The lesser redpoll, a tiny finch with a crimson cap, has declined 90% in the UK since 1970. Its welfare depends on birch and alder woodland and was once supplemented by garden feeding — but disease risks have complicated this picture.
Lesser redpoll welfare reflects both the decline of birch woodland and the emerging challenge of feeder-transmitted disease. The species benefited from garden feeding in the 1980s but has declined despite this supplementary food source — indicating that habitat loss is the primary driver. Birch woodland regeneration in upland areas supports redpoll populations. The disease concern that applies to siskins also applies to redpolls — both species can contract and spread finch trichomonosis and Mycoplasma through contaminated feeders. Responsible supplementary feeding with rigorous feeder hygiene reduces disease transmission risk while maintaining the welfare benefit of supplementary food in cold winters.