The Rook is a native of Great Britain and Europe and was brought to New Zealand by early settlers. Rooks are easily distinguishable by their shiny black plumage and are generally larger than a Magpie.
What is it?
Rooks are extremely clever, wary birds which learn quickly, making them difficult to control.
The Rook has a distinct call, a harsh 'Kaah' usually associated with crows, and breed between September and mid-October. During the breeding season, birds come together and use the same rookery every year with both male and female sharing incubation duties. 2-6 eggs are laid.
What is the problem?
From February to late August, individual groups form large mobs that move around the region looking for food. At this time, they become very transient and use a series of different roosting sites. When the rook population in an area increases, they can impact on new pasture and crop production, especially grain crops. Damage is likely to occur in spring when pasture and crops are emerging, or summer when pea crops are ripening. Barley, wheat and oat crops are generally damaged following germination when the leaf stem emerges from the soil. A small group of rooks will have a negligible impact, but a mob of 1,000 birds on a single field will thin the crop severely.
How to control it
Rooks are an eradication animal throughout the Southland region.
According to the Southland Regional Pest Management Strategy, occupiers are:
- prohibited from carrying out rook control on their properties including shooting and poison baiting;
- required to notify Environment Southland of the presence of rookeries on the land that they occupy;
- prohibited to sell, breed or distribute rooks;
- prohibited to keep rooks in captivity (including as a pet).