Brunton grew up in Henderson, and wanted to be a vet from an early age. She completed her undergraduate degree at the University of Auckland, and for her MSc studied the calls of southern black-backed gulls. In 1981 she embarked on a PhD at the University of Michigan in Ann Arbor, intending to study the behaviour of semi-social wasps – until the departmental colony died. She switched to the killdeer plover and graduated in 1987. Brunton did a two-year postdoctoral fellowship at Yale, occupying the office of the recently-retired Charles Sibley. In 1991 she returned to New Zealand to take up a lectureship as a biostatician at the University of Auckland. She joined the faculty of Massey University in December 2004, and founded the university's Ecology and Conservation Group. In 2008 she received a Claude McCarthy Fellowship by Massey for her reptile and bird research. In 2018, in recognition of the 14 PhD and 18 Master's students she had supervised since joining Massey she was awarded a Individual University Supervisor Medal by the university. At that time she had published over 120 scientific papers and received two Marsden grants. Since 2016 Brunton has been head of the Institute of Natural and Mathematical Sciences at Massey, based at the Albany campus in Auckland. Brunton is an advocate for eliminating introduced mammalian predators from New Zealand as part of the Predator-Free 2050 initiative. She was also a vocal opponent of Massey University's proposal to move most science faculty and courses to the Palmerston North campus.
Research
Much of Brunton's research is concerned with the sexual selection and song of southern hemisphere songbirds; in Australasian and tropical songbird species both sexes commonly sing and maintain territories, but in the northern hemisphere, where most behavioural research has been done, usually only males sing. One study examined the mating behaviour of New Zealand bellbirds, and how females distinguished between the friendly and hostile songs of other females. In 2002 Brunton was the first to quantify the song and singing behaviour of bellbirds; she discovered that both male and female birds have distinctive dialects, and that female bellbirds are the sex that disperses to find new territories. Her testing of the "dear enemy" hypothesis with bellbirds – the first time a female songbird had been tested – revealed they were more aggressive to neighbouring females than to strangers, the opposite of what the hypothesis predicted. She also examines the cultural evolution of bird song: how diversity and dialects arise and are maintained, how song memes spread, and the effect of birds dispersing to new habitats. One of her field sites is the predator-free island sanctuary Tiritiri Matangi, off the coast of Auckland, where with her student Michelle Roper she studied the ecological niche partitioning of bellbirds and hihi. Another site is Tawharanui Regional Park, north of Auckland, where she discovered by song dialect that the bellbirds which colonised the park had come fromLittle Barrier Island, not Tiritiri Matangi. In 2013 Brunton received an $820,000 Marsden grant entitled Untangling genes and culture: sex-based song traditions in New Zealand bellbirds,'' to study male and female dialects; it also supported other projects, including research into the song dialects of grey warblers in Tawharanui. Her other research interests and collaborations with PhD and MSc students include the welfare of lizard species after conservation translocation, analysing the chemical composition of kākāpō feathers to determine how diet has changed over time, foraging ecology of little penguins, and song dialects in the saddleback.
