Dr Todd McWhorter

Qualifications

Ph.D. Ecology and Evolutionary Biology (minor in Physiological Sciences), University of Arizona, Tucson, USA, December 2002. Dissertation Title: The integration of digestive, metabolic and osmoregulatory processes in nectar-eating birds. Advisor: Dr. Carlos Martínez del Rio.

M.Sc. Zoology and Physiology, University of Wyoming, Laramie, USA, December 1997. Thesis Title: Energy assimilation, protein balance, and water absorption in broad-tailed hummingbirds, Selasphorus platycercus. Advisor: Dr. Carlos Martínez del Rio.

B.Sc. Biological Sciences, University of California, Irvine, USA, May 1995.

Teaching Interests

Comparative physiology, vertebrate physiological ecology, environmental physiology, nutrition, conservation physiology.

I am currently the course coordinator for Animal Form & Function III (anatomy & physiology) taken by our 3rd year pre-veterinary undergraduates.  Any queries or administrative matters regarding this course should be directed to me.

I also teach into Animal Form & Function II, which is coordinated by Dr. Rachel Norris.

Research Interests

I am a comparative/ecological/evolutionary physiologist interested in how animals function and how function evolves.  Over the past decade my research has focused primarily on the mechanisms of digestion and nutrient absorption, modelling digestive capacity, nutritional ecology, kidney function, and salt and water balance.

More recently, my research program is expanding into the emerging area of conservation physiology and medicine- applying the concepts and methodologies of these fields to pressing problems in conservation of wildlife and biodiversity in general.

I am always happy to talk to students about potential summer research, honours and PhD projects.

Research Funding

Australian Research Council Discovery Projects- Research Grant "Sugar and water handling by honeyeaters and sunbirds" (DP0665730, 2006-2008), Murdoch University, Perth, Western Australia. $290000 AUD. Co-investigators: Dr. Trish Fleming (Murdoch University) & Prof. Sue Nicolson (University of Pretoria, South Africa).

Publications

Peer-Reviewed Journal Articles
Caviedes-Vidal, E., T.J. McWhorter, S.R. Lavin, J.G. Chediack, C.R. Tracy and W.H. Karasov. 2007. The digestive adaptation of flying vertebrates: high intestinal paracellular absorption compensates for smaller guts. Proceedings of the National Academy of Sciences of the USA 104(48): 19132-19137 (doi:10.1073/pnas.0703159104).

Fleming, P.A., S. Xie , K. Napier, T.J. McWhorter and S.W. Nicolson. 2008. Nectar concentration affects sugar preferences in two Australian honeyeaters and a lorikeet. Functional Ecology 22(4): 599-605 (doi:10.1111/j.1365-2435.2008.01401.x).

Hartman Bakken, B., T.J. McWhorter, E. Tsahar and C. Martínez del Rio. 2004. Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus. Journal of Experimental Biology 207(25): 4383-4391 (doi:10.1242/jeb.01238).

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 B 153(1): 89-94 (doi:10.1016/j.cbpb.2009.02.003).

Lavin, S.R., T.J. McWhorter and W.H. Karasov. 2007. Mechanistic bases for differences in passive absorption. Journal of Experimental Biology 210(15): 2754-2764 (doi:10.1242/jeb.006114).

Martínez del Rio, C., J.E. Schondube, T.J. McWhorter and L.G. Herrera. 2001. Intake responses in nectar feeding birds: digestive and metabolic causes, osmoregulatory consequences, and coevolutionary effects. American Zoologist 41(4): 902-915.

McWhorter, T.J., A.K. Green and W.H. Karasov. 2010. Assessment of radiolabeled D-glucose and the nonmetabolizable analog 3-O-methyl-D-glucose as tools for in vivo absorption studies. Physiological and Biochemical Zoology 83(2): 376-384 (doi: 10.1086/597524).

McWhorter, T.J., B. Hartman Bakken, W.H. Karasov and C. Martínez del Rio. 2006. Hummingbirds rely on both paracellular and carrier-mediated intestinal glucose absorption to fuel high metabolism. Biology Letters 2(1):131-134 (doi:10.1098/rsbl.2005.0388).

McWhorter, T.J. and W.H. Karasov. 2007. Paracellular nutrient absorption in a gum-feeding New World primate, the common marmoset Callithrix jacchus. American Journal of Primatology 69(12): 1399-1411 (doi:10.1002/ajp.20443).

