A major rural insurer has relaunched a campaign warning farmers of the dangers of birds nesting in their tractors.
FMG South Island regional manager Steve Beale says nests built in tractor engines easily catch fire and account for millions of dollars worth of claims each year.
Mr Beale says starlings in particular use the driest nesting material they can find, which is highly flammable, and can build a nest within 15 minutes.
"I've heard stories of farmers who've been driving their tractor round and birds have continued building the nest as they've been driving the tractor. They're very determined animals."
Mr Beale says the campaign encourages farmers to check for nests before starting their tractor, and to pop the hood when they finish using it to deter the birds from nesting there.
Since its initial launch of the campaign last year, the insurer says there has been a 30% reduction in the number of tractor fire claims.