationAustralian Government | Australian Research CouncilInvasive Animals Cooperative Research Centre