Keep a watch out for nesting rooks

Landowners are being asked to report rook sightings for targeted pest control before the non-native, large black bird becomes a problem on farms.

Rooks, which were introduced to New Zealand in the 1860s to control insect pests, are one of the most destructive farm production pest birds in the world. They feed on newly sown crops and destroy pasture and silage by tearing them up in search for grubs.

Waikato Regional Council biosecurity officer Andrew McConnell says entire paddocks have had to be completely resown after a rook invasion.

“Rooks can form breeding colonies of up to several hundred birds, and that’s definitely not something we want to be seeing.

“We’ve been managing rooks in the Waikato since 2002 and estimate the population is now fewer than 50 birds.

“However, this small number means it’s like looking for a needle in a haystack for them, which is why we need landowners’ help.”

The Waikato’s rook populations are mainly found in Te Poi, Matamata, Cambridge, Hamilton, Mangakino, Whakamaru and Taupo¯ .

Andrew says it’s a good time of the year to start seeing the rooks as it’s the breeding season, which is when they congregate together. In the Waikato, rooks generally build their rookeries in pine or eucalyptus trees, with a typical rookery holding three to seven nests.

He says it’s important that landowners contact the regional council if they sight rooks, rather than try to control them themselves.

“They’re very wary and we don’t want to scare them off elsewhere, so once again we don’t know where they are.”

To control rooks, council uses a toxin which it applies directly to a nest.

■ WIN: Do you know where rooks are breeding? Contact Waikato Regional Council on 0800 246 732 or rooksighting@waikatoregion.govt.nz and be in to win a $200 Hunting & Fishing voucher.