Willow Tits 2023

 

Willow Tits in the Scarborough District 2023

 

The British Willow Tit (Poecile montanus kleinschmidtii) population declined by 88% between 1970-2006 (Lewis, A.G., et al., 2009), the largest decline of any resident breeding bird in the UK. The population trend shows a consistent and continuous decline which was estimated at 3,400 pairs in 2009. No longer common enough to be monitored by the national Breeding Bird Survey, Willow Tits are monitored by the Rare Breeding Birds Panel. The species has also become locally extinct in South-East England and continues to decline in other regions, suffering a 50% contraction in breeding range from the atlas reports 1968-72 to 2008-11. A continued decline of this species (a unique and endemic British subspecies) will lead to further regional extinctions and isolated populations susceptible to chance events.

 

Having learned of the recent extinction of Willow Tit as a breeding bird in my old birding district of Barnsley, and from much of South Yorkshire, I was interested to start monitoring records received by Scarborough Birders. Reports from recent years suggested the population in the forests is potentially significant from a Yorkshire perspective. Two of our members, Ginny Leeming and Andy Malley, have reported most of the forest records in the last few years, so we began a process of capturing grid references from their frequent visits. I also obtained grid references for other reports around the Scarborough district.

 

The Willow Tit is a sedentary species with a relatively large territory, possibly up to 7 hectares. Known habitat preferences are for damp areas of scrub and young woodland, with a dense shrub layer of 2-4 metres in height. Drying out of habitat and loss of scrub and shrub layers in woodland are threats and may be ecological drivers of decline.

 

There are lots of areas of the traditional Willow Tit habitat throughout the extensive “Scarborough” forests, and many of the records were from these areas, particularly in Wykeham Forest. Conversely in Dalby Forest Willow Tits were often in the thickest stands of mature coniferous belts where Blue and Marsh Tits tend to be absent, although there were sometimes adjacent to young growth areas and weedy edges. In previous years records from the extensive higher Langdale Forest came from similar stands of dense mature coniferous forest.

 

Several pairs are still present in the lower elevations of the district, especially in the Vale of Pickering where suitable habitat still exists, but it is nowadays in the extensive mixed coniferous/deciduous forests managed by Forestry England where the main breeding areas are located.

 

 

 

Fig. 1 Distribution of Willow Tit records in the Scarborough Birders’ recording area 2023.

 

 

At Wykeham Forest it was found that Willow Tits were predominantly distributed around the forest edges where younger woodland habitat can be found, but some records came from more mature areas of the forest. The distribution of sightings suggests the forest and adjacent valleys might holds a minimum of 6 territories.

 

 

Fig. 2 Willow Tit records from Wykeham Forest area 2023

 

 

The more extensive Dalby Forest possibly holds more pairs of Marsh Tit Poecile palustris than Wykeham Forest, and here sightings of Willow Tit were predominantly from dense stands of mature coniferous woodland. In the United Kingdom this is not a traditionally recognised habitat type, more akin to the habitat of race Poecile montanus borealis found in Scandinavia. A study by Alatalo et al (Alatalo et al, 1985) found that in central Sweden, while Marsh Tit prefers deciduous woods, the Willow Tit mainly occupies coniferous forests. In an area studied with no Marsh Tits it was found the Willow Tits had significantly expanded the use of deciduous habitats. Perhaps in Dalby Forest there has been a shift in habitat preference by Willow Tits? Both species have been present for some time in Dalby Forest. The 2009 Scarborough District Bird Report (Addey N.W., 2010) said under Willow Tit; “Ringing in Dalby Forest showed that both Marsh and Willow Tits are widespread, three ringed at Staindale Lake and four at Seive Dale. Large numbers of Marsh were ringed at both sites, as is the norm”. The distribution of sightings suggests 10+ territories in Dalby Forest during 2023.

 

 

 

Fig. 3. Willow Tit records from Dalby Forest 2023

 

There is certainly observer bias in the 2023 distribution map of the Scarborough district, Dalby and Wykeham Forests both being regularly visited. The less visited forests of Langdale, Broxa, Sneaton, and Harwood Dale may well hold several territories of Willow Tits in each forest. Records have been received by Scarborough Birders from all these areas.

 

There is a feeling by long standing Scarborough birders that the population of Willow Tits has declined in the Vale of Pickering. A general reduction of wetland habitats with young deciduous woodland is likely to have influenced this. It’s encouraging that wetland habitat creation at Potter Brompton Carr in recent years will help. The species is recorded regularly at this site.

 

It is hoped that the findings in this short article will lead to a more detailed study of Willow Tits in the extensive forests managed by Forestry England west of Scarborough. A more detailed study of the breeding population and habitat preferences will hopefully help refine the woodland management practices.

 

 

References

Addey N.W., 2010, Scarborough District Bird Report 2009

Alatalo R.V. et al, 1985, Habitat Shift of the Willow Tit Parus montanus in the Absence of the Marsh Tit Parus palustris (Ornis Scandinavica)

Lewis, A.G. et al, 2009, Factors influencing patch occupancy and within-patch habitat use in an apparently stable population of Willow Tits in Britain (Bird Study)

Pinder S. ,2021, Back from the Brink. SP12 Project. Willow Tit (YWT)

 

 

Nick W Addey, Andrew Malley, Ginny Leeming

Email: nickaddey@dsl.pipex.com

 

1^st August 2024