Principal Biodiversity Species in Wales
The Population Status of Birds in Wales:
Population trend and distribution
A thinly distributed resident, with an easterly bias in Wales (Lovegrove et al. 1994). Willow tits have undergone rapid declines in the UK over the last 25 years. The RWBS showed significant declines in the UK over the last two decades, and the BBS a decline of 77% in the UK between 1994 and 2007. There is no trend data available specifically for Wales.
General: in Wales favoured habitats include well-structured alder and willow carr, mature alder woodland, mature scrub habitats, pre-thicket forestry plantings (where alder, willow and
streamside trees remain), and alder and willow-choked dune slacks. They often, but not always, favour wet woodlands with a good proportion of standing rotten wood and a well-developed shrub layer.
Nesting: willow tits excavate their own nest-holes, usually in rotten tree trunks or stumps that are sometimes only 7 or 8 cm in diameter. Birch and willow are often, but not exclusively used, as they rot easily.
Feeding: invertebrates are the chief prey in the breeding season, and at other times when available. Foraging occurs almost entirely within cover, and particularly in the shrub layer, rather than the canopy. Seeds, eg of alder and ash, are taken in autumn and winter and when invertebrates are in short supply, and are often stored for use in harsh weather.
35 Rapid (>50%) decline in UK breeding population over the last 25 years with no evidence to suggest that Welsh population has not declined in parallel. 36 Preliminary assessment for 2008 revision of Population Status of Birds in Wales: Red-listed.
Figure 33 Key areas for willow tit in Wales.