Clare McArthur

Lecturer

Background

I started off my research career at Monash University, Victoria, by exploring the relationship between tooth wear in kangaroos and their capacity to masticate their tough grassy diet during my BSc Honours (1983) year.  The variation in wear that I found between populations of kangaroos suggested an important link between how individuals cope with the diet they confront, how this varies with geography, and thus how populations may differ as a result of variation in individual characteristics. 

I stayed on at Monash for my PhD (1984 - 1988), during which time I investigated how tannins in eucalypt leaves affect digestion in ringtail possums.  Eucalypt are notoriously low in protein anyway, so if tannins suppressed protein digestion, it could have serious implication for those who eat them.  Ringtail possums, along with koalas, greater gliders and brushtail possums, are one of the few mammalian herbivores that do.  This early work suggested that tannins pose fewer problems to ringtails than to many other herbivores, presumably as a result of strong selective pressure from the fairly unique Australian eucalypt characteristics.

I spent the next two years in the United States (1988 - 1990) on an NSF funded project with biochemist Ann E Hagerman, and wildlife biologists Charlie T Robbins and Tom Hanley.  Here I was working on the influence of plant secondary chemistry on feeding in deer.  This included running feeding preference trials with mule deer in Washington State and with Sitka black-tailed deer in Alaska.  We were interested in bringing non-tannin phenolics into the ecological picture.  In contrast to tannins, these small compounds are more likely to act as toxins to herbivores.  By testing feeding preferences of deer offered a range of plants, we were able to show that deer chose the best plants – those which either maximised digestibility or minimised the non-tannin phenolic load.  They never chose the plants with lowest digestibility and highest toxic load.  This research highlighted the role and importance of these phenolics in the foraging ecology of browsers (consumers of woody plants).

I spent several years doing a post-doc back at Monash (1991 - 1994), further exploring how marsupial herbivores cope with leaf tannins.  This included a detailed study of the saliva of a range of species, from possums to wombats to kangaroos.  Salivary protein seems to be the first line of defence for many herbivores.  It is extremely efficient at binding dietary tannins and so leaves the dietary protein free to be digested.

For nine years (1995 - 2003) I was based in the School of Zoology, University of Tasmania, applying my understanding of foraging to the problem of browsing of tree seedlings in plantation forestry.  During much of this period, I also managed the Resource Protection Program within the Cooperative Research Centre for forestry.  By investigating the fundamental principles of foraging ecology to an applied problem, my research group has been able to discover several ways in which browsing damage can be reduced. 

Since 2004 I have been based at the University of Sydney.  My research group is focussed on but not confined to delving into the fascinating world of plant-herbivore interactions.  We are part of a larger research group within the School, APIG (Animal-Plant Interactions Group).