Professor Keith Christian

PhD (Zoology)

Course Coordinator

Research interests

  • Physiology and ecology in general, with emphasis on the physiological and behavioral adaptations of animals in response to the physical environment.
  • Principal research areas include comparative physiology, biological control, physiological ecology, thermoregulatory biology, animal energetics, and biophysical ecology.


I have supervised about 20 PhD and MSc students working on a range of ecological and physiological topics of amphibians and reptiles. I have also supervised projects involving the use of weaver ants as biological control agents in tropical tree crops.


  • Professional Skills (for Honours students)
  • Organisms and Environmental Change
  • Ecological Physiology

Recent significant publications (2005 - current)

Book chapters

Green, B, Christian, K. 2007. Field metabolic rates (FMRs) and water fluxes in free-living varanid lizards: A review.Pp. 240-246 in 'Advances in monitor research', Horn and Bahme (eds). Mertensiella.

Refereed Journal Articles

Firth, B., K.A. Christian, I. Belan, D. Kennaway. 2010. Melatonin rhythms in the Australian freshwater crocodile (Crocodylus johnstoni): a reptile lacking a pineal complex? Journal of Comparative Physiology Part B. 180:67-72.

Tracy, Christopher.R., K.A. Christian, and C. Richard Tracy. 2010. Not just small, wet, and cold: effects of body size and skin resistance on thermoregulation and arboreality of frogs. Ecology 91:1477-1484.

Tracy, C.R., C. Streten-Joyce,, R. Dalton, K.S. Gibb, and K.A. Christian. 2010. Microclimate and limits to photosynthesis in a diverse community of hypolithic cyanobacteria in northern Australia. Environmental Microbiology 12:592-607.

Reynolds, S., Christian, K.A., and Tracy, C.R. 2009. Application of a method for obtaining lymph from anuran amphibians. Journal of Herpetology 43:148-154.

Iglesias, S., C.R. Tracy, G.S. Bedford, T.J. McWhorter, and K.A. Christian. 2009. Seasonal effects on intestinal enzyme activity in the Australian agamid lizard, Lophognathus temporalis. Comparative Biochemistry and Physiology, Part B 153:89-94.

Peng, R.K., Christian, K. 2009. Determination and management of weaver ant, Oecophylla smaragdina (Fabricius) (Hymenoptera: Formicidae), marks on mango fruits. International Journal of Pest Management 55:27-30.

Nielsen, M.G., K. Christian, and H. Malte. 2009. Hypoxic conditions and oxygen supply in nests of the mangrove ant, Camponotus anderseni, during and after inundation. Insectes Sociaux 56:35-39.

Reynolds, S.J. and K.A. Christian. 2009. Environmental moisture availability and body fluid osmolality in introduced toads, Rhinella marina, in monsoonal northern Australia. Journal of Herpetology 43:326-331

Tracy, C.R., Christian, K.A., Betts, G., Tracy, C.R. 2008. Body temperature and resistance to evaporative water loss in tropical Australian frogs. Comparative Biochemistry and Physiology A 150:102-108.

Kearney, M., Phillips, B.L., Tracy, C.R., Christian, K.A., Betts, G., and Porter, W.P. 2008. Modelling species distributions without using species distributions: the cane toad in Australia under current and future climates. Ecography 31:423-434.

Peng, R.K., Christian, K. 2008. Potential for organic mango production in the Northern Territory of Australia using weaver ants, Oecophylla smaragdina (Hymenoptera: Formicidae). Acta Horticulturae 767:81-88.

Schultz T., Webb J.K., Christian K.A., 2008. The physiological cost of pregnancy in a tropical live-bearing snake. Copeia 2008:637-642.

Smith, J.G., Christian, K.A., Green, B. 2008. Physiological ecology of the mangrove dwelling varanid, Varanus indicus. Physiological and Biochemical Zoology 81:561-569.

Peng, R.K. and Christian, K. 2008. The dimpling bug, Campylomma austrina Malipatil (Hemiptera: Miridae), damage and its relationship with ants in mango orchards in the Northern Territory of Australia. International Journal of Pest Management 54:173-179.

Gibb, K., J. Beard, P. O'Reagain, K. Christian, V. Torok, and K. Opherl-Keller. 2008. Assessing the relationship between patch type and soil mites: a molecular approach. Pedobiologia 51:445-461.

Peng, R.K., Christian, K. 2007. The effect of the weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), on the mango seed weevil, Sternochetus mangiferae (Coleoptera: Curculionidae), in mango orchards in the Northern Territory. International Journal of Pest Management 53:15-24.

Seymour, R.S., Farrell, A.P., Christian, K., Clark, T.D., Bennett, M.B., Wells, R.M.G., Baldwin, J. 2007. Continuous measurement of oxygen tensions in the air-breathing organ of the Pacific tarpon, (Megalops cyprinoids), in relation to aquatic hypoxia and exercise. Journal of Comparative Physiology B. 177:579-587.

Nelson, J., Christian, K.A., Baudinette, R.V. 2007. Anatomy of the nasal passages of three species of Australian bats as related to water loss. Australian Journal of Zoology. 55:57-62.

Christian K.A., Webb J.K., T. Schultz, and B. Green. 2007. Effects of seasonal variation in prey abundance on field metabolism, water flux, and activity of a tropical ambush foraging snake. Physiological and Biochemical Zoology 80:522-533.