McWhorter, T.J. and M.V. López-Calleja. 2000. The integration of diet, physiology, and ecology of nectar-feeding birds. Revista Chilena de Historia Natural 73(3): 451-460.

McWhorter, T.J. and C. Martínez del Rio. 2000. Does gut function limit hummingbird food intake? Physiological and Biochemical Zoology 73(3): 313-324.

McWhorter, T.J. and C. Martínez del Rio. 1999. Food ingestion and water turnover in hummingbirds: how much dietary water is absorbed? Journal of Experimental Biology 202(20): 2851-2858.

McWhorter, T.J., C. Martínez del Rio and B. Pinshow. 2003. Modulation of ingested water absorption by Palestine sunbirds: evidence for adaptive regulation. Journal of Experimental Biology 206(4): 659-666 (doi:10.1242/jeb.00147).

McWhorter, T.J., C. Martínez del Rio, B. Pinshow and L. Roxburgh. 2004. Renal function in Palestine sunbirds: elimination of excess water does not constrain energy intake. Journal of Experimental Biology 207(19): 3391-3398 (doi:10.1242/jeb.01169).

McWhorter, T.J., D.R. Powers and C. Martínez del Rio. 2003. Are hummingbirds facultatively ammonotelic? Nitrogen excretion and requirements as a function of body size. Physiological and Biochemical Zoology 76(5): 731-743.

Napier, K.R., T.J. McWhorter and P.A. Fleming. 2008. Mechanism and rate of glucose absorption differ between an Australian honeyeater (Meliphagidae) and a lorikeet (Loridae). Journal of Experimental Biology 211(22): 3544-3553 (doi:10.1242/jeb.020644).

Napier, K.R., C. Purchase, T.J. McWhorter, S.W. Nicolson and P.A. Fleming. 2008. The sweet life: diet sugar concentration influences paracellular glucose absorption. Biology Letters 4(5): 530-533 (doi:10.1098/rsbl.2008.0253). Biol Lett 4(5) cover article, photo by T.J. McWhorter.

Tracy, C.R., T.J. McWhorter, C. Korine, M.S. Wojciechowski, B. Pinshow and W.H. Karasov. 2007. Absorption of sugars in the Egyptian fruit bat (Rousettus aegyptiacus): a paradox explained. Journal of Experimental Biology 210(10): 1726-1734 (doi:10.1242/jeb.02766). J Exp Biol 210(10) cover article.

Tracy, C.R., T.J. McWhorter, M.S. Wojciechowski, B. Pinshow and W.H. Karasov. 2010. Carbohydrate absorption by blackcap warblers (Sylvia atricapilla) changes during migratory refuelling stopovers. Journal of Experimental Biology 213(3): 380-385 (doi:10.1242/jeb.040071).

Book Chapters & Reviews
McWhorter, T.J. 2005. Carbohydrate hydrolysis and absorption: lessons from modeling digestive function. Pages 59-86 in Physiological and Ecological Adaptations to Feeding in Vertebrates, edited by J.M. Starck and T. Wang, Science Publishers Inc., Enfield, New Hampshire (ISBN 1-57808-246-3).

McWhorter, T.J. 2005. Paracellular intestinal absorption of carbohydrates in mammals and birds. Pages 113-140 in Physiological and Ecological Adaptations to Feeding in Vertebrates, edited by J.M. Starck and T. Wang, Science Publishers Inc., Enfield, New Hampshire (ISBN 1-57808-246-3).

McWhorter, T.J., E. Caviedes-Vidal and W.H. Karasov. 2009. The integration of digestion and osmoregulation in the avian gut. Biological Reviews 84(4): 533-565. (doi:10.1111/j.1469-185X.2009.00086.x). Invited review.

In Press

Barboza, P.S., A.F Bennett, J.-H. Lignot, R.D. Mackie, T.J. McWhorter, S. Secor, N. Skovgaard and M.A. Sundset. 2010. Digestive challenges for vertebrate animals: microbial diversity, cardio-respiratory coupling and dietary specialization. Physiological and Biochemical Zoology. Accepted 8 Dec 2009 (symposium synthesia paper PBZ-9058R).

Powers, D.R., J.A. van Hook, E.A. Sandlin and T.J. McWhorter. Arthropod foraging by a southeastern Arizona hummingbird guild. Wilson Journal of Ornithology. Accepted 3 Feb 2010 (MS # 09-179).

Community Engagement

Siemens Science Experience 2010: Cardiovascular physiology

Entry last updated: Wednesday, 22 Aug 2012