Willow Tit

The decline

The willow tit is one of Britain’s most alarming conservation stories. Since the 1970s, the British breeding population has declined by more than 90% — possibly the steepest long-term decline of any British resident bird. The reasons are complex and incompletely understood: loss of wet woodland and carr habitat, intensive management of coppice woodland that removes standing dead wood, drainage of wetlands, and possibly increased grey squirrel predation of nests. The species now has a fragmented, restricted distribution in northern and central England.

Excavating nest holes

Unlike most tits, which use existing cavities, willow tits excavate their own nest holes in soft, rotting wood. This requirement for standing dead wood — snags, rotten stumps, and dying trees — is a critical habitat need. They excavate a new cavity each year rather than reusing old ones. The loss of standing dead wood through woodland tidying and the removal of veteran trees has directly reduced nesting opportunities.

Marsh tit separation

The willow tit’s near-identical appearance to the marsh tit means precise identification requires care. Willow tits have a slightly larger, rounder head, a more extensive black bib, a dull (not glossy) black cap, and a pale panel on the closed wing caused by pale feather edges on the secondaries. The call is the most reliable feature — the willow tit’s nasal, buzzing “tchair” or “eez-eez-eez” is quite unlike the marsh tit’s sharp “pitchoo.”

Cold adaptation

Willow tits have a broader altitudinal and climatic range than marsh tits, extending into montane and boreal conditions across Europe and Asia. They are more cold-tolerant, with a slightly higher metabolic rate and a tendency to roost in snow burrows in extreme weather. This cold adaptation may reflect their ancestral association with wet, cool habitats rather than the warm, dry woodland preferred by marsh tits.