Autumn and winter bring significant changes to the bird populations of Scotland and Northern England. Birds that bred locally in spring and summer may move elsewhere, while large numbers of migratory birds arrive from Iceland, Greenland, Scandinavia, continental Europe and the Arctic.
Estuaries, wetlands, reservoirs, agricultural fields, upland habitats, forests and coastal areas can become important feeding, resting and roosting sites. Some sites that appear relatively quiet in summer can support substantial numbers of birds in winter.
For developers, planning consultants, engineers, architects, contractors and landowners, this seasonal change has an important practical consequence. Where a proposed development may affect wintering birds or the habitats they use, suitable surveys may be required before its potential effects can be properly assessed.
Survey requirements should be considered before the winter season begins. Waiting until a planning application is being prepared may be too late to obtain the necessary evidence within the project programme.
What is a winter bird survey?
A winter bird survey records the bird species present in a defined area during the non-breeding season. Depending on the site and proposed development, the work may examine:
- Species present
- Numbers of individual birds
- Distribution across the survey area
- Feeding and resting behaviour
- Roosting locations
- Flight directions and heights
- Movement between habitats
- Use of the site at different times of day
- Changes in activity through the season
- Connections with designated sites
- Responses to weather, tides or land management
The objective is not simply to produce a list of species. A robust survey should provide sufficient information to understand how birds use the site and how that use could be affected by a proposed development.
This evidence can then inform project design, planning, Environmental Impact Assessment, Habitats Regulations Appraisal, mitigation and, where necessary, longer-term monitoring.
When are winter bird surveys undertaken?
October to March is often used as a general description of the winter bird survey season. It is useful for initial project planning, but it is not a universal survey window.
Different species arrive, depart and move through sites at different times. Survey requirements can also vary by latitude, altitude, habitat, weather, tidal conditions and the nature of the development.
For example, NatureScot guidance for Scottish onshore wind farms describes autumn-to-spring survey periods that extend beyond the conventional October to March window for certain groups. Its recommendations include monthly counts between July and May for non-breeding waders, where relevant, and potentially twice-monthly counts between August and May for non-breeding geese, swans and other wildfowl.
Coastal bird surveys may need to cover the full range of tidal conditions. Surveys involving roosting geese may require observations around dawn and dusk. Migratory movements can also be influenced by weather, so some survey visits must be timed to coincide with conditions when bird movements are likely.
The appropriate programme must therefore be designed around the site, target species and the likely effects of the development.
Why can a single survey visit be insufficient?
Bird use of a site is rarely constant throughout winter.
A field may contain few birds on one visit but support a large flock several weeks later. Agricultural operations can alter food availability. Flooding can temporarily create suitable habitat. Cold weather can move birds between inland and coastal sites. Different species also arrive and depart at different points in the season.
A single visit provides only a snapshot. It may fail to identify:
- Periodic use by significant numbers of birds
- Regular dawn or dusk movements
- Important roosting locations
- Changes caused by crop rotation or field management
- Use during particular tidal states
- Short periods of migratory passage
- Movement between the site and nearby designated areas
For this reason, development-related winter bird surveys normally involve repeated visits spread across the relevant period. The number, timing and frequency of visits should be proportionate to the questions the survey needs to answer.
Which birds may be recorded?
The species of interest will vary considerably between sites.
Lowland agricultural land may support geese, swans, lapwing, golden plover, thrushes, finches and buntings. Wetlands and reservoirs can attract ducks, grebes, divers and other waterbirds. Estuaries and coastal habitats can support internationally important concentrations of waders and wildfowl.
Upland, moorland and forestry sites may require consideration of raptors, owls, grouse and other species that remain present in winter. Certain birds may use communal roosts or travel considerable distances between feeding and resting areas.
Not every recorded species will represent a significant development constraint. The assessment should focus on species and activities that could be affected by the particular proposal, while retaining sufficient flexibility to respond to unexpected findings.
Which developments may require winter bird surveys?
A winter bird survey is not automatically required for every planning application. The need should be established through proportionate ecological scoping.
Surveys are more likely to be appropriate where a proposal could affect:
- Wetlands, estuaries, reservoirs or coastal habitats
- Agricultural land used by feeding geese, swans or waders
- Regular bird roosts
- Moorland or upland habitats
- Woodland used by wintering raptors or other sensitive species
- Land close to an SPA, Ramsar site, SSSI or other designated area
- Habitat that may be functionally connected to a designated site
- Regular flight routes between feeding and roosting areas
- Areas with existing records of important winter bird populations
Projects that may need winter bird information include:
- Onshore wind farms
- Solar farms
- Electricity infrastructure
- Roads and transport projects
- Housing and commercial developments
- Industrial sites
- Forestry projects
- Quarries and mineral developments
- Flood defence and drainage schemes
- Coastal and estuarine development
- Recreational projects
- Estate diversification proposals
The scale of a project is relevant, but location and ecological sensitivity can be equally important. A relatively small development beside an important roost or within land used by birds associated with an SPA may require more careful investigation than a larger project in a location with limited bird interest.
