Rooks are already here but we're working to get rid of them.
Why rooks are pests
|Production threat||Environmental threat||Public threat|
Rooks are large black birds, native to Great Britain and Europe. They were introduced to New Zealand in the 1860s to control insect pests, but instead they threaten farms. Rooks first became a problem in the Waikato region in the Miranda area in 1968. Waikato Regional Council has been involved in controlling rooks since 2002 and we estimate the rook population in this region is now less than 200 birds. While it’s good news that numbers are so low, this makes surveillance and control challenging and we need to get rid of them permanently.
Rooks feed on newly sown crops, particularly cereals, peas, maize and squash, often pulling young plants from the ground to get the seeds. They can also damage pasture by tearing it up when searching for grubs. When large numbers of rooks are present, some damaged paddocks have had to be completely resown. In the past, farmers have had a whole season’s silage damaged by rooks tearing holes in the plastic wrapping. Rooks can form large breeding colonies, called rookeries, of several hundred birds. In the Waikato they generally build their rookeries in pine or eucalyptus trees. A typical rookery holds 3-7 nests, equating to 3-35 birds. Adults live in and about the rookery from early September until mid-December.
Listen to a rook calling (69kb).
Responsibility for control
Waikato Regional Council is responsible for the control of rooks. If you think you’ve seen any, call us.
In the past, rook control was carried out by individual landowners, but this proved ineffective.
Waikato Regional Council is responsible for controlling rooks. Landowners/occupiers in the Waikato are required to leave rooks and rookeries undisturbed because rooks are wary birds and will shift locations if pressured. However, landowners/occupiers are encouraged to report rooks on their properties and liaise with the council in areas where control programmes are in place. (See ‘more information’ section in this factsheet).
It is illegal to keep a rook as a pet, unless permitted by an authorised person. Waikato Regional Council monitors all rookeries to determine the range and density of rook populations and conducts all control operations to ensure its objectives are met.
How to control rooks
Do not attempt to control rooks yourself, unless permitted by an authorised person. Do not disturb their nests or approach the rooks as they will move elsewhere. Instead, report the rooks to Waikato Regional Council by calling us or using our rook sighting form.
Rooks have a distinctive harsh call, which is often described as 'caw, caw'.
|Plumage||Glossy black with a violet-blue tint,white face.||Black or grey with white to grey hind neck and/or back.||Black (male) or dark brown (female).|
|Size||30-50cm long||35-45cm long||Up to 25cm long.|
|Common call/s||‘Kaah’.||‘Quardle oodle ardle wardle doodle.’||Tuneful call. Harsh ‘tchink’if disturbed.|
|Distinguishing feature/s||Greyish skin flap on adult birds reaching from bill to nostrils. Dark grey bill.||White marking on wings and tail. Whitish bill with black tip.||Smaller bird. Bright yellow bill (male), brown bill (female).|
For advice and additional information on control methods, call our animal pest staff on freephone 0800 BIOSEC (0800 246 732).