Nielsen, M.G. and K. Christian. 2007. The mangrove ant, Camponotus anderseni, switches to anaerobic respiration in response to elevated CO2 levels. Journal of Insect Physiology. 53:505-508.

Tracy, C.R., G. Betts, C.R. Tracy, and K.A. Christian. 2007. Use of plaster models to measure operative temperature and evaporative water loss of amphibians. Journal of Herpetology 41:597-603.

Clark, TD, RS Seymour, K Christian, RMG Wells, J Baldwin, AP Ferrell. 2007. Changes in cardiac output during swimming and aquatic hypoxia in the air-breathing Pacific tarpon. Comparative Biochemistry and Physiology A 148:562-571.

Wells, R.M.G., Baldwin, J., Seymour, R.S., Christian, K.A., and Farrell, A.P. 2007. Air breathing minimizes post-exercise lactate load in the tropical Pacific tarpon, Megalops cyprinoides Broussonet 1782 but oxygen debt is repaid by aquatic breathing. Journal of Fish Biology 71:1649-1661.

Peng, R., Christian, K., and Gibb, K. 2007. Green ants as biological control agents of insect pests in tropical tree crops and forest trees. Entomological Society of Queensland News Bulletin 35:143-153.

Tracy, C.R., Christian, K.A., Reynolds, S.J., McArthur, L., Tracy, C.R. 2007. Ecology of aestivation in an Australian frog, Cyclorana australis (Hylidae). Copeia 2007:901- 912.

Christian, K. A., Tracy, C.R., Tracy, C.R. 2006. Evaluating thermoregulation in reptiles: an appropriate null model. The American Naturalist. 168: 421-430.

Peng, R.K., Christian, K. 2006. The effective control of Jarvis's fruit fly, Bactrocera jarvisi (Diptera: Tephritidae), by the weaver ant, Oecophylla smaragdina, (Hymenoptera: Formicidae), in mango orchards in the Northern Territory. International Journal of Pest Management 52:275-282.

Webb J.K., Shine R., Christian K.A. 2006. The adaptive significance of reptilian viviparity in the tropics: testing the maternal manipulation hypothesis. Evolution 60:115-122.

Nielsen, G.M., K.A. Christian, P.G. Henriksen, and D. Birkmose. 2006. Respiration by mangrove ants Camponotus anderseni during nest submersion associated with tidal inundation in northern Australia. Physiological Entomology 31: 120-126.

Young, J.E., Tracy, C.R., Christian, K.A. and McArthur, L. 2006. Rates of cutaneous evaporative water loss of native Fijian frogs. Copeia 2006: 83-88.

Peng, R.K., Christian, K. and Gibb, K. 2005. Ecology of the fruit spotting bug, Amblypelta lutescens lutescens Distant (Hemiptera: Coreidae) in cashew plantations, with particular reference to the potential for its biological control. Australian Journal of Entomology.44:45-51.

Webb J.K., Shine, R and Christian KA 2005. Does intraspecific niche partitioning in a native predator influence its response to an invasion by a toxic prey species? Austral Ecology 30:201-209.

Young, J.E, K. A. Christian, S. Donnellan, C. R. Tracy and D. Parry. 2005. Comparative analysis of cutaneous evaporative water loss in frogs demonstrates correlation with ecological habits. Physiological and Biochemical Zoology 78:847-856.

Tracy, C.R. and Christian, K.A. 2005. Preferred temperature correlates with evaporative water loss in hylid frogs from northern Australia. Physiological and Biochemical Zoology 78:839-846.

Wells, R.M.G., J. Baldwin, R.S. Seymour, K. Christian, T. Brittain. 2005. Red blood cell function and haematology in two tropical freshwater fishes from Australia. Comparative Biochemistry and Physiology A 141: 87-93.

Peng, R.K., Christian, K. 2005. Integrated pest management in mango orchards in the Northern Territory of Australia, using the weaver ant, Oecophylla smaragdina, (Hymenoptera: Formicidae) as a key element. International Journal of Pest Management 51:149-155.

Peng, R.K., Christian, K. 2005. The control efficacy of the weaver ant, Oecophylla smaragdina, (Hymenoptera: Formicidae), on the mango leafhopper, Idioscopus nitidulus (Hemiptera: Cicadellidea) in mango orchards in the Northern Territory. International Journal of Pest Management 51:299-306.

Refereed Conference Papers

Peng, R.K., Christian, K. 2006. Green ants as biological control agents in agroforestry. 31pp. In Bevege, D.I., Nikles, D.G., Dickinson, G. and Skelton, D.J. (eds). 2006. Where to from here with R&D to underpin plantations of high-value timber species in the seasonally-drytropics of northern Australia? Proceedings of a Workshop held 9-11 May 2006, Townsville Queensland. Published as a CD ROM by Private Forestry North Queensland Association Inc., Kairi, Q


Peng, R. and K.A. Christian. 2010. Ants as biological control agents in the horticultural industry. Box 7.2 in 'Ant Ecology', L. Lach, C.L. Parr and K.L. Abbott (eds.) pp. 123-125. Oxford University Press, New York.

Professor Keith Christian


T: +61 8 8946 6706
F: +61 8 8946 6847

Casuarina campus
Building Yellow 2, Level 2, Room 35

Postal Address:
School of Environmental and Life Sciences
Charles Darwin University
Darwin NT 0909