Why are winter bird surveys important for renewable energy projects?
Renewable energy projects are essential to the transition towards lower-carbon energy, but their location and design can raise specific ornithological considerations.
Onshore wind farms
Potential effects on birds include:
- Collision with turbine blades
- Displacement from feeding or resting habitat
- Disturbance during construction and operation
- Habitat loss or alteration
- Barrier effects on regular movement routes
- Cumulative effects with other developments
Vantage point surveys may be required to record flight activity, direction and height. Distribution and abundance surveys can establish how birds use the wider site.
NatureScot’s onshore wind guidance generally recommends at least two years of bird survey for relevant proposals, unless a shorter period can be justified and agreed. This reflects the potential for bird activity to vary between years. The precise requirement must be established through site-specific scoping and consultation.
Solar farms
Solar developments do not pose the same collision risks as wind turbines, but they can still affect birds through habitat change, construction disturbance, fencing, drainage alterations, lighting, or displacement from feeding areas.
Agricultural fields proposed for solar development may form part of a wider network of feeding habitat used by geese, swans, waders or farmland birds. A field does not have to be located within a designated site to be ecologically important to birds associated with that site.
Early survey information can help identify areas of greatest use and inform layout, buffers, habitat retention, construction timing and management proposals.
Electricity infrastructure
Overhead power lines and associated infrastructure can create collision, displacement and habitat effects. Survey work may need to identify regular flight routes, activity heights and movement between feeding and roosting locations.
The survey scope should reflect the nature and voltage of the infrastructure, the sensitivity of the site and the species potentially affected.
Winter birds and designated sites
Special Protection Areas are designated for the protection of important bird populations. Some are designated specifically for wintering or migratory birds.
A development does not have to be situated inside an SPA to affect its qualifying bird populations. Birds are mobile and may travel beyond a designated boundary to feed, rest or roost.
Land outside an SPA that supports its qualifying birds may be described as functionally linked land. Development on this land can potentially affect the bird population for which the SPA was designated.
Possible effects include:
- Loss of feeding habitat
- Reduced access to roosts
- Disturbance
- Changes to water levels or drainage
- Increased recreational pressure
- Noise and lighting
- Obstruction of movement routes
- Collision risk
- Effects acting in combination with other projects
Where a proposal could have a likely significant effect on an SPA, the competent authority may need to undertake a Habitats Regulations Appraisal. The developer must provide sufficient information to allow that assessment to be completed.
Survey information can be central to determining whether birds associated with a designated site use the development area, how frequently they use it and whether the proposed project could affect the integrity of the protected site.
The legal and planning context in Scotland
Wild birds are protected under the Wildlife and Countryside Act 1981, as amended. Additional protection applies to species listed in Schedule 1, particularly regarding disturbance around nests and dependent young.
Winter bird surveys are not required merely because wild birds are present. They are typically needed during the planning and environmental assessment process, where there is potential for a development to affect important bird populations, designated sites or habitats, and where decision-makers require adequate ecological evidence.
Where a plan or project could affect an SPA or another relevant European site, the Conservation (Natural Habitats, &c.) Regulations 1994, as amended in Scotland, may apply.
Scotland’s National Planning Framework 4 places considerable emphasis on biodiversity. It expects development proposals to minimise adverse effects on biodiversity and, where appropriate, to contribute to its conservation, restoration and enhancement.
NatureScot also makes clear that planning permission does not remove the need to comply with wildlife legislation. Suitable safeguards and mitigation must be incorporated into project planning and construction.
Early ornithological work helps applicants demonstrate that potential effects have been identified and addressed through the design process.
The legal and planning context in Northern England
In England, all wild birds are protected under the Wildlife and Countryside Act 1981, as amended, with additional provisions for Schedule 1 species.
Natural England’s standing advice states that a bird survey should be requested where existing information suggests wild birds may be present and where a proposal is likely to affect wintering birds or habitats capable of supporting them.
Where a proposal could affect an SPA, the Conservation of Habitats and Species Regulations 2017, as amended, may require assessment.
The National Planning Policy Framework for England also requires planning decisions to take account of biodiversity and protected sites. Its policies apply to effects originating both inside and outside designated areas where the protected biodiversity interest could be affected.
Local plans, local wildlife site policies and requirements associated with Environmental Impact Assessment may create further information needs.
Statutory Biodiversity Net Gain requirements in England do not remove the need to assess birds, protected species or designated sites. Habitat calculations and ornithological assessment address different questions and should be considered together where relevant.
Which survey methods may be used?
