Former resident.

Willow Tits were not recorded from North Hertfordshire until around 1937, and were considered scarce in this part of the County by Gladwin (1985).

Having reached a peak nationally in the 1970s, they have declined dramatically. A decline of 72% was estimated between 1994 and 2002. The causes of the decline are unknown, but competition for nest holes with Blue and Great Tits, predation of their nests by Greater Spotted Woodpeckers (Dendrocopos major), the drying out of preferred woodlands, and climate change have been suggested. Willow Tits are sedentary by nature and may be reluctant or unable to move to other suitable sites.   

Confirmed as breeding in four of Stevenage tetrads by both the 1973 and 1992 Breeding Atlases. They were considered to be common in the area in 1980, and were, thought to have been badly affected by the harsh winter of 1991. They are now probably extinct at Stevenage, having not been seen since 2004.

The records for the 1960s and 1970s are: pair nesting in Whomerly Wood 14 May 1967; Monks Wood/Whomerly Wood in the winter of 1969/1970; eight at Watery Grove 28 March 1971; nest with young in a Birch Tree, Box Wood 4 June 1971; seen excavating a nest site, Box Wood 21 April 1973; two pairs Astonbury Wood 1973 (one pair had well grown young in a nest box 9 June 1973); breeding Astonbury Wood 1974 and1975; breeding Broaches Wood 1974; breeding Watery Grove 1975; four Watery Grove 6 June 1976; breeding Astonbury Wood 1977 (nest found in the bottom of an Ash Tree which contained newly hatched young 29 May 1977); display noted Watery Grove 1977, 11 ringed, Box Wood 1978; Astonbury Wood 30 July 1978; three ringed Box Wood 1979; Astonbury Wood 13 April 1979.

The records for the 1980s and 1990s are: Watery Grove 1980; Astonbury Wood 14 and 23 April 1980; records from five sites around Stevenage 1981; seven ringed in Box Wood 1981; two Astonbury Wood 23 March 1986 and one on 13 Aril 1986; one at Mossbury Wood 27 March 1987; one at Astonbury Wood 15 April 1987; pair Box Wood 1April 1988; pair with the male bird in song Watery Grove 19 and 20 April 1988; pair Norton Green 30 March 1989; two at Astonbury Wood 16 July 1990 and 13 January 1992; one at Astonbury Wood 29 February and 8 March 1992; two Watery Grove 30 January 1994; Whomerly Wood 2 April 1996, 10 February and 7 April 1999.

The final record for Stevenage was of one feeding on a patch of Slender Thistles at Astonbury Wood on 4 December 2004.   

At Watery Grove they were present in the 1970s when both nest boxes and bored-out natural holes were inhabited. The Common Bird Census recorded their presence in the 1973, 1974, 1981, 1985, 1987, 1990, 1991 and 1997 breeding seasons, and as holding single territories in 1992, 1993, 1996 and 1998.