Blackbirds, robins and wrens all prefer hedgerows that are thick right down to their base, whereas little owls like hedgerows with tall trees, in which to nest and from which to hunt.
Mae’n well gan yr aderyn du, y robin a’r dryw wrychoedd sy’n drwchus hyd eu bôn, ond mae’n well gan y dylluan fach wrychoedd â choed tal ar gyfer nythu a hela.