A winter bird survey programme may combine several methods.
Desk study
The ecologist reviews designated sites, biological records, previous surveys, mapping, aerial imagery and information on relevant species.
This helps identify potential constraints, target species, survey boundaries and the need for consultation.
A lack of historic records should not automatically be taken as evidence that birds are absent. It may simply mean the site has not been surveyed previously.
Walkover or transect surveys
The surveyor follows a planned route, recording birds seen or heard, their numbers, behaviour and location.
This method can provide information on the distribution and abundance of birds in farmland, wetlands, woodland, moorland and other habitats.
Vantage point surveys
Observations are made from carefully selected fixed locations. These surveys can record flight paths, flight height, direction and activity.
They are particularly important for developments where collision risk or regular bird movements are relevant, including wind farms and some electricity infrastructure projects.
Roost and feeding-area counts
These surveys focus on locations used by birds for resting, feeding or gathering. Visits may need to take place around dawn or dusk.
High-tide and low-tide surveys
On estuaries and intertidal habitats, the distribution of birds can change substantially with the tide. Surveys may need to cover different tidal states and movements between feeding and roosting sites.
Species-specific surveys
Some projects require methods tailored to particular species or groups. The surveyor may need to consider raptors, geese, swans, waders, owls, divers or other birds with distinctive patterns of behaviour.
The final methodology should be justified, repeatable and capable of answering the assessment questions associated with the development.
How early survey work can improve a project
A winter bird survey should not be treated simply as a report needed to validate a planning application. The greatest value often comes from using the information while the project can still be adjusted.
Survey findings may influence:
- The project boundary
- Turbine or solar panel locations
- Access-track alignments
- Grid connections
- Construction compounds
- Drainage design
- Lighting
- Habitat retention
- Buffers around sensitive areas
- Construction timing
- Operational management
- Habitat enhancement
- Monitoring commitments
Avoiding an important feeding area or flight route at the design stage can be more efficient than mitigating a fixed layout later.
Early ecological input also helps project teams distinguish between genuine constraints and manageable issues. The objective is not to prevent development, but to identify a compliant and practical route forward.
What happens if the survey window is missed?
If suitable winter bird information is required but has not been collected, the project may face:
- Requests for additional information
- Delays in validating or determining an application
- Difficulty completing an Environmental Impact Assessment
- Insufficient information for a Habitats Regulations Appraisal
- Greater uncertainty about project design
- Late changes to layouts or construction programmes
- Objections from consultees
- A need to wait until the following survey season
Desktop records and historic survey information can be valuable, but they cannot always replace current site-specific fieldwork. Their usefulness depends on their age, coverage, methodology and relevance to the current proposal.
The appropriate response is not to commission every possible survey as a precaution. It is to obtain early advice, identify the questions that genuinely need to be answered and design a proportionate programme.
What should a winter bird survey report contain?
The scope will vary, but a professional report may include:
- A description of the development and survey area
- Relevant legislation, policy and guidance
- Desk-study findings
- Survey methodology
- Dates, times and weather conditions
- Survey limitations
- Species records and conservation status
- Maps showing distribution and activity
- Flight-path information where relevant
- Identification of important habitats
- Evaluation of ecological importance
- Potential development effects
- Recommended avoidance and mitigation
- Enhancement opportunities
- Requirements for further assessment or monitoring
The report should explain not only what was recorded but also what the findings mean for the proposed development.
How Veon Scotland can help
Veon Scotland provides professional ornithological and ecological support across Scotland and Northern England.
Our services can include:
- Preliminary ecological review
- Desk studies and biological record searches
- Winter bird survey scoping
- Distribution and abundance surveys
- Vantage point surveys
- Roost and feeding area surveys
- Wader and wildfowl surveys
- Survey mapping and data analysis
- Ecological Impact Assessment
- Ornithological input to Environmental Impact Assessment
- Support for Habitats Regulations Appraisal
- Mitigation and enhancement design
- Construction-phase ecological advice
- Post-consent monitoring
We work with developers, landowners, estates, engineers, architects, contractors, renewable energy companies and public bodies.
Our approach is proportionate and evidence-led. We seek to identify ecological requirements early, provide clear advice and help clients move projects forward while meeting their legal and planning responsibilities.
Plan now for the coming survey season
Late summer and early autumn are the right time to review potential winter bird requirements.
Not every project will need an extensive survey programme. Some may require targeted visits, while larger or more sensitive developments may need work covering a full season or more than one year.
The first step is to examine the site, surrounding habitats, relevant bird records, designated-site connections and the potential effects of the proposed development.
If winter bird surveys are required, early commissioning allows an appropriate programme to begin at the right time. It also gives the project team the best opportunity to use the results constructively during design and planning.
Contact Veon Scotland to discuss winter bird surveys for projects in Scotland and Northern England.