Dr Ivan Lawler

Dr Ivan Lawler

Adjunct Lecturer in Environmental Science

BSc Hons (JCU)


Research Interests

My primary research area is dugong ecology. In particular I am involved in estimating dugong abundance and distribution via aerial survey techniques. My aim is refine these methods using improved knowledge of diving behaviour to correct for sub-surface animals that are not seen during aerial surveys. The diving research is also now expanding also into the area of dugong feeding ecology and small-scale movements. Using new GPS-based tracking devices we can determine dugong locations several times every hour with an accuracy of less than a few metres. Combined with data on diving behaviour this will give us unprecedented information into the use of habitat by dugongs. I also have strong interests in herbivory. My PhD studies looked at the importance of a newly-discovered group of toxins for the feeding choices of marsupials browsing on eucalypt foliage (possums and koalas). The concentrations of these toxins vary dramatically from tree to tree, even within favoured food species. The implications of this are that some individual trees of food species are not available as food items. A species-based approach to estimating food abundance for these animals substantially overestimates food availability and habitat quality.

Brief description of research impact:

  • Contribution of data used in rezoning of Great Barrier Reef . The data collected by Prof Helene Marsh and myself is the key body of work on which understanding of the distribution and abundance of dugongs in the Great Barrier Reef is based.

  • Implementation of go-slow zones for dugong in Great Sandy Marine Park. Data on satellite tracked movement of dugongs and boater behaviour was used by Qld Environment Protection Agency in developing the zoning plans for the newly established Great Sandy Marine Park

  • Involvement of indigenous people in research and management of dugongs. A key problem in developing approaches for co-management of wildlife between management agencies and traditional owners is the lack of communication and understanding between both sides. I have contributed to this understanding by working with indigenous people and providing educational material to them.

Selected Publications:

Lawler, IR, Foley WJ, Eschler B (2000) Foliar concentration of a single toxin creates habitat patchiness for a marsupial folivore. Ecology 81: 1327–1338.

Marsh HD, Lawler IR, Kwan DM, Delean JSC, Pollock KH & Alldredge MR (2004) Aerial surveys and the potential biological removal technique indicate that the Torres Strait dugong fishery is unsustainable.Animal Conservation, 7, 435 – 447

Andre' J & Lawler IR (2003) Near infrared spectroscopy as a rapid and inexpensive means of dietary analysis for a marine herbivore, dugong Dugong dugon.Marine Ecology-Progress Series, 257, 257 - 266*

Foley WJ, Lawler IR, Moore BD, Marsh KJ & Wallis IR (2004) Diet selection in marsupial folivores of Eucalyptus: the role of plant secondary metabolites.In: The Biology of Australian Possums and Gliders (eds RL Goldingay & SM Jackson), 207 - 221. Surrey Beatty & Sons, Chipping Norton, NSW

For a full list of Publications browse ResearchOnline@JCU