Dr Duncan Mackay

Contact Details

Key Responsibilities

• Biodiversity & Conservation

Teaching

• Biodiversity & Conservation

Research

My research interests are in the general areas of conservation biology and the biology of insect-plant interactions. I am interested in the evolution and ecology of ant-plant mutualisms, in the conservation biology of invertebrates and in the evolution and ecology of host plant selection by herbivores.

 
Mutualisms are an important class of interspecific interaction that may have profound effects on community structure but which are relatively little studied in comparison with interactions such as competition and predation. Ants are a very important component of the Australian fauna and may have manifold effects on local ecosystems through their foraging and nest-building activities. According to one estimate, approximately 75% of plant species in the Australian flora show some kind of adaptation associated with ants. One way in which plants attract ants as mutualistic partners is through the provision of nectar rewards via specialised glands called extra-floral nectaries (EFNs). 

With Dr. M.A. Whalen, I have worked on variation in EFN structure within the endemic Australian plant genus Adriana. We are examining some of the ecological factors causing variation in the effectiveness of the mutualism between ants and Adriana over a wide geographic range.  We have experimentally investigated the consequences for these plants of excluding ants at several widely-separated localities across Australia. We have also examined the ant and herbivore faunas associated with several euphorb tree species in Papua New Guinea and northern Queensland. The leaves on the saplings of these tree species have extrafloral nectaries that attract ants and we quantified the diversity and abundance of the ant and herbivore faunas on these saplings as well as experimentally examining the effects of ant visitation on herbivory by excluding ants from branches of several tree species. I am currently working with Dr. Whalen on the seed biology of plants in the genus Adriana, concentrating on the role of ants in dispersing seeds.

I am also conducting research in the area of conservation biology, concentrating on the effects of habitat disturbance on animal-plant interactions such as pollination and the use of invertebrate communities as 'bioindicators' of environmental change. I have recently supervised several Honours projects in this area, including studies on the effects of acid drainage from tailings dumps on stream invertebrates, the effects of grazing on spider communities on mound springs, the effects of fire-trail formation on seed dispersal by plants and the effects of invasive ants on native invertebrate communities. Current PhD students in our lab that I am supervising are working on the invasion biology of Argentine ants, the conservation biology of a rare and endemic plant species, the conservation biology of butterflies and the molecular systematics and conservation genetics of members of the plant family Frankeniaceae. 

See publication list

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