Rooks are classified as a production threat as they feed on newly sown crops. Photo / Forest & Bird
Rooks are classified as a production threat as they feed on newly sown crops. Photo / Forest & Bird
Waikato Regional Council is calling in the big guns in the fight against the pest bird species rook: drone technology.
Rooks were introduced to New Zealand in the 1860s to control insect pests but turned out to be a pest themselves as they feed on newly sown crops or cereal crops.
The birds can also damage pasture by tearing it up during their search for grubs, exposing bare soil to erosion and encouraging weed germination.
Rooks breed from early September until mid-December and if left uncontrolled, they can form large breeding colonies, called rookeries, of several hundred birds. The largest colony found in New Zealand had nearly 1000 nests.
Waikato Regional Council biosecurity officer for pest animals, Imre Reuter-Rosewood, said the council was using drone technology to locate rook nests in the Waikato so targeted control could be carried out.
“Views from the drone camera allow [us] to confirm nesting activity, or that subsequent control has been successful,” he said.
“For a rookery identified outside of Tīrau this spring, we got a really good look at the nests from the drone and after control didn’t find any further sign of rook activity.”
Waikato Regional Council’s Imre Reuter-Rosewood and Timothy Beale with some of the tools used in rook surveillance. Photo / Waikato Regional Council
Another rookery was identified close to Taupō, where 10 rooks had been building multiple nests. This was the largest rookery found in the region for some years.
Further rook hotspot areas are between Paeroa and Taupō, in particular around Mangakino, Whakamaru, Tīrau and Ōkoroire.
Reuter-Rosewood said it was important for the team to do follow-up checks of hotspots even after “targeted control” has been carried out.
“Rooks are known to nest again ... sometimes building two nesting sites up to 2km away at the same time.”
Reuter-Rosewood said despite the sightings, the council was making good progress in eradicating the bird, with fewer than 50 rooks thought to remain in the Waikato region compared with the hundreds that were present in the past.
Imre Reuter-Rosewood and Timothy Beale monitoring drone video of a rookery on farmland near Tīrau. Photo / Waikato Regional Council
“What we are dealing with now in the Waikato are the last remnants of the rook population.”
To catch the last remaining birds, the council is also asking for the public to report any sightings.
So far this spring there have been 24 confirmed rook sightings, similar to the numbers identified last year.
“It’s important that landowners don’t try to control the birds themselves, as this can scare them away, creating additional work for us to locate them again,” Reuters-Rosewood said.
People can report rook activity and sightings to the Waikato Regional Council by calling 0800 800 401.
