hunt_falconry_select_gamebird_effect

hunt_falconry_select_gamebird_effect = {
	random_list = {
		5 = { # Pheasant
			modifier = {
				factor = 2
				$PROVINCE$ = {
					OR = {
						terrain = farmlands
						terrain = plains
						terrain = hills
					}
				}
			}
			set_variable = { name = $VAR$ value = flag:pheasant years = 3 }
		}
		5 = { # Bustard
			modifier = {
				factor = 2
				$PROVINCE$ = {
					OR = {
						terrain = steppe
						terrain = plains
						terrain = drylands
						terrain = desert
						terrain = oasis
					}
				}
			}
			set_variable = { name = $VAR$ value = flag:bustard years = 3 }
		}
		5 = { # Grouse
			trigger = {
				$PROVINCE$ = {
					OR = {
						geographical_region = world_europe_north
						geographical_region = world_europe_west_britannia
					}
				}
			}
			modifier = {
				factor = 2
				$PROVINCE$ = {
					OR = {
						terrain = mountains
						terrain = hills
						terrain = taiga
						terrain = forest
						terrain = plains
					}
				}
			}
			set_variable = { name = $VAR$ value = flag:grouse years = 3 }
		}
		5 = { # Quail
			modifier = {
				factor = 2
				$PROVINCE$ = {
					OR = {
						terrain = mountains
						terrain = hills
						terrain = steppe
						terrain = plains
					}
				}
			}
			set_variable = { name = $VAR$ value = flag:quail years = 3 }
		}
	}
}

As written in game/common/scripted_effects/00_hunt_effects.txt.