In 2012 AON New Zealand insurance broker Ian Parker warned machinery operators to be wary of the potential for birds' nests causing fires. He cited one case where a client cleared a nest out of a tractor an hour before he used it, and the tractor caught fire.
"Within an hour that bird had rebuilt its nest. They can shift a lot of material in a short space of time," Parker said.
"Often the nests can't be seen with a cursory look because they go right up under the bonnet, so it pays to check thoroughly. And it's not just tractors. All farm vehicles are susceptible."
AMP Walker Mackie's Tim Mackie said he knew of a $180,000 tractor that was destroyed by fire a month after the owner bought it brand new.
He advised leaving the bonnet open at night to deter birds from nesting and as a reminder to check before using the machine next day.