"I contacted police and they came out to have a look at it — they identified them as shotgun holes," Rurawhe said.
"They opened a file but I'm not sure we will find out who did it ... still, it is concerning, not what we want out here."
He believed Higgins contractors had been asked to replace the sign.
Police said they issued general cautions to hunters participating in duck shooting season.
Acting Superintendent Mike McIlraith issued a statement to hunters advising them not to "wing it" during the weekend.
"I can't emphasise enough the importance of handling firearms safely.
"It is critical hunters treat every firearm as loaded, always point firearms in a safe direction and to check your firing zone."
"Anyone who is planning to use a firearm is required to have a valid firearms licence and comply with the New Zealand Arms Code.'
The NZ Transport Agency, responsible for installing and maintaining the signs, said it was "a real concern that a firearm may have been discharged unsafely in a public area".
NZTA's regional transport systems manager Ross I'Anson said the issue arises from time to time in rural areas and is certainly not isolated to this sign.
Rangitikei district councillor Soraya Peke-Mason, who lives in Ratana, was also worried by the incident.
"This a rural area and it has its challenges," she said.
"It could have been done by anyone ... maybe someone who doesn't like Ratana.
"It has happened before in and around the cemetery ... people had been possibly visiting loved ones at the cemetery, had a couple of beers and got a gun out of the boot of the car."