The fieldfare is a large, handsome thrush that visits Britain in winter from Scandinavian breeding grounds, with welfare tied to berry crop abundance and the severity of northern European winters.
Fieldfare welfare depends on berry crop abundance in autumn and the ability to access earthworms in unfrozen soil during winter. Hard frosts that freeze ground eliminate worm access, forcing birds to subsist entirely on berries until stocks are exhausted. Years with poor berry crops combined with severe winters can cause significant mortality in UK wintering populations. Garden apples left on trees or the ground provide critical supplemental food during cold snaps.