Willow Tit

Listen to example recordings of the main vocalisations of Willow Tit, provided by xeno-canto contributors.

This species can be found on the following statutory and conservation listings and schedules.

UK Birds of Conservation Concern	Red listed
Species of European Conservation Concern	Least Concern
IUCN Red List of Threatened Species (global)	Least Concern
Schedule 1 license required (to disturb)	No
Birds Directive Annex 1	No
Listed on the Annexes of	Bern(III), NERC (41)

Willow Tits have been in decline since the mid 1970s, and have become locally extinct in an ever-growing number of former haunts. The UK conservation listing was upgraded from amber to red in 2002. Atlas surveys during 2008-11 found that the species had virtually disappeared from the southeastern part of its English range since 1988-91 (Balmer et al. 2013). The continuing decline in the CBC/BBS index through the 1990s, following a brief period of stability during the 1980s, is replicated in the CES abundance trend. All UK breeding records since 2010 should be forwarded to the Rare Breeding Birds Panel, who have developed specific recording criteria. Willow Tit has shown a decline across Europe since 1980, but has declined to a lesser extent in central and eastern Europe than in the north, west and south (PECBMS: PECBMS 2007, PECBMS 2020a>).

UK breeding population

-96% decrease (1967–2022)

Owing to historic declines, by 2007–11 the distribution of Willow Tits was concentrated in a crescent from northeast England to south Wales with several scattered outposts. The species is very sedentary so, not surprisingly, the winter and breeding distributions closely match one another. Declines continue and some outlying populations on these maps may no longer exist.

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Occupied 10-km squares in UK

No. occupied in breeding season	558
% occupied in breeding season	18
No. occupied in winter	691
% occupied in winter	23

European Distribution Map

European Breeding Bird Atlas 2

Breeding Season Habitats

Most frequent in

Scrub

Relative frequency by habitat

Relative occurrence in different habitat types during the breeding season.

Willow TIts have virtually disappeared from the southeastern part of their English range since 1988–91. Apparent hot spots in southern England, East Anglia and the southern Midlands have vanished in the space of just two decades. Despite a rather constant population decline, range loss accelerated from 10% between the 1968–72 Breeding Atlas and the 1988–91 Breeding Atlas to 50% subsequently and has likely continued.

Willow Titi is a localised and declining resident, recorded throughout the year.

View a summary of recoveries in the Online Ringing Report.

View number ringed each year in the Online Ringing Report

Maximum Age from Ringing	10 years 4 months 18 days (set in 1984)
Typical Lifespan	3 years with breeding typically at 1 year
Adult Survival	0.63   (Male: 0.65±0.02 Female: 0.6±0.02)
Juvenile Survival	0.59 (in first year)

Wing Length	Adults	59.7±2 | Range 57–63mm, N=702
	Juveniles	59.5±1.8 | Range 57-62mm, N=716
	Males	60.4±1.6 | Range 58–63mm, N=62
	Females	59±1.9 | Range 56–62mm, N=94

Body Weight	Adults	10.0±0.7 | Range 9.00–11.0g, N=500
	Juveniles	9.90±0.6 | Range 9.00–10.9g, N=544
	Males	10.2±0.7 | Range 9.20–11.0g, N=43
	Females	10.0±0.8 | Range 8.70–11.4g, N=68

Feather measurements and photos on featherbase

Ring size	A
Field Codes	2-letter: WT | 5-letter code: WILTI | Euring: 14420

For information in another language (where available) click on a linked name

Causes of change

Willow Tits have declined in woodland, probably because of habitat degradation. How this relates to demographic trends is unclear.

Further information on causes of change

Little evidence is available regarding changes in the demography of this species but CES trends suggest a decline in productivity since 1983 (see above). Lampila et al. (2006) found that adult survival was the main driver of Willow Tit populations in northern Finland, although a study in Norway recorded adult survival of around 50% (Hogstad & Slagsvold 2018) which is in line with the survival rates for Blue Tit and Great Tit published in this report. Both these studies were in boreal forests, so the processes may not be the same as for the British population. The British subspecies shows very different habitat preferences to the Fennoscandian one, preferring wet woodland rather than conifers, emphasising that Continental studies may not be very relevant to population change in the UK.

