Rooks, Crows, Jackdaws, Magpies and Jays are all part of the Corvid family and are considered to be a pest bird species, all are on the general licence and subject to control methods, they both injure or destroy song or game bird nests and eggs. Most are considered as an agricultural pest and can cause serious crop damage, or consume large amounts of animal food and can injure livestock.
Rooks are frequently associated with jackdaws and nest communally in tall trees, they frequent mixed arable farmland and grassland with scattered woodland. They are normally seen in large numbers and damage emerging and pre-harvest cereal crops. They will take other birds eggs and feed from dead or sick animals.
Crows are normally seen singly or in pairs, they frequent farmland, towns and parks. They nest singly in trees. The most notorious damage caused by crows is to new born lambs, however this is usually when the lamb is either dead or seriously ill.
Jackdaws frequent farmland, sea cliffs, cathedrals, castles, churches and derelict buildings, they like to nest on ledges, holes and in domestic chimney stacks. Jackdaws will nest in large numbers in city buildings and cause damage by contamination from droppings and blocked chimneys.
Magpies are a large black and white bird and easily distinguished from other corvids, they are normally found in small flocks. They prefer areas with scattered trees and shrubs and recently becoming a common urban species, they nest in hedges or trees and build a characteristic large dome shaped nest. Will feed on carrion or take small chicks.
Jays are the most colourful of the crow family. Usually frequent in deciduous and coniferous woodland, parks and mature gardens. They mainly feed on acorns, nuts, seeds and insects, but also eats eggs and nestlings of other birds and small mammals.
Other than lethal methods there are two basic ways to solve corvid problems, exclusion and deterrents.
Excluding includes, bird netting, bird spikes and bird wire along with other systems.
Deterrents come in a variety of forms that include gels, low level electric shock, water jets, to lasers and the Agrilaser systems.