hunt_falconry_select_waterfowl_effect

hunt_falconry_select_waterfowl_effect = {
	random_list = {
		5 = { # Swan
			trigger = {
				$PROVINCE$ = {
					NOT = { geographical_region = world_africa }
				}
			}
			modifier = {
				factor = 2
				$PROVINCE$ = {
					OR = {
						terrain = oasis
						terrain = wetlands
						terrain = floodplains
						is_riverside_province = yes
					}
				}

			}
			modifier = {
				factor = 2
				$PROVINCE$.county.holder.top_liege = { employs_court_position = keeper_of_swans_court_position }
			}
			set_variable = { name = $VAR$ value = flag:swan years = 3 }
		}
		10 = { # Goose
			modifier = {
				factor = 0.5
				$PROVINCE$ = {
					OR = {
						terrain = desert
						terrain = desert_mountains
						terrain = jungle
						terrain = drylands
					}
				}
			}
			set_variable = { name = $VAR$ value = flag:goose years = 3 }
		}
		10 = { # Duck
			modifier = {
				factor = 2
				$PROVINCE$ = {
					OR = {
						terrain = oasis
						terrain = wetlands
						terrain = floodplains
						is_riverside_province = yes
					}
				}
			}
			set_variable = { name = $VAR$ value = flag:duck years = 3 }
		}
	}
}

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