There are several hypotheses that have been put forward to explain the cause of population declines of Willow Tit. One is that deterioration in the quality of woodland as feeding habitat for this species through canopy closure and increased browsing by deer (Perrins 2003, Siriwardena 2004, Fuller et al. 2005, Newson et al. 2012) has been important. The area of wet woodland and scrub is also thought to have declined as a result of drainage and the occurrence of increasingly dry summers (Vanhinsbergh et al. 2003). A field study based on former CBC sites and other woods that were known to have held the species in the past provided good evidence that the sites still holding Willow Tit tended to be wetter, so drying out of woodlands may have been a factor (Lewis et al. 2007, 2009a, 2009b). Siriwardena (2004) analysed long-term CBC trends and found that, although population trends have been stable in their preferred, wet habitats, Willow Tit have declined in woodland, probably because of habitat degradation.

A second hypothesis is that nest predation pressure, from Jays, Great Spotted Woodpeckers and grey squirrel, for example, has increased, both because some of these predators have grown more abundant (Harris et al. 1995, this report) and because restrictions in nest-site availability are likely to have forced more birds into suboptimal, more vulnerable sites. In the study mentioned above, Siriwardena (2004) found increases in Green Woodpecker abundance on CBC plots at the same time as declines in Willow Tit abundance, but this is unlikely to reflect a causal link - this woodpecker being unrecorded as a nest predator. A negative relationship between Great Spotted Woodpecker and Willow Tit abundance on farmland plots is more likely to reflect a real population effect, but farmland is only a minor habitat for the species, so it is unlikely that such a relationship has biological significance for Willow Tits nationally. There were no significant associations with other avian potential nest predators. Supporting this result, Lewis et al. (2007, 2009a, 2009b) found that sites that were known to have held the species in the past and that were still holding Willow Tits did not differ in the density of potential nest predators. In a study which monitored 128 nests over 2014-18 in Greater Manchester, predation accounted for 60% of the 45% of nests that fai

Thirdly, increases in the local populations of behaviourally dominant, sympatric species such as Blue Tit, Great Tit, Marsh Tit and Nuthatch could have led to increased competition, especially for nest-holes. There is little direct evidence specifically concerning foraging interactions involving Willow Tit in the UK but it is possible that increases in other tit species have placed extra pressure on Willow Tit populations through competition for food or nest sites (Vanhinsbergh et al. 2003). In Lanarkshire, central Scotland, Great and Blue Tits were found commonly to take over the nest sites of Willow Tit (Maxwell 2002, 2003) but it is unclear how widespread this phenomenon is. In the Greater Manchester study mentioned above (Parry & Broughton 2019), eviction by Blue Tits caused 23% of first breeding attempts to fail, but only 3% of second attempts, so the ability to re-lay may limit population level effects of usurpation. Excluding evicted and predated nests, 98% of eggs in this study resulted in fledged chicks, suggesting that competition for food was not an issue at this site, at least during the nestling stage. In the analysis of long-term CBC trends carried out by Siriwardena (2004), no negative relationships were found between Willow Tit and its potential competitors. Again, this was supported by field data from Lewis et al. (2007, 2009a, 2009b), who found that sites that were known to have held the species in the past and that that were still holding Willow Tits did not differ in the density of avian competitors.

Overall, therefore, habitat deterioration is the strongest candidate as the cause of Willow Tit decline nationally. As well as increasing woodland drainage, degradation has been hypothesised to have occurred via a reduction in nest-site availability resulting from falls in the amount of dead wood and number of dead trees in woodland reducing nesting opportunities (Vanhinsbergh et al. 2003). This has yet to be tested formally, however, probably because historical data on quantities of dead wood are not available.

Information about conservation actions

The long-term decline of this species is most likely to have been caused by habitat degradation, and hence conservation actions and policies which aim to restore and create habitat are most likely to benefit this species.

Wet woodland also seems to be a particularly important habitat for Willow Tits, and one study found that soil water content was the only significant difference between sites which were still occupied and those which had been abandoned. This study concluded that "Habitat provision for Willow Tit should involve provision of young woodland patches with moist soils" (Lewis et al. 2009a). Another study identified deadwood of silver birch, elder and alder as the most frequent trees used for nest sites (Parry & Broughton 2019). Deterioration of the woodland understorey is also believed to be important (see Causes of Change section, above); actions to promote understorey habitat could include management to create a more open canopy and to control deer numbers.

It is also possible that increased interspecific competition for food and nest sites might be having some negative effects on local Willow Tit numbers, although the evidence does not suggest that this is likely to be the main cause of the general population decline. Nevertheless, it might be prudent to discourage the increased provision of food and nest boxes within and near Willow Tit strongholds as a precaution.