Action Plan: Willow Tit

Breeding Birds of Conservation Concern in Shropshire
Species Action Plan

 Willow Tit

Status

  • Uncommon breeding species
  • Shropshire: Red List
  • National (BoCC4): Red List
  • Breeding population estimate from The Birds of Shropshire: 140-200 pairs

Distribution (geographic and habitat requirements)

Willow Tit is a species of wet woodland and scrub, often associated with waterbodies and waterways. Its main requirement is for suitable nest sites in the form of standing deadwood. Fresh nest cavities are excavated annually and so a regular turnover of suitably decayed stumps are required – birch (Betula spp), willow (Salix spp) and elder (Sambucus nigra) are the main tree/shrub species that provide this resource, though other species can also be used.

In Shropshire, local surveys have revealed that conifer plantations are utilised quite consistently by Willow Tit, particularly in the south of the County. This is clearly because many plantations still have a reasonable understorey of young birch, willow and elder to provide nest sites, but it also may be due to a lack of competition from other woodland bird species. Interestingly, this does not appear to be the case in neighbouring Staffordshire, where this species appears quite widespread (anecdotal evidence) but local surveys of conifer plantations have all been negative. This may be due to the plantations being on lower, drier ground, with different tree species (conifer and deciduous).

Additional data from local survey work since 2016 seems to indicate that the species is still widespread throughout the County. Its population stronghold in the UK seems to be around the Greater Manchester and Yorkshire areas, but recent local studies indicate that Shropshire and Staffordshire also may hold important populations.

We currently have no reliable examples of loss of Willow Tit from any site/region in Shropshire, although a review of old records is planned, to attempt to find such examples.

Population Trend

Willow Tit was found in 337 tetrads in fieldwork for the 1985-90 Atlas, but only 68 in 2008-13. It had disappeared from 269 tetrads (80%). There are not enough in Shropshire or the West Midlands for local trends to be found by the BTO Breeding Bird Survey, but nationally it has found an 82% population decline in England between 1995 and 2018.

Monitoring

Surveys using audio playback are the only reliable method to find Willow Tit. This has become the official adopted method of the National Willow Tit survey, led by the RSPB. As Willow Tit are generally very thinly spread, suitable areas of habitat on a tetrad-by-tetrad basis (an area of 2x2km squares) will be located and surveyed.

Instructions for fieldworkers are already available (see The Shropshire Willow Tit Survey page)

Bird Atlas methodology is not ideal for mapping Willow Tit, so although the level of disappearance between the two Atlases is undoubted real, the actual distribution is likely to be under-recorded on the Atlas map.

Local surveys have been in place since 2016. Annual reports have been compiled most years, but a full analysis and mapping exercise should be carried out to show the distribution of confirmed records, together with population estimates wherever possible.

Previous County records will also be searched to highlight hotspot areas that have not yet been covered using the playback survey method. Analysis of local survey results will help identify new target areas to survey, and better understand the species’ distribution.

The survey data will be used to identify the areas where density appears highest. These areas should be the target of repeat monitoring to look for signs of decline every 5-10 years, with increased frequency if volunteer availability allows.

Willow Tit territory size and dispersal is still poorly understood. A project involving nest-monitoring and/or ringing birds at major sites will be considered, but would present difficulties, not least catching enough birds/locating enough nests to make it worthwhile!

Reasons for decline

Multiple hypotheses have been put forward to explain the steep decline in the UK including:

  • Deterioration in woodland habitat quality (in regard to deadwood availability).
  • Increased predation from Great Spotted Woodpeckers (which have increased in the UK).
  • Increased competition from other tit species which have been demonstrated to usurp Willow Tit from nest sites.

No real evidence has been found for the latter two, but there is some evidence of woodland quality being a factor. In particular, drainage and drying out of sites is likely to be a strong factor. (See BTO BirdTrends for more details and the relevant references here.)

Habitat loss is presumably also a factor, as with most other species. Clear-felling of forestry sites in Shropshire may impact them. Development on brownfield sites in areas such as Telford, which is known to have a population, could also be impacting them. Willow Tit are still going ‘under the radar’ in respect to this.

Climate change may be an underlying factor. Willow Tit is species likely to suffer range reductions as conditions become warmer (presumably, again, linked to dryer conditions, which provide less suitable habitat). This would be in-keeping with the loss of the species from the south of the UK. With consistently warmer temperatures in recent years, how long might it be before we start seeing large-scale disappearance from sites in the Midlands?

Actions towards recovery

Areas within and adjoining the ‘major population areas’ identified by the monitoring should be the priority for habitat management and landowner engagement. However, the thinly spread distribution of the species means that habitat management at a site level is unlikely to make much difference (unless the site in question is large enough to hold multiple territories, such as Whixall Moss or some of the large forestry areas).

There are currently no demonstrable practical management guidelines available for Willow Tit, but presumably ensuring that deadwood is left standing and that sites are not drained or cleared of scrub/trees has to be sound advice.

Artificial habitats such as nest-boxes are of limited use and take-up of these has been shown to be quite poor. Due to territory size, boxes would have to be spread out over a vast area meaning that monitoring would be very intensive.

Engagement with major landowners such as Forestry Commission, Shropshire Wildlife Trust and Natural England will help raise the profile of this species and its requirements. Engagement with local councils and commenting on planning applications in areas where this may pose a threat to the species, such as around Telford, will also be undertaken. Further surveys would be required to support this.

When there is sufficient knowledge, and perhaps in collaboration with RSPB, a guidance document for landowners will be produced, to help raise awareness and provide guidelines for habitat management.

Constraints to delivery

  • Lack of volunteers: Initial surveys in 2016-2017 were quite well received, but numbers of participants has dropped off sharply since.
  • Survey difficulty: Willow Tit are not easy to find and this could put people off conducting surveys, especially in areas where they are particularly thinly spread.

Targets

Starting in 2021

  • Review the “Instructions to Surveyors” before the season starts, and recruit and brief surveyors.
  • Continue targeted surveys, including at newly-identified sites and new areas.
  • Begin engagement with landowners, particularly Forestry Commission and SWT, to apply the “Actions towards recovery” above on all suitable parts of their sites.
  • Produce an up-to-date distribution map of Willow Tit, identifying major population areas, together with a revised population estimate.
  • Analyse previous records, and compare with the current distribution, to establish whether there are examples of disappearance from particular areas / sites.

Future years

  • Survey any additional sites where Willow Tit has apparently disappeared in the last 25 years or so, and any “Actions towards recovery” are carried out.
  • Repeat the survey of major population areas when appropriate.
  • Produce a guidance document for landowners, to help raise awareness and provide guidelines for habitat management.
  • Establish a system for monitoring Planning Applications.
  • Ensure effective monitoring of Willow Tit during the next bird Atlas, planned to start in 2027.

 Relevant Non-SOS Projects

The National Willow Tit survey, led by the RSPB, was carried out between 2019 and 2021. All local data from 2016 onwards was fed into this survey, and it will hopefully show how Shropshire compares nationally with this more detailed approach.

There are several other local county-based projects in the UK which are linked by the RSPB Species Recovery Network, of which Jonathan Groom is a member. Their annual newsletter is a good source of information

These national results will be taken into account in the annual review of this Action Plan.

Jonathan Groom
Species Champion
October 2020

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Page updated: 13/11/2020