Scenarios of how the deadly act played out include the possibility the kiwi had a nest in the bush near the road and the parent bird was fighting off a stoat trying to get at its egg.
That might explain why the nocturnal bird was out during the day, and why they were both on the road and hit at the same time, according to the DoC ranger Mr Stenbeck spoke to.
Another possibility is that the kiwi was run over first and the stoat was contemplating making a meal of the dead bird when it too was hit.
The only good thing about the sad outcome is that there is now one less stoat preying on kiwi in the area.
The stoat is a member of the mustelid family, along with weasels and ferrets, introduced to New Zealand in the 1880s to control rabbits and hares. While they remain a problem, their numbers are being reduced in many Northland locations due to predator control in DoC reserves and by landcare and conservation groups.
Stoats are considered "public enemy number one" for New Zealand birds, according to DoC. The vicious, agile killers also prey on rodents, and insects (particularly weta), lizards, freshwater crayfish, birds, eggs, hedgehogs and fish. Stoats are strong swimmers, known to have crossed water gaps of more than 1km to reach islands.